environmental impact assessment and environmental … · 8.1.2.1 project impacts on terrestrial...

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THE SOCIALIST REPUBLIC OF VIET NAMMINISTRY OF AGRICULTURE AND RURAL DEVELOPMENT

CENTRAL PROJECT OFFICE

MEKONG DELTA WATER RESOURCES DEVELOPMENT PROJECT

FEASIBILITY STUDY UPDATE

ENVIRONMENTAL IMPACT ASSESSMENTAND

ENVIRONMENTAL ACTION PLAN

ANNEX I

August, 1998

HASKONING B.V. CONSULTING ENGINEERS AND ARCHITECTSin association with

EUROCONSULT and DELFT HYDRAULICS

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The Socialist Republic of VietnamlMARDICPOMekong Delta Water Resources Development Project

6.4.4.3 Electricity ............................... 496.4.5 Cultural, Aesthetic, Historic Features .496.4.6 Agricultural and Production .496.4.7 Household Energy Supply .49

7. DESCRIPTION OF 0 MON-XA No SUB-PROJECT 50

7.1 Rationale for 0 Mon-Xa No Sub-Project .................................................... . . ... 5072 Detailed Sub-project Description . . ................................................. 0 . .... 50

7.2.1 Original Sub-project Concept . . . .. 507.2.2 Current Status of Sub-project Implementation . . . . 50

7.2.2.1 Water Control System .................................................... : .... 507.2.2.2 Changes in Land Use from OM-XN-FS to Current Conditions ._. .....,.,,,,,,,,,,Sr0

7.2.3 Remaining Elements of Sub-project Implernentation .. . .51

7.2.4 Land Use Scenario for Environmental Review . . . .51

8. IMPACT ASSESSMENT FOR 0 MON-XA No SuB-PROJECT 52

8.1 Detailed Descniption of Expected Environmental bnpacts 528.1.1 Impacts on Physical Resources . . . .52

8.1.1.1 Sub-prect Impacts on Soils . . .... 528.1.1.2 Sub-project Impacts on Salinity in the Sub-Project. . . .528.1.1.3 Sub-project Impacts on Surface Water Hydrlogy ... . ........................ 528.1.1.4 Sub-project Impacts on Surface Water ouaity . . ................................. . _. 548.1.1.5 Sub-project Impacts on Downstream Surface Water Quality . .... ..... 558.1.1.6 Project Impacts on Groundwater Resources . ............................................ _ . . 558.1.1.7Project Imnpacts on Air Quality . . . . ................... . .... . _ . 568.1.1.8 Project Impacts on Canal Bank StbTilty .. .................................... 56

8.1.2 Impacts on Ecological Resources 6.. . .8.1.2.1 Project Impacts on Terrestrial Ecosystms Within the Sub-Project . . . 568. 1.2.2 Project Impacts on Terrestrial Ecosystems Outside the Sub-Project . . .568.1.2.3 Impacts on Aquatic Ecosystems Wfitin the Sub-Project ... ........ 578.1 2A Sub-project Impacts on Aquatic Ecosystems Outside the Sub-Project ...................... 5................... 578.1.2.5 Project Impacts on Protected Areas Within Sub-Projet . . ..... A.............. .... 578.1.2.6 Sub-project Impacs on Downstream Protected Areas ................................................ . ___ 57

8.1.3 Impacts on the Socio-economy . . . .57

8.1.3.1 Sub-project Impacts on Public Health ...... . .5.................... . _ .. _78. 1.3.2 Impacts on Drinking Water Suppiy Wthin Sub-Project . ............ .................. 5.......... _._._. 588.1.3.3 Project Impacts on Downstream Drinking Water Supply .......................................... _ _. 588.1.3.4 Project Impacts on Fisheries ....................... 588.1.3.5 Project Impacts on Human Setlements, Communities, and lnfrstructure ... 598.1.3.6 Sub-project Impacts on Cultural, Aesthetic, Historic Features . . .598. 1.3.7 Project Impacts on Agricultural Dveopment .. . ............................. 598.1.3.8 Project Impacts on Household Energy Supply ..................................... ... 608.1.3.9 Project Impacts on Transportation and Navigation .... . . . .............................. 60

9. ENViRONMENTAL ACTION PAN FOR 0 MON-XA No SUB-PROJECT 61

9.1 Summary of Environmental Mitigation .......... .................... 61

92 Environmental Monitorng ..................... ..... 619.2.1 Proposed Expansion of the Surface Water Quality Monitoring System . .619.2.2 Cost Summary for Expanded Water Quality Monitoring Program . .62

10. EXISTING ENVIRONMENT OF THE QUAN Lo PHUNG HIEP SUB-PROJECT 66

w ~~~~10.1 General Deciton_ - -......... se.....____6

10.2 Physical Resources. ........................

10.2.1 Climate....... .6810.2.2Soils..6810.2.3 Surface Water Hydrology, Salinity, and Addity..69

MDWRDP, Feasibility Study UpdateAnnex I, Environmental Impact Assessment and Environmental Action Plan. August 1998 iii

The Socialist Republic of Vietnam/MARD/CPOMekong Delta Water Resources Development Project

10.2.3.1 Surface Water Hydrology ..................... 6910.2.3.2 River and Canal Network ..................... 6............ ... 6910.2.3.3 Precipitation Regirme ................. . 6910.2.3.4 Mekong River Flows .. 6910.2.3.5 Ocean Tides .. 7010.2.3.6 Current Hydrological Regine of the Sub-project area .7010.2.3.7 Salinity ....................................... 7110.2.3.8 Surface Water Acidity .. 7110.2.3.9 Within Sub-project Surface Water Quality .. 72

10.2.4 Groundwater Resources .. 7210.2.5 Air Quality .. 73

10.3 Ecological Resources .......... .. ......................... .. 73

10.3.1 Land Use and Vegetaton Cover .7310.3.2 Terrestrial Ecosystems Wdhin the Sub-Prject .73

10.3.2.1 Nipa Pam .7310.3.2.2 Use of Terrestrial Ecosystem Resources by Local Households .74

10.3.3 Aquatic Ecosystems Within the Sub-Project .................................. 7410.3.4 Siodiversity Within the Sub-Project .. 7........................... 7410.3.5 Protected Areas Within the Sub-Project .7510.3.6 Ecosystems and Protected Areas Outside the Sub-Prject .75

10.3.6.1 Coastal Wetlands Protecbtion and Develpment Project ...................................................... 7510.3.6.2 Protected Areas Under the National System or' Prtected Areas . .75

IOA- Socio-economac Resources . . .. . ......... .. __76

10.4.1 Populabon, Demnography, and Ethnic Compositioi ....................................... 7610.42 Drinking Water Supply Within Sub-Project .7610.4.3 Disease and Public Health ............................... ........ 7710.4.4 Drinking and Domestic Water Supply Outside the Sub-Projec ....................................... 7710.4.5 General Infrastructure and Industry .77

10.4.5.1 Transporttion ..... . . . . .... . . . 7710.4.52 Level of Idustiasa.on.. .................. ... . 7710.4.5.3 Elecity ..... ............. .78

10.4.6 Cultural, Aesthetic, Historic Features . . . . 7810.4.7 Household Energy Supplyu..p ly................................................. 78

11. DEscRIPTION OF QUAN LO PHUNG HIEP SUB-PROJECT 79

11.1 Rationale for QLPH Sub-Proect . ........................ 7911.2 Proposed Water Resources Devebpmen Syst__.........-.. 7911.3 Detailed Sub-project Descripton._ s............. 80

11.3.1 Originl Sub-project Concept ........................ . _ . _. _ . ...... 8011.3.1.1 Primary Sluices for Prevention of Saliny hnrusion Fron South Chin Sea .. ... 8011.3.1.2 Water Supply Canals for Prevention of Salnity intusion from Gulf of Thaland and ForFreshwater Supply .......... _.__. __80-

t1.3.1.3 Secondary Dra..age Canls ......................................................... 8111.3.1.4 On -Farm Water Control System . ......... ..... ..._ ... _1

1 1.32 Current Status of Sub-project Implementation . . . . .81;11.32.1 WaterControlSystem ..................... . ..... _ ._ _ . .... . 8111.32.2 Changes in Land Use from 1991 to Current CondiKtos . .... 81

11.3.3 Remaining Elements of Sub-project Implementation ..... 8211.3.4 Proposed Land Use ..... 82

12. IMPACT ASSESSMENT OF QUAN LO PHUNG HIEP SUB-PROJECT 84

12.1 Detailed Description of Expected Environmental Impacts. 8412.1.1 Impacts on Physical Resources .. 84

12.1.1.1 Project Impacs on Surface Wastr Hydrology . ...................................... 8712.1.12 Project Ipacts on Sols ...................... .... . .. . ...... 8412.1.1.3 Project bnpacs on Wifthin Sub-project Surface Water Qusllty ._._ 812.1.1.4 Sub-project brpacts on Downsren Surface Waer Quality ._ . . . 89 .12.1.1.5 Project Inpacts on Groundwater Resoure .. . 9112.1.1.6 Project kpacts on Air Qualty.--...... . .. .............. . ..12.1.1.7 Project Impab on Canal Bank Stabilty ............................... . _ . ...... 91

12.12 Impacts on Ecological Resources ...... ..................... . .92

MDWRDP, Feasibility Study UpdateAnnex I, Environmental Impact Assessment and Environmental Action Plan, August 1998 iv

The Socialist Republic of Vietnam/MARDICPOMekong Delta Water Resources Development Project

12.1.2.1 Project Impacts on Terrestrial Ecosystems Within Sub-Project .................................................. 9212.1.2.2 Project Impacts on Terrestrial Ecosystems Outside the Sub-Project .......................................... 9212.1.2.3 Project Impacts on Aquatic Ecosystems Within the Sub-Project ................................................ 9312.1.2.4 Sub-project impacts on Aquatic Ecosystems Outside the Sub-Project ....................................... 9312.1.2.5 Impacts on Protected Areas Wthin the Sub-Project ..................................................... 9312.1.2.6 Sub-project impacts on Downsteam Protected Areas ............................................... 93............. 93

12.1.3 Impacts on Socio-economic Resources .9412.1.3.1 Project Impacts on Publir Heath .9412.1.3.2 Project Impacts on Water Supp Wthin the Sub-Project .9412.1.3.3 Project Impacts on Downstream Drinking Water Supply .9512.1.3.4 Project Inpacts on Subsistence Resource Harvesting .9512.1.3.5 Project mpacts on Hunan Settements, Communities, and Infrastructure .9612.1.3.6 Project Impacts on Cultural, Aesthetic, Historic Featues .9612.1.3.7 Project Impacts on Commodity Production .9612.1.3.8 Project Impacts on Household Energy Supply6 912.1.3.9 Project Impacts on Transportation and Navigation .97

1 3. RECOMMENDED ENV1RONMENTAL MANAGEMENT PLAN FOR QUAN LO PHUNG HIEP SUB-PROJECT 98

13.1 Environmental Mitigation Measures ... . . 9813.2 Environmental Moniorng. . . . .98

13.2.1 Proposed Expansion of the Surface Water Quality Monitoring System .................... ............... 9813.2.2 Cost Summary fbr Expanded Water Quality Monitoring Program .......................................... 101

14. INSTITUmONAL ARRANGEMENTS FOR A MDWRDP MONrToRING PROGRAM 103

15. SUPPORTING DOCUMENTATION 104

Soil Classfficaton System ...... ...... .. ..... ............... .. . .. IMain Soil Groups in the QLPH Area ._

MDWRDP, Feasibility Study UpdateAnnex I. Environmental Impact Asssment and Environmental Action Plan. August 1998 V

The Socialist Republic of Vietnam/MARDtCPOMekong Delta Water Resources Development Project

LIST OF TABLES

TABLE 1: SYNOPTIC INFORMATION FOR DISTRICTS, SOUTH MANG THIT SUB-PROJECT._...................._5TAsLE 2: SYNOPTIC SOCIO-ECONOMIC INFORMATION FOR DISTRICTS, SOUTH MANG THIr SUB-

PROJECT . ...... . ............... _....TABLE 3: DISTRIBUTION OF SOIL TYPES, SOUTH MANG THIT SUB-PROJECT .._TABLE 4: INFLOW AND OUTFLOW IN THE DRY SEASON, SOUTH MANG THIT SUB-PROJECT (M3/S)._...8TABLE 5: WATER QUALuTY, DUYEN HAI DISTRICT, JANUARY 1995, DOWNSTREAM OF THE SOUTH

MANG THIrr SUB-PROJECT . ............. .... . _ . . .. _. _ . . .. .10TABLE 6: LAND USE SCENARIOS, SOUTH MANG THIT SUB-PROJECT.._..._ - --- 19TABLE 7: ANNUAL FERTIUSER AND PESTICIDE I HERBICIDE USE: PRESENT, WIHOUT AND WffITH

PROJECT IMPLEMENTATION (ALL SUB-PROJECT AREAS) ...... 27TABLE 8: WATER QUALITY PARAMETERS MEASURED IN THE MEKONG DELTA WATER QUALrTY

MONITORING NETWORK. ....................... ___... . ... . ..... ... 36TABLE 9: RECOMMENDED ENVIRONMENTAL ACTION PLAN, SOUTH MANG THIT SUB-PROJECT. 37TABLE 10: INCREMENTAL COSTS FOR EXPANDED SURFACE WATER QUALITY MONITORING NETWORK,

SOUTH MANG THIT SUB-PROJECT................ ................TABLE II: SYNOPTIC INFORMATION FOR DISTRICTS, 0 MON-XA No SUB-PROJECT ... 43TABLE 12: SYNOPTIC SOCIO-ECONOMIC INFORMATION, 0 MON-XA No SUB-PROJECT ........ ........ . .43TABLE 13: REPRESENTATIVE WATER LEVELS, PEAK OF RAINY SEASON (OCTOBER), 0 MON-XA No ...45TABLE 14: LAND USE SCENARIOS, 0 MON-XA No SUB-PROJECT .................... 5.1....... _1TABLE 15: WATER LEVELS FOR PEAK OF RAINY SEASON (OCTOBER), CURRENT AND FUTURE

CONDmONS, 0 MON-XA No SUB-PROJECT .. .................-............. 54TABLE 16: RECOMMENDED ENVIRONMENTAL ACnON PLAN, 0 MON-XA No SUB_PROJECT ... 63TABLE 17: INCREMENTAL COSTS FOR EXPANDED SURFACE WATER QUALITY MONITORING NETWORK,

0 MON-XA No SU.-PROJECT.. . ....... ................ 64TABLE 18: SYNOPTIC LAND USE INFORMATION (1997), QUAN Lo PHUNG HIEP SUB-PROJECT . 67TABLE 19: SYNOPTIC SOCIO-ECONOFMC INFORMATION, QUAN LO PHUNG HIEP SUB-PROJECT ........ 67TABLE 20: DISTRIBUTION OF ACID SULPHATE SOL (ASS), QUAN Lo PHUNG HIEP SUB-PROJECT (%)69TABLE 21: CHARACTERISTICS OF THE SOUTH CHINA SEA AND GULF OF THAILAND.._._..-._..._._.70TABLE 22: INFLOW AND OUTFLOW IN RAINY AND DRY SEASON, CA MAU PENINSULA (M3lS) ...... ..... _.74TABLE 23: LAND USE (1997), QUAN Lo PHUNG HIEP SUB-PROJECT..-........._......_.....74TABLE 24: ORIGINALLY PROPOSED PRIMARY SLUICES, QUAN LO PHUNG HIEP SUB-PROJECT .. _...80TABLE 25: LAND USE SCENARIOS, QUAN LO PHUNG HIEP, PHASE I AND 11 ............. 82TABLE 26: LAND USE SCENARIOS, BA RINH TA LIEm . .. . .....-. . ...... ...... 83TABLE 27: LAND USE SCENARIOS, TIEP NHAT ............................. . _ 83TABLE 28: INFLOW AND OUTFLOW IN RAINY AND DRY SEASON, CA MAU PENINSULA: 1991, CURRENT

AND AFTER COMPLETION OF PHASE I, Il (M31s) . ........ .... .................... _ . . . ..... _. 88TABLE 29: WATER LEVELS ALONG THE QUAN Lo PHUNG HIEP CANAL IN THE DRY AND RAINY SEASONS86TABLE 30: CHANGES IN WATER LEVELS AT VARIOUS LOCATIONS OUTSIDE THE QUAN Lo PHUNG HIEP

AREA ._.................................�... .96TABLE 31: RECOMMENDED ENVIRONMENTAL ACTION PLAN, QUAN LO PHUNG HIEP SUB-PROJECT .99TABLE 32: INCREMENTAL COSTS FOR EXPANDED SURFACE WATER QUALITY MONITORING NETWORK,

QUAN Lo PHUNG HIEP SUB-PROJECT. ..................... ...... ___ 102

MDWROP, Feasibility Study UpdateAnnex 1. Environmental Impact Assessment and Environmental Action Plan, August 1998 . Vi


LIST OF FIGURESFIGURE 1: RAINFALL FOR THREE MONITORING STATIONS, SOUTH MANG THIT SUB-PROJECT. ...............6FIGURE 2: DISTRIBUTION OF SOIL CLASSES, SOUTH MANG THiT SUB-PROJECT ..................FIGURE3: CURRENTrSRmuToNOFLANDUSE, SOUTH MANG THITSuB-PRojEcT .................... 12FIGURE 4: CHANGE IN LAND USE, 1991 TO 1996, SOUTH MANG THIT SUB-PROJECT.........FIGURE: ENC oZI osmoFPOPUUA4, SOuTH MANG T TSuP E........14FIGURE 6: SUmmARY OFENRoNmrrAL PACTS, SoUH MANGTHTSust oEcT........22FIGURE 7: RAINFALL, CAN THO (1960-1994) ........ ...... . .......-...-. 44FIGURE 8: DeW UnONOFMAINSOLTPES, 0 MON-XA NOSUBW R..ECT .... .................FIGuRE 9: SUMMARY OF ENVIRONMENTAL IMPACTS, 0 MON-XA NO SUB-PROJECTr-...--...--..-...53FIGURE 10: MONTHLY MEAN RAINFALL DATA, QUAN Lo PHUNG HIEP SUB-PROJECT..........................-68FIGURE 1 1: SUMMRY OF ENVIRONMENTAL IMPACTS, QUAN LO PHUNG HIEP SUB"PROJECT ._....85

MOWRDP, Feasibilit Study UpdateAnex I,, Enviromental Impact Assessment and Environmental Action Plan, August 1990 Vii

The Socialist Republic of Vietnam/MARD/CP0Mekong Delta Water Resources Development Project

ACRONYMS AND ABBREVIATIONS

AAS Actual Acid Sulphate SoilsDANIDA Danish Intemational Development AgencyDARD Department of Agriculture and Rural DevelopmentDOSTE Department of Science, Technology and EnvironmentEJA Environmental Impact AssessmentEAP Enrwonmental Action PlanEU European UnionFAO Food and Agricultural OrganisationFPZ Full Protection ZoneFS Feasibility StudyHIH householdHY High yield(ing)IDA Intemational Development AssociationIPM Integrated Pest ManagementkV kilo-VoltMARD Ministry of Agriculture and Rural DevelopmentMDMP Mekong Delta Master PlanMDWRDP Mekong Delta Water Resources Development ProjectMRC Mekong River CommissionNIAPP National Instue for Agricultural Planning and ProjectionPFS Pre-Feasibility StudyGLPH Quan Lo Phung HiepSA Summer Autumn riceSida Swedish Intermational Development AgencySIWRP Sub-institute for Water Resources PlanningUSD United States DollarUSDA United States Department of AgricultureUSEPA United States Environmental Protection AgencyWS Winter Spring rice

MDWRDP, Feasibility Study UpdateAnnex I. Environmental Impact Asseasment and Environmental Action Plan, August 1998 viii


%AN I n Ints knpacts, nifgabon and morr

EXECUTIVE SUMMARY

This report is the Environmental Impact Assessment and associated Environmental ActionPlan for the Mekong Delta Water Resources Development Project (see map, Appendix A)comprising three Sub-projects:

* South Mang Thit;* 0 Mon-Xa No;* Quan Lo Phung.

This EIA was prepared with the configurations of the Sub-Projects as conceived,designed, and described in documents and information available as of May 1998. In thesereviews, the Consultant considered environmental issues compiled from:

(i) a review of the feasibility studies prepared by the MDMP and ESSA;(ii) environmental issues raised in the reports prepared for this FS Update; and(iii) discussions with the IDA Preparation missions.

The World Bank guidelines for the major environmental impacts to be expected fromdrainage and irrigation and agricultural production projects (World Bank 1991) were used.As the basis for the preparation of this report, any applicable national requirements werealso taken into account.

Major social issues were identified as a part of the environmental review, and anassessment made of their importance. For details on these aspects, the reader is referredto the series of other Annexes to the Main report for the FS Update.

Environmental impacts

All three Sub-Projects will have a number of important positive environmental and socio-economic impacts:

- Improvements in surface water hydrology and soil grade for the purposes ofagricultural production;

- Increasing agricultural production; and- Improvements in transportation through the excavation of new canals and

reshaping of existing canals and of rural access roads and bridges;- Improvements in drinking and domestic water quality through the

implementation of a Rural Water Supply and Sanitation component.

South Mang Thit Sub-Project

The South Mang Thit Sub-project is envirornentally feasible. The Sub-project will have anumber of positive impacts on environmental and socio-economic conditions, and thereare no Sub-project activities that are assessed to have significant negative environmentalimpacts that can not be effectively mitigated.

MDWRDP, Feasibirty Study UpdateAnnex I, Environmental Impact Assessment and Environmental Action Plan, August 1998. S.1


The environmental issues with respect to the Sub-project are:

li) Increasing surface water and shallow groundwater contamination from biocides andperhaps nutrients from fertiliser application caused by increasing cropping intensity;

(ii) Public health impacts of an estimated 30% increase in pesticide use.(iii) Possible effects of increasing application of biocides and fertilisers on environmental

and socio-economic resources inside and outside the Sub-project area;(iv) Requirements for resettlement and compensation; and(v1 Impediment to water transportation across the major Sub-project sluices.

Sub-project impacts on terrestrial and aquatic biota, and overall biodiversity, both insideand outside the Sub-project area, are expected to be acceptable overall, largely due to thealready impoverished biodiversity in the Sub-project.

Effects of altered hydraulic regimes and land use are expected to have minimal effects onsurface water quarity through the generation of acid and associated constituents inrelatively small areas of acid soils. Special considerations for land use in areas of shallowacid soils is not required.

0 Mon-Xa No Sub-Project

The 0 Mon-Xa No Sub-project is environmentally feasible. It will have a number ofpositive impacts on environmental and socio-economic: conditions.


(i) Increasing surface water and shallow groundwater contamination frorT' nutrientsfrom fertiliser application caused by increasiing cropping intensity, continuedmovement to triple rice cropping,

(ii) Decreasing inputs of natural sources of nutriients because of enhanced floodprotection;

(iii) Loss of 400 to 600 tonnes per year of fish catch as a result of a sluice operationregime that provides flood protection and drainage for rice cultivation. Theestimated annual net income loss to Sub-project households is about USD1 50,000;

(iv) Requirements for resettlement and compensation; and(v) Impediments to water transportation across the major Sub-project sluices.

Effects of altered hydraulic regimes in canal systems and land use are expected to haveminimal effects on surface water quality through the generation of acid and associatedconstituents in the areas of mainly moderate and slight acid soils. Special land useconsiderations in areas of shallow acid soils are not required.

Quan Lo Phung Hiep Sub-project

The Quan Lo Phung Hiep Sub-project is environmentally feasible. It will have a number ofpositive impacts on environmental and socio-econornic condritons. There are no Sub-project activities that are assessed to have significant environmental impacts that can notbe effectively mitigated.

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(i) Increasing surface water and shallow groundwater contamination from biocides andperhaps nutrients from fertiliser application caused by increasing cropping intensity;

vii) Possible effects of increasing application of biocides and fertilisers on environmentaland socio-economic resources inside and outside the Sub-project area.

(iii) Requirements for resettlement and compensation; and* (iv) Impediment to water transportation across the major Sub-project sluices.

Environmental Action Plan

The proposed Environmental Action Plan for the MDWRDP contains two components:recommendations for environmental mitigation and recommendations for environmentalmonitoring.

Environmental Mitigation

The recommended environmental mitigation activities common to all Sub-projects are:

(i) continuation of education on IPM techniques for rice cultivation and farm workersafety in pesticide and herbicide application through provincial Plant Protection Sub-departments. Experience in applying [PM techniques in the Mekong Delta showsdecreases of the number of pesticide applications to over 80%, and increases inpaddy production of about 0.7 tonne/ha/year. Hence, a successful IPM programmecan negate the otherwise expected negative impacts.

Iii) sluice operation for flushing of the water control systems when water qualitydeteriorates. Depending on the Sub-project layouts and sluice configuration,flushing can generally be appried in the dry season by letting fresh water in at hightide and draining it out through the downstream sluices during low tide.

(iii) implementation of a Rural Water Supply and Sanitation component under theMDWRDP and other rural development programmes sponsored by GOV and

- donors;(iv) implementation of the Resettlement Action Plan for project affected people;(v) provision of boat lifts and transhipment facilities near major project sluices to

alleviate impediments to navigation, as integrated in project design; and(vi) canal excavation and disposal of spoil soil would have to follow specific

methods to minimize release of acids into fields, depending on the localconditions and the severity of the acid sulphate soils.

Point (iii) above is not environmental mitigation that would be required because ofnegative impacts of the Project. It would considerably improve living conditions for ruralhouseholds; it is therefore included into the Project.

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Annex 1, Environmental Impact Assessment and Environmental Action Plan, August 1998 S.3

The Socialist Republic of VietnamIMARDICPOMekong Delta Water Resources Development Project

Environmental Monitoring

The proposed environmental monitoring plan is an expansion of the existingSurface Water Quality Monitoring Network. Thirty additional surface water qualitymonitoring stations are proposed. Monitoring would consist of basic surface waterquality parameters, pesticides, and bacteria and coliform. Incremental annualoperating costs are estimated to be USD157,000.

A fisheries survey (USD 90,000) is proposed, especially focussing on the 0 Mon-Xa No area where it will be interesting to follow what the effects of providing fullflood protection would be on the natural species composition, reproduction, catchetc. and to monitor how the anticipated alternatives would develop.

A study on rice-fish farming systems (USD 60,000), which seems to be promising.The study would build on recent research and extension work on rice-fish farmingsystems {Annex VI).

MDWRDP, Feasibility Study UpdateAnnex 1, Environmental Impact Assessmem and Environmental Action Plan, August 1998 S.4

The Socialist Republic of Vietnam/MARDlCPOMekong Delta Water Resources Development Project

1. INTRODUCTION AND BACKGROUND

This report is the Environmental Impact Assessment (EIA) and associated EnvironmentalAction Plan (EAP) for the Mekong Delta Water Resources Development Project. It isproduced as part of Feasibility Study (FS) updates for three Sub-Projects in the MekongDelta in preparation for IDA financing:

* South Mang Thit, (SMT)* 0 Mon-Xa No, (OM-XN), and* Quan Lo Phung Hiep, (QLPH)

1.1 Oveal Objectives of the EIA-EAP

The objectives of this environmental review are to:

(i) Review all environmental reports available with the Ministry of Agriculture and RuralDevelopment agencies in Viet Nam, especially paying attention to the effects ofacidification, water pollution, salt intrusion, and water quality; and

(ii) Conduct an Environmental Impact Assessment and prepare an EnvironmentalAction Plan for the Project.

1.2 Genral Approach to the EIA

In this review, social issues are identified as a part of the EIA, and an assessment is madeof their importance. For a further treatment on these aspects, the reader is referred to theother Annexes of the Main Report:

Annex II: Resettlement Action Plan;Annex IV: Groundwater and Rural Water Supply and Sanitation;Annex V: Soils and Agronomy; andAnnex VI: Fisheries and Aquaculture.

This EIA-EAP is based on the environmental issues raised:

li) in the feasibility studies prepared by the MDMP Project for SMT (HEC-2 - NEDECO,1994) and OM-XN (SIWRP - NEDECO, 1994) and the pre-feasibility study preparedfor QLPH (SIWRP - HEC-2 - ESSA 1992);

(ii) in the Social and Environmental Study Update for the three Sub-projects, preparedby the SIWRP in preparation of this TA (September-October 1997);

(iii) by the IDA team during their various missions to the Viet Nam to discuss projectpreparation with MARD/CPO and the TA team in preparation of the MDWRDP; and

(iv) in the Inception Report and in the Interim Report for this FS Update, and thecomments received thereupon.

The World Bank guidelines for the major environmental impacts to be expected fromdrainage and irrigation and agricultural production projects (World Bank 1991) were used.The methodology applied in preparing the EIA and EAP is given in Appendix D.

Three reports containing the draft EIA and associated EAP for each of the sub-projectswere prepared in November 1997 and were reported as annexes to the Interim Report ofDecember 1997. This final document incorporates reviews and comments made by IDA

MDWRDP, Feasibility Study UpdateAnnex I, Environmental Impact Assessment and Environmental Action Plan, August 19981


staff and CPO, and integrates the separate documents into a single EIA for the entireProject.

The environmental reviews for the separate Sub-Proiects, however, can still be treated inthis document as independent assessments.

1.3 Outline of this Report

This report consists of three major sections; each section is devoted to one of the Sub-projects. The general format for each Sub-project is as follows:

* Description of the Exsting Envronment. T his is synthesised from availableinformation on the Sub-project area and field visits, supplemented by the relevantSocial and Environmental Study Update report (SIWRP), information from similarlocations in the Mekong Delta if relevant, and interviews with scientists andplanners working in national and provincial institutions;

* Project Descrption upon which the EIA was conducted. It is a synthesis ofinformation contained in the FS, supplemented by updated information obtainedduring the course of the FS update. It describes, using the best availableinformation, what engineering works have been constructed and what land usechanges have occurred since the completion of the FS, and what is being proposedfor completion of the Sub-project;

* ImpactAssessmnent, an evaluation of the environmental impacts of the Sub-project;* Environmental Action Plan for the Sub-project, consisting of mitigation and

monitoring requirements as well as arrangemfents for implementation.

The main report is supplemented by a series of appendices.

Appendix A: Maps

Appendix B: Soils of the Mekong River Delta Description and Guidelines for Use

Appendix C: Trends in Surface Water Quality in the Quan Lo Phung Hiep Area

Appendix D: Impact Assessment Methodology

MDWRDP, Feasibility Stidy UpdateAnnex 1, Environmental Impact Assessment and Environmental Action Plan, August 1998 2


SOUTH MANG THIT SUB-PROJECT

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The Socialist Republic of Vietnam/MARDfCPOMekong Delta Water Resources Development Project

2. EXISTING ENVIRONMENT OF THE SOUTH MANG THIT SUB-PROJECT

2.1 General Description

The South Mang Thit (SMT) Sub-project was one of the five high. priority projects thatwere selected for feasibility studies {FS) as a result of the preliminary evaluation in the firstphase of the MDMP (NEDECO 1990-1994). The main objective of the FS was todetermine the optimal plan for sustainable and integrated use of the resources in the Sub-project area in order to increase the productivity and to improve the living conditions ofthe local people.

The SMT Sub-project as proposed in the FS is consistent with the development strategyrecommended in the MDMP, October 1993. The Sub-project.consists of about 225,680ha of the Mekong Delta and includes most of Tra Vinh Province and part of Vinh LongProvince. Tra Vinh province is one of the poorest in Viet Nam, with per capita income andliving standards well below the national average. The area of specific concern in thisEnvironmental Review is known as Regions A, B and C in the original FS. The Sub-projectarea includes nine districts'.

The SMT area is a coastal plain with low, flat elevation ranging from 0.4 to 1 m. The areacontains two specific topographical regions. The region to the north of inter-provincialRoad No. 36 with low and flat topography, and the region to the south of that roadconsisting mainly of flat lands intersected by higher elevation sandy ridges.

About 1,131,000 (1996) people live in the SMT area. These people are mostly Kinh,although almost one-quarter is Khmer. Land is mainly used for agriculture, and thereremains only a small amount of unused land.

Synoptic information for the Sub-project area is presented in Table 1 and Table 2.

A very small portion of Cau Ngang District is in the coastal Region D. For the purposes of thisEnvironmental Review, however, it was assumed that all of Cau Ngang District lies withinRegions B and C of the Sub-project. This made the tasks of data assimilation, review, andpresentation easier and more efficient than if the District had been allocated more exactly tothe two Regions. The conclusions reached in this review would be the same under eitherapproach.

MDWRDP, Feasibility Study UpdateAnnex 1, Environmental Impact Assessment and Environmental Action Plan, August 1998* 4

The Socialist Republic of Vietnam/MARD/CPOMekong Delta Water Resources Development.Project

rak 1:ShtvmfwAvbkr 4 & 7?ia6PrhR

Gross Area Population Agr. Area 3 Rice 2 Rice 1 Rice Other Agr. Fish Forest other(ha) (ha)

SMT 225.682 131,247 171.837 33,282 47,306 61.536 29,713 2.352 1,211 50,282

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AW Etdwic Composidon (%tArea Populatn Total Ave. HH Agr. Lid Land/HH % HH With Fresh(hal No. HH Size No. Agr. Mi (ha) (ha) Khnh KhArp HOJ Otheas Water

ubpolect 225,682 1,131,247 221,168 5.21 180,528 138,260 1.07 75.8 22.9 1.3 0.0 38.1TM On 26,531 159,797 25,614 5.30 19,607 17.371 0.89 92.5 7.0 0.5 0.0 30.3VtuiLMm 22,489 135,064 30,750 5.47 23,39 18.914 0.80 94.0 5.8 0.4 0.0 65.3Tra Vumh 4,843 70,284 13,887 5.06 1,858 2,283 1.23 80.5 10.1 9.3 0.1 49.7Cong Lon 28,905 162,737 29,750 5.47 22,774 28,101 1.15 94.0 5.6 OA 0.0 21.4CouKe 24,118 125,010 23,595 5.30 18,062 22,141 1.23 70.9 28.6 0.5 0.0 73.6VWeucn 22,110 110,651 21,488 5.15 18,448 19,820 1.21 70.3 28.1 1.5 0.0 51.2ChauT &nh 37, 762 131,559 24,621 5.15 18,848 23,978 1.27 84.8 34.6 06. 0.0 9.87MCu 26,656 11i,991 25,732 5.74 19,697 23,942 1,22 42.1 56.8 1.3 0.1 6.4

Cau Ngan 32,268 106,172 25,732 5.12 19.097 15,291 . 0.B3 83.8 35.5 0.7 0.0 48.5

' This Information was not available at the District level, but was only available for the entire Sub-project. The proportion of the total households In each districtthat were assigned to be agricultural was therefore set as the Project-wide proportion.

MDWROP, Feasibility Study UpdateAnnex I, Environmental Impact Assessment and Environmental Action Plan, August 1998 5


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2.2 Physical Resources

2.2.1 Climate

Two distinct seasons occur in the SMT area: the rainy (or wet) season from Mayto November; and the dry season from November to April. Roughly 90% of theannual rainfall is concentrated in the rainy season and provides a mean annualrainfall of about 1,400 mm (1977-1997) (Figure 1).

Dry spells lasting up to 30 days in some years may occur in June and July.Temperature and radiation conditions are excellent for producing tropical foodcrops. The fluctuation of the mean monthly temperature is less than 3 degrees(25.4-28.2'C). Relative humidity usually exceeds 80%. Potential evapo-transpiration is about 140 mm per month.

2.2.2 Soils

There are three main different soil types in the SMT area (Table 3): Sandy soils (6%),Alluvial soils (61%), and Acid Sulphate soils (33%). The FS of 1994 indicates that about12,000 ha are underlain with shallow acid soils fi.e. with an acid generating layer lessthan 50 cm deep), representing about 5.4% of the total Sub-project area (Figure 2).

MDWRDP, Feasibility Study UpdateAnnex l, Environmental Impact Assessment and Environmental Action Plan, August 1998 6

The Socialist Republic of VietnamnMARDlCPOMekong Delta Water Resources Development Project

Tdhbb rliratslp.. ScaEAfre 1Mbpqsc

Sol Types Area (ha)Sandy SoilSandy depression sods 284Sandy ridge soils 15,240AAk/l SoibNon active Ailuvial sis 2,349Acive Aluvwil soIs 8,892Recaetly actnve Alluvial sois 26,125Non affected Aluvial sois on sandy ridges 45,047Sightly affected Aluvial sois on sandy ridges 11,235Modoetely affected Alluvial sods on sandy ridges 908Slightly saline Akuial soils 35,931Modeately sain Alluvial soils 21,722Strongly saline Auvial soils 6,057Acdd Su42haft SalkNon-affected sain I potentially acid sulphate soils 41,210Sightly-ffected saie/ potentially acid suihte sods 7,575Moderately affected saine otentiap y acid siphat sois 3,286StroV affected saine Ipotenti acid suiphe sois 15,520Non affected salW acdve acid sdphate soils 2,787Sightly affected s actve aid sdphte sois 13,330Moderately affect saire acive acid siphate sois 411

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2.2.3 Surface Water Hydrology, Salinity, and Acidity

22.3.1 Suface WawHy&WOgy

Four main factors influence the surface water hydrology of the Sub-Project: precipitation,river flows, ocean tides, and canal flows. A summary of current inflows and outflows forSMT (dry season) are provided in Table 4.

MDWRDP, Feasibility Study UpdateAnnex I, Environmental Impact Assessmnent and Environmental Action Plan, August 1998 7


Parmeter Before 1993 Current ConditonsINFLOW:

Predpiaion 0 0From Bassac River 14 18From Co Chien River 18 26From Mang Thit River 21 23FsomOcean 60 63

TOTAL INFLOW 113 130

OUTFLOW:

To Bassac River 4 4To Co Chbn ver 4 5To Mang Thit River 0 0ToOcean 65 66

TOTAL OUTFLOW 73 75

INFLOW imnus OUTFLOW: 40 55

River Flows - The Mekong River is the only practical source of fresh water for irrigationduring the -dry season. Flows into and out of the Tonle Sap Lake in Cambodia influencethe discharge hydrograph of the Mekong River significantly. December and Januaryaverage flows approximately double downstream of Phnom Penh compared withupstream, because of the water release from the Tonle Sap Lake. In February, thedischarge downstream of Phnom Penh is about 4,300 m3 /s compared with about2,700 m3/s upstream. Approximately 50% of the flows at Phnom Penh enter the SouthChina Sea via the Bassac River. The Bassac, the Co Chien, and Mang Thit riers (theMang Thit River connects to the Bassac and Co Chien rivers) are the sources of freshwater during the dry season for the Sub-project.

Canal Network - Many main canals, primary canals, and creeks with a total length of 875km connect with the main rivers. Together with about 2,000 km of secondary canals andsome 10,000 km of on-farm canals, they provide a dense overall canal network. Thesurface water network serves both for drainage and for irrigation water supply.

Precipitation - The major feature of the precipitation regime is that most of the annualprecipitation falls during a seven month period, from May to November. Rainfall isextremely low from December to April (Figure 1).

Tides - Ocean tides with amplitude of up to 3.00 m have a strong influence on the Sub-project area. Along the Mang Thit River, the tidal amplitude is still up to 2.20 m.

Hydrological conditions determining the rationale for the SMT Sub-project are:

(i} salinity intrusion;(ii) water-ogging;(iii) inundation; and(iv) a shortage of fresh water for agriculture in the dry season.

These constraints are caused by the insufficient capacity of the existing canal networkand by a lack of sufficient water control structures.

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The Socialist Republic of vietnam/MARD/CPOMekong Delta Water Resources Development Project

2.23.2 Sa&#iny

Situation Prior to Initiation of Sub-project: In the absence of sluices to prevent the inflowof saline water, the tide penetrated deep into the area. It brought saline water in thecanals and creeks that would be the source of irrigation water, causing a too high salinityfor irrigated agriculture in the dry season.

Existing Situaton: Some of the engineering works idlentified in the SMT-FS have alreadybeen constructed (Section 3.2.2). Salinity intrusion in the Sub-project area reducedgreatly, although not to the point that irrigated agriculture in the dry season can beundertaken throughout the entire Sub-project area.

223.3 Aidety

In the Sub-Project:

(i) there are no long term surface water quality monitoring stations maintained by theSIWRP under its Water Quality Monitoring Network;

{ii) there are no water quality monitoring stations in the national EnvironmentalMonitoring system, maintained by the National Environment Agency of Viet Nam;and

(iii) till date, only one surface water quality campaign has been conducted (by RIA-2) asa part of the SMT-FS under the MDMP Project (1992).

ft is likely that the surface water quality in the area is similar to other parts of the MekongDelta. Water is contaminated by sewage, is largely eutrophic, and it can be assumed thatits quality has not substantially changed since the preparation of the SMT-FS3. Thedevelopment of the area since the preparation of the SMT-FS, construction of sluices andcanal excavation, has reduced the area effected by saline/brackish water and hasimproved drainage conditions. Hence, water quality has possibly inproved to some extentin both seasons.

There are acid soils in the area, but there are different descriptions of the patterns of thisacidity.

The SMT Update report states tat: "Special attention is given to the problem of acidwater in the South Mang Thit. At its eastern side, water quality in the rivers and canaisappears relatively favourable in terms of acidity, the pH varies from about 6.5 to over 8,but is normally around 7-7.5. In contrast, at its western side, distinct seasonal acidityinfluences occur. During the early part of the rainy season, the pH drops from normalvalues (6-7) to below 4 and under the influence of rain water it is flushed (leached) fromthe strongly acid sulphate soils."

The SMT-FS, however, states that: min areas adjacent to acid soils, surface watermay seasonally become slightly acid."

A soil map generated for the entire Mekong Delta as a part of the MDMP Project (seemap, Appendix A) suggests that acid water is not an issue for the Sub-project area.

3 Coliform levels were reported to be as high as 480,000 MPNilOO ml. and E.coli levels werefrom 4 to 100,000 MPN/1 00 mlJ (based on 14 samples).



Although it is not possible to demonstrate the spatial and temporal distribution of acidgeneration and transport in the Sub-project area, continued improvements in the watercontrol system since the early nineties have already enhanced the drainage and flushingconditions. It is experienced in the Ca Mau Peninsula, where acid sulphate soils are muchmore widespread and where land reclamation took place at massive scale over the pastten years, that improved drainage and flushing gradually leads to an improvement insurface water quality. This offsets the impact of acid release from the soil after oxidationin the dry season (see Appendix C).

The surface water downstream of the Sub-project area, in Duyen Hai District(Region D of the original SMT-FS) demonstrates the influence of marine waters(Table 5) on the surface water quality. The limited sample set generally indicatesgood quality water that meets most of Viet Nam's coastal water qualitystandards".5.

&ab KWwVAy MW iDsf rzWy I=ob~of Siwe nduA& 7M&Ap9sd

No. pH SS CL7 NO, NH, Tot Fe SOD.1 8.0 330 4,490 0.04 0.13 3.90 162 8.4 115 8.750 0.06 0.10 3.44 123 8.0 180 8,070 0.09 0.20 3.66 184 8.3 20 7,180 0.05 0.11 0.97 165 8.0 130 9,650 0.10 0.15 0.82 22

All datea except pH are in mg/l

2.2.4 Groundwater Resources

The only available source of information on groundwater resources is from the MDMPProject (Working Paper no. 2) and in the SMT FS the following conclusions were reached:

li) the groundwater quality in the norh-eastem portion of the SMT area is generallypoor;

'ii) the groundwater in the lower two thirds of the SMT area appears to be generally ingood supply;

iii). in the central part of the area, the MDMP Thematic Study indicates thatgroundwater is available only at depths of more than 350m. This is partly bome outby the SMT FS that indicates that the central part is brackish. This area is alsocovered by a shallow aquifer with water of inconsistent quantity and quality. Thisshallow aquifer is not even mentioned in the SMT FS as a useful source of water,even for irrigation purposes; and

(iv) the proposed major source of freshwater supply, the Pleistocene Aquifer wasalready showing signs of bacterial contamination at some locations (see Page 24 ofthe groundwater supply annex of the SMT FS). The SMT FS containsrecommendations for treatment of groundwater before use which are alsoincorporated in the rural water supply and sanitation component of this MDWRDPproject.

* MOSTE, 1995, Provisional water quality standards.' The exceptions are iron and suspended solids, which may be an artifact of the sampling

locations. It appears from the original data that some of the sampling points were located invery small canals, which are unusually turbid. High total iron levels are usually associated withhigh suspended solids because of the high iron adsorbed onto the suspended sediments.This may need to be figured into the implmentation of the Rural Water Supply and SanitationComponent of the Sub-project.

MDWRDP, Feasibility Study UpdateAnnex I. Environmental Impact As essment and Environmental Action Plan, August 1998 10


2.2.5 Air Quality

As is the case with surface water quality, none of the air quality monitoring stations inthe national Environmental Monitoring system maintained by the National EnvironmentAgency of Viet Nam are located in or near the Sub-project area. Therefore, there are nolong-term records of air quality from the study area.

Notwithstanding this lack of information, air quality is generally very good. Tra Vinh is themajor urban centre within the area, it is still relatively non-industrialised, and there are nomajor sources of air pollutants to affect air quality either locally or over the entire Sub-project area.

2.3 Ecological Resources

2.3.1 Land Use and Vegetation Cover

Figure 3 contains the land use in the Sub-Project in 1997. The data presented are basedon figures provided by the Provinces and have been adjusted for the area within the Sub-project boundary. The Sub-project is dominated by agriculture, with about 80% of theland devoted to agricultural production; most of this is rice agriculture. Vegetation cover iscurrently very limited, with only about 1 % of the Sub-project designated as Forest. Thereis also vegetation in the form of Nipa palm in canals (Section 2.3.2), as well as in theform of scattered trees planted around landholdings for environmental protection and forfuelwood supply.

Land use has changed dramatically since the SMTArS was completed (Figure 4). Theimportant changes are:

6i) an increase in the area of triple rice cropping, which replaced double and single ricecropping. Much of this has occurred in Region A and B; and

(ii) a decrease in .Other* land, indicating bringing fallow land under agriculturalcuttivation.

2.3.2 Terrestrial Ecosystems

There are no intact terrestrial ecosystems remaining wifin the Sub-Project7. Practically allthe land is in use for agricultural production, human setdements, or open water in theform of canals. There are about 1,221 ha of forested land (Table 1). This area is in factlocated in Region D, just at the boundary of the Sub-project area and is part of theCoastal Wetlands Protection and Development Project (Section 2.3.5).

2.3.21 NWpa Pab,

Salinity control sluices have altered the salinity regime in the Sub-project. This already hadan impact on Nipa palm, estimated at the time the SMT-FS was prepared to occupyabout 4,200 ha. Quantification of the reduction in Nipa palm was not possible.

7 This confirms a similar assessment made in the Environmental Impact Assessment to the FSINEDECO 1994).

MDWR3P, Feasibility Study UpdateAnnex I, Environmental Impact Assessment and Environmental Action Plan, August 1998 11


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MDWRDP, Feasibility Study UpdateAnnex I, Environmental Impact Assessrnent and Environmental Action Plan, August 1998 12


23.22 Use of Ten'estdal Ecosystem Resoures by Local Households

Residents of the Sub-project area are likely similar to residents in other parts of the Deltaand rely on terrestrial ecosystems as supplemental source of off-farm or non-farmbenefits (see for example, GEC Ltd., 1997). Terrestrial biota that is captured may be usedfor domestic, subsistence purposes, or may be sold to local markets. Levels of use ofterrestrial resources in the Sub-project area are likely to be lower than in other parts of theDelta (such as U Minh in the Ca Mau Peninsula) because of the generally more degradedand impoverished terrestrial ecosystems in the Sub-project.

2.3.3 Aquatic Ecosystems

With the construction and enlargement of canals, the surface area of open water hasincreased in recent times. This has created new areas for fish within the area.

Due to already completed sluices, which prevent saline water intrusion, the fish speciescomposition is changing from a composition that fluctuated between freshwater to salinewater species to predominantly freshwater species throughout the year.

2.3.4 Biodiversity and protected areas

The Sub-project area contains few biodiversity resources, because of the almost completeabsence of natural terrestrial ecosystems.

There are no areas that are either part of Viet Nam's existing or proposed national systemof protected areas. In addition, the provinces do not maintain protected areas witin theSub-project area.

2.3.5 Downstream Ecosystems and Protected Areas

The coastal areas of Tra Vinh Province contain substantial mangrove ecosystems. Theseareas have been identified in the Viet Nam National Environmental Action Plan (WorldBank 1995) as priority ecosystems for sustainable management and protection. Tnisecosystem is degraded, due to land conversion for shrimp aquaculture and cutting forfuelwood.The MARD/World Bank Coastal Wetlands'Protection and Development Project is a majorinvestment project along the entire marine coastline of four provinces in the Mekong Deltaincluding Tra Vinh. One component consists of a Full Protecton Zone (FPZ) along thecoast of Region D. Investment costs for Tra Vinh Province were estimated to be aboutUSD 4 million (GEC Ltd. 1996).

2.4 Socio-conomy

2.4.1 Population, Demography, and Ethnic Compositon

The Sub-project contains a young, rapidly growing, almost exclusively nrral, already densepopulation of about 1,131,000 persons. Population gmwth rate since the FS has beenabout 2.3% per year.

The predominantly rural population (save for Tra Vinh town and the district towns) isdispersed, but due to inundation as weR as requirements for communication and

MDWRDP, Feasibility Study UpdateAnnex 1, Environmental Impact Assesment and Environmental Action Plan, August 1998 13


transportation, the population is unevenly distributed. It is concentrated on natural levees,along the banks of canals and rivers, and beside roads. Most farm families live in smallsettlements situated at the intersections or along the banks of the canals and rivers.

The population of the Sub-project area is 75% Kinh, 23% Khmer, and slightly more than1 % Hoa. There is considerable variation in the ethnic composition among the districts.Almost 60% of the population of Tra Cu District, is Khmer, while more than 90% of thepopulation of Vung Uem and Cang Long Districts is Kinh (Figure 5).

QuThrt CU

T mu Ca C i b~~~ C I __

Tm onVU'w I t I I II I I_

.~~~~ -

- MO MO Ia0 S10 l10 0D D MO "MO

791tI 6 Edhri caoSpow of popubftm SouSh M&Wx 7hft &Ab-

Household size in the Sub-project area is about 5.2 persons, and ranges from s.'ightlymore than 5 in Tra Vinh to 5.74 persons in Tra Cu (Figure 5). Arable land per householdaverages 1.07 ha, -and varies very iittle throughout the Sub-project area. These figuresmean that arable land per person averages slightly more than 2,000 ml.

2.4.2 Driinkg Water Supply Wthin the Sub-Project

Currently, about 50% of the Sub-project population has access to freshwater fromgroundwater wells, a considerable increase from an estimated 25% in 1992.

This percentage varies greatl fromdistrict to district. In two districts (Chau Thanh andTra Cu), almost no household has access to secure freshwater, while in Cau Ke Districtmore than 3 out of 4 households has a secure freshwater supply.

2.4.3 Disease and Public Health

The Subproject area experiences most of the well-known tropical diseases, namelymFlaria, Dengue fever, and encephalitis, as well as diseases such as tuberculosis andcholera. Basiterial corTtarination in surface water and the use of surface water by ahighproportion of the population means that waterlome diseases of bacterial origin areprevalert. We were not able to obtain updated details on disease and public health for the

MDWRDP, Feasibility Study UpdateAnngx o, unvironmental Impact Assessment and Environmntal Actidon Plan, August 1998 14


Sub-project. The findings on disease prevalence and public health contained in the FSlikely still hold, because:

(i) not all the population has access to clean drinking water;(ii) surface water is extremely contaminated; and(iii) developments that would have caused the surface water quality to improve, like

construction of sluices and canals, may not yet have a significant impact.

2.4.4 Downstream Water Supply

Drinking and domestic water supply downstream of the Sub-project area is in a bettercondition. About 65% of the residents of Duyen Hai District already has access tofreshwater for drinking and domestic use (information from the SMT Update study). Thisis largely due to UNICEF groundwater well construction activities, as well as an EU-funded micro-credit project in the coastal zone of Tra Vinh province (GEC Ltd. 1996).

2.4.5 General Infrastructure and Industry

2A.&1 Transportaion

Navigation - The main navigation takes place along the main channels of the Mang Thit,Co Chien, and Bassac Rivers. The channels can accommodate ships with a capacity ofover 1,000 tonnes. Large ships usually pass the Bassac River mouth en-route to the CanTho port and upstream up to Phnom Penh. In the recent past, several canals wereexcavated for navigation, irrigation, and drainage, including the Tra Ngoa - Thong NhatfTong Ton, My Van, Bung Truong - Ngai Chanh, and February 3d.

Roads - Compared to other provinces of the Mekong Delta, the road network in VinhLong and Tra Vinh Province is quite well developed. There are 650 km of roads of allstandards (except rural roads). The National Road No. 53 connects Vinh Long town to TraVinh town; some inter-provincial roads link the districts and small towns with Tra Vmhtown.

.4.5.2 Level of I AIIAao

The level of industrialisation in Vinh Long and Tra Vinh provinces is extremely low. Onlyabout 8% of the provincial GDP comes from the secondary sector. There are no largeindustrial factories or enterprises, and the most recent foreign investmrent statistics forTra Vinh Province (mid-November, 1997) indicate very low levels of industrial investment.The enterprises engaged in industry are mainly ice lproduction, rice milling, and smallscale, outdated sugar processing factories. A new large capacity sugar mill to beconstructed in 1998/1999 would handle the sugarcane production of an area of5,000 ha.

2.4.&3 .eldt

Although a 65 kV electricity grid has been established to all the districts in the SMT area,this system supplies only the district capitals. The 15 kV electricity grid links Tra Vinhtown to some of the Sub-project villages but not all of the rural population has access toelectricity. The total number of households with electricity is estimated at approximately10%.



2.4.6 Cultural, Aesthetic, Historic Features

There are no cultural, aesthetic, or historic features in the Sub-project area at risk byworks to be constructed for the Sub-project.

2.4.7 Agricultural Production

In 1997 the Sub-project area produced about 0.96 million tonnes of paddy. This is a 25%increase since 1991, and can be attributed to the increasing area of triple rice and doublerice cropping. In addition, there has been some increase in diversification of cropsproduced; particulariy maize is grown on small plots in the northem part of the Sub-project.

2.4.8 Household Energy Supply

Trees are used for fuelwood, house construction, fumiture, and fruit cultivation. Very littlenatural forest remains save for some small pockets throughout the Sub-project.

Fuelwood is extremely important throughout all of Viet Nam. It comprises about 90% ofthe domestic energy consumption at the national level. The World Bank (1995) identifiedthe Mekong Delta as being a deficient region with respect to fuelwood supply. Duyet(1991) estimated that requirements are 0.1 m3 per capita per year. NEDECO (1991)estimates that this should increase to 0.2 m 3 by the year 2000. For the Sub-project, thisis equivalent to a requirement of between 27,000 m3 and 44,000 m3 fuelwood atpresent. The SMT Update mentions that there have been extensive scattered treeplanting programs throughout the Sub-project. This has to continue to meet futurerequirements.

MDWRDP, Feasibility Study UpdateAnnex 1, Environmental Impact Asessment and Environmental Action Plan, August 1998 16


3. DESCRIPTION OF SOUTH MANG THIT SUB-PROJECT

3.1 Ratonale for South Mang Thit Sub-Project

The main issues that formed the rationale for the South Mang Thit Sub-project were:

(i) salinity intrusion;(ii) water-logging;(iii) inundation; and(iv) shortage of fresh water for agrculture in the dry season.

These constraints are caused by the insufficient capacity of the existing canal networkand by a lack of sufficient control structures.

3.2 Detailed Sub-prqect Desciption

3.2.1 Original Sub-project Concept

The original Sub-project concept consisted of the following items.

Protection from Saruft Intuion and Dry Season Freshwater Supply - In order to preventsalt water from entering the SMT Sub-project area, MARD proposed the construction of11 sluices. The sluices would operate (semi-) automatically depending on differences inwater levels at either side of the gates. Generally, lower water outside wil cause thegates to open, while lower water inside will cause the gates to close. During the dryseason, the sluices are kept closed to keep saline water out of the area and to preventfresh water from flowing to the sea. Flushing of canals by means of opening the sluicesat low tide would be done in the dry season to improve surface water quality whenneeded.

Improved Drainage - Expansion of the existing canal system through new canals andenlargement of existing canals (in total about 305 km of primary and 1360 km secondarycanals) would improve drainage and reduce inundation. Drainage is enhanced by thesluices because in the rainy season the gates are kept closed during rising tides.

Improved Freshwater Distribution - A number of water control sub-systems, consisting ofsecondary and tertiary sluices, secondary and tertiary canals, and improvements to maincanals, where needed.

Improved Transportaion Infrasuct - About 71 bridges related to canal reshapingwould serve as mitigation for interruption in waterway transport caused by the sluices.Boat lifts will be provided to mitigate impediments to small boat transport.

3.2.2 Current Status of Sub-project Implementation

The details of the status of the implementation of the Sub-project are contained in theMain Report and Annex Vill, and are summarised in the following sections.

MDWROP, Feasibility Study UpdateAnnex I, Environmental Impact Assessnent and Environmental Action Plan, August 1998 17

The Socialist Republic of VietnamlMARD/CPOMekong Delta Water Resources Development Project

3.22?1 Watr Conol Systern

The following components of the Sub-project have been completed, or are underconstruction in 1998:

(i) nine sluices are under construction or have been constructed: Tra Cu, Nha Tho,Trem, Vam Buon (completed before 1998), Cha Va, Thau Rau, Bac Trang, Ba Tramand Diep Thanh (under construction in 1998) (see map, Appendix A). Seven ofthese were components of the original FS. Where required, the canals associatedwith these sluices have also been developed;

lii) three main canals have been enlarged (Tra Cu, Nha Tho, and Vam Buon), and anumber of canals have been or are being constructed (Bang Da, Thong Nhat, LuongHoa, 3 February, Cau Hanh, Tra Ot, Chinh Plu, Tong Ton, Chanh Sam, Long, Hiep,and Ba So). Not all canals were excavated up to design dimensions.

3.22 Ch9es in Land LI. bum FS to nt Cndions

The ongoing implementation of the SMT Sub-project has already brought about land usechanges consisting mainly of (Figure 4):

(i) an increase in triple rice cropping of about 13,000 ha, largely in Region A;'ii) concomitant decreases in single and double rice cropping, again largely in Region A;

and(iii) a decrease in the overall area of land classified as 'Other', signifying a conversion

of land previously not used for agriculture into some type of culftivation.

Most of these changes have occurred in the upstream part of the Sub-project. Land usePatterns in the downstream part have changed little since the completion of the SMT-FS.This is largely because most of the improvements in water supply and drainage since thecompletion of the SMT-FS have not yet allowed intensifying cropping in the downstreamareas.

3.2.3 Remaining Elements of Sub-project Implementation

The elements of the Sub-project still to be implemented in addition to ongoing work in1998 (5 primary sluices, 82 km primary canal enlargement, 4 secondary sluices and 32km embankment) are:

(i) 8 main sluices;(ii) 92 secondary sluices;(iii) 12 main canals to be enlarged or deepened to increase drainage capacity;(iv) 14 secondary canal systems to be enlarged or deepened(v) continued improvement of the rural transportation system. Especially related to

bridges on the canal system;(vi) continued implementartion of the on farm water management system; and(vii) a programme of rural water supply and sanitation.

3.2.4 Land Use Scenario for Environmental Review

The future land use that can be practised in the SMT area, after project implementationwas determined during the preparation of the project. The land use planning is reported in



Annex V of the FS Main Report. Comparing the future situation with what could happenwithout system completion, major changes would be (Table 6):

0) an increase in the area culivating three crops per year, with most of this increaseoccurring in the form of triple rice and double nce/upland crops;

(ii) an increase in the area for sugarcane.

TawLad saiE,M J"V*&bpvw

land use (ha) PFrsent Without With W-WO1997 Project Project

Gross area 225,682 225,682 225,682 0

1. Agncultuuil area 171,837 171,837 171,441 -396(a) Annual crops 148,732 146,812 144,442 -2,370

-Tnile crowing 33282 46.954 98.206 5 2tbiple nce 33,282 31,954 61,206 29,252double rice + upland 0 15,000 37,000 22,000

-Dbuble cropoina 47g306 47.039 26.436 20,603double rice 47,306 47,039 26,436 -20,603Rice + upland 0 0 0 0

-Sinale crow 68.144 52.819 19.800 -019PtRice 61,53B 46,211 7,000 -39,211sugar cane 6,608 6,608 12,800 6,192

(b) Fruit/homestead 23,105 25,024 26,999 1,975

2. Forest 1,211 1,211 1,211 03. fishery 2352 2352 2352 04. Spewal se land 50,282 50,282 50,677 396

Cropping Intensities %) 166% 182% 230%Crop Diversification ( 3% 8% 14%

MDWRDP, Feasibility Study UpdateAnnex I, Environmental Impact Assessment and Environmentall Action Plan, August 1998 19


4. IMPACT ASSESSMENT FOR SOUTH MANG THIT SUB-PROJECT

Figure 6 contains a summary of the expected environmental impacts of the SMT project.The detailed rationale for the assessment of specific impacts is given below.

4.1 Detaled Descripton of Expected Environmental Impacts

4.1.1 Impacts on Physical Resources

4.1.1.1 Sub-prqject Impact on Sods

Sub-project Activites: Impact AssessmentConrcion and Operaion of Canals Postve and SignificantChanges h Lad Use Posiive and Significant

ConstmctFon and Operaton of Canals, and Changes in Land Use - Salts are expected toleach out frDm the soils rapidly. The consequent increases in soil grade areestimated to reach 10-20% within a period of 2 to 3 years.

Fresh water flushing causes leaching of the oxidised sulphates from soils, whichincreases- productivity of acidic soils. The actual increase of the productivitydepends on the amount of disturbance of the soil (e.g. ditching and landpreparation, etc.) and the depth of the pyritic layers. It is estimated that theproductivity on these soils increases with 10-30% within a 3 to 5 year period

4.1.1.2 Subpmect impacts on the Surfce Water RegIke

Sub-plojectActivites: Impact Assessment:Consuucin and Opeation of Cnals Posive and SigcantOperation of SiLiwc Positiv and Sgnificant

Construckon and OperatFion of Canals and Opeation of Shices - The overall hydraulicconditions in the Sub-project will improve, with improved freshwater supply in the dryseason. The completion of the water control system will have considerable positiveeffects on water levels in the area during both seasons. The change in the hydraulicregime in the area is essentially the objective of the project. The sluices prevent salinewater intrusion in the dry season. The improved canal system will allow fresh water to beconveyed mainly from the intake canals located along the Bassac River in Tra On Districtand from the Mang Thit River. This allows for irrigation of the entire area. In the rainyseason, the sluices will operate for drainage.

The effects on water levels relate to the change in regime, but not so much on maximumwater levels or flow velocities. In the dry season, the central and southern part of SMTwould in future be supplied with freshwater instead of experiencing saline water intrusion.The change in water levels will be limited to some 0.10 m at certain locations. Acontinually fluctuating water level (by tidal influence) in the past is changing towards asituation in which water levels in the central and southem areas will be more constant.These changes are assessed as positve and significant.

In the rainy season, the improved canal system together with the operation of the sluiceswill bring a considerable improvement to drainage conditions. Increased conveyancecapacity of canals together with preventing high tides to enter again, by autornatic

MDWRDP, Feasibility Study Update

Annex I, Environmental Impact Asesment and Environmental Action Plan, August 1998* 20


operation of the sluice gates, will prevent inundation and reduce water logging in thefields.

MDWRDP, Feasibility Study UpdateAnnex 1, Environmntdal Inct Asssment and Environmental Action Plan, August 1998 21


Sub-projeot Activit_ Environmental Resources _Physical _ - _ Ecdogical Socio-econorric

n~~~~~~~~~ ~ ~~~ 11 Cj x z Construction ac Operf on of Canals P P P I _ I I m I p M P _ MOperation of Sluices _ P P I _ M I S I _ I P M I PChangos h iJn Use and Commoqft Productdon P I I I_ P I _ I _ M I P _ PPopulation Growth MI I I I I I I _ I I M i P M PAppcatlon of Fers_l _ _ _ _ I I M I PAppicaton of Pestcides M I _ I-I I I _ I M M I pActivities Outside the Sub-oiect MPrRvision of ural Water Supply and Sanitation P P PConstructlon of Rura Acce Roads and Budges __ __ __ P P

Rgw, a Sta,mmay of wum4wm,ntdh k.cb. South aW~ S17* 6-n*o

b -l -ND IMpaW; l-qgricaM SSl*fcu. Ablty to Mit Lh*own or Not Pombe; M - gnfin and Migabs; UUIrdown; P-Posive Ond Sigift



4.1.1.3 Sub-prject Impacts on Salnity

Sub-project Activites: Impact Assessment:Constction and Operation of Sluces PosWive and Sigrificant for AgictuiWal

ProductionUPstream Actvties InsknNicatl

Construction and Operation of Skkies - The salinity regime of the Sub-project is expectedto change substantially. The current situation during the dry season is that already a largearea is prevented from saline water intrusion. Wrth the completion of the water controlsystem, the surface water salinity of the entire Sub-project area is expected to be lessthan 4 ppt being the limit for use as irrigation water for paddy.

Upstream Activites - The continuing development of the Mekong Delta for increasedagricultural production in the recent past has lead to the situation that at present about15 to 15.5 million ton of paddy is produced annually. A 50% increase as compared toproduction levels in 1991/1992 (MDMP, 1994). The increase was partly obtained fromthe project area but mainly from delta wide development. The impact of the higher waterabstractions on salinity intrusion on the main branches of the Mekong River system andthus on the project area can be assessed as follows..

Comparing the present production figures with those projected in the MDMP, we see thattriple rice cropping is progressing more rapidly than anticipated in the defined ModerateLand and Water Use Scenario of the MDMP. Under these scenarios, some 15.2 milliontonnes of paddy per year would be attainable without a further increase in salinityintrusion as compared to 1991. In the Intermediate Scenario, about 15.6 million tonnes ofpaddy per year could be produced. This would result in a limited increase (3-6 km) offurther salinity intrusion in the Mekong River branches, but a substantial increase of some25 km would result in the Vam Co Rivers. The Extreme Land and Water Use Scenario,without restrictions on water abstractions, flood control and triple rice cutvation wouldresult in a paddy production in the Mekong Delta of 21 .5-million tonnes per year.

The conclusion could be that, as far as paddy production is concemed, since 1991/1992delta development has progressed along the line of the Extreme Scenario. By looking atthe production figures of 1997/1998, the- Delta is about halfway that scenario.

The current water abstractions do not necessarily follow the same trend as predicted inthe Extreme Development Scenario because an impressive change is taking placetowards the use of rice varieties of short duration. The 90-95 days varieties are nowwidely used, while the short duration varieties applied in the early nineties were of the105 -110 days types. The change is taking place in triple and double crop systems; thisgives more flexibility in the cropping pattems and results in less irrigation water use.Under the present TA for the preparation of the MDWRDP, both impacts cannot bequantified for the whole Mekong Delta. It would require an update of the MDMP.

Mathematical modelling of water flow and salinity propagation continued to improve sincecompletion of the MDMP Project. The results now obtained are believed to be moreaccurate and in line with observations of saline water intrusion in the southern part of theDelta.

In the MDMP simulations the 4g/1 salinity isolate was predicted to reach some 10 kmupstream of the Mang Thit River branch on the Co Chien River. This would happen with aprobability of occurrence of 10% (1 in 10 years low flow hydrograph as upstream


The Socialist Republic of VietnamnMARD/CPOMekong Delta Water Resources Development Project

boundary condition, and maximum water abstraction of the Extreme Scenario). Underaverage conditions, the situation would be closer to that predicted in the IntermediateScenario.

The modelling undertaken under this TA for the preparation of the MDWRDP, shows thatin case the limits of the Extreme Scenario for agricuttural production would be reached infuture, the 4 gil salinity isoline could reach the Mang Thit River. This could happen in 5 to10 years. In resuming the model simulations, no changes were made in the pattems ofwater abstractions, which were taken from the 1993-1994 studies to provide boundaryconditions for the simulations with the sub-models needed for the Sub-project. Theintroduction of the 90 days rice varieties has a significant positive impact on water useand hence on salinity intrusion. Salinity of 4g9/ is most likely not to reach the Mang ThitRiver under Extreme Scenario Water Use and 10% probability.

Positive impacts in reduction of saline water intrusion in the main branches of the riversystem are to be expected from flow regulation on the upper Mekong in China as well asfrom dams on Mekong tributaries in Laos. The Mekong River Commission (MRC) providesthe platform for the Mekong basin countries to discuss sharing of any additional water inthe dry season. Eventually, the Mekong Delta in Viet Nam could benefit also from suchdevelopments.

4.1.1X - Subproject kpacts on Swfece Water QuaOty

Pioject Activites: Impact AssessmentConstucto and Operato of Canas ad Sices PostveChages in Lwd UseeRural Wae Supy and Sanitaion PostiveAppicaton of Ferthes InsignificantAppicaton of Pestickd Unknown, MitigableUtuem Activitws .Itigable0pemon ofSluices Insigrnifcn

Construction and Operaion of Canals and Sluices, and Changes in Land Use - Asubstantial proportion of the Sub-project is underlain with acid soils with a relatively smallproportion of shallow acid soils. These areas are already releasing acidic water at theonset of the rainy season. However, this concerns a relatively low quantity of acid watercompared to the flushing capacity of the canal system. With the completion of the canalimprovements and the sluices, the flushing conditions will improve further. Hence,implementation of the SMT Sub-project would have positive impacts on acidic waterconditions.

The impact of increasing the flushing capacity and enhancing drainage on the reduction ofacidic surface water conditions is already observed in the Quan Lo Phung Hiep area. InCLPH, acid sulphate soils are far more widespread and more severe. In that area,extensive developments took place over the last ten years and a trend can now beobserved that the surface water quality is gradually improving. This is reported inAppendix C.

In SMT, with much less acid sulphate soils and better drainage conditions aftercompletion of the Sub-project as compared to QLPH, it can safely be assumed tha evenif canal excavation results in the temporary release of acids into surface water, this maynot be noticed because of the flushing capacity of the water control system.

MDWRDP. Feasibilry Study UpdateAnnex I, Environmental Impact Assessment and Environmental Action Plan, August 1998 24


Rural Water Supply and Sanitation - Without improvements in sanitation and propertreatment and disposal of household wastes, the increasing population will continue todegrade the surface water quality of the Sub-project. Pollutant levels within the Sub-project already appear to exceed most national and intemational water quality standards.The implementation of the proposed Rural Water Supply and Sanitation component as apart of the Sub-project would improve these conditions to some extent. This is assessedas positive.

Application of Fertilisers - From the future land use plan it is estimated that 73,700tonnes of fertiGiser will be required annually instead of the estimated 35,400 tonnes atpresent (Table 7). Compared to the future situation without implementation of the Sub-project, an increase of 32% could be expected with Sub-project implementation.

The limited data available suggests that the surface water quality in the area is already, oris close to, eutrophic. It is expected that incremental fertiliser inputs will not substantiallychange the water quality status of the Sub-Project. Total surface water volume in thearea will increase as a result of the expansion of the canal network and the reshaping of alarge numbers of existing canals. Hence, concentrations of nutrients would not increaseby the same rate as the fertiliser application rate increase. In addition, the completion ofthe water control structures will enable flushing of the canal system at low tide. Thisimpact is therefore assessed as Insignificant.

Application of Pesticides - It is estimated that approximately an additionalUSD 1,436,000 per year would be spent on pesticides and herbicides compared to acurrent application valued at USD 2,150,000 per year (Table 7). Compared to thesituation without implementation of the Sub-project, about a 30% increase could beexpected with the Sub-project. This impact is assessed as Unknown because existingbaseline information on pesticide concentrations in the Sub-project environment is non-existent. The most common compounds are Azodrin, Methyl Parathion, and- Basudin1OH, with various forms of other herbicides and rodenticides being used.

Both mitigation and monitoring are recommended.

With respect to mitigation, This is best accomplished with an IPM program. TheMARD/IDA Agricultural Rehabilitation Project comprises a Plant Protection Sub-Component, which is being implemented in 35 provinces through the provincial PlantProtection Sub-departments. All provinces in the Mekong Delta participate in theprogramme. In each of the provinces of interest to the MDWRDP, so far roughly 10,000farmers were trained on plant protection in 52 Farmer Field Schools. In addition, 20demonstration sites for tolerant rice varieties to Brown Plant Hopper and Blast diseasewere established. Results obtained are very encouraginge: On average the number ofpesticide applications in IPM fields reduced by about 90%, participants spent about 30 to40% less on pesticides, while production increased by 0.7 tonnelhatyear. Apart from theenvironmental benefit, application of IPM increases the farmers' profit by about USD 15per ha per year. It is recommended that the spreading of IPM techniques be continued,possibly this can best be realised through national programnes and not be set upspecifically for the Sub-projects of the MDWRDP.

Pesticide monitoring in the environment is proposed and should become a formal part ofthe overall water quality monitbring program.

MARD/IDA, Review of implementation in 1997 and Workplan for 1998, Plant Protection Sub-Component, Agricultural Rehabilitation Project.



4.1.1.5 Sub-project Impacts on Downstmam Surface Water Quality

While surface water quality inside the project area may change as a result of the project,it is unlikely that this will be the case outside the Sub-Project. The soil acidity in the Sub-Project is not sufficiently extreme (relative to, for example, the south-westem part of CaMau or the Plain of Reeds) to create areas of very low pH in the early rainy season, thatwould impact on the waters downstream of SMT. Moreover, the marine waterenvironment which will be maintained in this coastal region, would have a neutralisingeffect on acidity.

Pesticide concentrations could increase in the surface waters of the Sub-Project,particularly in the dry season when cropping intensity increases. In the past stagnantwater prevailed in the canals and the creeks where the tides from two sides met. Withthe project's sluices the water can be exchanged when needed by opening of the gatesat low tide9 .

By keeping the sluice at the boundary with the coastal area closed, all flushing is directedtowards the main rivers. Therefore, correct system operation warrants against theoccurrence of detrimental effects on water quality or environmental resources in generaloutside the project area, save for perhaps localised degradation immediately outside ofthe primary sluices whenever the flushing takes place.

Surface water quality monitoring downstream of the Sub-project is still recommended asto provide a waming system to identify any eventual unexpected impacts. This will bepart of the Coastal Wetlands Protection and Development Project.

4.1.1.6 Nrject Impacts on Groundwate

Project Act vites: Impact Assessmen7tApplcation of FeriliseLs IngifticantApplicaion of Pesuddes IndgriScantRural Water Supply Componem Posiive_

Application of FertiTsers - While shallow groundwater systems may become increasinglyeutrophic as a result of increased fertiliser application, deeper aquifers, which are themain source of drinking water supply, are likely to remain unaffected. Groundwatermonitoring will be extended under the ongoing Ground Water Study Mekong Delta.

Appflcation of Pestcides and Herbicides - The assessment is the samne as that forincreased use of fertilisers. There is a chance that increased total application of pesticidesand herbicides will contaminate shallow groundwater systems. Deep groundwateraquifers will almost certainly be unaffected.

Either periodically in the dry season or when they are first opened at the beginning of the rainyseason

MDWRDP, Feasibility Study UpdateAnnex 1, Environmental Impact Assessment and Environmental Action Plan. August 1998 26


Ttk 7rkdp9ffmlrr6 YIhatk wwiq

CULIVABLE FERTILIZER - PESTICIDES I HElBICIDES FERn1LIZER PESnICIDES I HERBICIDESMEAS (x 1000 kg) (x 1000 USO) (kgha) (USOIh)

Present Future present wIthout wlth W-WO present witheut wlth W -WO present without with W-WO present without with W WO_______________ (ha) (ha)-

SOun tWIG wrIT 171.037 171,44i 35.381 s5.s57 73,693 17,736 2,140 2,759 3,585 326 205.9 325.6 429.0 184.2 12.5 16.1 20.0 4.0

0 SDO4 XANO 37.21 36,105 12,109 14,012 10.211 4,3Jt 760 806 020 12 326.9 397.8 520.6 122.7 20.6 21.7 22.2 e.s

QUJM LO PHUNGt HI 130,370 130.636 21,627 37,365 42.928 6.663 1.088 1.631 1,6s7 . 236 165.1 285.3 328.0 43.0 8.3 12.5 14.3 1.9

IHARINH TALIEN 26,751 26.s83 8.7s0 8,281 11,665 3,504 356 418 543 127 214.9 309.6 448.3 136.7 13.4 1s.6 20.4 4.9

nESP NHAT 44,664 44,471 0,807 13,800 18.334 4.534 632 716 S17 181 210.6 309.0 412.3 103.3 14.2 16.0 10.4 2.3

411,462 400,9032 4.734 130,216 166,031 36,811. 4,995 6.330 7,632 1,202 205.9 316.6 405.0 s6.e 12.1 15.4 18.6 3.2

SOUtH MANO niIT 41.6% 41.8% 100% 158% 208% 132% 100% 128% 167% 130% 100% 158% 200% 132% 100% 128% 1S7% 130%o MON XA NO *.0% .o0% 100% 122% 158% 130% 100% 105% 107% 101% 100% 122% 159% 131% 100% 105% 108% 102%QUAN LO PHUNO HI 31.6% 31. 8% 100% 173% 19% 115% 100% 150% 172% 114% 100% 173% 199% 11U% 100% 1 50% 172% 115sOA RINH TA LIEM U .8% 85% i00% 1u44 2S 1143% 100% 11s% 152% 131% 100% 144% 208% 144U 100% 116% 153% 131%_ _EP NHAT 10.9X 10.0X 100% 141 167% 1% 100% 113% 129% 114% 100% 141% U8$% 13J% 100% 113% 1J0% 111%

MDWRDP, Feasibility Study Update

Annex 1, Environmental Impact Assessment and Environmental Action Plan, August 1998 27


The fact that many of the pesticides and herbicides being used in the Sub-project area arepersistent organochlorines, however, creates sufficient concem that it is worth while toinclude pesticide monitoring within the Project. Widespread application of IPM (seeSection 4.1.1.4) would reduce the risk of contamination of groundwater aquifers.

Rural Water Supply and Sanition - Groundwater is the only source of water thatconsistently meets national and intemational drinking and domestic water standards. It isestimated that about 57,000 m3/day of groundwater would need to be extracted by theyear 2000 to meet household drinking water demands. The upper Pleistocene aquiferpossibly has an elastic reserve of only 25,000 m3/day. For remote rural areas, the Projectwill provide rural water supply systems, complementary to works ongoing or proposed byother intemational organisations (ADB, UNICEF). Exploitation of the deeper aquifers inparticular for towns, will become a necessity very soon.

An increasing population, in the absence of sewage treatment, will mean higher levels ofbacteria and coliform in the canal systems of the Sub-Project. This includes shallowgroundwater aquifers. This will almost certainly not contaminate deep groundwateraquifers.

The Ground Water Study Mekong Delta that started in April 1998 will enhance theexisting monitoring network and investigate groundwater resources, rechargemechanisms of the aquifers and quality of ground water. Hence, no monitoring activitiesare proposed under the MDWRDP.

4.1.1.7 Prjwt hnpacts on Ah Qualty

There are no Sub-project activities that will adversely affect air quality in or outside theSub-project Area.

4.1.1.8 Pwject knpacts on Canal Bank Stably

Projca A cdvi ImpctAssessmentConstruction and Operation of Canas lin5fic.Changes in Land Use and Corwnodiy Productio lrsigriicafTtPopulation Growth IrfctContuction of Rural Access Roads and Bridges Posve and Sgufkcant

The Sub-project will create increased transportation opportunities and requirements by:

(i) increasing the water transportation routes with the construction of irrigation anddrainage canals; and

{ii) increasing the agricuttural outputs and increasing the imports of agricultural inputs(e.g. fertiliser).

The use of canals for waterways transport will increase. The trends will not necessarilyhave an impact on canal bank stability because smaller boats are already equipped withengines of capacity suitable to the boats used. The dimensions of the canals and thesmall farm -size are unlikely to result in the widespread use of larger, high powered, boats.



4.1.2 Impacts on Ecological Resources

4.1.21 Project mpacts on Tersid Ecosystems

fmjL-it AcbW: Impact AssessrnentOperation of Sluieos Insi^fcarntChanges in Land Use and Commnocky Production signsficantPopubbon Growthi kWg;fimAppication of Pesicdes arW Horbiddes hrsi^ficant

Operation of Sluices - The water control system will essentially convert the-Sub-projectarea from an area whose ecology at places still fluctuates between manne (dry season)and freshwater (rainy season) to an area whose ecology is completely freshwater. Thischange is already underway through the partial completion of the water corntrol system.

The salinity changes brought about by the operatiorn of the primary sluices wll cause agradual decline of Nips palm scattered along the canals inside the Sub-project. Nipa palmleaves are a source of housing material and income -to Nipa palm sellers and traders. Thisimpact is assessed as insignificant because throughout the SMT area, up to the Mang

*Thit River, which only very rarely experiences saline water, (below 4 pptl Nipa palm is stillgrowing abundandy. Farmers' loss of i'ncome from reduced harvesting of Nipa leaves willlargely be compensated by the increased benefits frorn agricutture because of the project.

- ~ ~ ~ ~ i .

Improved living conditions of the population in SMT anwd elsewhere in fth delta will lead tochanges in types of houses. More durable types of houses are already replang theSethatched houses made of Nipa palm leaves, thereby reducing the market for Nipa saves.

Caunges in Land Use and Commodity Producfom - Since hardly any natural terrestrialecosystems remain in SMT and land use changes mainly relate to intenshfied use ofacready agricuetuad undea, ther will be no impact on terrestio ecosysters as a resut ofthe project

Te saion Growth - itnis unlikegy that harvest pressure on edprimar terrestrial ecosystemsand associated species would derease as a resuct of the Sub-project, parectilariy withcortnued population growth. This impact is assessed as Insignificant, because of thealready high degradation of these ecosysterns within tle Subwprojeclt

Apprcation of Hervicides and Pesofides - The application of pesticiSes and herbicides witoincrease under the anticipated future land use. Predictions rf tae magnitude of anyimpacts of biocides on tenesti al resources in the Sub-project atea cannot be made, giventhe absence of baseline data in this case and the almost non existence of naturalterrestrial ecosystems. Contnuation of [PM training (see Section 4.1.1.4a isrecommended.

P a1.22 Growth- ktaisui an hanest pressur7 Ouexst tMePrroet

ftect Acdvides: Impact Assessment:Can associd Opecieson of Culd InsigdcuroftitChwlgo in Land Use InsigrifntmAcoitcaion of Fptiis Insigr nc, aetntapplready of Phighdegs Iotheitib-cntIpOpecadon of SHces in oficde

MDWRDP, Feasibility Study UpdateAnnex 1, Environmental Impact Assessment and Environmen:I Action Plan, August 1998* 29

The Socialist Republic of VietnamlMARDlCPOMekong Delta Water Resources Development Project

These effects would be indirect and mediated through changes in surface water quality.Effects of the Sub-project on surface water quality outside of the Sub-project areassessed largely as Insignificant (Section 4.1.1.5). It is for these reasons that the impactsof the Sub-project on terrestrial ecosystems outside the Sub-project are also assessed asInsignificant. Despite this assessment, Viet Nam's investment in the rehabilitation ofterrestrial ecosystems in Duyen Hai District through the MARD/WB Coastal WetlandsProtection and Development Project supports earlier recommendations made above forsurface water quality, monitoring.

4.123 Prject knpacts on Aquatic Ecosysms Wthn the SubProect

Projca Ac6vu Impact Assessmnent:Construction and Operation of Canals and SLices SigriftcuM No Need for MigaWionChanges in Land Use Posive and SignficntPopuation Growth InsignificantApplcation of Pesticides and Herbicides lnsiniflcant

Construcfion and Opeation of Canals and Sluices - There will be a shift inside the Sub-project area from a partial brackish water ecosystems and biota, to freshwaterecosystems and biota; this shitt has already started due to the partial construction of theSub-project. This impact is assessed as Significant but overall the biomass andproductivity of the aquatic ecosystems is expected to change only litte. These impactsare acceptable and there is therefore no need for mitigation activities.Changes in Land Use - Realisation of the future land use plan for SMT requires ther5eshaping or enlargement of a large number of canals. This will automatically increasethe total area of aquatic ecosystems within the Sub-project area and this is assessed as aPositive Impact (see Annex Vl).

Application of Pesticides and Herbicides - The assessment, comments, andrecommendations made in Section 4.1.2.1 for terrestrial ecosystems within the Sub-project apply equally well here. While the application of-pesticides and herbicides willincrease, it is not possible to predict the magnitude of any impacts of biocides on aquaticecosystems within the Sub-project because of the absence of baseline data. Mitigationand monitoring recommendations made pertaining to continuation of IPM training (seeSedtion 4.1.1.4), as well as pesticide monitoring apply here as well.

4.1.24 Subprict Impact on Aquatic Ecosystems Outse te Sub-Project

The assessments made above for impacts on Terrestrial Ecosystems within the Sub-project (Section 4.1.2.1) are also valid for aquatic ecosystems outside the Project.

41.25 Project knpacts on BiodVwi Wrtfh7i and Outside the Sub-pnrisct

The predicted Sub-project impacts on terrestrial and aquatic ecosystems described above(Sections 4.1.2.1, 4.1.2.3) imply the following for overall biodiversity impacts within anddownstream of the Sub-Project:

(i) a shift in biodiversity resources to freshwater forms;(ii) insignificant effects on biodiversity from increases in fertiliser and pesticide

application.

4.1 26 Arvject Impacts on f tcw d Ames Withi Sub-Prject



There are no protected areas within the Sub-project area.

4.12.7 Sub-prject Impacts on Downstrea Protected Areas

Project Activfites: ImpactAssessment:Consucion and Opeion of Canals insignificantChanges in Land Use ad Agricull Producwon IsignificatPopUation Growth InsignificantAppication of FerisEs InsignificantAppication of Pesfcides InsigNificantOperation of Sluices Isignificant

These impacts are assessed as Insignificant. The assessment of inpacts on TerrestrialEcosystems outside the Sub-project area (Secton 4.1.2.2) applies equally well here. Theonty protected area downstream of the Sub-project will be the FPZ of the MARD/iDACoastal Wetiands Protection and Development Project. While only a fraction of the waterthat may be decreased in quality makes its way from the SMT area through the La Bansluice to the FPZ, there would be extensive and rapid mixing with saline water.

4.1.3 Impacts on the Socio-economy

4.1.2.1 &Subpnihct kmwact on ,Pahk Heat

Project Actfvies: Impact Assessment:Operation of Sluices Posibe tough decreases m salktyPopulation Growvth Wnsignhl.fAppication of Ferlisers mgnifgcinAppcation of Pestcides MtgaeProvison of Rual Wat supply Positive

The level of public health in the Sub-project (as it is for most of the rural population in theMekong Delta) is related primarily to water quality for domestic use. The quality of waterf6r domestic use will almost certainly improve as a result of the Sub-project withimplementation of the Rural Water Supply and Sanitation Program and through flushing ofthe canal system when needed in the dry season as well as through improved drainage inthe wet season. The following changes in surface water quality are expected:

(i) Disappearance of saline water;(ii) - likely increased nutrient concentration from increased fertiliser application;liii) likely increased pesticide concentration from increased pesticide application; and(iv) little change in bacterial contamination.

These are also the general expected impacts on shallow groundwater. Mitigation for mostof these potential impacts would be implementation of the Rural Water Supply andSanitation component in the Project. The provision of freshwater for drinking use throughimplementation of the RWSS component of the Sub-project could partially-deal with themajor public health issues of the Sub-project area (i.e., gastrointestinal diseases). Thisshould include public education and enhancement of environmental awareness in propersanitaion principles10.

to Reference is made to Annex IV, Rural Water Supply and Sanitaion component, prepared forthe MDWRDP.

MDWRDP. Feasibility Study UpdateAnnex I, Environmental Impact Asseasment and Environmental Action Plan, August 1998 31


There is concem about the effects of increasing pesticide use on human health, especiallyof the farmers applying the pesticides. Recent work in the Philippines"1 suggests thatthese effects may be considerable. Mitigation against these impacts would consist ofimproved extension services for improved on-farm management practices for non-poiritsources of these chemicals, including IPM training. As shown in Section 4.1.1.4 resultsof the ongoing IPM programme are encouraging.

4.1.3.2 Impacts on Ddnking Water Suppy, Within Sub-Phrquct

Project Activiies: Impact Assessment:AU Sub-project Activites Positive on Pub6c Health

Insignificant with respect to subace waterqualityUnknown with respect to shallowgrodwaterNone with respect to deep groundwater

Sub-project effects on drinking and domestic water quality will depend on the source ofwater used for drinking and domestic water:(i) those households that rely on deep groundwater aquifers for drinking and domestic

water supply will be unaffected by any Sub-project activities because the deepnessof the wells and the relative disconnectedness of these aquifers from the surfacesituation;

(ii) those households that rely on shallow groundwater aquifers for drinking anddomestic water supply may be affected by the Sub-project. Potential impacts areincreases in pesticide contamination and bacterial contamination. The Rural WaterSupply component and other RWSS programmes will mitigate this; and

(iii) those households that continue to rely on surface water for drinking and domesticwater supply will continue to face a degraded water source. The RWSS componentalso includes the implementation of improved systems (filter units) for use ofsurface water in those areas where ground water is unsuitable for humanconsumption.

*Water levels in the drinking water supply wells are not expected to be influenced by theSub-project.

4.1.3.3 Project Impacts on Downsream Ddnknng War Supply

Households living downstream of the Sub-project area cannot use surface water fordrinking water because high salinity levels in the creeks and canals which are in openconnection to the sea. The inpact from the Project on downstream drinking water supplyis assessed as insignificant.

4.1.3.4 Project knpacts on Human Settlemnt, Communtes, and InffhstucWr

PrjectActivites: ImpactAssessmentConstruction of Slucea Significant md fmitigableCoristruction mid Operation of Canads Significant wid nitgConsruction of Rural Access Roads and Bridges Sigrtficant and Positive

Rola, Agnes and Prabhu Pingali. 1993. Pesticides, Rice Productivity, and Health Impacts in thePhilippines. In: Paul Faeth. Ed. Agricultural Policy and Sustainability: Case Studies from India,Chile, the Philippines, and the United States. World Resources Institute. pp. 47-57.

MDWRDP. Feasibility Study UpdateAnnex I, Environmental Impact Assessment and Environmental Action Plan, August 1998 32


Construction of Sluices - because of sluice construction, some households will need to beresettled. This is a significant effect, but can be mitigated through the implementation ofa resettlement plan according to Vietnamese and World Bank requirements. This impact isbeing dealt with by the Resettlement Action Plan component of the Project (Annex 11).

Construction and Operation of Canals - Similar to the effects of sluice construction theconstruction of new and enlargement of existing canals will displace households. This is asignificant effect, but will be mitigated through the implementation of a resettement plan.This impact is [being dealt with by the Resettlement Action Plan component of theProject.

Construction of Access Roads and Bridges - Provision of this type of infrastructure, willsignificantly improve transportation and communication throughout the Sub-project area.Basically this component aims at constructing roads to new, as well as to replacement ofvery old and deteriorated bridges crossing canals which have to be widened.

4.1.3.5 Subprojc hnpacts on Cutural, Aesthetc, Histonc Featues-

Improving fresh water supply to Region C requires amongst others the enlargement of theTan An Dai Su canal which runs through Tieu Can district town. Enlargement at thatplace would cause unacceptable disturbance of society, hence a new canal section by-passing this district town is included in the Sub-project in order to avoid resettlementissues and of local society disturbance at Tieu Can.

4.1.3.6 Piject k*pcts on AgcuItu Pducion

AnrojectActivides: ImpactAssessment:PJI Allject Acdvits SPostv

The effects of the Sub-project on the socio-economy will be positive as demonstrated bythe high economic retum (27%) and the significant increase of farmers' income levels.

4.1.3.7 Prqet kmpact an HOsehl Enwgy Supply

Visual observations during field missions suggest that a large number of scattered treeshave been planted throughout the Sub-project area. It appears that many householdshave planted trees on the small embankments around their agricultural land, in quantitieswell above what would be required for subsistence fuelwood supply. They may be sellingthe wood for income. It appears that fuelwood supply constraints are gradually beingalleviated throughout the Sub-project area.

4.1.3.8 Project inpacts on Transpottion and Navygaon

Project Actvidies: Impact AssessmentConstuction of Shices MitgabeOpeaion of Skices MitlgChwiges in Land Use Positive and SignificantConsttion of Rura Access Rods and Brides Positive ad Signficant

Construction and Operation of Sluices - More constant water levels, reduced currents andchannel improvement will benefit local waterway transportation inside the Sub-projectarea.



The primary and smaller sluices will form a barrier to water transportation, particularly inthe dry season when they will generally remain closed continuously during the periodfrom early March to early May. The sluices will make navigation more inconvenient, moretime consuming and more expensive for the many communities inside the Sub-project.This will be mitigated by the construction of rural access roads and bridges, and by theprovision of hand or motor operated cross-sluice shipment systems (boat lifts) for smallerboats at all sluices that will form a barrier between inside and outside the Sub-projectarea.

Changes in Land Use - Intensified land use after project implementation will result inmore waterways transport, which is the dominant transport mode in the area for bulkcommodities such as agricultural inputs and products. The additional canals that will beconstructed for irrigation and drainage will provide a greater waterway density forinhabitants of the area.

Construction of Rural Access Roads and Bddges - Provision of these types of facilities canonly improve the movement of people, materials, and commodities in the Sub-projectarea.

No monitoring is recommended.



5. ENVIRONMENTAL ACTION PLAN FOR SOUTH MANG THIT SUB-PROJECT

The proposed Environmental Action Plan for the South Mang Thit Sub-project ispresented in Table 9 at the end of this Chapter. It contains two components:recommendations for environmental mitigation and recommendations for environmentalmonitoring.

5.1 Summary of Environmental Mifigation

The recommended environmental mitigation activities are:(i) Continuation of IPM training programmes for rice culftivation and farm workers

safety in pesticide and herbicide application. It may be possible to expand (or atleast replicate) the IPM Component of the IDA-financed Agncultural RehabilitationProject (see Section 4.1.1.4);

{ii) implementation of the Rural Water Supply and Sanitation component for scatteredrural households of the Sub-Project;

Oiii) implementation of the Resettlement Action Plan for project affected persons; and(iv) provision of boat lifts in the direct vicinity of major sluices;(v} operating of sluices at low tide for flushing of the system in the dry season in

order to improve water quality; and(vi) application of special soil excavation techniques for canal works in order to

minimise the release of acids from the spoil soil dumped along canal banks.Techniques consist of i) covering of the worst pyritic material with good topsoil; and ii) provision of drainage ditches at the field side of the newembankment and connecting the ditches to the canals so as to prevent acidwater to enter the paddy fields at the start of the rainy season.

Point (ii} above is -not an environmental mitigation that would be required becauseof eventual deleterious impacts of the Sub-project.- It is an action that wouldimprove conditions for Sub-project households should therefore be maintained inthe Sub-project.

5.2 Environmental Monitoring

The core of the proposed environmental monitoring plan is an expansion of the existingSurface Water Quality Monitoring Network for the Mekong Delta.

5.2.1 Description of the Existing Water Quality IMonitoring Network

The SIWRP is responsible for the water quality monitoring in the Mekong Delta; thenetwork is in operation since May 1985. The system belongs to the Water QualityMonitoring Network Project in the Lower Mekong Basin sponsored by Sida through theMekong River Commission (MRC). In the first phase (1985-1988), the monitoring in themain rivers and in the Plain of Reeds was carried out In the second phase (1988 topresent), the network has been extended to the Ca Mau Peninsula and Long XuyenQuadrangle areas.

The main objectives of the overall MRC project are to:

(i) set up a water quality monitoring network in the Mekong basin and apply modemtechniques for water analysis;

MDWRDP, Feasibility Study UpdateAnnex 1. Environmental Impact Assessment and Environmental Action Plan, August 1998 35


(ii) identify the sources of pollution and assess the impacts caused by developmentactivities;

tiii) establish a data bank for water quality in the Lower Mekong basin;(iv) propose measures for management of water resources in general and improving

water quality in particular; and(v) develop a system of water quality criteria guidelines for Mekong River riparian

countries.

The existing network consists of:

* 5 stations in the main rivers'12

* 14 stations in the Ca Mau peninsula* 15 station in the Long Xuyen quadrangle* 13 stations in the Plain of Reeds* 7 stations for pesticide monitoring

Water samples are collected on the 1 5, day of each month (except for pesticide stations,which are sampled four times per year). The water samples are taken 20 cm under watersurface in the middle of the river or canal from the indicated reference point. This is donein order to reduce the risk that the water sample is polluted from local sources andtherefore would not reflect the reliable water quality for main water body of interest. Aseries of basic water quality parameters are collected (Table 8).

* The rrm t a Sonainm a0 of *eq IN02a s* pH * Potukn no) . Amyranx s CofKeitw (BEC u Alysts (HCe31 s Total Nlwyin nmf Totd such slics ceSS s t Cinide (CoA e ass en d P04r s• Cdku (Ca) *uv (So - 5 ffilis* Manesu (lwg * Total bun (Fd) * Dissolved onm (DO)

• SOD, 0 Akrninium AD * Chwrci oxVgen deri (COD)* Sometrace me

The SIVWRP maintains a laboratory containing about $300,000 of equipmernt and has astaff of eight water quality a nalysts. The staff is trained systematically in a number offields such as analytical chemistry, limnology, water qu ality assessment, data processing,and environmental impact assessment.

12 Some sampling for bottom fauna in the Mekong River has also been conducted.


I Ite bocgalist liepublic ot VietnamlMARDICPOMekong Delta Water Resources Development Project

TdkN~*wnw,thf.Pedrmnnutac t &I Abh I?*Q &Pbp9

n nmental Issue Assessment Recommended Action Cost Inplemwntation Indicative Timetable

ResponsUlfty for ImplementationCapital Cost Recuwant Cost

MitigationEffects of Pesticide Use Assessed as Insigifcant, Frosin od training for To be taken up tough P1rovicial Pant Shaud begn as soon ason Envonnwntal but outdated types of IPM technkiues, as well regkind or natind PtotectionSub- pot".le, patuWal InResources pesticdes at wae stEA as pestickide selection aro prog|me departments weas where rrutlple

used rmke nitigation use, as a pat of cropping occurs. Thisdesirable extension prowram. It type of extenson stould

mny be, possle to qucidy expand kito otherexpand the IPM areas as croppinCOIpornt of the [DA- nternity inreassfhnced A uralRehabiltaton Poject.

Suh.roet Effects on Miiga Ful IrnplerentatiDn of Progranme Is desgned d cosd undsr FkRal Water Supply component of FSDnr*iki angd Domestc Rural Water SupplyWater Oudaty caused by componet hi te Projectmost Suretn sd othw erRWSSobIvIdes zprorammes.Sub-prect Effects on khpas whic may occur can be mitWted wvh riplenentation of Rual Water Supply compnent and other RWSS progranmesPblic HealthResattet of Mtaltga Reseme Acton Pla A Resettlemnent Action Plan cmponet was prepared for the MDWRDPHousehold as a result ofSlice Consintction wd

Csnal Constucion andErmgenwnt

Navgation Constraints Mtigabs provision of cross-duic hcuded In cost estiates SIO 418 IncLded Induced by Constuctio s*ment systems for for proect works Imnplmentatin Schedule

and Operation of Sices sler boats at all sluices for Prolect Worksthat will form a barrerbetwen Inside ntdoute the Sub-Proect

Monitoring!3

Success of Famers Household suveys of hclded in RAP See RAP See RAPRese uner resetled househodsReseP nent Action Plan Indicatinu sodb _conorIc

'3 The continuation of normal hydraulic monitoring performed to update and maintain the hydraulic model. Is assumed to be maintained. Operating Costs enteredunder monitoring Items are annual costs.

MDWRDP, Feasibility Study UpdateAnnex 1. Environmental Impact Assessment and Environmental Action Plan, August 1998 37

I he Socialist Republie of Vietnem/MARO/CPOMekong Delta Water Resources Development Project

concitionEffects on Surface Water GeneralV Insigfcant Expansion of Surace USD 4t000 for SNPRP wth support of From start of the ProjectQuakitY Ind and Outside Wide and ouAtside of the Water OuaEy Mb moitoring aid midyss provircial DARD to establish as much of athe SubProject Sub-project area Network to include eight base"lie database as

Ur*nowwn downstream of adcltkxn monitoring possibeSUb-ojeCt statons witNnk Sub-

project and two additiondstatons outsidt the Sub-project (aee ma,Appdx Al



5.2.2 Proposed Expansion of the Surface Water Quality Monitoring System

The water quality monitoring system is proposed to be expanded to deal with thefollowing Sub-project issues:

(i) surface water pollution from intensified agricultural activities, including fertilisersand pesticides. This would also allow for monitoring of the expected small changesin water quality from changes brought about to acid soils;

lii) surface water pollution from domestic wastes;(iii) possible downstream impacts of the Sub-project.

The following enhancements are proposed:

Surface Water - 10 additional stations are proposed (see map, Appendix A):

8 additional stations inside the Sub-Pmject1 station on the Tra Ngoa Canal1 station on the Rum Soc Canal1 station on the Dua Do Canal1 station on the Tra Ech Canal1 station on the Tra Vinh Canal1 station on the Bac Trang Canal1 station on the Luong Hoa Canal1 station on the 3 February Canal (inside the Sub-Project)

2 additonal stations outside the Sub-Project:1 station on the 3 February Canal (outside the Sub-Project)1 station on the Lang Sac Canal

The stations outside the Sub-project are included in order to have data available of thesame day; the monitoring programme under the Coastal Wetand Project could providedata on different (days)

A monthly sampling regime will be maintained. Because the Sub-project is stronglyimpacted by tides, water samples will be collected at low and high tides: total 240 newwater samples per year..

Pesticides - Surface water samples will be collected at 10 places of intensive riceproduction. These locations will be close to surface water morntoring stations for costefficiency. At the same time, fish samples will be taken in local markets to monitor bio-accumulation. As pesticides use tends to be highest in the Summer-Autumn crop whenconditions are most favourable for pests to develop, samples should be collected at fourperiods: June, August, December, and April. This makes for a total of 80 pesticidesamples each year: 40 surface water and 40 fish samples.

Bacteria - These should be analysed for the monthly samples at the 10 surface waterquality monitoring stations inside the Sub-project (120 samples per year).

The Division for Hydro Geology and Engineering Geology for the South of Vliet Namundertakes ground water quality monitoring. The programme will be extended urder theGround Water Study Mekong Delta that stared in April 1998.

MDWRDP, Feasibility Study UpdateAnnex I, Environmental Impact Assessment and EnvirQnmental Action Plan, August 1998 39


No additional laboratory equipment is required for the monitoring programme becausesample facilities are available in Ho Chi Minh City (SIWRP, EPC and other institutes andcompanies). Analysis of water samples can be undertaken by the existing facilities.

5.2.3 Cost Summary for Expanded Water Quality Monitoring Program

Table 10 contains an estimate of the incremental costs required for the expanded waterquality monitoring program.

Td x 10: Vfrd uf W NcyA AMut SmouAbg 71*&bp

Total IUSD)Recurrent Costs: Incremental Annual Fhxed Costs

lh*i Rate lo. Totdl

Staff Per year 3,600 1 3,600

Facilities monffs 200 12 2,400

Recurrent Costs: Incremental Annual Sampling CostsNA Fa. NoPAn 7pIg

LVfs S&n7f MAaT7 Pam Mission Total

Car km 400 0.50 12 2,400

Boat Boat-days 5 50 12 3,000Field expense person-days pe trip 21 20 12 5,040Samplecollection Fbeddaysperstatio 10 10 12 1,200

Recurrent Costs: Incrementa Annual Analysis CostsAfWdw TotW Afew

- anMwof SwnplAd S&7rAsw Pwr YewL** ARJASDJ A) Now Stadwi Per Year ToW

Hydro/gicalDataAcqisitidon 2,000

Surface water 30 10 12 240 7,200

P.s*idesSurface water 100 10 4 40 4,000

Fish 100 10 4 40 4,000

BRctedsSurface water 15 10 12 120 1,800

Total 36,640

Total (round figure) 37000



0 MON-XA NO SUB-PROJECT



6. EXISTING ENVIRONMENT OF 0 MON-XA NO SUB-PROJECT


The 0 Mon-Xa No Sub-project was one of the five high priority projects that were selectedfor feasibility studies as a result of the preliminary evaluation in the first phase of theMDMP The main objective of the FS was to determine the optimal plan for sustainableand integrated use of the resources in the Sub-project area in order to increase theproductivity and to improve the living conditions of the local people.

The OM-XN Sub-project as proposed in the FS is consistent with the developmentstrategy recommended in the MDMP, October 1993. The Sub-project area consists of45,430 ha and covers part of provinces of Can Tho and Kien Giang (see map,Appendix A. The Sub-project area includes parts of five Districts.

About 236,000 people live in the Sub-project area. These people are comprised almostexclusively of Kinh 4, with very small percentages of Khmer and Hoa. The land is mostlyused for agriculture and there remains almost no unused land.

Synoptic information for the Sub-project area is presented in Table 11 and Table 12.


6.2.1 Climate

Two distinct seasons occur in the 0 Mon-Xa No area: the rainy (or wet) season from Mayto November; and the dry season from November to April. Roughly 90% of the annualrainfall is concentrated in the rainy season and provides a mean monthly rainfall of about140 mm (Figure 7). Dry spells lasting up to 15 days in some years may occur up to Julyor August. The mean monthly temperature fluctuates litde more than 3 degrees (25.5 -28.6°C), and relative humidity usually exceeds 80%. Potential evapotranspiration is about100 mm per month.

6.2.2 Soils

The OM-XN-FS identified 26 different soil types in the Sub-Project. Alluvial soils (49%)and acid sulphate soils (29%) dominate the Sub-project area. The OM-XN-FS indicatesthat about 2,600 ha are underlain with severely acid soils. This represents about 5.7% ofthe total Sub-project Area (Figure 8).

14 Kinh is the Vietnamese term for the Vietnamese ethnic group; Hoa for the Chinese ethnicgroup.



7M6 I1 :Sxlt bhfrMiXst OA**XaAb &bprAr

Name Area Pop n Agr. Triple Double Single Upland Orchard Fishery Forest Special Other- | Area Rice Rice Rice I land |infra. etc)

0 Mon - Xa No 45,430 236,243 39.130 19,823 9,841 223 3,543 5,727 196 39 4,180 1,886

Tv I2 s P pwd, *.txNw*I*inu*1 OA-XAb&*p*d

Name | Agr. | Total HH Aver.HH Agr. HH Ag. Lnd Agr. |Kmh | % Khmer % HoaP PtotiDSn sielLand/HH %KM

OMon-XaNo 11O,720 48,213 4,90 32,800 39,130 1.19 98% 1% 1%

MDWRDP, Feasibility Study UpdateAnnex 1, Environmental Impact Assessment and Environmental Actlon Plan, August 1998 43


o U.I FE Mw AP Ma An U AM SWp Oct mA C

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The Socialist Republic of VietnamJMARDlCPOMekong Delta Water Resources Development Project

6.2.3 Surface Water Hydrology, Salinity, and Acidity

6.23.1 Surface Water Hydrology

The present irrigation and drainage system in the area is essentially an open river andcanal network constructed over the years. The main and primary canals were typicallyexcavated at 3-5 km intervals while the secondary canals (connecting canals) wereusually laid out at 1.5-2 km spacing. Lay-out of the tertiary water control facilities isgenerally more variable from place to place depending on local conditions (mostly varyingfrom 100 to 500 m spacing, on average 250 m).

There are three essential features of the hydrological regime of the Sub-Project

li) in the dry season, water supply for irrigation is limited in those areas where thespacing between secondary canals is more than :2 km;

(ii) in the rainy season, because of high river discharge, rainfall and poor drainageconditions, the project area is inundated at a large scale with water depths of 0.3-1.0 m from the middle of August to the end of November; the inundation periodvaries over the area, in the northem part it is limited to 1.5 to 2 months, in thedepression area inundation occurs almost annually for 4 months (Table 13);

Taiw 7 Ohfi.XaAb

Canal Node Land Bevabon Cuwet Condionsmax. Mb. Avg.

OMon UpstrenM 0.8 1.67 0.84 1.19Central 0.4 1.33 0.65 0.88

Downstram 0.4 1.08 0.45 0.62,W9 Upsveam 0.8 1.67 0.67 1.13

Central 0.4 1.36 0.61 0.90Downsream 0.5 1.06 0.40 0.58

Xa No Upstream 0.8 1.71 0.31 1.07Central OA 1.37 OA5 0.89

Downstream 0.7 1.03 0.22 0.47

6.23.2 Salty

Salinity intrusion is only a problem at the extreme westem end of the Sub-project duringthe dry season (see map, Appendix A) and only under extreme low flow conditions in theMekong River system. It is not considered a constraint to agricultural production.

6.2.4 Within Sub-project Surface Water Quality

In the Sub-Project area:

(i) there are no long term surface water quality monitoring stations maintained by theSIWRP under its Water Quality Monitoring Network Project;

(ii) there are no water quality monitoring stations in the national EnvironmentalMonitoring system maintained by the National Envirornment Agency of Viet Nam;and

(iii) there has only been one surface water quality campaign conducted, as a part of theOM-XN-FS under the MDMP.

MOWRDP, Feasibility Study UpdateAnnex I, Environmental Impact Assesment and Environmental Action Plan, August 1998 45


It is therefore not possible to make any quantitative assessment of the current waterquality conditions within the Sub-project. It is likely that the surface water quality issimilar to that in other parts of the Mekong Delta:

(i) it is contaminated by human sewage15 ;lii) it is largely eutrophic'6; and(iii) it has not substantially changed since the OM-XN-FS.

The exception might be changes in water quality brought about by increased fertiliser andbiocide inputs to the Sub-project with the increase in agricultural cropping intensity since1992. No developments took place in the Sub-project area since the OM-XN-FS thatwould have caused the surface water quality to improve.

624.1 Sunfce Water Acdfriy

There are acid soils in the Sub-project area that do generate acid water, but it is acceptedthat the effect of the acid soils on surface water quality is generally a minorenvironmental issue in the Sub-Project1'7. A map of surface water pH generated for theentire Mekong Delta as a part of the MDMP (see map, Appendix A) suggests that acidwater is not an issue for the OM-XN Sub-project. In addition, data presented in the OM-XN-FS indicate that pH levels never fall below 5.5.

6.2.5 Downstream Surface Water Quality

Existing downstream surface water quality is unknown because there are no surfacewater quality monitoring stations maintained by either the SIWRP or the NationalEnvironment Agency of Viet Nam located in or near the Sub-project. Surface water leavesthe Sub-project at the extreme westem end of the Sub-project where it enters the Cai TuRiver and flows to the Gulf of Thailand through the Cai Lon estuary.

6.2.6 Groundwater Resources

The only available sources of information to be found on groundwater resources comefrom the MDMP and the OM-XN FS. In the OMXN FS the following conclusions werereached"':

{i) there are five groundwater aquifers in the Sub-Project,(ii) the quality of the most shallow groundwater aquifer is very poor, much like the

quality of the surface water in the canals;liii) the groundwater in the remaining aquifers is of good quality;

'$ Coliform levels were reported to be as high as 460,000 MPN/100 ml. and E.coli levels weremeasured up to 240,000 MPN/1 00 ml in the OM-XN-FS.

la Total N levels reported in the OM-XN-FS were up to 1.167 ppm, a level considered to indicatea eutrophic status.

" This conclusion was reached in all reports reviewed on OM-XN during the preparation of thisEnvironmental Review.

$ These conclusions are confirmed in Annex IV, Groundwater and Rural Water Supply andSanitation, prepared for the MDWRDP.


The Socialist Republic of VietnamIMARD/CPOMekong Delta Water Resources Development Project

6.2.7 Air Quality

None of the air quality monitoring stations in the national Environmental Monitoringsystem maintained by the National Environment Agency of Viet Nam is located in or nearthe Sub-project area. Therefore, there are no long-term records of air quality in the studyarea.

Notwithstanding this lack of information, air quality is generally very good in the Sub-project Area. There are no major urban centres within the Sub-project area, and there areno major sources of air pollutants to affect air quality either locally or over the entire Sub-project Area.

6.3 Ecological Resources


Table 14 in Section 7.2.4 contains the current land use in the Sub-project. The Sub-project is dominated by agriculture, with about 86% of the Sub-project devoted toagricultural production; most of this is rice agricutture. Vegetation cover is currenty verylimited; only 36 ha of the Sub-project are designated as Forest Most of the vegetationoccurs in the form of scattered trees planted around landholdings for environmentalprotection and fuelwood.

6.3.2 Terrestrial Ecosystems Within the Sub-Project

There are no intact terrestrial ecosystems remaining witiin the Sub-Project" area.Practically all the land within the area is in use for agriculua production, humansettlements, or open water in the form of canals.

6.3.3 Aquatic Ecosystems Within the Sub-Project

The area of open water has increased in recent fmes, with the construction andenlargement of canals. While this has created new aquatic habit within the Sub-project,it is likely that this habitat is relatively poor because of fishing by local households. Duringthe rainy season, the rice fields are inundated and local fish species spawn and grow inthe flood plain20.

6.3.4 Biodiversity Within the Sub-Project

The Sub-project contains few biodiversity resources, because of the almost completeabsence of terrestrial ecosystems within the Sub-project.

6.3.5 Protected Areas Within the Sub-Project

There are no protected areas that either are a part of Viet Nan's existing or proposednational system of protected areas. In addition, neither Can Tho nor Kien Giang Provincesmaintain any provincial level protected areas within the Sub-project

This confirms a similar assessment made in the Environmental Impact Assessment to the OM-XN-FS.

2° Reference is made to Annex VI, Fisheries and Aquacutur. prepared for the MDWRDP.

MDWRDP, Feasibility Study UpdateAnnex I. Environmental Impact Assessment and Environmental Action Plan, August 1998 47

The Socialist Republc of Vietnam/MARD/CPOMekong Delta Water Resources Development Project

6.3.6 Downstream Ecosystems and Protected Areas

There are no ecosystems or protected areas of note downstream of the Sub-project area.

6.4 Socio-economy

6.4.1 Population, Demography, and Ethnic Composition

The Sub-project contains a young, rapidly growing, almost exclusively rural, already densehuman population of about 236,000 persons. Population growth rate since thecompletion of the OM-XN-FS has been about 2.2% per year. The OM-XN-FS predicted aSub-project population of 235,000 by the year 2000.

At the time the OM-XN-FS was completed, 94% of the population was classified as rural,at present this is reported to be 78% 21. Due to the problem of inundation as well asrequirements for communication and transportation, the population is unevenlydistributed. Most farm families live in small settlements situated at the intersections oralong the banks of the canals and rivers.

The population of the Sub-project area is 98% Kinh, about 1 % Khmer, and about 1 %Hoa. Household size in the Sub-project is about 4.9. Arable land per household averages1 14 ha, with arable land per household in Kieng Giang higher than that of Can Tho.

6.4.2 Drinking and Domestic Water Supply Within the Sub-Project

Currently only about 10% of the Sub-project population has access to freshwater fordrinking and domestic use through groundwater wells. This percentage varies fromdistrict to district. The districts of Kien Giang (Giong Rieng and Go Quao) have almost noaccess to suitable water supply. In some districts of Can Tho, about 1 in 8 households.has access to suitable water supply.


The Sub-project area experiences most of the well-known .tropical diseases, namelymalaria, Dengue fever, and encephalitis, as well as diseases such as tuberculosis andcholera. The universal presence of bacterial contamination in surface water supplies, plusthe use of surface water for domestic purposes by a high proportion of the population,means that water-bome diseases of bacterial origin are extremely prevalent. The findingson disease prevalence and public health contained in the OM-XN-FS probably stWI hold.

6.4.4 General Infrastructure and Industry

6A.4.1 Tranpo,ion

Water transportation remains the major means of transport in the Sub-projecL The roadsystem has been upgraded with 188 km of roads since the time the OM-XN-FS wasprepared.

2 Sodto-oconomic study update, OM-XN, SIWRP 1997.



6.4.4.2 Level of Indusitalisation

The level of industrialisation in the Sub-project area is extremely low. There are no largeindustrial factories or enterprises in the area; most of the enterprises engaged in industryin the Sub-project are mainly ice production, rce milling, and small scale, outdated sugarprocessing factories.

&4.4.3 ElRwcity

A 65 kV national electric network connects all the district centres in 0 Mon-Xa No. Thetotal number of households in the Sub-project with electricity is estimated to be less than20%.


There are no cultural, aesthetic, or historic features in the Sub-project that are at risk fromthe Sub-project.

6.4.6 Agricultural and Production

The Sub-project currently produces about 300,000 tonnes of paddy per year. This is a40% increase in total rice production from the time the OM-XN-FS was completed, and isprimarily due to a much larger area of triple rice cultivation in the northem andsoutheastem part of the sub-project area. Triple cropping is now widely practised usingshort duration varieties of 90 days. These varieties started to become available since1993. Use of short duration varieties makes triple cropping possible. However, highrainfall and river discharge still cause flooding, with the result that autumn-winter ricecrop has a low yield (2.8 t/ha on average).


Forests and trees in the study area are used for various purposes, including fuelwood,house construction, furniture, food, and environmental protection. Very litte, if any,natural forest remains.

Fuelwood is an imnportant issue in the study area (It is throughout all of Viet Nam as thebuming of wood supplies about 90% of the domestic energy consumption nationally).World Bank (1995) identified the Mekong Delta as being a deficient region in Viet Namwith respect to fuelwood supply. Duyet (1991) estimated that fuelwood requirements are0.1 m3 per capita per year; NEDECO (1991) estimates that this annual per capita wouldincrease to 0.20 m3 by the year 2000.



7. DESCRIPTlON OF 0 MON-XA NO SUB-PROJECT

7.1 Rationale for 0 Mon-Xa No Sub-Project

The rationale for the 0 Mon-Xa No Sub-project is that flood control and improved waterresources management will enable farmers to intensify agriculture and increase incomes.

7.2 Detiled Sub-project Description


Three altematives were reviewed in the OM-XN-FS:

li) improvement of irrigation and drainage, and full flood protection at primary WaterControl Unit (WCU) level;

(ii) improvement of irrigation and drainage, and full flood protection at secondary WCUlevel;

(iii) improvement of irrigation and drainage, and full flood protection at the project level.

The OM-XN-FS recommended Aftemative 3, consisting of:

fi) excavation of primary canal KH8;(ii) construction of 3 primary sluices, one on canal KH8 and two on canal KH9;(iii) excavation of 230 km of secondary canals;(iv) construction of 48 secondary sluices;(v)- construction of embankrnents to provide flood protection to the level of a 10%

frequency of exceedance.


7,21 Water Cnto Syt

Since 1992, the following components of the Sub-project have been completed:

(il KH8 canal has been constructed;(ii) 170 km of secondary canal has been excavated;(iii) farmers have constructed embankments that enable triple rice cropping, but that do

not meet full flood protection requirements; and(iv) sluice construction has not taken place.

7.222 Changes in Land Use orn OM-XNl-FS to Currnt Condidtons

Land use in the Sub-project has changed dramatically since the completion of the OM-XN-FS:

(i) there has been a 9% increase in the land devoted to agriculture;(ii) triple rice cropping has increased by almost 19,000 ha; this type of land use now

occurs on 44% of the Sub-project area and more than 50% of the existingagricultural land;

(iii) there have been concomitant decreases in single and double rice cropping;

MDWRDP, Foasibility Study UpdateAnnex 1. Environmental ImDact Assessment and Environmental Action Plan, August 1998 50


(iv) the area of land used for agricultural commodities other than rice (i.e., upland) hasincreased by a very modest amount.


Altemative 3 is still the preferred option for the Sub-project water control system. Thismeans that the remaining elements of the water control system to be developed include:

(i) excavation or widening of 95 km of secondary canal;(ii) construction of the three primary sluices and 32 secondary sluices;(iii) upgrading of the system of dikes and embankmnents for flood control (114 km); and(iv) a program of rural water supply and sanitation.

The number of secondary sluices has been reduced as a result of furter mathematicalmodel simulations. Especially along the 0 Mon canal the sluices as originally plannedappeared to contribute little or not at all to drainage and only very litde to dry seasonwater supply.

7.2.4 Land Use Scenario for Environmental Review

The important details of the land use are as follows (Table 14):

(I) a slight increase in cropping intensity from about 2.26 to 2.44;lii) an increase of the area with three crops per year, with most of this increase in the

form of double rice/upland, and a modest decrease in triple upland crop; and(iii) a complete loss of area cultivating two annual crops per year and sugarcane.

T.* 74 $ld'M OAlzXAAb&bpW

Land use (ha) Present Whout Proect With Proect W-WO

Gross was 45,430 45,430 45,430 0

7. Agnculturalaea 39,130 39,130 38,804 - 326

(a) Annual crops .33,403 32,831 31.929 - 902

- Triie n ropi 19,823 19.823 27.929 8.106Triple rice 19,823 19.823 17,929 - 1 894Double nce + upland 0 0 10,000 10,000

- Double croPno 9814 9242 0 - 9.242Double rice 9,814 9,242 0 -9,242Rice + upland 0 0 0 0

- w!on± 3m 376 66 4J 00Rice 223 223 0 - 223Sgr cane 3,543 3,543 4.000 457

(b) Fnjtorchards 5,727 6,299 6,874 575

2 Forst 39 39 39 0X1 Rshey 196 196 196 04. Special we And 4,180 4,180 4,180 3265. Otwe 1,886 11,886 1,886 0Cropping Intense (%) 226 225 244COpD Drication (% 4 4 16



8. IMPACT ASSESSMENT FOR 0 MON-XA NO SUB-PROJECT

Figure 9 contains a summary of the expected environmental impacts of the 0 Mon-XaNo Sub-project. The detailed rationale for the assessment of specific impacts is givenbelow.

8.1 Detailed Description of Expected Environmental Impacts


8.1.1.1 Subprojectknpacts on Sos

Subproject Actvites: ImpactAssessmentConsvucton and Operation of Sluices Sigrificant and fitigable

Consbvctiond Opevtlon of Suices - The sluice operation rules (see 8.1.1.3) willpermit a high degree of drainage and flood protection. This will significantly reducethe degree of bringing fertile nutrients from sediments on the agricultural land. Thiswill lower the rate at which soil nutrients are naturally replenished, possibly leadingto increased requirements for fertiliser. Although sediment content in the MekongRiver is low (0.3 g/l on average in the flood season to almost zero in the dryseason), the phenomenon of soil enrichment is reported by farmers to be ofimportance for the northem area of the Sub-project (say up to canal K4000).Overall, the impact is assessed as acceptable because at present the rice crop forwhich the sediments are of interest suffers greatly from flooding; the project willremove the flood constraint and this will significantly increase yields andproduction.

8.1.12 Sub-project kpacts on Salhty in te Sub-%c

No effects are expected of Sub-project activities on salinity of surface water. Low flowconditions under which salinity conditions at the downstream tip occur are rare (less than1 in 1 0 years). If this would occur, the downstream sluices can be closed for the periodof occurrence to prevent saline water intrusion.

As regards to ongoing or future developments upstream in the Mekong Delta or in theMekong River basin, the analysis presented in Section 4.1.1.3 is also relevant to the OM-XN Sub-project. In view of its location upstream of saline water intrusion in the main riversystem, impacts of upstream developments are insignificant for the Sub-project.

8.1 .1.3 Subprwjet kpwets on Swface Wat Hdrokgy

Sub-project Acties: ImpactAssessmentConstuction and Opeion of Canas and Sices Posive and Sirificant

Cons&ucion and Operaon of Carms and SkAes - The project introduces the polderconcept for water management, the project provides for full flood protection byembankment and sluices, which significantly improve drainage. The sluices will operate asfollows:

MDWRDP, Feasibility Study UpdateAnnex 1. Environmental Impact Assesment and Environmental Action Plan, August 1998 52


Sub-proect Activity Enviromnentai Resources _ _____._____.

Phvslcd Ecologicui _--d ~~9d

F ll : | X ~~~~.iI |; j :1

________________ jflt~ijll'jt@ tIIijjijf,Consutdonof sltdcos _ M P IConsction nd Operationof Canals M P I _ __ I __ P __ _ __ I P M p P POperationof Skuies P I _ I | I | IChanaesinLandUseand CommodityProdtcition _ _ _ _ _ _ _ _ _I I PPopulation Growth _ _ _ _ I __ _ _ _ P PAppication of Fetllsers . . _ I _ P __Application of Pesticdes M M M M| PActivides Outsido the Sub-proIect…_…Provisionof FltalWeterSupplyandSanitation _ _ _ -P - - -_ - -_ _ -P -Constuction of Rwel Aces Roads and lrifdes , _ - -_ P P l PI

f!2 Sbnmwdmem2W'Ws~ OP*m.Xah8hR*

W8- No hI. RiAicat SS ate AMIbMilbaft U*"rNot P M 9ftanludYaMgrA UU"i% Pf*Jde SISrifiat

MDWRDP, Feasibility Study UpdateAinex 1, Environmental impact Assessment end Environmental Action Plan, August 1998 53


(i) during the dry season, water levels inside the area will be higher than in the existingsituation to make irrigation of the fields easier. At the same time, water has to beconveyed through the system to areas south of OM-XN. To accomplish this,secondary and primary sluices will be open during the high tide Iwhen the waterlevel outside is higher than inside) and closed during low tide (to avoid water toflow out again, with the exception of the KH9 downstream sluice that remainsopen for conveyance of fresh water to the downstream areas);

(iil during the rainy season, all sluices will be open when water levels outside of theSub-project are lower than inside and closed during high tide. This is by far themost important aspect of the Sub-project.

The overall hydrological conditions in the Sub-project are expected to improvesignificantly, with improved drainage in the rainy season. While average water levels arepredicted to change very lite, peak water levels are expected to be substantially reduced(Table 15).

7fb1 1& VAArhv&frpikkmr1smn 1 atwarid*Aw . OM xKrb&Vbp

Canal Node Land Cwrnt CO _o A _tenati 3_e:Ev. Max. Mm. Avg. Max. MWn. Avg. Max. AM. Avg.

0 upstm 0.8 1.67 0.84 1.19 1.70 0.85 1.24 0.03 0.01 0.05Mon - Central OA 1.33 0.65 0.88 1.29 0.70 0.90 -0.04 0.05 0.02

Downsram 0.4 1.08 0.45 0.62 1.09 0.54 0.67 0.01 0.25 0.05KH9 Upstrem 0.8 1.67 0.67 1.13 0.83 0.55 0.75 -0.84 -0.12 0.38

Central 0.4 1.36 0.61 0.90 0.81 0.53 0.69 -0.25 -0.08 -0.21Dowrnteam 0.5 1.06 0.40 0.58 0.81 0.28 0.47 -0.25 0.12 -0.11

Xa No Upstream 0.8 1.71 0.31 1.07 1.74 0.30 1.07 -0.64 -0.01 0.00Central 0.4 1.37 0.45 0.89 1.37 0.41 0.87 0.00 -0.04 .0.02

Dowrsteam 0.7 1.03 0.22 0.47 1.03 0.19 0.44 0.00 -0.02 -0.03

8.1.IA Subb.pPv ect kmpcts on Sunface Waetr Qualty

Project Activities: Impact AssessrnentConstructon and Operabon of Canals InsignificantChanges in Land Use and Commodity Production InsignificantPopulaion Growth iApplicaon of Ferers nhApplcation of Pesticides Unknown, MtpbleOpamion of Slices Insigfifican

Construction and Opertion of Canals and Changes in Land Use and CommodityProduction - The conclusions reached in the OM-XN-FS are supported. Only a smallproportion of the Sub-project is underlain with shallow acid soils. The improved drainageto be achieved by the project will enhance flushing of acid water out of the area towardsthe Gulf of Thailand. Downstream of the project area seawater will neutralise acid waterquickly. Moreover, pH values seem not to reach levels lower than 5.5. The importance ofdrainage and flushing in controlling acidity in surface water is being-demonstrated in theQuan Lo Phung Hiep area in the Ca Mau Peninsula (see Appendix C). The trend observedin that area would also take place in OM-XN.

Population Growth - Wihout improvements in saniation and proper treatment anddisposal of household wastes, an increase in the number of people living in the Sub-project area will continue to degrade the surface water quarity. This is assessed asInsignificant, because pollutant levels already exceed most national and internationalwater quality standards. The existing population is already having a signfficant impact on



surface water quality through sewage and domestic waste. An increasing population willhave little incremental impact. The RWSS component to be implemented under theMDWRDP and other programmes will contribute to reduce surface water pollutionalthough the'effect can not be quantified.

Application of Fertiisers - It is estimated that approximately an additional 4,400 tonnes offertiliser will be required annually for the entire Sub-project over and above estimates offertiliser application without the Project, about a 30% increase. The limited data onsurface water quality suggest that the surface water quality is already, or is close to,eutrophic. It is expected that the incremental inputs will not substantially change thewater quality status. This impact is therefore assessed as Insignificant.

Applcation of Pesticides - From the future land use It is estimated that approximately anadditional USD 12,000, or a 1 % increase, would be spent on pesticides and herbicidesapplications annually for the entire Sub-project, over and above estimates of pesticide andherbicide applications without the Project. This is about a 7% increase over currentestimated pesticide and herbicide use throughout the Sub-project. This impact is assessedas Insignificant even though existing baseline monitoring information on pesticideconcentrations is non-existent, because the incremental pesticide and herbicideapplications are predicted to be very small.

Both mitigation and monitoring are recommended, however. From an environmentalperspective, monoculture is never desirable without an effective program of IPM. Ideally,crop diversification is to be encouraged, but recent land use trends make this perhaps adoubtful proposition. As an aktemative, continuation of ongoing IPM training isrecommended (see Section 4.1.1.4).

.1.1.5 Sub-poljct knpacts on Downsteam Suiface Water QuaGty

Surface water quality, particularly with respect to biocides, are not expected to furtherdegrade in the surface waters of the Sub-project, because of the expected very limitedincrease in pesticide use and the further spreading of IPM.

& 11.6 Project impacts on Groundwat Resouwes

Project Activities: Impact AssessmentRural Water Supply and Saritaon UnknownAppUcation of Feablets InigriflcaRural Water Suply Cononent lUnkiown

Rural Water Supply and Sanirtaon - Deep groundwater aquifers are the only source ofwater that consistently meets national and intemational drinking and domestic waterstandards. It is estimated that about an additional 15,000 m3/day of groundwater wouldneed to be extracted to meet remaining household drinking and domestic waterdemands'. The recharge rate of the aquifers that could potentially supply drinking wateris unknown at this time. The Ground Water Study for the Mekong Delta, which started inAprl 1998, plans to investigate the recharge mechanisms of the aquifers. An arearelatively close to the project area has been selected for these investigations (LongXuyenl.The shallow aquifer will likely become more degraded than it is now, from increasingbacterial contamination from an increasing population and the absence of sewage

Estimate from Annex IV, Groundwater Resources nd RWSS, prepared for the MDWRDP.

MDWRDP, Feasibility Study UpdateAnnex 1, Environmental Impact Assesment and Environmental Action Plan, August 1998 55


treatment facilities. With the implementation of the Rural Water Supply and Sanitationcomponent of the project, this aquifer will be used less as a freshwater supply source.

Apprication of Fertilisers - While shallow groundwater systems may become increasinglyeutrophic as a result of increased fertiliser application, deep groundwater systems willlikely be unaffected.

Application of Pesticides and Herbicides - Water quality, particularly with respect tobiocides, is not expected to degrade in the aquifers, because of the expected very limitedincrease in pesticide use and the further spreading of IPM.

Average water levels in the canals will not deviate substantially from current conditions tocause an impact on ground water recharge of the shallow aquifers.

8.1.1.7 P,wct Impact on Ak Quafty

There are no Sub-project activities that will adversely affect air quality in or outstde theSub-project Area.

8.1.1.8 FjPmect hipacts on Caa Bank Stabty

ProjctAct ImpactAssessment_Costuction and Opation of Cwnas kwifica,tChange in Land Use and Cmmodity rodction InsignficanPopulation Growth ku-gfmConstrution of Rura Acces Roads -an Bndges Pod a- iriiai

The Sub-project will create increased transportation opportunities and requirements by:

{iii) increasing the water transportation routes with the construction of im-gation anddrainage canals; and

(iv) increasing the agricultural outputs and increasing the imports of agricultural inputs(e.g. fertiliser).

The use of canals for waterways transport will increase. The trends will not necessarilyhave an impact, on canal bank stability because smaller boats are already equipped withengines of capacity suitable to the boats used. The dimensions of the canals and thesmall farm size are unlikely to result in the widespread use of larger, high powered, boats.


8.121 Pjct hnpacts on Tenws aEcosystws Witfin the Sub-pct

No impacts on terrestrial ecosystems are expected, as there are no existing naturalterrestrial ecosystems within the Sub-project.

8.1.22 Pkoject Impacts on Tomsnd Ecosystwns Outside to Sub:f t

No impacts on terrestrial ecosystems are expected outside the Sub-project. Mangroveand Nipa palm exist in the surface waters immediately downstream of the Sub-project.As observed in Section 8.1.1.4 pesticide applications would only marginally increase. It isto be noted that the estimates on pesticide applications did not take into account theeffect of IPM. If IPM would indeed spread out in future (see Section 4.1.1.4) pesticide



residues in surface water would go down. Mitigation and monitoring recommendationsmade pertaining to continuation of IPM training, a well as pesticide monitoring at a limitednumber of stations apply here as well.

8.1.23 Impacts on Aquatfc Ecosystems Withn the SubP4roject

Pn7ieccAcd~ Impact Assessment:Comnction and Opeaion of Canls PosiiveOperatio af Skime : hsrrignrficat Appcstion of Pestcides and Heabicies Unknown, Mitgable

Construction and Operation of Canals - Part of the Sub-project involves a modest increasein the canal density for drainage and irrigation water supply to facilitate intensifiedagriculture. This will automatically increase the total area of aquatic ecosystems withinthe Sub-project area and this is assessed as a Positive Impact.

Appricaton of Pesticides and Herbicides - The observations made on pesticideapplications and impact on surface water quality (Section 8.1.1.4) apply equally wellhere.

8.1.24 Subproject Impacts on Aquatic Ecosystms Outside the Sub-Pfct

The assessments made above for impacts on surface water quality downstream of theSub-project are also valid for aquatic ecosystems outside the Sub-project.

8.125 Pfoject Impacts on htectdAis Wthin Sub-Projct

There are no existing protected areas inside of the Sub-project.

8.1.26 Sub-progect Impacts an Downs,wam P,otected Aw

There are no existing protected areas outside the Sub-project.

8.1.3 Impacts on the Socio-economy

8.1.3.1 Sub-prject Impacts on Pubic Health

ProjectActivies: Impact AssessrnerApplcation of Fenilisers lraficApplicadon of Pesticids MWgableProvision of Rural Water Supply Postive

Public healff - The public health situation in the Sub-project is related primarily to waterquality for domestic use. The quarrty of water for domestic use wiU improve with theimplementation of the Rural Water Supply and Sanitation Programmes.

The provision of freshwater for domestic use through implementation of the rural watersupply and sanitation programmes could deal with the major public health issues of theSub-project area li.e., gastrointestinal diseases). The sustainability of his componentdepends on maintenance of the water supply system, and public education/environmentalawareness regards sanitation principles".

23 Reference is made to Annex IV, Rural Water Supply and Sanitation component prepared forthe MDWRDP.



8.1.3.2 impacts on Dink1ing Water Supply Withn Sub-ect

ProjectActivites: ImpactAssessment:All Subtproject Aces Insigrificant with lespect to urface water

quaRyIreigrificant with respect to shallowgroundwaterNone with espect to deep groundwater

Sub-project effects on drinking and domestic water quality will depend on the source ofwater used for drinking and domestic water:

li) those households that rely on deep groundwater aquifers for drinking and domesticwater supply will almost certainly be unaffected by. any Sub-project activities

- *- - because the deepness of the wells and the relative disconnectedness of theseaquifers from the surface situation;

(ii) those households that rely on shallow groundwater aquifers for drinking anddomestic water supply may be affected by the Sub-project. Potential impacts areincreases in pesticide contamination and ongoing bacterial contamination. The RuralWater Supply component may mitigate this to some extent; and

(iii) -those households that continue to rely on surface water for drinking and domesticwater supply will continue to face a degraded water supply. Again, the Rural WaterSupply and Sanitation component would mitigate this to some extent.

Water surface levels in the drinking water supply wells will not to be influenced by theimplementation of the Sub-project.

8.1.3.3 Project Impacts on Downsmtram Drnkg Water SvpP/Y

Since no significant changes in quality of surface water leaving the project area isexpected there are no impacts to those households outside the Sub-project that rely onsurface water as their source of household water supply.

&1.3.4 Project Impacts on Fisheres

Project Activites: Impact Assessment:Construction of Entankent and Operadon of Sluces kIsiificntConsruction of Camals Posiie

Construction of Embankment and Operation of Sluices - The assessment of the Projectsimpact on fisheries and aquaculture is provided in Annex VI. The impact of the Sub-project is assessed as acceptable overall, because no commercial fishing takes place andsubsistence flood plain fisheries is already limited. Moreover, rice-fish farming systems areactually being developed and promoted in 0 Mon District, this is an attractive altemativeto subsistence fishing in canals.

The project provides for flood protection embankments and water control by theoperation of sluice gates. The local fish species living in the canals spawn mainly duringthe early rainy season. At that time, the fields are not yet inundated. The reduced canalwater levels resutting from improved drainage prevents the rice fields to becomeinundated in the September to November period, reducing the spawning areasconsiderably but spawning is less during that period.

MDWRDP, Feasibility Study UpdateAnnex 1, Environmental Impact Assessment and Environmental Action Plan. August 1998 58


The operation of the sluices can theoretically be organised in the way that canal waterlevels are more or less maintained above field level, allowing farmers to let fish enter thefields. The limited water depths maintained in the rice fields will reduce fish production ascompared to the present situation.

The impact of flood protection on flood plain fisheries is considered as insignificant,because farm households surveyed reported that only 0.4% of their total income derivesfrom fisheries. Partly this comes from fishing in the canals throughout the year and partlyfrom fish catch in the rice fields during the rainy season. Fish catch from canals canincrease due to the excavation of 60 km of new canals. The loss of the modest fish catchon flood plains will largely be compensated by the significant increase in income fromfarm income to be expected through the implementation of the Sub-project.

The diversity of biological resources is expected not to change. Black fish speciesencountered at present, will remain in the area because of the periods of opening of thesluice gates.

Increased canal water fisheries and rice/prawn or rice/fish farming systems can mitigatelosses in floodplain fisheries as an effect of the Sub-project. A fisheries survey isrecommended. A fisheries survey is recommended; it should inventory speciescomposition and fish catch before, during, and at the end of project implementation.

&1.35 Proj*tnImpacts on Hum Settlmeits, Communit, and Infmastrctw

P!roject ActiviVes. Impact Assessment:Cosuctiorn of sliices ad cawls MigaeConstruction of ErnbanWnn Podse" VWd Skifig

Construction of sluices, embankment, and canals - because of sluice construction, somehouseholds will need to be resettled. This is a significant effect, but can be mitigatedthrough the implementation of the resettlement plan. This impact is being dealt with bythe Resettlement Action Plan component of the project (Annex II).

Construction of Embankment - Provision of this type of infrastructure, will significantlyimprove transportation and communication throughout the Sub-project area. The floodprotection embankment will also serve as a road. All sluices to be constructed areprovided with bridges.

8.136 SubWoject Impacts on Cubwl, Aestheic, Ifaft Featums

Neither Can Tho nor Kien Giang Provinces identified any cultural, historic, or aestheticfeatures that would be affected in any negative way by the Sub-project.

8.1.3.7 Projet Impacts on Agdltura D Devma/pmet

ProjectActivities: ImpactAssessmentAl Project Activits PoSv

The effects w1ll be positive, as demonstrated by the economic rate of return of 27% andthe significant level of increase in farmers' income.

MDWROP, Feasibility Study UpdateAnnex I. Environmental Impact Assesswent and Environmental Action Plan, August 1998 59


8.1.3.8 Project Impacts on Household Energy Supply

Visual observations during field missions suggest that a large number of trees have beenplanted. Many households have planted trees on the bunds demarcating their property, inquantities well above what would be required for subsistence fuelwood supply. They maybe selling the wood for income. Fuelwood supply constraints are gradually beingalleviated throughout the Sub-project.

8.1.3.9 Project knpacts on Transportfaon and Navigation

Project Activites: /mpactAssessment:Constrion and Operation of Sluices SONWigtConstructon and Operaion of Canals Posive and SignficaConstucton of Emfbankme and Bridges Postve and Significat

Construction and Operation of Sluices - The sluices in the Sub-project will form a barrierto water transportation, when the gates are closed. The project comprises as a mitigationmeasure boatlifts near sluice locations. On the other hand, the sluices are equipped withbridges providing an important improvement in crossing the canals.

Construction of Canals - Waterways transport is the dominant mode of transportation;canal reshaping and the additional canals that will be excavated for irrigation water supplyand drainage will provide a greater waterway density for inhabitants of the Sub-project.

Construction of Embankment and Bridges - Provision of these faclities will improve themovement of people and materials in the Sub-project.

Another mitigation measure to alleviate negative effects on navigation will be theprovision of loading and unloading facilities for transhipment of goods at some sluices.Locations of the boat landing stages have to be determined during tub-projectimplementation in consultation with the local authorities and the local people.

MOWRDP, Feasibility Study UpdateAnnex 1, Environmental Impact Assessment and Environmental Action Plan, August 1998 60

The Socialist Republic of Vietnam/MARD(CPOMekong Delta Water Resources Development Project

9. ENVIRONMENTAL ACTION PLAN FOR 0 MON-XA NO SUB-PROJECT

The proposed Environmental Action Plan for the 0 Mon-Xa No Sub-project is presented inTable 16. It contains two components: recommendations for environmental mitigationand recommendations for environmental monitoring.

9.1 Summary of Environmental Migation

The recommended environmental mitigation activities are:

(I) implementation of a Rural Water Supply and Sanitation component to coverscattered rural households within the Sub-Project;

(ii) implementation of the defined resettlement action plan for the Sub-project affectedpersons;

(iii) provision of boat lifts and transhipment facilities near sluices; and(iv) continuation of IPM training for rice cultivation and farm worker safety in pesticide

and herbicide application. It may be possible to expand the Plant Protection Sub-Component of the IDA-financed Agricultural Rehabilitation Project (see Section4.1.1.4).

9.2 Environmental Monitoring

The core of the proposed environmental monitoring plan is an expansion of the existingSurface Water Quality Monitoring Network. This network is described in Section 5.2.1.



(i) water pollution from intensive agriculture activities, including fertilisers andpesticides in surface water, and in fish. This would also allow for monitoring of theexpected small disturbances in water quality from changes to acid soils;

(ii) water pollution from domestic wastes in surface; and(iii) possible downstream impacts of the Sub-project.

The following enhancements are proposed:

Surface Water - 8 additional stations are proposed inside the Sub-Prject (see map,Appendix A):

3 stations on the KH9 Canal2 stations on the KH8 Canal1 station on the 4000 Canal1 station on the Ranh Hat Canal1 station on the 14000 Canal

A monthly sampling regime will be maintained. Because the Sub-project is impacted bytides, water samples will be collected at low and high tides; in total 192 new samples peryear to be analysed.



Pesticides - Surface water samples will be selected in eight places of intensive riceproduction; these locations will be close to surface water monitoring stations for costefficiency.

Bacteria and Colform - Monthly samples at the eight surface water quality monitoringstations inside the Sub-project should be analysed on bacteria and colifomm (96 samplesper year).

9.2.2 Cost Sumrnary for Expanded Water Quality Monitoring Program

Table 17 contains an estimate of the incremental costs required for the expanded waterquality monitoring programme.

MDWRDP. Feasibility Study UpdateAnnex I, Environmental Impact Assessment and Environmental Action Pan, August 1998 62

The Sociallt Republic of Viotnam/MARDICPOMekong Delta Water Resources Development Project

Tib 1&6.m1 _dwTiduw*dar)p(a 0MbrX&AbIpbprjr

Enoleet iss Assessment Recommended Action Cost Inplementation ndicative lmetable!tRespo lty for menmentation

Capital Cost Refutie CostMitigationEffects of Pesticide Use Assessed as lnIOlat Provisin of veining for To be taken up ttrough Provicid Plnt Potection Should begin as soon ason En*hovmntal given the high bvels of IPM tedques, as wll natiorn or regbnal Sub-deparmnts possble, partlcululy InPesources pesticide use tt re as pesticid selction id progrannes ereas where triple

ready used and the use as a part of extensin cropping OocUrS. Thiswmal hicrentdal program, type of IPM trainingpestcde use that I should quickly expandexpected wih the Sul. into other areas asprolet. Mitigon b sI croppin intensityremomnyn e. crases

Effects on Drin*g and MWgabm of furldDomesti Wter uatty Water SuppI Program to P aogram costed under RWS compent of MDWRDPcaused by most Sub- cover scattered nural

StupEct Effe on Man negative Iwcts which maV occw can be mitit with kpwmentation of sural Water Supplv PogrwmPublc HealthResettlment of House- Mtgabis Resenlment Action Planholds as s rem"t of Skdom Costed under RAP comporwnterd Cana Constxutonaid EriargsemwntNagation Cotraints Migb Provison of boat Ifts for Costed under District Water Resources hi km with *JIInduced by Constrcon smaler boats at ae skices n ucs kestment staff, IMC or leasd to constructonand Opeation of Slces that wil form a bsrrir private enterprise

between iside andoute the Stb-ptosct

. MonitoringSucaess of Faem Househol suveys of incuded In RA See RAP See RAPResetld under resetted househldsResettement Acton Plan Indicating F sodoconom

conrtionEffects on Suface Wter Generaly insignificant Exparson of Surface SIWRP wi spu of Should begin imediateltruaNty s and Ow ie kuid Sub-proct -a Water oualty Monitoring povici DAR0 and to estabih as much of aX Suubmcwn U onstrew m of Network to Include siht DOSTE staff basene database as

Sub-Project adIilod monitoring possibestations within Sub-



Tab 17: kJxwne w w frsfaqwik&de WVQ r(h',tlyN*lc O&bi.XaAbSuhpw

Total(USD)

Recurrent Costs: Incremental Fixed Annual CostsLkis Rae No. Total

Staff ply 3,600 1 3,600

Faciftes rmonft 200 12 2,400Recurrent Costs: Incremental Annual Sampling Costs

No. Aw No. Sampfg_tU SmpIng Mibn Rat ARbMs Total

Car km 440 0.50 12 2.640

Boat Boat-days 5 50 12 3,000

Fieid expense person-das pervip tr21 20 12 5,040

Sample colection field days perstations 8 10 12 960

Recurrent Costs: Incremental Annual Analysis CostsMan-t Total NOw

-w,b' of Swpfad SAmnPerLtat*c (W) awl AbSft*8W Per Year Yeaw Total

hWhological DaoAcqti 2,000

Sudece water 30 8 12 192 5,760

Surface water 100 8 4 32 3,200fish 100 8 4 32 3,200

sachiSurface water 15 8 12 96 1,440

Toted 33,240Total urou-d figure) 35,000

MDWRDP, Feasibility Study UpdateAnnex I, Environrmental Impact Asessment and Environmental Action Plan, August 1998 64


QUAN LO PHUNG HIEP SUB-PROJECT



10. EXISTING ENVIRONMENT OF THE QUAN LO PHUNG HIEP SUB-PROJECT


The EA for the Quan Lo Phung Hiep Sub-project of the MDWRDP chapters relates to thearea of QLPH Phase I and 11 24, excluding the area where shrimp culture is practised at alarge scale, the Ba Rinh Ta Uem (BRTL) and the Tiep Nhat (TN) areas.

The QLPH Phase I and 11, with a gross area of 178,888 ha, is located in Soc Trang andBac Ueu provinces (see map, Appendix A). It is the only priority water resourcesdevelopment project identified in the MDMP for the Ca Mau Peninsula. According to thePFS and MDMP, the development potential is greatest in these areas, as compared to thesouthem part of QLPH.

Ba Rinh Ta Liem, with a gross area of 30,949 ha, is located to the northern of theQLPH Phase I area. The northern boundary is formed by a canal network betweenthe QLPH canal and Ba Rinh, the eastern and southern boundary is the NationalRoad No.1, the western boundary is the Tan Lap canal and the Nhu Gia River.

The Tiep Nhat area, with a gross area of 53,910 ha, is located near the mouth ofthe Bassac River which forms its eastem boundary; its southern boundary is theMy Thanh River and the western boundary is formed by the Ba Xuyen and Nhu GiaRiver and the Xang Phu Huu canal.

The area between the BRTL and TN areas in fact is BRTL Phase Ill, but is notincluded in the Sub-project because its development is being prepared as part ofthe ADB sponsored Rural Infrastructure Development Project.

Essentially, the Sub-project area is a low-lying, flat portion of the Mekong Delta with verysmall variations in elevation. The central part is slightly lower than the edges, wherelevees up to a meter high can be found along riverbanks. The central depression is largeand is usually inundated in the wet season. The major man-made feature in the Sub-project is the extensive canal network. Nearty all of the Sub-project area is under 1.5 mabove sea level, and there are large areas where the land surface is less than 0.3 mabove sea level.

The population in the Sub-project area was estimated at 904,000 in 1996. Thepopulation comprises mostly Kinh25, with lesser numbers of Khmer and Hoe26. The land ismostly used for agriculture.Synoptic information for the Sub-project area is presented in Table 18 and Table 19.

24 For simplicity reasons, the area is referred to as QU Phase I and 11 or QLPH I - It.2 the Vietnamese term for the Vietnamese ethnic group21 the Vietnamese term for the Chinese ethnic group


The Socialist Republic of Vie tnam/MARD/CPOMekong Delta Water Resources Development Projact

Ta1b (19 l W 97a, CkwLDoRx#M4,&hpqf

Name Ares PopWn Agr. Area Tripe Double Single Upland Orcwd Fiheris Forest Special Settled Canas Falow OtherRICe nice Pica land |inra. etc.) and ries land

OLPH Phase I & H 178,888 574,853 130,979 . 62,502 46,271 4,871 17.335 13,954 3,241 1 5,344 2,268 4,986 4,499 13,635Ba R - TsTa Lem 30,950 '130,842 26,750 . 21,854 1,887 2,155 1.054 29 - 1,091 2,255 567 258Tihp Nhat 653,910 198,278 44,665 . 30499 6,731 2,802 4e633 1,790 604 1 1.722 888 3,851 390 -Total 283.748 903,973 202,394 , 114.655 64,889 .9828 23,022 15,773 3.845 8.157 S,411 9.388 5.147 13.635

Tdb 1.*s&c_*J*maw .oinLfhtialdp& qt*

Name Aar. Po'n Total HH Aver. HH eke Agr. HH Ar. and Ar. LandHH % Kinh %Khner _% HoOLPH Phaso In 448,349 107,449 6.36 83,430 130,979 1.67 86% 11% 3%So Fthh-Ts Liam 10,594 24,456e 5.35 19,735 26,750 1.38 es9% 29% |2%TiepNht 161.832 37,061 5.35 30.419 44,e65 1.47 6e% 42% | 2%TOTAL 712.775 16889.7 5.35 133.684 202,394 1.46 77% 20% 3%




10.2.1 Climate

There are two distinct seasons in the Mekong Delta (and therefore in the Sub-projectarea): a wet season generally from May to November and a dry season generally fromDecember to April. Southwest monsoon winds prevail during the wet season andnortheast winds predominate during the dry season. Despite strong seasonal patterns toprecipitation, annual variation in rainfall from one year to another is not great. Roughly,90% of the annual precipitation falls during the rainy season (Figure 10).

Mean monthly rainfall during this period usually exceeds 200 mm, and can be as high as400 mm or more. Most of the precipitation in the rainy season occurs in the form ofintense tropical storms.

Montly nean rainfall data for the QLPH Sub-project areaStatons Soc Tnng & Ba Lbu

g~~~o -- .…-~~mig-DI

t --- 1 1 1 1 eeni1

.la 1* "tm- ot9S

The temperature is uniformly warm and the air uniformly humid throughout the year. Atthe town of Soc Trang, for example, over the ten-year period 1979 to 1988, meanmonthly temperature has fluctuated less than 3 degrees (25.4° - 28.20C), and relatvehumidity was routinely greater than 75% (ESSA 1992).

There is a noticeable climate gradient extending from the southwestem corner QLPH areatowards the northeast. Higher rainfall and fewer hours of sunshine characterise thesouthwestenM zone compared with the northeast. Annual precipitation varies by asurprisingly large amount across the Ca Mau Peninsula, ranging from more than 2,500mm north of Ca Mau, to less than 1,500 mm along the South China Sea coastal stripeast of Bac Lieu. Over a forty-year period, the average anrual rainfall at Ca Mau was2,380 mm compared with 1,559 mm at Phung Hiep (State Committee for Science andTechnology 1986; Insitute of Hydrometeorology 1986a, 1986b). This also means thatthe period when the rainy season begins varies slightly across the peninsula.

MDWRDP, Feasibility Study UpdateAnnex I, Environmental Impact Assssment and Environmental Action Plan, August 1998 68


10.2.2Soils

There are ten different soil types in the Sub-project area {see Appendix B for details ofeach classification). All soils in the Sub-project area are clayey, have low porosity, andtherefore they drain very slowly. The distribution of acid sulphate sois in the Sub-projectis shown in Table 20.

TJ22nfMLm4A&A* Q4O, Qmaffxip5fl6W

Type of ASS Ouan Lo Phug Hiep I & II Ba Rinh - Ta Liem Tiep NhatPotential weak ASS 8 13 0Active weak ASS 36 8 0Potential strong ASS 5 1 0Active song ASS 17 2 2Other 34 76. 98

10.2.3Surface Water Hydrology, Salinity, and Acidity

10.2.3.1 , Swface WaterHydrology

There are five factors influencing the surface water hydrology of the Sub-project area: theprecipitation regime, the Mekong River, the ocean tides, natural rivers connecting theSub-project area with the oceans, and the canals in the Sub-project area.

102.3.2 River and CmalNet work

Primary canals cross the Sub-project area in roughly a grid pattern, intersecting andconnecting with fve major natural rivers: the Cai Lon; the Ong Doc; the Bay Hap; theGanh Hao; and the My Thanh. These, coupled with the low relief of the Sub-project areaand the surrounding Ca Mau Peninsula provide multiple routes for drainage out of theSub-project area.

fA2.3.3 P6Wcdaon Reghn

The major feature of the precipitation regime is the fact that most of the annualprecipitation falls during a six-month period, from approximately May to November.Evaporation averages about 3 mm per day. This means precipitation by itself is unable tosupply fresh water to the Sub-project area during the dry season.

10.2.3.4 Metng AiverFlows

The Mekong River is the only practical source of freshwater for irrigation during the dryseason. Rows into and out of the Tonle Sap in Cambodia change the flow pattern of theMekong River significantly. December and January average flows in the Mekong River areapproximately doubled downstream of Phnom Penh compared with upstream, because ofthe release of very large flows from the Tonle Sap during these months.

Approximately 50% of the Mekong River flows enter the South China Sea via the BassacRiver. The Mekong River splits into two major channels downstream of Phnom Penh. Thewest channel carries about 20% of the total flow; the remainder entering the easternchannel (Chien River). Part of this flow joins to the Bassac River, at a cross over channel(Vam Nao pass) approximately 150 km upstream from the mouth of the Bassac River.



Water flows to the Ca Mau Peninsula via a number of canals north and northeast of theSub-project area: the Cai San, Thot Not, Thom Rom, 0 Mon-Xa No, Nang Mau, PhungHiep, and the Dai Ngai Canals, as well as a series of canals running through the WestBassac area (KH canal system). These canals supply water from the Bassac River to theentire southem Ca Mau Peninsula and not just to the Sub-project area. Water movementin the canals is entirely driven by the tidal force.

1023.5 Ocean rids

The South China Sea and the Gulf of Thailand are extremely different (Table 21), withthe tidal amplitude and highest tide level being substantially higher in the South China Seathan in the Gulf of Thailand. In addition, the South China Sea is somewhat more salinethan the Gulf of Thailand. In both cases, however, the high tides are substantially higherthan the land elevation of the Sub-project.

(My Tnhu)Souf IRach Gba) GAf ofCQm Sea Thalad

Tial Ampiude 3.0 m 0.7mSirStV 33 ppt 25 pptH.geT Tide Lewl +1.6 m +0.5 m

102.3.6 Cunw Hydmiogf nl Regin of the Sub-pnr*t aow

Simulations of the VRSAP model, maintained by the SPWRP, reveal how the abovementioned factors determrine the major hydrological features of the Sub-project area(Table 22). This is reported in Annex Ill.

T&&bM %vdawhiin anddys CoMAdouA in3

Rakw Season (Octb*) DIV Season (eParameter 1991 Cunent 1991 Cunt

______________________ ~~Condition Condd=onINFLOW:

Precipitation 630 630 0 0From Basc River 284 345 100 195

TOTAL INFLOW 914 975 100 195

OUTFLOW:

My Thanh Rver 60 103 14 15GanhHaoRver- 52 77 10 10

Tota/ i Soh Chha See 112 180 24 25

Ong Doc River 44 38 25 23Cai Lon - Cai Be 366 396 117 106

Total to Gulf of Th,bnd 410 434 142 129

TOTAL OUTFLOW 52 614 166 164

INFLOW nmirs OUTFLOW: 392 361 -86 41

MDWRDP, Feasibility Study UpdateAnnex I, Environmental Impact Assesment and Environmental Action Plan. August 1998 70

The Socialist Republic of VietnamlMARDlCPOMekong Delta Water Resources Development Project

Key features of the hydrology of the Sub-project area are:

{i) due to low water levels in the Bassac River in the dry season, freshwater supplyfrom the Bassac River is much less than in the rainy season, about 57% of rainyseason flow. In the peak of the dry season, current water withdrawals in the CaMau Peninsula and West Bassac region are approximately 4% of available BassacRiver flow.

0i) in the rainy season, precipitation is a much more dominant source of fresh water tothe Sub-project area than the Bassac River, with approximately 70% of freshwatercoming from precipitation and 30% from the Bassac River; and

(iii) most of the water in the Sub-project drains to the Gulf of Thailand. In therainy season, about 70% of the total outflow is to the Gulf of Thailand andthis increases to about 80% in the peak of the dry season.

The construction of canals and sluices in the Ca Mau Peninsula and West Bassacregion to date has had two major effects:

li) drainage in the rainy season has improved. Total outflow in the rainy season is now63% of total inflow, as compared to 1991 conditions when total outflow wasestimated to be 57% of total inflow. Freshwater arriving on the fields as

- precipitation (beyond that required for agricultral production) is more able to drainout of the Sub-project. This is important for the-flushing of acid water.

(ii) waterlogging and inundation, major factors impeding agricultural development in thepast, is now less frequent and is reduced area wise.

10.2.37 Sasdy

Prior to Construction - Before the salinity intrusion protection works started, the Sub-project area experienced extensive salt-water intrusion. An isohaline map generated fromthe VRSAP simulation of the early February 1990 condition (see map, Appendix A)demonstrates very clearly the effect of this salinity intrusion. AJmost the entire southemCa Mau Peninsula was under the influence of marine water. Only the northeastern part ofthe Sub-project area experienced dry season sarinity conditions less than 4 ppt.

Current Condiftons - The recent construcion of the primary canals and additional sluiceshas pushed back the 4ppt isohaline to the approximate boundary between Phase I and 11(see map, Appendix A). Approximately one third of the area has freshwater during the dryseason. This has improved water quality for agriculture.

102.3.8 Swface WarAcity

The SIWRP operates a water quality monitoring network throughout portions of theMekong River Delta (see Section 5.2.1 and map, Appendix A). Basic surface waterquality data has been collected from the main canals since the late 1 980s, but it is onlysince the early 1 990s that the data are thought to be sufficientdy reliable andrepresentative of actual conditons.

There are 14 monitoring stations in the OLPH Sub-Project area (see map, Appendix A), ofwhich 12 stations were used in the water quality analysis. The stations are welldistributed over the whole Sub-project area.

MDWRDP, Feasibility Study UpdateAnnex I. Environmental Impact Assessment and Environmental Action Plan, August 1998 71


QLPH Phase I and 11, excluding shrinp areas OLPH Phase IlIl, including the shrinp areasCM1 CM5CM2 CM6CM3 CM7CM4 CM8CM1 2 CM9CM13 CM14

In view of the widespread occurrence of acid sulphate soils in the QLPH area and thegeneration of acids when such soils are reclaimed, it is interesting to analyse changes inwater quality in the area because development took place since the late 1 980s. Large,relatively sparsely populated areas were put in use for agriculture and shrimp aquaculture.Data on water quality and canal excavation work was obtained from the SIWVRP and theprovinces. The analyses is presented in Appendix C. The general trend observed is thatacid surface water conditions gradually improve as a result of the larger volumes of waterflowing through the enlarged and expanded canal system, and through the operation ofthe sluice gates.

10.23.9 .Whn Sub-prect Swdace Water Quality

Apart from surface water acidity, water is generally polluted. Some representativeexamples are:

Trophic Status - Surface waters in the Sub-project area are eutrophic. Total N levelsacross all stations in the Ca Mau monitoring network over the entire 1992 to 1997 periodare on average 1.44 mg/l. Total P averages 0.16 mg/A and NH4-N averages 0.136 mg/l.Statistical regressions of these three water quality parameters at representative stationsindicate no significant increases in nutrient concentrations in the Sub-project area in thepast six years.

Bacteria and Colfofnm - While traditional helicopter latrines have largely been replaced byother systems, there is little or no septic treatment of human waste in the Sub-projectarea. Bacterial contamination of surface waters comes from drainage of these rawwastes. Bacterial and coliform levels within the Sub-project area continue to usuallyexceed permissible levels for drinking and domestic use. However, canal water is notused for drinking use.

10.2.44Groundwater Resources

No additional data on groundwater were obtained during this assessment. It is reasonableto assume that the assessment made of groundwater resources in the original PFS is stillvalid27. Confined aquifers with good ground water supplies exist under the Ca MauPeninsula. Carbon-14 analyses of the water indicate long transit times from the source.The depth of the good aquffers varies from 100 m to 400 m with much of the Sub-project area having an aquifer at 100 to 120 m. The aquifer is artesian, and, in the areabetween Ca Mau - Bac Lieu canal and the South China Sea, many of the wells exhibit apiezometric head above ground level, causing wells to overflow. In the area north andeast of Ca Mau and along the main Sub-project canals, the piezometric head fwatersurface in wells) is about 1 to 3 meters below ground surface.

27 This is confirmed by Annex IV, Groundwater and Rural Water Supply and Sanitation, preparedfor the MDWRDP.

MDWRDP, Feasibility Study UpdateAnnex I, Environmental Impact Assessnent and Environmental Action Plan, August 1998 72

The Socialist Republic of VietnamiMARDlCPOMekong Delta Water Resources Development Project

Groundwater forms an increasingly important source of water for drinking and domesticuse in the Sub-project. There are about 10,000 wells in the Sub-project. Groundwaterquality varies with the depth of the well, with deeper wells having little or no bacterialcontamination and shallower wells having increasingly dangerous levels of bacterialcontamination. Salinity does not appear to be a problem with deeper groundwater wells.

10.2.5 Air Quality

None of the air quality monitoring stations in the National Environmental Monitoringsystem maintained by the National Environment Agency of Viet Nam are located in ornear the Sub-project area, and there are therefore no lpng term records of air quarity fromthe Sub-project area.

Notwithstanding this lack of information, air quality is generally very good in the Sub-project area. Soc Trang and Bac Lieu are the major urban centres within the Sub-projectarea. While it is growing quickly, it is still relatively non-industrialised, and there aretherefore no major sources of air pollutants to affect air quality either locally or over theentire Sub-project area.

10.3 Ecological Resouces


Table 23 contains the current land use in the Sub-project. The land use is dominated byagriculture most of this is rice agriculture. Vegetation cover is currently very limited, withonly slightly more than 1 % of the Sub-project designated as Forest. About 2% of theSub-project is classified as unused; field visits to some of these areas revealed somelimited vegetative cover in the form of aquatic grasses and wild rice. There is alsovegetation in the form of Nipa palm along canal banks as well as in the form of scatteredtrees planted around landholdings for environmental protection and fuelwood.

10.3.2Terrestrial Ecosystems Within the Sub-Project

There are no intact terrestrial ecosystems remaining within the Sub-project area, save forperhaps the Melaleuca Forest Enterprise in QLPH Phase I. Practically all the land withinthe Sub-project area is either in use for agricultural production or human settlements).Most of the terrestrial ecosystems in the QLPH have come under human influence ofsome sort, particularly for the production of agicultural, fisheries, and forestry products,as well as for human settlement. Very smafl pockets of more or less natural ecosystemsstill exist, including forests of mangrove, Nipa palm, Melaleuca, and sedges.

10.3.21 N4o. Pahn

Sub-project construction activities have already had an impact on Nipa palm resources,estimated in the PFS to occupy 1,578 ha. Nipa palm, which grows and develops inbrackish water, no longer survives along the Nhu Gia, Cai Trau, Ngan Dua, Sac lieu,Phuoc Long, and Vinh My Canals. It is estimated that more than half of the 1991 level ofNipa palm, about 815 ha, is degenerated due to salinity changes caused by alreadycompleted portions of the Sub-project. f these numbers are correct, about 750 ha ofNipa palm remain in the Sub-project area.



Tabb2Lr(1997), anLoPxhm 6p~

Land use (ha) QLPH I and 11 BRTL TN

Gross a 178,888 30,950 53,910

1. Agnkulwal area 130,979 26,751 44,664

(b) Annual crops 113,643 25,644 40,031

.Tride cropoinaq 0 ° °Triple rice 00 0Doublerice + upland 0 0 0

- Double roDin 62.502 21.654 30.499Double rice 62,502 21,654 30,499Rice + upland 0 0 0

S kx5e a1po ?.142 4.042 9533Rice 46,271 1,887 6,731Sugar cane 4,871 2,155 2,802

(b) FrnUorchards 17,335 1,107 4,633

2. Forest 3,241 0 604

3. Ishery 13,954 29 1,790

4. Special useland (water, 30,715 4,170 6,851hifasutw, settlement areas)

1o.3Z2 Use of Tersril Ecosystem Resourcs by Local Househols

Levels of use of terrestrial resources in the Sub-project area are likely to be lower than inother parts of the Delta (such as U Minh) because of the generally more degraded andimpoverished terrestrial ecosystems.

10.3.3 Aquatic Ecosystems Within the Sub-Project

The area of open water has increased in recent times, with the construction ofapproximately 275 km of new primary and secondary canals and the rehabilitation andenlargement of more than 300 km of existing primary and secondary canals. While thishas created new aquatic habitat within the Sub-project, it is likely that this habitat isrelatively depauperate because of poor and sometimes acid surface water, and fishing bylocal households.

There has been a shift in the composition of aquatic biota to predominantly freshwaterforms throughout the year from a composition fluctuating between freshwater-dominatedto saline water dominated in the eastem part of the project due to already completedsluices.

10.3.4Biodiversity Within the Sub-Project

While ESSA (1 992b) documents the various species that might have one time beenfound in the Sub-project area, it is likely that the Sub-project area contains litte or nobiodiversity resources, because of the almost complete absence of terrestrial ecosystemswithin the Sub-project and the poor surface water quality.



10.3.5 Protected Areas Within the Sub-Project

There are no protected areas in the Sub-project area that are either a part of Viet Nam'sexisting or proposed national system of protected areas.

10.3.6Ecosystems and Protected Areas Outside the Sub-Project

There are a number of important ecosystems lying outside but near the Sub-project. Inparticular, the coastal areas of the four provinces contain the largest areas of intactmangrove and Melaleuca in Viet Nam. These areas have been identified in both the VietNam National Environmental. Action Plan (World Bank 1995) and the Viet NamBiodiversity Action Plan (Govemment of Viet Nam 1994) as priority ecosystems forsustainable management and protection. Minh Hai Province (now divided into Ca Mauand Bac Ueu Provinces) once possessed the largest area of both mangrove and Melaleucaforests in Viet Nam. Estimates are that about 300,000 ha of Minh Hai province wascovered by coastal forests and wetlands prior to the American war and recentunsustainable exploitation. Now, only about 67,000 ha of mangrove remain, and the areaof Melaleuca, although a higher proportion of its original area than mangrove, is smallerstill.

10.3.6.1 Coastl Wetlands fPrtcon and Development Poet

The MARDAiDA Coastal Wetlands Protection and Development Project is a majorinvestment project along the entire marine coastline of four provinces including SocTrang, Bac Lieu, and Ca Mau. One component of this Project consists of theestablishment of a Full Protection Zone (FPZ) along the coast, outside the Sub-projectarea.

10.3.62 oeced Aims Under te Natonl System of Protecs dAreas

There are six protected areas outside but near to the Sub-Project area:

(i) Vinh Thanh Bird Sanctuary in Bac Ueu District - a 125 ha remnant of an extensivecoastal forest severely damaged during the American war and by subsequent woodcutting; it was declared as a sanctuary in 1962. It is an important breeding site forwater birds. Protection is relatively good, although the threats are poaching,insecticides used in the adjoining rice fields, and continued destruction ofmangroves in the surrounding area;

(ii) Bau Sen Bird Sanctuary in Dam Doi District - a 129 ha patch of moderatelydegraded mangrove declared as a sanctuary in 1985. The site is particularlyimportant to water birds. Principal threats are poaching, contin.ued mangroveharvesting, and altered water regime due to agricultural activities in the surroundingarea;

(iii) Cha La Bird Sanctuary in Cai Nuoc District - a 20 ha patch of much degradedmangrove forest, under some form of official protection since 1940. ft is importantas a breeding site for waterfowl. The site is very degraded, and principal threatsinclude poaching and mangrove cutting;

(iv) Ong Trang Nature Reserve in Ngoc Hien District - 1,540 ha on two uninhabitedislands formed by delta aggradation processes, established as a nature reserve in1993. Successional processes are very active in the reserve, and main threats aretree cutting and insufficient resources for demarcation and actual reserveestablishmrent;

MDWRDP, Feasibility Study UpdateAnnex I, Environmental Impact Assessment and Environental Action Plan, August 1998 75


Iv) Dat Mui Special Reserve Forest in Ngoc Hien District - a 4,474 ha remnant of alarge mangrove forest in Ca Mau Cape established in 1987. The degradation of thereserve is almost complete, due to shrimp aquaculture and mangrove cutting forfuelwood. This site once had the best mangrove in all Viet Nam; and

(vi) Vo Doi Nature Reserve in U Minh District - about 4,000 ha in size; this is the onlyreserve that contains substantial Melaleuca resources.

DANIDA, as part of grant assistance to the Coastal Wetlands Protection andDevelopment Project, is funding the rehabilitation of five of these protected areas (li) toIv), above).

10.4 Socio-econornic Resources

10.4.1 Population, Demography, and Ethnic Composition

The Sub-project area contains a young, rapidly growing, almost exclusively rural, alreadydense human population of about 904,000. Population growth rate since the completionof the PFS has been about 3.2% per year. This is a rate about 50% higher than thenational average and reflects immigration into the Sub-project area.

The predominantly rural population is dispersed, but due to the problem of inundation aswell as requirements for communication and transportation, the population is unevenlydistributed. It is concentrated on natural levees, along the banks of canals and rivers, andbeside the roads. Most farm families live in small settlements situated at the intersectionsor along the banks of the canals and rivers.

The population of the Sub-project area is 77% Kinh, 20% Khmer and 3% Hoa. There isconsiderable variation in the ethnic composition among the Sub-project districts,however. The eastern districts have more than 20% Khmer, while most of the otherdistricts have less than 10% Khmer.

Household size in the Sub-project is about 5.35, and ranges from 4.6 in My Tu to 7.3 inBac Ueu. Arable land per household averages 1.46 ha, and ranges from 1.11 in Bac Ueuto-2.93 ha in My Xuyen. These figures mean that arable land per capita averages slightlymore than 3,000 m2, and ranges from about 1,406 M2 in_ Bac Ueu to approximately5,300 m2 in My Xuyen.

10.4.2 Drinking Water Supply Within Sub-Project

The proportion of the population with access to groundwater wells appears to haveincreased since the preparation of the PFS. It is estimated that, at present, 60% of theSub-project area population has access to safe water, this figure was 39% in 1991.Despite this, 40% of the Sub-project population still lacks ready access to good qualitywater for drinking and domestic purposes.

Surface water2P quality in the Sub-project area is extremely poor, particularly with respectto salinity, organic matter, and bacterial contamination; it is therefore almost never usedas a drinking water source. Canal water appears to still be extensively used as a souce ofdomestic water. While traditional latrines have been replaced by other systems, there is

21 Surface water in this context means canal water as well as any pond or dug well created byindividuals for human water supply.


The Socialist Republic of Vietnam/MAROICPOMekong Delta Water Resources Development Project

little or no septic treatment of human waste in the Sub-project area. Bacterialcontamination comes from drainage of these raw wastes.


The Sub-project area experiences most of the well-known tropical diseases, namelymalaria, Dengue fever, and encephalitis, as well as diseases such as tuberculosis andcholera. The universal presence of bacterial contamination in surface water, plus the useof surface water for domestic purposes by a high proportion of the population, meansthat water-borne diseases of bacterial origin are extremely prevalent. We were not able toobtain updated information on disease and public health. The findings on diseaseprevalence and public health contained in the PFS likely still hold, however, because notall the population has access to clean drinking water and because surface waters remainextremely contaminated.

10.4.4 Drinking and Domestic Water Supply Outside the Sub-Project

We were not able to obtain information on drinking water supply outside the Sub-projectarea. Visual observations, however, suggest that drinking and domestic water quality isalso poor outside the Sub-project area for reasons similar to those inside the Sub-projectarea.

10.4.51General Infrastructure and Industry

10.4.5.1 Tiwnspo,tai

Water transportation is the dominant mode of transportation in the Sub-project area. Themajor water routes are the Ca Mau-Bac Lieu, QLPH, and Chac Bang Canals.

Land transportation within the Sub-project area is still underdeveloped. The maintransportation routes are:

{i) National Highway 1A, the most important route connecting the Sub-project area- with the outside. It is located along the southeastem border of the Sub-project area;

and(ii) National Highway 961 connects Ca Mau and Kien Giang provinces. There is a plan

to rehabilitate this road because it is in poor condition for transportation.

The land transportation system in the Sub-project area now connects district centres andabout 80% of the villages; in general, the road surface is such that they are usable onlyfor the dry season.

10A5.2 Level of

There are no large-scale industrial enterprises existing in the Sub-project area. Somemedium-scale industrial enterprises exist including ice, milling, and sugar enterprises. Thetotal number of industrial faclities in the Sub-project area is about 6,500, but most ofthese are household level enterprises.

MDWRDP. Feasibility Study UpdateAnnex 1, Environmental Impact Assessment and Environmental Action Plan, August 1998 77


10.4.5.3 Eec#ity

Although a 65 kV electricity network exists in the Sub-project area, electricity is beingsupplied only to district centres and towns. There is no electricity supply at the villagelevel, and the estimated proportion of households that use electricity in the Sub-projectarea is about 20%.


There are no cultural, aesthetic, or historic features in the Sub-project that are at risk fromthe Sub-project.


Forests and trees in the Sub-project area are used for various purposes, includingfuelwood, house construction, fumiture, food, and environrental protection. Very littlenatural forest remains save for small pockets of Melaleuca and mangrove, and there isonly one Melaleuca plantation forest in the Sub-project.

MDWRDP, Feasibility Study UpdateAnnex I, Environmental Impact Assossment and Environmental Action Plan, August 1998 78


11. DESCRIPTION OF QUAN LO PHUNG HIEP SUB-PROJECT

11.1 Rationale for QLPH Sub-Project

The major issues that form the rationale for the QLPH Sub-project are:

li) the climatic regime is characterised by two distinct seasons: a wet season fromMay to November receiving approximately 90% of total annual precipitation, and adry season from December to April, receiving the remaining 10% of total annualprecipitation;

(ii) river flows from the Bassac River, the only practical source of large quantities offreshwater in the dry season, reflect this temporal discontnuity in precipitation;

(iii) low elevation, with a mean elevation of 0.2m above sea level, and a maximumelevation of 1.2m;

(iv) tides in the South China Sea fluctuate widely, with the high tide reaching up to 1.5meters above sea level daily;

(v) the area is essentially flat, with elevations in the central part of the Sub-project areabeing lower than at the periphery;

(vi) a sizeable portion of the Sub-project area is underlain by acid-bearing soils ofvarying depth, strength, and activity;

(vii) durirn the past one hundred years, a network of canals was excavated across theCa Mau Peninsula to provide drainage and transportation routes. These canalsintersect and connect with the natural rivers thereby providing multiple routes forboth fresh water and saline water to move throughout the Sub-project area.

(viii) the area is connected to both the Gulf of Thailand and the South China Sea througha dense network of canals and natural rivers.

These features of the QLPH area described above combine to create the followingproblematic conditions:

(i) extensive salt water intrusion from the South China Sea as a resutt of tidalfluctuations, existence of canals and low elevation, particularly during the dryseason when the combined effects of precipitation and Mekong River flows areinsufficient to keep the salt water from entering much of the Sub-project area;

(ii) salt water intrusion from the Gulf of Thailand via the Cai Lon River during the dryseason;

(iii) low supplies of freshwater in the dry season caused by the still insufficient capacityof the canal system for moving freshwater to the Sub-project area from the BassacRiver; and

(iv) poor drainage caused by the low elevation particularly in the central parts of thearea, and by the lack of canals designed specifically for drainage.

11.2 Proposed Water Resources Development System

The MARD plan comprises the following main elements:

* protection from salinity intrusion - 12 primary sluices (i.e. sluices located onprimary canals) along the southem and eastem boundary of QLPH.

* increased fresh water supply through - a series of main and primary canalexcavations and enlargements, the KH system

MDWRDP, Feasibility Study UpdateAnnex 1, Environmental Impact Assessmnt and Environmental Action Plan, August 1998 79


* improved drainage - a series of secondary canals.* improved fresh water distribution - an on-farm management and water control

system, consisting of tertiary canals, and canal improvements.

The stated objectives of implementing this project as identified by the various Ministriesand levels of govemment in Viet Nam are to alleviate the water-related problemsidentified above, namely:

(i) reduce the intrusion of saline water into the QLPH area, particularly in the dryseason;

(ii) increase the supply of fresh water to the QLPH area for agricultural production,particularly in the dry season;

(iii) improve the drainage capacity of the existing canal system;(iv) improve the fine-scale distribution of freshwater throughout the project area; and(v) take advantage of the altered hydrological and salinity regime by increasing both

extension and intensification of agricultural production.

11.3 Detailed Sub-prject Descripdon


11.3.1.1 -fnaqy Sfuce for PAwvendn of Sahnty Intrson Fium South Ch in Se

In order to keep salt water from the South China Sea from entering the QLPH area, theSIWRP and HEC-2 proposed twelve sluices; implementation would start at the easternside of the area (Table 24). These sluices would operate automatically according todifferential water levels on either side of the gates. Generally, lower water outside thaninside will cause the gates to open, while lower water inside than outside will cause thegates to close. Gates will therefore close on rising tides, low precipitation,-and runoffperiods, and would open during falling tides, and high precipitation and runoff periods.

Tlfb2t av amlmMM brg

Nunmer Nune Gate WYth Sil Ev. Deap1 FRow(m) (ml Imris)

1 My Phuoc 2x7.5 -3.5 70-802 Cai Trau 1x5.0 -3.0 203 Thanh Tn tx7.5 -3.0 304 cal sap 1x7.5 -3.0 505 VwAh My 1x7.5 -3.0 40-506 Pho sih 2x7.5 -3.0 704807 ChuCti 1x10.0,2x7.5 -3.5 120-1508 Lang Tram 1x7.5 -3.0 509 Ca Mau lxlO.0 -3.5 70-10010 Bach Nguu 1x7.5 -3.0 5011 1 Thi Binh 1x7.5 -3.0 40-5012 MY Tu 1x7.5 -3.0 40-50

11.3.12 Water Suppy CanliII& for Pnwfrw of Saitry kInrion hwn GWf ofThaland and For Fjshwar Supply

The primary sluices described will not be able to provide protection from salinity intrusionfrom the Gulf of Thailand through the very wide Cai Lon River at the western side of theQLPH area. Construction of additional sluices in that estuary to prevent salinity intrusion

MDWRDP, Feasibility Study UpdateAnnex I, Environmental Impact Assement and Environmental Action Plan, August 1998 80


from the Guff of Thailand is practically impossible. In addition, the existing primary canalsinside the Sub-project area and to its north joining the Bassac River with the Sub-projectarea are insufficient to provide an adequate supply of freshwater during the dry season.Therefore, HEC-2 and the SIWRP proposed that existing primary canals to be enlargedand new ones dredged; this is called the KH system.

li) three canals, designated as KH6, KH7, and KH8, to be dredged;(ii) existing canals, designated as Cai San, KH1, Thot Not, Thom Rom, 0 Mon, Xa No,

Nang Mau 2, and Dai Ngai to be enlarged; and(iii) new primary canals in water control units 30a (24 krm) and 32 (19 km).

Except the Nang Mau 2 canal, all these canals have already been completed.

11.3.1.3 Seclady Dtang Canas

HEC-2 and the SIWRP have proposed dredging and maintaining a series of additionalsecondary canals in portions of the Sub-project area. These are to be constructed in orderto convey fresh water for supplementary irrigation in the beginning and at the end of therainy season until February, and to improve the drainage of water in low-lying areas.

11.3.1.4 On-Fan Watar Cwom Systan

The main system is designed to bring freshwater from the Bassac River into the Sub-project area. The on-farm water control system (tertiary system), consisting of a series oftertiary sluices, additional .tertiary canals, and fieldl bunds will enable the distribution offresh water throughout the area protected from salinity intrusion by the primary andsecondary sluices.


11.3.21 Water Conwm Syarn

The following components of the QLPH Project have been completed:

li) seven of the 12 primary sluices have been constructed, 2 main sluices are underconstruction in 1998;

(ii) 14 of the 26 smafl sluices have been constructed;(iii) almost all main and primary canals have already been excavated or enlarged;(iv) approximately 35% of the secondary canals for water distribution witin the project

have been excavated or enlarged;(v) the proportion of the on farm water control and management system that has

already been constructed is unknown.

112.22 Changes Xi Land Use *m 7997 to C:uft Cndion

Land use in the project area has changed greatly since the completion of the PFS. Themajor changes that have occurred may be summarised by:

li) a large decrease in the area of "unused", uncultivated land, from more than 90,000ha in 1991 to about 10,000 ha in 1996;

(ii) concomitantly, a large increase in the area under cultivation, about 40,000 ha;

MDWRDP, Feasibility Study UpdateAnnex I, Environmental Impact Asesment and Environmental Action Plan, August 1998 81


(iii) a shift from single to double rice cropping, with the land area devoted to double ricecropping increasing 5-fold;

(iv) modest increases in the area devoted to agricultural commodities other than rice;and

(v) increases in aquaculture. This has been largely in the form of extensive shrimpfarming in Gia Rai and Hong Dan districts in Bac Lieu Province as well as in Ca MauProvince outside the Sub-project area.


The elements of the Sub-project still to be implemented are:

0i) the remainder of the construction and enlarging/deepening of the canal system;{ii) constructing the remainder of the on-farm management system; andliii) a programme for rural water supply.

11.3.4 Proposed Land Use

The proposed land use in the three areas of the Sub-project is shown in Table 25, Table26, and Table 27. The improvements of the canal system will allow shifts from single todouble cropping or from double to triple.

Land use (ha) Present Without With W-WO1996 Project Project

Gross area 178,888 178,888 178,888 01. Agricultural area 130,979 130,979 130,530 -449

(a) Annual crops 113,643 112,776 108,688 -4,089

- Triple croopina Q 14000 20000 6000triple rice 0 10,500 15,000 4,500double rice+ upland 0 3,500 5,000 1,500

-Double croopino 62.502 58.260 65.088 6.827double rice 62,502 58,260 65,088 6,827rice+ upland 0 0 0 0

-Sinale cropoina 51.142 40.516 23.600 -16.916rice 46,271 37,016 18,600 -18,416sugar cane 4,871 3,500 5,000 1,500

(b) Fruit/homestead 17,335 18,202 21,842 3,640

2. Forest 3,241 3,241 3,241 03. Rshery 13,954 13,954 13,954 04. Special use land 30,715 30,715 31,163 449

Cropping Intensities (%) 148% 166% 181%Crop Diversification (%) 3% 4% 5%

MDWRDP, Feasibility Study UpdateAnnex I, Environmental Impact Assesment awd Environmental Action Plan, August 1998 82


Tath 2fi mas mhmh TL;wn

Land use (hal Present Without With W-Wo1996 Project Proiect

Gross area 30,950 30,950 30,950 01. Agrcultural area 26,751 26,751 26,585 -166

la) Annual crops 25,697 25,644 25,320 -324

Triple croppinm 0 0 10.000 10.000tripie rice 0 0 6,000 6,000double rice+ upland 0 0 4,000 4,000

- Double crowpina 21.654 21.654 12320 9334double rice 21,654 21,654 12,320 -9,334rice+ upland 0 0 0 0

-Single cropoing 4.042 3 989 3 000 989rice 1,887 1,834 0 .1,834sugarcane 2,155 2,155 3,000 845

1,054 1,107 1,265 158

2. Forest 0 0 0 03. Fishery 29 29 29 04. Speciel use land 4,170 4,170 4,336 166Cropping Intensities 1%1 181% 181% 222%Crop Diversification 1%) 5% 5% 12%

Tdbb27:LdnwsmLa TrmpAhLand use (ha) Present Without With W-WO

1996 Project ProjectGross area 53,910 53,910 53,910 0

1. Agncultural area 44,664 44,664 44,471 -193

(a) Annual crops 40,031 39,568 38,911 -657

-Triple cropoino 0 0 10000 10 000triplerice 0 0 0 0double rice + upland 0 0 10,000 10,000

- Double cropping 30.499 30,499 24.411 -6.087double rice 30,499 30,499 24,411 -6,087Rice + upland 0 0 0 0

- Single cropping 9.533 9.069 4.500 -4.569rice 6,731 6,267 0 -6,267sugar cane 2,802 2,802 4,500 1,698

(b) Fruit/homestead 4,633 5,096 5,560 463

2. Forest 604 604 604 03. fishery 1,790 1,790 1,790 04. Special use land 6.851 6,851 7,045 193Cropping Intensities 4%) 168% 168% 200%Crop Diversification (%) 4% 4% 17%



12. IMPACT ASSESSMENT OF QUAN LO PHUNG HIEP SUB-PROJECT

Figure 11 contains a summary of the expected environmental impacts of the Quan LoPhung Hiep Sub-project. The detailed rationale for the assessment of specific impacts isgiven below.

12.1 Detailed Description of Expected Envronmental Impacts


111.1.1 ~Pujc knpacts an Sos

Project Activitfes: Impact AssessmentConstcn and Operaon of Canal InsificanChanges i Land Use and Commodit Puion Sigrifict and Positive

Construction and Operation of Canals and Changes ki Land Use and CommodityProduction - In areas of the Delta near to the major rivers, silt deposited on paddy fieldsduring flooding contributes to the nutrient supply to the plants. This is particularly true ofpotentially acidic soils. In this Sub-project however, flooding is not an important factor in'the hydrology of the areas. Sedimentation is therefore not an important component of thenutrient supply to the Sub-project area as most of the Sub-project's areas are relativelyremote from silt sources. Even in the northern sections of the Sub-project, with increasedwater supply from the Bassac River, this source of nutrient is unlikely to contributesignificantly to increased yields.

Research results from the Plain of Reeds and recent experience with the Tam PhuongProject in Tra Vinh province suggest that the productvity of problem soils (heavily salineand especially active acidic soils) can be increased through increasing supplies of freshwater. In Tam Phuong, increased yields were quickly observed upon construction of theproject, although it is not clear how much of the increase was due to reductions insalinity, and how much to increases in soil productivity.

Changes in land use and commodity production - Estimated increases in soil grade forsaline soils are expected to be increases of at least 10% to 20% within 2-3 years as thesalts leach out of the soils quickly. Increases in productivity in acidic soils result as acidand accompanying by-products of the oxidisation process are leached with fresh waterflushing. Depending on the amount of disturbance to the soils because of ditching andland preparation, and the depth of the pyritic layers, productivity on these soils willincrease 10-30% within 3 to 5 years.

MDWRDP, Feasibility Study UpdateAnnex L. Environmental Impact Assessment and Environmental Action Plan, August 1998 84

The Socialist Republic of Vietnam/MARD/CPO,Mekong Delta Water Resources Development Project

Environmental ResourcesPhvslcd clc Scoeonc

Conshution and Operetion of Canl I _ I M I = I = _ I _ I = U =

Chw F Lsrd Use and Cwmn ProFd_ M U _ M u P PIU U M _ P M MPopuatin Growhi Icn~ I uPm I I I I U I I uPs PP PApplication of Posilsers =l = = _ u M I _ I P

ActMtaesOutside the Sub-vrolect… - - - - - - - - - - - -

ProWsion of Rural Wats Supply PConsbtndo of Rurd Access Ro ardsw Bldges _ __ __ _ P ___ _ _ _ _ _ _ _ _ _ _ P _ P

U ^ Noln hk * SS*atA M oy b MtL UnorIPO*R M- SjiAt wdx u & LMk U P4 mard Slbn t


Tho Socialist Republic ot Vietnam/MARD/CPOMekong Delta Water Resources Development Project

Dry SeasonLocetkDn 1991 Curent phase I/1 Corrofee Subct Difference

Max Min Avg. Max Min Avg. Max Min , Avg. Max Min Avg. ->I, It - >811

TraCtu 0.67 -0.71 0.19. 0.35 0.00 0.18 0.29 -0.13 0.09 0.29 -0.12 0.10 -0.09 -0.08Hong Dan 0.37 -0.12 0.20 0.31 0.00 0.10 0.18 -0.17 0.00 0.19 -0.16 0.01 -0.18 -0.15PhuocLorig 0.35 -0.11 0.19 0.30 0.02 0.16 0.14 -0.17 -0.03 O.15 -0.18 -0.02 -0.18 -0.17Pho Shnh 0.38 -0.30 0.17 0.32 -0.05 0.16 0.09 -0.18 -0.08 0.11 0.19 -0.05 -0.24 -0.21Ca Mas 0.84 -0.67 0.11 0.62 -0.49 0.11 0.87 -0.80 0.09 0.05 -0.21 -0.10 -0.20 -0.21

rAiny SeasonLocS&AP 1991 Curfent PMase, Copere St&-*wt Diffemene

Max Min Avg. Max Min Avg. Max Min Avg. Max Min Av9. >I',1 >111Tra Cu 0.78 OA7 0.50 0.63 0.35 0.45 0.62 0.34 0.44 0.52 0.34 0.44 -0.01 -0.01Hong Dan 0.61 0.41 0.60 0.50 0.28 0.38 0.46 0.24 0.34 0.48 0.25 0.36 -0.04 -0.03Ph"oc Long 0.83 0.41 0.51 0.50 0.30 0.39 0.41 0.24 0.33 0.43 0.26 0.34 0.08 -0.05Pho SBih o0.87 0.41 0.52 0.53 0.32 0.42 0.39 0.21 0.29 0.40 0.26 0.33 -0.13 -0.09Ca Mau 0.88 -0.09 0.48 0.88 -0.12 0.44 0.92 -0.13 0.47 0.45 -0.14 0.27 +0.03 -0.18



1Z1.1.2 Proct Impacts on Sunrace Water Hydrology

Project Activities: Impact Assessment:Construction and Operation of Canals Positive and SigrificantOperation of Slices Posiive and Sigrificant

The overall hydrological conditions in the Sub-project are expected to improvesignificantly, with improved freshwater supply in the dry season, and improved drainagein the rainy season (Table 29).

Freshwater supply from the Bassac River in the dry season with the Sub-project is about8 m3/sec greater with the project than under current conditions. This is due to theenlargement of the existing primary canals, the excavation of the additional water supplycanals and the irrigation requirements in the dry season.

The project will have marginal effects on canal water levels inside the Sub-project areaduring the rainy season. During the dry season water levels would decrease by up to 0.2m (Table 28). This will be caused by i) the primary sluices, which will remainpermanently closed during the dry season and therefore prevent ocean water fromentering; and ii) pumping for irrigation.

VRSAP model simulations predict that, with the completion of the entire QLPH project,water levels in the southwestem part of the Bac Ueu - Ca Mau canal may increase up to20 cm during the dry season on the incoming tide. The overall hydrological effects areexpected to be minor and somewhat localised, and this is assessed as an insignificantimpact on hydrology. The water level increase causes that the floors of houses located inbetween the sluices on the primary canals and the Bac Lieu - Ca Mau canal'would beflooded regularly at high tide. The households affected by the ongoing construction oftrhe Lang Tram and Pho Sinh sluice are being compensated for this impact according tothe guidelines as defined in the Resettlement Action Plan.

MDWRDP. Feasibility Study UpdateAnnex 1. Environmental Impact Assessment and Environmerital Action Plan, August 1998 87


Jabb 2R:hbwami2xwilsamdy_n C>AMdi 1991, aa wd Rin,tIkr3

I Rainy Season (October) Sean(F )Parameter 1991 Current Rhaset,/ 1991 Curerd Phase 1,I

CondUcInsr*bINFLOW:

Precipiaon 630 .630 630 0 0 0FromnBassacRiver 284 345 346 100 195 202

TOTAL INFLOW 916 975 976 100 195 202

OUTFLOW:

MyThanhRer 60 103 104 14 15 16Ganh Hao Rwer 52 77 95 10 10 18

ZOO/ to stduCh iAe II1 t80 199 24 25 34SW

44 38 43 25 23 22Ong Doc River 366 396 379 117 106 49Ca Lon - Cai Be

410 434 421 142 129 71Total to GUf of 7hahnd

521 614 620 165 154 106TOTAL OUTFLOW

395 361 357 65 41 97wYFLOW nianOUTFLOW:

111.1.3 Arjet kncs on WXin Sub-p c Sutace Wat QuaWty

Project Activites: lmpact AssessmentConstruction and Operation of CarWs see Section 12.1.1.2Changes in Land Use and Comodity Producion 8 Seon 12.1.1.2Popdaion Incease h _Appkcaion of Fertilisers InsignifiAppEcaion of Pesticidos UnknownUpstream Activibes NoneOperadon of Suces Insignicanl

Population Growth - There is no doubt that, without improvements in sanitation andproper treatment and disposal of household wastes, an increase in the number of peopleliving in the Sub-project area will continue to degrade the surface water quality of theSub-project. This is assessed as insignificant, however, because pollutant levels withinthe Sub-project already exceed most national and intemational water quality standards. Itmay be worth considering financing such a rural sanitation program as part of the Sub-project support services.

Application of FerTilsem - It is estimated that approximately an additional 13,700 tonnesof fertiliser will be required annually for the entire Sub-project over and above estimates offertiliser application without Sub-project implementation. About a 97% increase overcurrent estimated fertiliser use throughout the Sub-project. As the surface water of theSub-project is already eutrophic, it is expected that these incremental inputs will notsubstantially change the water quality status of the Sub-Project. In addition, the systemoffers the possibility to exchange water during low tide by the opening of the sluiceswhenever required. This impact is therefore assessed as Insignificant.


The Socialist Republic of VietnamIMARDICP0Mekong Delta Water Resources Development Project

Application of Pesticides - It is estimated that without mitigation approximately anincrease of 17% of pesticides and herbicides will be required annually for the entire Sub-

project over and above estimates of pesticide and herbicide application without theProject (see Table 7). This is about a 55% increase over current estimated pesticide andherbicide use throughout the Sub-project. This impact is assessed as Unknown butpotentially Significant. Existing baseline information on pesticide concentrations in theSub-project environment is inadequate to estimate the pre-project conditions, but theexpected increase is substantial.

Both mitigation and monitoring are recommended. With respect to mitigation, it isrecommended that IPM training be continued (see Section 4.1.1.4). With respect tomonitoring, pesticide monitoring in the environment should become a formal part of theoverall Sub-project monkoring program.

Upstream Actvities - Simulations of the effects of required water abstraction for dryseason irrigation on mainstream migration of salt water indicate that the OLPH and theBRTL areas are unlikely to be affected. In the dry season the TN area already faces salinewater in the main rivers surrounding the area future land use in the dry season is limitedto whatever water remains availbale when the sluice gates would be closed. In addition,water resources development projects on the Mekong River upstream of the MekongDelta may occur and cause an impact to the Sub-project Isee Section 4.1.1.3). Theseissues, however, would require a review of the entire Delta, including the environmentalcomponent.

OPeration of Sluices - This impact is assessed as Insignificant. Operation of the sluicesystem in the rainy season is expected to improve surface water quality in the Sub-project (see Appendix C). The situation may be somewhat different in the dry seasonbecause contaminants may build up in the inside of a largely closed sluice system. It isworth noting that the results presented in Table 29 and Table 28 are from simulationswith the VRSAP model in which it was assumed that the sluices remain closed during theentire dry season.

The issue with respect to surface water quality impacts is one of relative scale. Surfacewater in the Sub-project is already degraded in many aspects and does not meet moststandards for domestic water use, drinking water use, or many environmental criteria foraquatic biota. In addition, the flushing at the beginning of the rainy season allows for anybuild-up of pollutants to be very quickly removed from the canal network as isdemonstrated in Appendix C. This would likely cause little or no damage to areasdownstream of the Sub-project because an adequate waming system is already in place.It notifies the public, through the media, of the times of opening of sluice gates wheneverthe drainage water is of too bad quality (acid) for any use downstream.

121.1.4 Sub.poje Impcts on Dow rtwn Swf*ace War Qualty

Proiject Activies: Impact Assessmentcaswuction and Opation of Cwna Significam and nWgabeChanes i Land Lbe and Conimoit Producton Sgimi and mitigablePopLiton Growth IhsificatApplication of Fertler kotr ficun tAppication of Pesficides Sigrificnt ad mitiabieOperation of Skices Srific antd mitgable



Construction of Canals, Changes in Land Use, Operation of Sluices and Appflcations ofPesticides - The Sub-project has impacts on downstream surface water quality mainly viathe drainage of acid water and increased pesticide use from inside the QLPH area to thecoastal area. The potential degradation of surface water quality outside the Sub-projectfrom acidity and increased application of pesticides is a serious issue for two reasons:

(il much of the outside, downstream areas contain shrimp farms, an important sourceof foreign exchange for Viet Nam; and

lii) Viet Nam is investing in the rehabilitation of large portions of the area outside of theSub-project area through the Coastal Wetlands Protection and Development Project.

There has been no long term monitoring of surface water quality in the areas immediatelyoutside of the Sub-project area (see map, Appendix A). The Water Quality MonitoringNetwork has no stations in these areas. However, from the data available from thestations inside the area and the known flow pattems, it is obvious that the outside areareceives contaminated water from the QLPH area. To what extent changes occur withthe accelerated development of the QLPH area, is difficult to say. The analysis of therecent trends in surface water acidity in the Ca Mau Peninsula (Appendix C) demonstratesthat since long the area severely suffers from prolonged periods of very acid water, butbecause of the improved drainage and flushing the situation is gradually improving

Mitigation for this issue is already taking place in the sense that a waming system exists.Acid water conditions are easily observed in the field29, it occurs annually and starts soonafter the first heavy rains. The operation regime of the sluices is made known to thepublic through the media, informing them when the gates will be open for drainage andthe level of acidity expected. In this way, farmers are advised not to use the surfacewater for domestic purposes or for water exchange of their shrimp ponds.

Mitigation of increased pesticide use should consist of rigorous implementation of an IPMprogramme (see Section 4.1.1.4). Water quality monitoring should also be implementedto be able to detect unexpected major changes in surface water quality and shouldinclude:

(i)- expansion of the existing Surface Water Quality Monitoring Network so thatadverse impacts can be quickly detected if and when they occur and systemflushing can be initiated;

(ii) preparation of a detailed cumulative effects model of changes in surface waterquality caused by the Subproject.

Overall, the impacts of the Subproject on outside surface water quality are assessed asSignificant and mitigable.

"' Becaus the ydrological dynamcs n the Subaje and surroumi areas are exuemey corrnicated,peae preeicion merthds w not vabi yet. Te siatio not ake a ver sstem reivig ponsource (or even norpoitm sourc) pouon loads aid for which simple huistic mods can be usd topredict the consequene of Polution badirg. Forecaing of degradfton of watr qua must tae htoaccount fe copated hydrolgical situation in the region. The best way to aclieve this is to enhancea modd such as VRSAP so ta it is capable to predict irportant water quty paramwetes. VRSAPcurrently does not have tis capabll, possbly, it would be better to bid a new model usin modenhydrodyraric modeln tdchnues and softwar.



12.1.1.5 Poject Impacts on Groundwater Resources

Project Activiies: Impact Assessment:PoptAation Growth UnknownApplication of FeTss InsgHicntAppOcation of Pestcides InsinificantConstruction ard Operation of Canais InsigriicntOperation of Shces Irsignficat

Population Growth - Deep groundwater aquifers are the only source of water thatconsistently meets national and intemational drinking and domestic water standards. It isestimated that an additional 24,000 m3/day of groundwater extraction would be requiredto meet household drinking and domestic water demands that are not currently met bygroundwater"; the recharge rate of the deep aquifers is unknown at this time (Annex M.

In addition, an increasing population, in the absence of sewage treatment facilities, willmean greater levels of bacteria and coliform in the aquatic systems of the Sub-project.This includes shallow groundwater aquifers. This will almost certainly not contaminatedeep groundwater systems.Application of Fertlisers - While shallow groundwater systems may become increasinglyeutrophic as a result of increased fertiliser application, deep groundwater systems willlikely be unaffected.

Application of Pesticides and Herbicides - The assessment is the same as that forincreased use of fertilisers. There is a chance that increased total application of pesticidesand herbicides will contaminate shallow groundwater systems; deep groundwateraquifers will be relatively unaffected. The fact that many of the pesticides and herbicidesbeing used in the Sub-project area are persistent organochlorines, however, createssufficient concem, hence, IPM training and that pesticide monitoring within the Sub-project area has to be undertaken.

Constmiction and Opeation of Canals, Operation of Sluices - The Sub-project will havemarginal effects on water levels in the Sub-project area during the rainy season. Canalwater levels will decrease during the dry season by up to 0.2 m 0. These effects areassessed as Insignificant for reasons discussed earlier.

121.1.6 Project mnpacts on Ak Qualy

There are no project activities that will adversely affect air quality in or outside the Sub-project area.

1Z1.1.7 lrject Impwct on Canal Bank Stabiy

P)vect AcDvfios Impact AssessmentConstruction and Operation of Canls MiigableChanges in Land Use and Commodty Pmodution MitigblePopuaion Growth MidgableCosucon of Rwal Access Roads and ridpes Positivw and Significant

The Sub-project will create increased trarsportation requirements and opportunities in theSub-project by:

° Reference is made to Annex IV, Groundwater and Rural Water Supply and Sanitation, preparedfor the MDWRDP.

MDWRDP, Feasibility Study UpdateAnnex I, Environmental Impact Asesament and Environmental Action Plan. August 1998 91


(i) increasing the surface water transportation routes with the construction andoperation of irrigation and drainage canals;

(ii) increasing the agricultural outputs exports (from the Sub-project area) andincreasing the imports of agricultural inputs (e.g. fertiliser); and

(iii) increasing population.

All this will increase the use of canals for boat transportation. The trends will notnecessarily have an impact on canal bank stability because smaller boats are alreadyequipped with engines of capacity suitable to the boats used. The dimensions of thecanals and the small farm size are unlikely to result in the widespread use of larger, highpowered, boats.


1212.1 roject mpacts on Tenstril Eosystems Writn Sub-Prjct

Pno*ecrAcdisies Impact AssessmentOperafon of Sluices MitigablePopulation Growth IrsignificantAppcatgon of Pestcides and Herbicides

Operation of Sluices - The water control systems will essentially convert the areas froman area whose ecology fluctuates between marine (dry season) and freshwater (rainyseason) to an area whose ecology is completely freshwater. The salinity changes broughtabout by the operation of the primary sluices will cause a decline in Nipa palm. It isestimated that there are about 750 ha of Nipa palm remaining and an unknown area ofscattered mangrove, especially in the westem part of the Sub-project (westernmost partof Phase 11). This is an unavoidable but acceptable impact which can not be mitigated(see Section 4.1.2.1)

Application of Herbicides and Pesticides - The application of pesticides and herbicides willincrease. No mitigation is specifically recommended for this impact, although training inIPM should continue

121.2.2 Prqiwct Impacs on T&F7VV&WECoSYSIWS Ou0Ae the SMPrt

PIrojectActvMies: Impact Assessment:Constuction and Operabon of Canals s SecionChanges in Land Use ad Covwdt Production UnwmPopulaton Growth kisigdficantApplication of Ferlilisels UnkownApplication of Pesticides UnknownOperation of Skices Iksigniicant

The potential degradation of terrestrial ecosystems outside the Sub-project is a seriousissue because Viet Nam is investing in the rehabilitation of large portions of the areaoutside of the Sub-project area CWPDP. The mitigation and monitoring recommendationspresented in Section 12.1.1.4 are also recommended here. The specificrecommendations are expansion of the existing Surface Water Quality MonitoringNetwork to quickly detect adverse impacts, and the development of a detailed cumulativeeffects model of changes in surface water quality which could be part of the proposedwater management study in the MDWRDP.

MDWRDP, Feasibility Study UpdateAnnex I, Environfnental Impact Asessmnent and Environmental Action Plan, August 1998 92


1212.3 Projet Impacts on Aquatc Ecosystems Witfin tte SubProject

Project Activiies: Impact Assessment:Canon and Opration of Cais Sigrtfca and positveOperation of Sluices Significant and positiveChaes in Land Use and Commodity Production Sigrificai and rigabePopulation Growth nsignificantApplication of Pesticides and Herbicides Mitigable

Construction of Canals and Operation of Sluices - There will be a shift inside the Sub-project area from brackish water ecosystems and biota to freshwater ecosystems andbiota. This impact is assessed as Significant and positive overall because with theoperation of the sluices drainage improves leading to shorter periods of severe acid waterin the canals.Changes in Land Use and Commoity Production - Part of the Sub-project involvesincreasing the number and size of canals. This will increase the total area of aquaticecosystems within the Sub-project area and this is assessed as a Positive Impact.

Popuation Growth - The assessment, comments, and recommendations made in Section12.1.2.2, above, for terrestrial ecosystems within the Sub-project apply equally well here.ft is unlikely that already high levels of fishing will decrease as a result of the Sub-project.This impact is assessed as Insignificant because of the already high degradation of theecosystems within the Sub-project.

ApPrication of Pesicddes and Herbicides - The assessment, comments, andrecommendations made in Section 12.1.2.2, above, for terrestrial ecosystems within theSub-project apply equally well here. While the application of pesticides and herbicides willincrease, predictions of the magnitude of any impacts of biocides on aquatic ecosystemscan not be made given the absence of baseline data. Mitgation and monitorngrecommendations made pertaining to continuation of IPM training, as well as pesticidemonitoring apply here as well.

I.1.24 Sub-prjt Impacts on Aquat Ecosystm Outs Me Sub-r c

The assessments made above for impacts on Outside Surface Water Quiality outside theSub-project are also-valid for aquatic ecosystems outside the Sub-project.

121.25 Imacts on ProtecdAJU U i7 Mhe Sb-"ect

There are no formal protected areas within the Sub-project. As mentioned in Section10.3.5, the province of Soc Trang has one area of Melaleuca that it is considering forprotection. The PFS indicated that Melaleuca resources inside the Sub-project would beunaffected by changes in the hydrology brought about by the Sub-project. This reviewsupports that conclusion, and any impact of the Sub-project on this Melaleuca area islikely to be Insignificant.

121.26 S 5b.pmject knpacts on Doowrstram PftectAteas

Pofiect Activtes: Impact Assessment-Construction and Operation of Cas UnknonChanges F Lnd Use and Commodt Pductn UnknowPopulon Grvwth UnknonApplication of Fertilisers UnkwnIApplication of Pestiides Unknown



Opraton of Sluices Insignicacit

The assessment of impacts on Terrestrial Ecosystems outside the Sub-project area appliesequally well here. The risk of impact will vary with the distance of the Protected Areafrom the Sub-project. The protected areas most at risk is the Bau Sen Bird Sanctuary inDam Doi District and the Bac Lieu Bird Sanctuary, two of the protected areas whoserehabilitation is being supported through the DANIDA-funded project (Section 10.3.5).

12.1.3 Impacts on Socio-oconomic Resources

1Z1.3.1 Project hIpacts on Pubc Heua '

ProjectActivites: Impact Assessment:Opration of Suices Pose ftwogh decreaes in salityChanges in land Use and Commrodity Producton InsignificantPopulation Growth nsficantAppicaton of Ferlisers InsignificantAppOcation of Pesbcides Mitigable

The level of public health in the Sub-project las it is for most of the rural population in theMekong Delta) is related primarily to water quality for domestic use. The quality of waterfor domestic use will almost certainly improve as a result of the Sub-project withimplementation of the Rural Water Supply and Sanitation Program. The following majorchanges in surface water quality are expected:

(i) decrease in salinity;(ii) likely increased nutrient concentration from increased fertiliser application;(iii) likely increased pesticide concentration from increased pesticide application; and(iv) little change in bacterial contamination.

These are also the generally expected impacts on shallow groundwater. Mitigation formost of these potential impacts would be implementation of the Rural Water Supplycomponent of the Sub-project. The provision of freshwater for domestic use throughdesign and timely implementation the rural water supply and sanitation component of theSub-project could deal with the major public health issues of the Sub-project area (i.e.,gastrointestinal diseases). The sustainabDlity of this component depends on themaintenance of the water supply systems, and public education/environmental awarenessin proper sanitation principles.

There is concem about the effects of increasing pesticide use on human health, especiallyof the farmers applying the pesticides. Recent work in the Philippines suggests that theseeffects may be considerable. Therefore, continuation of IPM training (see Section(4.1.1.4) is recommended.

1z1._u2 ject kmpwXan Wae Supply Wit h h Sub-Puct

Project Activites: ImpactAssessmenritAP Subprject Acivites sigiHicant with espect to srface water quaity|

Unknown with rmspect to sholw groW ndwaterNone with respect to deep grondwater

31 This section is primarily based on public health impacts of the Sub-project as mediatedthrough changes in surface water quality.



Sub-project effects on drinking and domestic water quality will depend on the source ofwater used for drinking and domestic water:

(i) those households that rely on deep groundwater aquifers for drinking and domesticwater supply will almost certainly be unaffected by any of the Sub-project Acdvitiesbecause the deepness of the wells and their relative disconnectedness of theseaquifers from the surface situation;

(ii) those households that rely on shallow groundwater aquifers for drinking anddomestic water supply may be affected by the Sub-project. Potential impacts arefrom increases in pesticide contamination and domestic waste water discharge;

(iii) those households that continued to rely on surface water for drinking and domesticwater supply will continue to face a degraded water supply. It has been assessedelsewhere in this EiA that the Sub-project will not improve surface water quality,and may in fact degrade it further (Section 12.1.1.3, Section 12.1.3.1)

Water levels in the drinking water supply wells are not expected to be influenced by theproject. Water levels are controlled by pressure in the confined aquifer which underlies thearea, and the proposed changes in surface water in the canals imposed by the project aretoo small to affect significantly the pressure in the confined aquifer.

Implementation of the Rural Water Supply and Sanitation programme would have apositive effect.

12..33 Projet Impacts on Dobwnslrwn Dthng Watar Supply

To the extent that there are impacts of the Sub-project on surface water quality outsidethe Sub area (Sectionl 2.1.1.4), this will impact on water supply outside the Sub-projectfor those households that rely on surface water as main source of household watersupply. This impact is assessed as Unknown because of:

(i) the lack of baseline surface water quality data outside the Sub-Project;(ii) the inability to make quantitative predictions about the magnitude and extent of

Sub-project impacts on incremental pesticide concentrations in surface water; and -(iii) a lack of information on the proportion of households outside the Sub-project area

that currently rely on surface water for drinking and domestic water supply.- t

12.13A. Pq. Impacts on Subssen Resowe Hrvesing

Project Activites: Impact AssessmentChanges in Land Use and Craodity Production Positive aid S;ificmtPopulation Growth SigrficantApplication of Pesticdes InsigifCitOperation of Suices Significant

In the Mekong Delta, households rely on fishing for a relatively small proportion of theirincome. It is expected that any positive or negative changes in the status of biologicalresources within the Sub-project will have similar effects on the levels of biologicalresource harvesting. Increases in canal area should improve fish resources. Improvementsare expected in the level, extent and duration of acid surface water which wil havepositive effects on fish. Decreases in surface water quality perhaps through pesticidesmay have some effect on fish. Finally, increases in human population through regularpopulation growth will increase harvest pressure on these resources. No mitgadon ormonitoring is recommended.



12.1.3.5 Project knpacts on Human Settlements, Communiies, andInfrastrucu

Project Activites: Impact Assessment:Constucion of Slihces MtigableOperation of Suices MitigableConstrucdon and Operation of Cnals MifigablePopulation Growth Mitigable

Construction of Sluices and Constnuction and Operation of Canals - because of sluiceconstruction, new canal construction, and enlargement of existing canals, somehouseholds will need to be resetted. This is a significant effect, but can be mitigatedthrough the implementation of the resettlement plan. This impact is being dealt with bythe Resettement Action Plan component of the FS update (Annex 11.

The RAP provides for independent monitoring of the households to be resettled to ensurethat resettlement is implemented according to plan.

Operation of Sluices - Table 30 indicates the changes in water level that may beexpected immediately to the outside of the sluice at various locations. In the dry season,the water levels in the canals outside the southeastem portion of the Sub-project may be0.2 m higher than at present. Compensation is being provided to those householdswhose houses would be flooded regularly at high tide.

Thbb3 aww,,n ha ri ah^ bl m'k ie baoRuSP

Location Situaton 1989 Exist 1997 Phae I. U and mMax Min Avg. Max Min Av8. Max Min Avg.

Pho Sinh 1.3 40.8 0.4 1.5 40.8 0.4 1.6 -0.9 0.4Chu Chi 1.3 40.9 0.4 1.6 -1.1 0.4 1.7 -1.1 0.4

ang Tram 1.0 40.1 0.5 1.0 -0.1 0.5 1.1 -0.1 0.5Sluice 21 1.0 40.1 0.5 1.0 40.1 0.5 1.1 0.1 0.5Sluice 22 0.9 -0.1 0.5 0.9 40.1 0.4 1.1 40.1 0.5Sluice 23 0.8 0.2 0.5 0.8 0.1 0.5 0.9 0.2 0.6Sluice 24 Q0.7 0.2 0.5 0.6 0.2 0.4 0.6 0.2 0.4Sluice 25 0.6 0.0 0.3 0.6 0.1 0.3 0.6 0.1 0.3

1Z1.3.6 Projwt Irpacts on Cuitwd, Aestetc, Histonc Foatxw

Bac Ueu and Soc Trang provinces did not identify any cultural, historic, or aestheticfeatures that would be affected in any negative way by the Sub-project.

121.3.7 Projct npacts n Cormoity Poducon

Project Activites: Impact Assessment:All Sub-project Activities Positive

These effects will be positive and are the major justification for the Sub-project in the firstplace.

121.3.8 Pljct kmpacts on HousehoSi Energy Supply

Visual observations during field missions substantiate the assertion made in the SNWRPUpdate that a large number of scattered trees have been planted throughout the Sub-project. It appears that many households, have planted trees, largely Melaleuca andEucalyptus, on the bunds demarcating their property, in quantities well above what would

MDWRDP, Feasibility Study UpdateAnnex I, Environrnental Impact Assessument and Environmental Action Plan, August 1998 96


be required for domestic fuelwood supply. They may be selling the wood for income. Itappears that the fuelwood supply constraints are gradually being alleviated throughoutthe Sub-project. The increase in land area allocated to forestry would alleviate theseconstraints even further.

121.3.9 Project kmpacts on Transportaon and Navigation

Pmject Activies: Impact AssessmentConsruction of Slucas MingableOperation of Skicos MitigableChanges m Lnd Use and Comofdty Production Positive and SignificantConsuucton of Rual Access Roads and 8ridges Positve and Significant

Construction and Operamon of Sliwes - water levels that are more constant, reducedcurrents and channel improvement and dredging which will accompany the constructionof the sluices should benefit local transportation inside the Sub-project.

The primary and smaller sluices will form a barrier to water transportation, particularly inthe dry season when they will generally remain closed. The construction of the sluiceswill make navigation more inconvenient, more time consuming and more expensive forthe many communities inside the Sub-project. Visual observations of some of the sluicesalready constructed along the National Highway indicated that local residents havealready set up their own system and procedures for moving materials from one side ofthe sluice to the other. Materials were seen being moved by cart from one boat on oneside of the sluice to another boat on the other side of the sluice. The project provides forboat lifts to be constructed at sluice sites.

Changes in Land Use and Commodit Producton - Water transportation is the dominantmode of transportation in the Sub-project area, and the additonal canals that areconstructed for water supply and drainage will improve communication for inhabitants ofthe Sub-project area.

Construction of Rural Access Roads and Bridges - Provision of these types of facilities canonly improve the movement of people and materials in the Sub-project.



13. RECOMMENDED ENVIRONMENTAL MANAGEMENT PLAN FOR QUAN LOPHUNG HIEP SUB-PROJECT

The proposed Environmental Action Plan for the QLPH Sub-project Phase I and 11 ispresented in Table 31. It contains two components: recommendations for environmentalmitigation and recommendations for environmental monitoring.

13.1 Environmental Mitigation Measures

The recommended environmental mitigation activities are:

(i). implementation of a Rural Water Supply and Sanitation component to coverscattered rural households within the Sub-Project;

(ii). implementation of the defined resettlement action plan for the Sub-project affectedpersons;

(iii). provision of boat lifts and transhipment facilities near sluices; and(iv). Continuation of IPM training for rice cultivation and farm worker safety in pesticide

and herbicide application. It may be possible to expand the IPM Component of theIDA-financed Agricultural Rehabilitation Project.

13.2 Envi Moitorng

The core of the proposed environmental monitoring plan is an expansion of the existingSurface Water Quality Monitoring Network (see Section 5.2.1 for a description of theexisting programme). A comprehensive enhancement of the surface water qualitymonitoring network is recommended.



li) eventual future development of the Phase IlIl area;(ii) possible downstream impacts of the Sub-project, particularly those areas that

receive water from the Phase IlIl area of the Sub-Project;(iii) potential contamination of shallow groundwater and fisheries, primarily by

,- pesticides; and(iv) bacterial contamination of surface and groundwater resources.

The following enhancements are proposed to the Water Quality Monitoring Network:

A total of 11 additional stations are proposed (see map, Appendix A):

7 additional stations inside the SbPrmject2 stations on the Ngan Dua-Bac Ueu Canal1 station on the Chu Chi Canal1 station on the Pho Sinh Canal1 station on the QLPH Canal1 station on the Bach Nguu River1 station on the Lang Tram Canal


The Socialist Republic of Vietnam/MARD/CPO.Mekong Delta Water Resources Development Project

TrA31mw111:1rmnac*rirpb GCUr ofRxsKrp&S6prA

Enviotalentof issue Assessmert Recommended Action Cost Inpleentation kxcadtve Timetable

Capial cost Recurnt CostMitigationEffects of Pesticid Use Asassed aso Posion of traoing for To be taken up by Provincial Plt Proection Should begin as soon ason Ea*on6ms but outdated types of IPM technius, as wd regona or national Sridspmtmant possile. begkh*l hI theResoucre pestkides tht ar stE as pestcide secion snd progreanis eestemnnst pert of the

used roke m hgation use as a par of extendon Sub-proect, pawtbuliv hIdesabl prowarn Weas wure mutipl

copph oc us. Thistype of extension shoudexpand westward intoPhase m ls k Isconsructed

Subproet Effects on M abla Imleetation of duraeODrihi end Oroamsc Water Supply PRogram A snd porm is ded In th Subpct, se le Water Sw* copot of FS wdae (Amex PiWater Ouwi caued bymost boectaivitlesSub-prolect Effects on Related to 1PM and RWSS prgrensPubic Health

----t--d oe Pesetuent t Action Plan RAP prepared for MOWRDP. Annex I of FS updteHouseholds a resulh ofSluice ConsructionNavigation Constris Mt e pvsn of hano About USD 11,000 each SlO's Mitigation houd be fittedhduced bV Construction operated coss-uke to already constuctedand Opeation of Slices nant systems fbr slices ed design and

wnaler boats at aN eMcoe conwuction kcorporatedthet wE form a barbr hito conructbon ofbetween inside and remaining kdhcesoutside the Sub-Proiect

MDWRDP, Feasibility Study UpdateAnnex 1, Envitonmental Impact Assessment and Environmental Action Plan, August 1998 99


Tth31:Pmwrhdwadrmmba*wd. IhwLOft)wV1&bP&tf owmd

Environrtd issle Assessment Recomeninded Action Cost Implementadon nictivdve Timetable_Responsky for ikpleentaion

Ca4il Cost Racumwt Cost

Monitoring32

Effets on Surface Water Ganer#V hksdncant Expansion of Surface SIWRP with suppot of Shoiu beghi nmdlatelyQult Iide OUtsie hid Sublproject wea Water Cualty Moritorkg provkiW DARD and to establish as much of afe Sub toleqct Unknwwn downstream of Network to kckida seven DOSTE staff basAie dfatabase as

Siiwroect. parthady tadditlon mo"itorkV poswih respect Phase l1 station wlt* Sub-

project and four adc5ionastations outda the Subproject Isee map,ANpenix Al

Success of Famlis Household sunveys of *O.OOO per year Pfoject M nagent Household surey dsudRestled under resettled households Oflce be done prior to

R Ment Acdon Pbn kindba flo-on resettnWent ard ernnulyconition thereafter

32 The continuation of normal hydraulic monitoring performed to update and maintain the hydraulic models is assumed to be maintained.

MDWROP, Feasibility Study UpdateAnnex I. Environmental Impact Assessment and Environmental Action Plan. August 1998 100

The Socialist Republic of VietnemIMARD/CPOMekong Delta Water Resources Development Project

4 additional stations outside he Sub-Project1 station on the Ho Phong-Ganh Hao Canal1 station on the Ganh Hao River1 station on the Ong Doc River1 station on the Cai Lon River

A monthly sampling regime will be maintained. Because the Sub-project is stronglyimpacted by tides, water samples will continue to be collected at low and high tides. Intotal 264 new samples per year wIll be taken.

Pestiddes - Surface water samples will be selected at five places of intensive riceproduction; these locations will be close to the seven additional sampling sites proposedinside the area for cost efficiency. At the same time, fish samples will be taken in localmarkets to monitor bioaccumulation. Pesticide use tends to be highest in the Summer-Autumn crop when conditions are most favourable for pests developmerrt. Therefore,samples should be collected at four periods: June, August, December, and April. Thismakes for a total of about 40 pesticide samples each year 20 surface water and 20 fishsamples.

Bacteria and Coifom - These should be collected monthly at the 7 surface water qualitymonitoring stations inside the Sub-project (total of 84 samples per year).

13.2.2 Cost Summary for Expanded Water Quality Monitoring Program

Table 32 contains an estimate of the incremental costs required for the expanded waterquality-monitoring program.

MDWRDP, Feasibility Study UpdatAnnex I, Environmental Impact Assessrent and Environmental Action Plan, August 1998 101

The Socialist Republic of VietnamtMARDlCPOMekong Delta Water Resources Development Project

Tabb32amep. rpd&uji Ki uvyMwVAWv* _ lLoRkW&bpS

TotalIUSD)

Incremental Fixed CostsIh,t Rate No. Taot

Staff ply 3,600 2 7,200

Eqipmont Mantenec % Equipnrrnt 5 31,500 1,575Cost

FactWes Month 200 12 2,400Reporting on ends in water qL in OLPH 1, n p-V 26,000Incremental Sampling Costs

Af& Per A.No Sn&sg

Car kln 700 0.50 12 4,200

Boat boat-dys 5 50 12 3,000Fied exes parwndays per

trip 21 20 12 5,040SarVi4e collection fied days per

stations 11 10 12 1,320Incremental Analhis Costs

AonthS Total NewNAonhmof S. W6d SwpA Per YVw

tha' Ct AMD) Aew Satons Am Yew TOWh ,gicalDat-Acquisn 2,000

Sfaoce wae 30 11 12 264 7,920

Aefest'-sSurface water 100 5 4 20 2,000fish 100 5 4 20 2,000

BectenaSurface water- 15 7 12 84 1,260

Total (rounded figunre 66,000



14. INSTITUTIONAL ARRANGEMENTS FOR A MDWRDP MONITORING PROGRAM

Careful and continuous monitoring of the Sub-projects is required to measure the impactsof project implementation. It would be useful to continue monitoring of the benefits aftercompletion of the project works.

The first step would be to develop a Project Monitoring and Evaluation System, whichwould be acceptable to all parties of the loan. The elements of this system would be:

(i) the establishment of a database of key indicators of the progress of the Project;(ii) the development and execution of a baseline survey before the Project commences

to establish the pre-program status of these essential indicators, as a base againstwhich to measure progress as the Project moves ahead. The Bank's guidelines andprocedures wIll be considered in designing these surveys as well as the overallproject monitoring and evaluation activities;

(iii) the development of a system to collect data from all segments of the Program on aregular basis to generate Project Monitoring reports in the required frequencies andtime frames. It is recommended that the monitoring be conducted at the districtlevel and be aggregated where necessary;

(iv) the development by the CPO of a computerised database where informationcollected will be stored, collated, analysed, and from which the periodic reports willbe generated;

(v) after the first year of operation, an independent appraisal of the monitoringsystem will recommend corrections or additions to the system as required todeal with any deficiencies identified.

MDWRDP, Feasibility Study UpdateAnnex I. Environrnental Impact Assessment and Environmental Action Plan, August 1998 103


15. SUPPORTING DOCUMENTATION

Dent, D.L and M.E.F. van Mensvoort. 1993. eds. Selected papers of the Ho Chi MinhCity Symposium on Acid-Sulphate Soils. ILRI Publication No. 53.425 pp.

Duyet, N.V. 1991. Study on Forestry Development, General Development Project ofQuan Lo Phung Hiep Area - Mekong Delta. Ministry of Forestry Forest Inventory andPlanning Institute. 30 pp and diagrams.

ESSA Ltd. 1992a. Water control project for the Quan Lo/Phung Hiep area Mekong Delta,Vlet Nam: A pre-feasibility study. Final technical report. Prepared for Ministry of WaterResources, Socialist Republic of Viet Nam. 302 pp.

ESSA Ltd. 1992b. Water control project for the Quan Lo/Phung Hiep area Mekong Delta,Viet Nam: A pre-feasibility study. Final technical report appendices. Prepared for Ministryof Water Resources, Socialist Republic of Viet Nam.

GEC Ltd. 1996. Environmental and social review of the buffer zone component. Finalreport prepared for World Bank Coastal Wetlands Protection and Development Project.166 pp.- -

GEC Ltd. 1997. Environmental Review Of Proposed Sources Of Growth For SustainableAgriculture And Biodiversity Protection In The U Minh And Plain Of Reeds Subregions OfThe Mekong Delta. Phase 1 Report. Prepared for World Bank. 78 pp.

Govemment of the Socialist Republic of Viet Nam. 1994. Biodiversity Action Plan.VIEI91 /G31. 212 pp.

Khue, N.N. 1991. The Vietnam rivers system and plains mathematical model for flow andsalt concentration by the Sub Institute for Water Resources Planning and Management,1991.

Mekong Secretariat. 1985. Tam Phuong water control project appraisal mission report bythe Interim Committee for Coordination of Investigations of the Lower Mekong Basin.

Mekong Secretariat. 1986a. Progress report on the construction of the Tam Phuongwater control project by the Interim Committee for Committee for Coordination ofInvestigations of the Lower Mekong Basin.

Mekong Secretariat. 1986b. Tam Phuong water control project - report of theimplementation review mission - Interim Progress Report by the Secretariat of the InterimCommittee.

Mekong Secretariat. 1987. Tam Phuong water control project, Viet Nam - Stage 1.Progress Report 2 by the Interim Committee for Coordination of Investigations of theLower Mekong Basin.

NEDECO. 1991. Mekong Delta Master Plan, Working Paper No. 1, Volume 1, Main text -Surface Water Resources and Hydraulic Modelling. Govemment of Viet Nam, MekongSecretariat, State Planning Committee, United Nations Development Program (UNDP),World Bank. 180 pp.

MDWRDP, Feasibility Study UpdateAnnex I, Environmental Impact Assessment and Environmental Action Pan, August 1998 104


NEDECO. 1991. Mekong Delta Master Plan, Working Paper No. 1, Volume 2: Appendices- Surface Water Resources and Hydraulic Modelling. Govemment of Viet Nam, MekongSecretariat, State Planning Committee, United Nations Development Program (UNDP),World Bank.

NEDECO. 1991. Working paper No. 2: Groundwater resources and water supply.Prepared under Mekong Delta Master Plan. 109 pp.

NEDECO. 1991. Mekong Delta Master Plan. Working Paper No. 3 - Irrigation, Drainageand Rood Control. Govemment of Viet Nam, Mekong Secretariat, State PlanningCommittee, United Nations Development Program (UNDP), World Bank.

NEDECO. 1991. Mekong Delta Master Plan, Working Paper No. 4 - Agriculture.Govemment of Viet Nam, Mekong Secretariat, State Planning Committee, United NationsDevelopment Program (UNDP), World Bank. 91 pp.

NEDECO. 1991. Working paper No. 5: Forestry. Prepared under Mekong Delta MasterPlan. 71 pp. -

NEDECO. 1991. Mekong Delta Master Plan. Working Paper No. 6. - Fisheries &Aquaculture. Government of Viet Nam, Mekong secretariat, State Planning Committee,United Nations Development Program (UNDP), World Bank. 65 pp.

NEDECO. 1991. Mekong Delta Master Plan, Working Paper No. 7, - Transportation &Navigation. Government of Viet Nam, Mekong Secretariat, State Planning Committee,United Nations Development Program (UNDP), World Bank. 68 pp and Maps.

NEDECO. 1991. Mekong Delta Master Plan. Working Paper No. 10 - Soils. Govemmentof Viet Nam Mekong Secretariat, State Planning Committee, United Nations DevelopmentProgram (UNDP), World Bank. 41 pp.

NEDECO. 1991. Thematic study on the use of acid-sulphate and saline soils in theMekong Delta. Final Report. Prepared under Mekong Delta Master Plan. 160 pp. plusappendices.

NEDECO. 1993. Thematic-study on environmental impacts. Volume 1: Main report -environmental profile. Prepared under Mekong Delta Master Plan. 143 pp.

NEDECO. 1993. Thematic study on environrmental impacts. Volume 5: Indicativeassessment of long-term impacts of agricultural intensification on water quality. Preparedunder Mekong Delta Master Plan. 42 pp.

NEDECO. 1993. Master plan for the Mekong Delta in Viet Nam. Prepared for World Bank.144 pp.

Ministry of Water Resources. 1994. Mekong Delta Master Plan: South Mang ThitIntegrated Irrigation and Drainage Project Feasibility Study. Volume 1: Main Report. 154PP.

Ministry of Water Resources. 1994. Mekong Delta Master Plan: Secondary CanalDevelopment Project Feasibility Study: 0 Mon-Xa No. Volume 2: Main Report. 100 pp.

MDWRDP, Feasibifity Study UpdateAnnex 1. Environmental Impact Assessment and Environmental Action Plan, August 1998 105

The Socialist Republic of VietnamtMARDOCPOMekong Delta Water Resources Development Project

NEDECO. 1994. South Mang Thit Integrated Irrigation and Drainage Project. Feasibilitystudy: Environmental Impact Assessment. Prepared under Mekong Delta Master Plan. 77PP.

NEDECO. No date. Review and assessment of public health in the Mekong Delta.Prepared under Mekong Delta Master Plan. 25 pp plus attached tables and appendices.

SCP Fisheries Consultants. 1996. Viet Nam coastal aquaculture sector review. FinalReport submitted to Asian Development Bank. 174 pp. plus appendices.

Scura, E, and J. Lampietti. 1996. World Bank Coastal Wetlands and Development Project(CWPDP): Review of coastal aquaculture component. 20 pp. plus appendices.

Sonntag, N.C. and P.J. McNamee. 1989. Eco-development planning for the QuanLo/Phung Hiep area of the Ca Mau Peninsula, Viet Nam. Final report by ESSAEnvironmental and Social Systems Analysts Ltd. for Mekong Secretariat. 135 pp.

Sub-institute for Water Resources Planning and Management ISIWRP). 1997. Social andenvironmental study update for the South Mang Thit Project. Ho Chi Minh City. 20 pp.plus appendices, data tables, and figures.

Sub-institute for Water Resources Planning and Management (SIWRP). 1997. Social andenvironmental study update for the 0 Mon-Xa No Project. Ho Chi Minh City. 34 pp. plusappendices, data tables, and figures.

Sub-Institute for Water Resources Planning and Management (SWRP). 1997. Social andenvironmental study update for the Quan Lo Phung Hiep Project. Ho Chi Minh City. 34pp. plus appendices, data tables, and figures.

Thu, LT. 1991. Review and Assessment of the Real Situation in Pubfic Health and SocialWelfare at the Quan Lo/Phung Hiep area, Mekong Delta, Viet Nam. Ministry of HealthInsttute of Hygiene and Public Health. 92 pp.

To, Tuong Phuc. 1991. An overview of water management of acid sulphate soils.Intemational Rice Research Instue. Unpublished paper. 20 pp.

World Bank. 1991. Environmental assessment sourcebook. Volume II: Sectoralguidelines. Technical Paper No. 140. 282 pp.

World Bank. 1991 b. Operational Directive 4.01: Environmental Assessment. 22 pp. plusAnnexes.

World Bank. 1995. Viet Nam: Environmental program and policy priorities for a socialisteconomy in transition. 328 pp.

,

MDWRDP, Fasibility Study UpdateAnnex I. Environmental Impact Assessment and Environmental Action Plan, August 1998 106


APPENDIX A: MAPS

Location of Sub-Projects.

Surface water acidity for Mekong Delta.

Existing and planned major sluices for SMT Sub-project.

Salinity intrusion map for SMT Sub-project.

Proposed water quality monitoring network for SMT Sub-project.

Base map and proposed Expansion of Surface Water Quality Monitoring Network for OM-XN Sub-Project

Base map of QLPH Sub-project.

Soils map of QLPH Sub-project

Isohaline (ppt=4) map for QLPtI- Sub-project

SINRP Proposed Surface Water Quality Monitoring Network expansion for QLPH Sub-project.

MDWRDP, Feasibility Study UpdateAnnex 1. Environmental Impact Assessment and Environmental Action Plan, August I 998

* | ~~~~~~B A N 0 O 'VI TRi VUNG NGHIEtN CIYUO MON XA NO, NAM MANG THIT, OUAN LO PHVNG HIEP

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APPENDIX B: SOILS OF THE MEKONG RVER DELTA: DESCRIPTION ANDGUIDEUNES FOR USE

Soil Classification System

The soil classification presented below is based upon a three-level definition system:

Sog Groups: All soils that share similar processes of formation and development aregrouped into a similar soil group. For example:

- saline soils: soils subject to salinisation processes (e.g. salinity intrusion);

acid-sulphate soils (ASS's): ASS's share similar processes of accumulation forpyritic materials though the intensity of pyrite accumulation and sulfidic contentsmay differ from unit to unit. In addition, secondary processes such as salinityintrusion can affect them.

Soil sub-groups: These are classfied based on differences in forms of materialaccumulation during their formation. For example:

- potentialASS: ASS's that have only pyritic materials in their soil profile;

- actualASS: ASS's with appearance of oxidised jarosite layers.

Soil units: Soil units are classified based on diagnostic criteria observed during fieldsurveys. For example:

- based on status and intensity of salinity intrusion, saline soils (SS) can be dividedinto: Saline soils under mangrove, strong SS's, moderate SS's etc.

- sbased on depth of appearance of the diagnostic horizon(s) and scope of salinityintrusion, ASS's can be divided into: salino-ASS's, shallow ASS's, active ASS'setc.

Main Soil Groups in the QLPH Area

1. Sandy Soil (C,):

These are located on coastal sandy ridges in Bac Ueu, Vinh Loi, Vi Thanh. These soils areformed on fossil ridges of sands they forming crescents along the coastal fringe. Thesoils' properties and orientation for land use are characterised by sandy texture (sand(0.02-2 mm) comprising up to 60-70%). The soil solution is neutral, is rather poor inorganic matter, toal nitrogen, phosphorus and potassium.

2. SOlW eSos (M,, M,, M, MA:

Saline soils have a rather wide distribution in the QLPH region. However, they are mostlyconcentrated along the coastal areas bounded to the west by the National Highway.Saline soils are formed on riverine and marine sediments, tidally influenced deposits, andtidal muds.

MDWRDP, Feasibility Study UpdateAnnex I, Environmental Impact Assmesm and Environrmental Action Pan, August 1998 App.B.1

The Socialist Republic of Vietnam1MARD/CPOMekong Delta Water Resources Development Project

In the QLPH region, two salinisation processes are observed:

(i) permanent salinity intrusion occurs quite close to the coastal zones. Soils aresubject to by direct and frequent impacts of tidal movement

(ii) soils with seasonal salinisation are influenced by salinity intrusion during the dryseason when seawater penetrates inland.

In the QLPH region,: re-salinisation can occur quite often due to shifting from rice croppingand/or from forest cuttings to shrimp farming and due to canalisation efforts.

Four saline soils are distinguished:

saline soiis under mangroves. These soils are formed mostly on tidal muddy deposits;located closely to the coastal zones and frequently inundated by tides. These soils are stillunder deposit'on by the sea; the vegetational cover is mainly of salt-tolerant species witheffects on land consolidation, such as: Mam (Avicennia spp.), Duoc (Rhizophora spp.),Vet (Bruguiera spp.) etc. The soils have AC-type profile, are quite young and immature,and swampy-conditions are often observed. They show neutral reaction (pH 6-7), andhigh salinity (C1-: 0.7%, EC: 12-14 ms/cm). OM and N contents are rather high,potassium is especially rich. It is advisable to reforest and protect existing mangroves inthese soils; small areas can be shifted to shrimp and fish farming.

strong SS's (V4. Formed on mixed riverine-marine deposits and located along the coastalareas but more inland than the SS's under mangroves. They tend to be higher in reliefand water drainage and show only minor impacts of tides. The vegetation is salt-tolerantgrasses and reeds. These soils are mature, and have undeveloped AC-type profile. Soillayers are uniform and light brown in colour. They are neutral to marginally alkaline inreaction (pH 7.0-7,9), high in salinity (EC: 1D-14, Cl: 0.6-0.7%), and relafively rich inexchangeable cations. Mg + + contents are usually higher than those of Ca + + (Mg 2 +:10-12 meq/100 g, Ca 2+: 4-6 meq/100 g). They arerather rich in OM and total Ncontents, relatively rich in potassium, and poor in phosphorus. These soils can bedeveloped with industry-scale shrimp farming, salt cropping. Some areas can be shifted tofruit growing, upland crops etc. or rainfed rice.

moderate salne soils (MI). These soils are formed on mixed nverine-marine depositslocated far inland. Most of the area has been ameliorated for rainfed rice. The relief is flatand of good drainage; it is not directly influenced by tides. The soils usually have the AC-type profile, the B-type horizon is brown and/or reddish-brown mottding is observed insome areas. The soils are rather mature with clearly blocky structure. They are neutral inreaction (pH: 6.5-6.9), moderately saline (EC: 4-6 ms/cm, Cl-: 0.25-0.35%); they arerather high in exchangeable cations (Ca+ + 5-6 meq/100 g), Mg 2+: 5-9 meq/100 gr.),relatively high in OM and total N, rich in potassium and medium in phosphorus. Thesesoils show good potential for wet rice cropping. Double cropping of rice and other uplandcrops are possible when the soils are continuously ameliorated and/or supplied with freshwater.

slight salie sois (M). Formed on riverine-marine sediments, these soils are not influencedby tides. salinisation is through capillarity. These soils have long been in use with rice asthe principal crop (1-2 crop per annum) and some other upland crops, such as:sugarcane, beans (pulses), vegetables, fruits - e.g. banana, coconut, cashews etc. Thesoil profile is of A(B)C or ABC types and the soils' development is rather mature. It isneutral in soil reaction (pH 5.5-6.5), rather low in salinity, especially in topsoils

MDWRDP, Feasibility Study UpdateAnnex 1, Environmental Impact Assessment and Environmental Action Plan, August 1998 App.B.2


(EC 1-2.5ms/cm) (CI- 0.1-0.2%1, rather high in exchangeable cations (Ca2+ 5-6meq/100 g, Mg2+ 7-9 meq/100 g). These soils are rather low in OM and total Ncontents and medium in total potassium. The soils are of heavy texture. These soils havepotential for 1-2 crops of rice as well as other highly valued crops, such as vegetables,fruits etc.

3. Acidsulphatesofls (S.,, SP2, Si,, SR):

Acid sulphate sois {ASS's) in the QLPH area are sub-divided into two sub-groups andeight soil units. ASS's develop from sediments of tidal swamps and marine swamps,sediments of tidal creeks and peat sediments (also generally derived from tidal swampsand marine swamps). Tidal swampy sediments are non-stable alluvium covered bymangrove vegetation and are subject to permanent influence of tidal regimes. Marineswampy sediments are located inland at large and concentrated scales. Theydemonstrate low relief, hence they are profoundly inundated during much of the year,facilitating the accumulation of organic clayey materials. The most typical property ofthese sediments is the presence of sulphides (the source for formation of soil acidity)under the natural anaerobic conditions created by frequent inundation of brackish water,slow rate of sedimentation and presence of mangrove vegetational cover.

Beside sediments, natural vegetation plays an importarnt role in formation anddevelopment of ASS's. Discovery of fossil wood in Hong Dan, Thoi Binh districtsdemonstrate the presence of widespread ancient forests. The presence of largemangroves in coastal areas in Gia Rai, Vinh Loi etc. creates favourable conditions forformation and development of potential acid sulphate soils. However, characteristics ofASS's will be quite different from each other when they are derived from dffferentvegetation despite arising in the same sediments.

ASS's in the QLPH show two types of sulfidic layers:

(i) a pyritic layer with accumulation of acidic-potentially materials under the anaerobicconditions from permanent inundation, the contents of S03 are over t.75% (equiv.0.75% S). pH is rather high when the soils are wet, however when it becomes dryor is oxidised with H202, pHs rapidly decrease. All ASS's that have only pyriticlayers in their profiles are classified in the sub-group of POTENTiAL ACIDSULPHATE SOILS.

(ii) a jarositic layer with a B horizon occurring during the development of ASS's whenthe pyritic layer is exposed to aerobic conditions. Jarosite will occur as straw-likeyellow motting. Soil pH is less than 3.5. This jarositic layer (the Bi horizon) is theindicator horizon for actual ASS's. All ASS's that have a jarositic layer in theirprofiles are classified in the sub-group of POTENTIAL ACID SULPHATE SOILS.

Based on the depth of appearance of PYRMC and JAROSMC layers, sub-groups ofASS's are more detailed sub-classified. In this study, two levels of the Cp and B, horizonsare defined:

i) C, and B, are 'shallow" when they are between 0-50 cm deep.(ii) CP and BX are "profound" when they exceed 50 cm in depth.

Eight ASS units are identified in this report:

MOWRDP, Feasibility Study UpdateAnnex I, Environmental Impact Assessment and Environmental Acion Plan, August 1998 App.B.3

The Socialist Republic of VietnamJMARDlCPOMekong Delta Water Resources Development Project

Shallow potental ASS's under mangroves (S,g Mm) Formned on'tidal swampy or tidalcreek sediments under mangrove vegetation. These soils are concentrated in coastalzones in Gia Rai, Vinh Loi. They are in flat, low relief zones, subject to frequent tidalinundation and alluvial sedimentation. The soil profile is of AC,, immature, mixed withmany semi-decomposed OM, and permanently saturated with water. The pyritic layer (C)is very shallow: around 3D-50 cm deep from the soil surface. The soils are less acid underpermanently wet conditions. When drying, then wetting occurs (i.e. they are oxidised) pHdrops substantially. Toxicity levels in soil solution are rather high, including: SO42-, Ct, Alland Fe3 . They are relatively rich in exchangeable cations, with Mg2+ generally higherthan Ca2 '. OM contents are very high, esp. in the Cp horizon under semi-ecomposedforms. Total N is high rich, soils are moderate in P, rather rich in K, and rather heavy insoil texture. For land use, these soils preferably should be planted to mangroves. Umitedareas can be developed for shrimp farming. In any case, these soils should avoid anyaerobic conditions and soil disturbances. If not, pyritic materials will be exposed foroxidation.

Profound potential ASS's under mangroves (SM Mml,. These soils are similar to those ofshallow potential acid sulphate soils in terms of properties and formation. The most basicdifference is a more profound appearance of the pyritic layer: the Cp horizon usually.occurs at 60-120 cm deep. Land use options for these soils are broader that shallowpotential ASS's. Generally, they should be confined to afforestation and forest protectionor limited shrimp farming.

Saline shagow potential ASS's (S,1M). Formed on tidal creek sediments, located furfterinland in large concentrations in Hong Dan, Thoi Binh, Thanh Tr etc. in low relief (areaswith he most profound and prolonged inundation during the year). The pyritic layer isdeveloped and maintained under anaerobic conditions. Fossil mangrove vegetation playeda role in formation of acidity is the mangrove; the present vegetational indicator on theselands are Eleochans spp. and MeJaeAc leucodendra. The soil profile is AC,-type. Cp isshallow, occurring within the first 20-50 cm from the surface. The soils are less mature,rich in organic debris and frequently in reduced conditions. The soils are acidic in reaction,esp. in the pyritic horizon. Differences in wet and dry pH are quite distinct. Toxicity levelsare high, esp. SO;2-, Al3+, Fe3+. Salinity is lower than other soils. Exchangeable cationsare also low and Mg2+ is no longer higher than that of Ca2 +. They are rather rich in OMcontents; N, P and K are also low. Soil textures are very heavy. For the most part, thesesoils are now uncultivated or newly cleared for development. Idealy, they should bereserved for plantings of Melaleuca or other acidity-tolerant crops, such as pineapple.Avoiding oxidising the pyritic layer, and preventing loss of a covering water layer is ofprime importance in managing these soils. When making raised beds, pyritic soils shouldnot be taken up to the soil surface.

Saline profound potential ASS's (Sp2M). These soils are similar to saline shallow potentialASS's in terms of properties and formation. Both are intermingled in the ASS's regions inthe north and north-west of the QLPH region. A basic difference between tem is that inthis type, the pyritic layer Ithe C, horizon) is found deeper: usually. 60-120 cm. Risks fordamage to crops and water bodies are less in this soil type. Besides possibilities forgrowing Melaleuca, Eucalyptus, pineapple etc., these soils can be used for rice farring(especially during the rainy season).

Saline shagow actual ASS's (S,,M). These soils are derived from marine swarnpysediments, located far inland in large areas north and north-west of Thanh Tn, Hong Dan,Thoi Binh, Ca Mau Town etc. in low relief with deep and prolonged inundation. Again,

MDWRDP, Feasibility Study UpdateAnnex I. Environmental Impact Assessment and Environmental Action Plan, August 1998 App.B.4


fossil mangroves played a role in their forrnation with traces at 60-70 cm depth. Thepresent vegetational indicators on these lands are Eleocharis spp. and Melaleucaleucodendra. Due to natural drainage as well as canalisation and Melaleuca deforestation,the pyritic layer becomes oxidised and acidified, A typical profile is of AB1C,. In someareas the C, is completely oxidised forming the types ABiB or ABTBC which can be onlymapped on the soil maps of larger scales. The soils are less acidic in topsoil but quiteacidic at the jarositic layer where toxics are rather high, (especially SO4

2 and A 1 . Totalexchangeable cations are rather low in comparison to other soils in the QIPH region.These soils are rather rich in OM and total N, but are poor in P and K. Soil texture ismostly clayey. Due to a shallow B horizon and a high toxicity, the most part of these soilsis uncultivated and Eleocharis spp. is dominant. Umited areas are cultivated to rice, butyields are poor. It is proposed to reserve these soils for Melaleuca.

Sarme profound acal ASS's (S"M). These soils have similarities in fomnation, propertiesand distribution with those of saline shallow actual ASS's; large concentraons arerecorded in Hong Dan and Thanh Tri. The BA usually occurs at 60-120 cm depth. Due to adistribution on higher relief and a more mature development, profile types are also morecomplicated. Because of a more profound pyritic layer, the surface toxicity is ratherlimited. Much of this area is developed for 1-2 rice crops; some is planted with pineapple,sugarcane, cashew etc. It is advisable to control oxidation of the pyritic layer and to avoidtransport of pyritic and jarositc materials to the surface. With availability of fresh water,the agricultural potential of these soils is good: 2-3 crops may be feasible.

Actual ASS's (S,l). Formed on marine swampy sediments, located far inland, and notsubject to salinity impacts. Therefore, they are found only North of Thanh Tri district withsmall areas in low relief and depressions. The soil profile is ABEC., or AB,C. The Si horizonis quite shallow: 20-50 cm from the surface. The soils are very acidic, even at the topsoil.Toxicities are very high, esp. S042' and AJl; Cl is low. Exchangeable cations are thelowest compared to other soils. They are rather rich in OM and total N, poor in P and K,and highly clayey in texture. These soils are mostly uncultvated. Melaleuca, Eucalyptsor pineapple are preferred for development, if necessary.

Profound actual ASS's (SR). Similar in formation to the shallow actual acid sulphate soils,these are concentrated north-east of Thanh Tri district. ABqCp or AqC is the typical profile.The jarositic layer is at 60-110 cm deep; hence, low acidity and toxicity in topsoil. Thesesoils can be planted with rice during rainy months; with available fresh water, 2-3 *ropsof rice with rather high yields can be realised.

4. Peary soils (T.):

Peaty soils in the QLPH region are very limited in area. Generally, they are the reducedspotty remnants of the larger U Minh dome located in areas of low and submerged relief.Therefore, these soils are not typical and not usually exploited.

The peat layer is quite thin (20-50 cm) and low in OM percentage. Pyritic clayey layersare found underneath the peaty materials; this report terms them as acidic paty soils. Assoon as the peaty layer is lost, the pyritic materials will be strongly acidified, causingacidification hazard to adjacent areas. Therefore, peat should not be exploited. Instead,their natural vegetation cover should be preserved, or Melaleuca afforestation used torehabilitate its former status.

MDWRDP. Feasibiiy Study UpdateAnnex I, Environmental Impact Assessment and Envronmental Action Plan, August 1998 App.B.5


APPENDIX C: SURFACE WATER QUALUY IN QUAN Lo PHUNG HIEP

/ntroduction

Various reports of the Sub-Institute for Water resources Planning (SIWRP) and theMekong Delta Master Plan Project refer to the U Minh (Thoi Binh) area in the CaMau Peninsula as always having suffered from prolonged periods (up to six month)of high acidity (pH < 5.5) due to the presence of large areas of acid sulphatesoils.

Environmental concems in connection to the development of acid sulphate soilsare related to many aspects like the use of surface water for domestic watersupply, for agriculture, fisheries and aquaculture.

Release of acid water into canals can be caused by subsurface drainage from theland after reaching field capacity, by acids leached from excavated spoil materialat the beginning of the rainy season, or by the combination of both effects.

The limited data availability (and its accessibility) on past and ongoingdevelopment and potential environmental impacts in the QLPH area has often leadto fragmented analysis. First of all, it takes considerable effort to obtain allrelevant data and subsequently to analyse the data set systematically in order toget the full picture of what is happening in the area, and to arrive at a judgementto what extent development of the area is causing environmental deterioration.The TA team for the preparation of the MDWRDP for the first time was able toobtain the data and to make an analysis.

Data

In March 1998 the following data was received from the SIWRP, from theprovinces and from the Meteorological Dept.:

(i). the complete database on water quality 1992-97 at 12 stations in QLPH(monthly values of many parameters);

lii). various hydraulic modelling simulation results for the Ca Mau Peninsula;(iii). canal excavation work, by sub-areas, undertaken between 1988 to 1997

(see figure);(iv). daily rainfall 1992 to 1997 at three stations (Ca Mau, Bac Lieu and Soc

Trang).

Suwface water quality monitorng network

The water quality monitoring program for the Mekong Delta is described in section5.2.1 of the main text of this EIA-EAP report.

MDWRDP, Feasibility Study UpdateAnnex 1, Environmental Impact Assessment and Environmentd Action Plan, August 1998 App.C.1

The Socialist Republic of Vietnam/MARD/CP0Mekong Delta Water Resources Development Project

The programme maintains 14 monitoring stations in the Ca Mau Peninsula (see map,Appendix A), of which 12 stations were used in the water quality analysis. The other twostations showed major data gaps. The stations are well distributed over the whole QuanLo Phung Hiep area':

Phase i and , exckudni sh wns Phas U, inucing the shrn, araCM1 CM5CM2 CM6CM3 CM7CM4 CM8CM12 CM9CM13 CM14

Analysis

Canal excavation

In total 1,045 km canals (170 km primary and 875 km secondary) were excavatedin the QLPH area during the period 1988 to 1997. 60 % of this excavation tookplace during the last four years:D 1994:105 km;* 1995: 1 10 km;* 1996: 200 km;* 1997: 200 km.

Canal excavation took place for about 25 % in non-pyritic soils, for about 40 % inpotential ASS and for about 35% in active ASS. From year to year there have notbeen major deviations in this pattem Isee figure at the end of this appendix).

Data on tertiary canal development, and on earthwork required for shrimp pondconstruction (covering about 30,000 ha land area) in the severe acid soil areas inthe southern part of the phase If area could not be obtained.

A deterioration of water quality, both in terms of acidity and toxicity levels, whichcould be expected as a result of the considerable amount of canal excavation,through leaching by rainwater of acids formed in the dry season in spoil materialon canal banks, as well as by reclamation of fallow ASS areas, could not bedemonstrated from the data analysis. This is shown in the figures at the end ofthis appendix34. The figures show the cumulative frequency distributions of pH andof Aluminium concentration per year for the indicated water quality monitoringstations.

-" The area indications for QLPH phae 1, II and IlIl originate from the QLPH project's originalimplementation schedule.

- pH data is available for 6 years (1992-1997), Al data is available for 5 years (1993-1997);monthly sampling at high and low tide. Cumulative frequency distributions were made for eachyear, for purpose of clarity in presentation, distributions are shown for 1 993, 1995 and 1997.The other years show distribution patterns in line with the observed trend. E.g. in the southempart of CLPH, phase lIl including the shrimp area, in 1993 20.5% of all samples taken in thatarea showed pH below 4.5. in 1995 this is 15.5% and this decreased to 10.5% in 1997.

MDWRDP, Feasibility Study UpdateAnnex I, Environmental Impact Assessment and Environmental Action Plan, August 1998 App.C.2


On the contrary, in recent years water quality is improving gradually, especially in1996 and 1997 (when some 40% of canal excavation work took place of the totalexcavation work considered in the ten year period). The affected area alsobecomes smaller. The contribution of the acids from excavated spoil soil toincreased acidity levels in canals is, at least in this area, offset by the improvedflushing capacity through the area.

It is to be noted-that no special construction methods that would mitigate therelease of acids from the spoil areas were applied for the disposal of the excavatedsoil.

Flushing and improved drainage conditions

Total water inflow from the Bassac increased (in October) from 284 m31 in 1991to 345 m3/s in 1997, an increase of 59 m3/s. Total outflow to the South ChinaSea and the Gulf of Thailand increased from 521 m3/s in 1991 to 614 m31s, anincrease of 93 m31s. (see Table 29 in the main text of this EIA-EAP report).

The improved flushing and drainage is caused by:

Wi. the almost full completion, as part of the original Quan Lo Phung Hiep Projectconcept, of construction of the so-called KH system (new and improved mainand primary canals in the West-Bassac region) to convey more water fromthe Bassac River towards the Ca Mau Peninsula;

'ii). completion of construction and operation of the sluices along the southemboundary of QUPH for drainage in the rainy season (apart from saline waterintrusion prevention in the dry season); Under influence of the tide of theSouth China Sea, the sluices open automatically when the water leveloutside falls below the water level inside the Quan Lo Phung Hiep area. Thegates close automatically when at rising tide the water level outside of thearea becomes higher than inside. It is especially the prevention of largevolumes to flow back into the area that improves the drainage conditions;

(iii). the increased canal density in QLPH.

Rainfall

At the onset of the rainy season and after some 200 to 300 mm of cumulativerainfall, which is sometimes reached in April and always reached in May, theacidity of surface water in the area of concern rapidly increases from neutral tolevels between pH 4 to 3. This occurs either in the same month or in the followingmonth. Monthly water sampling for water quality analysis does not allow a moreprecise analysis on the timing of occurrence in relation to rainfall for which dailyrecordings are available.

MDWRDP, Feasibility Study UpdateAnnex I. Environmental Impact Assesment and Environment Acton Plan, August 1998 App.C.3

The Socialist Republic of VietnamtMARD/CPOMekong Delta Water Resources Development Project

Effect of saline water on surface water ascdity

Till present, saline water still intrudes (but gradually less far into the area since thetime that construction of the sluices started) from the Ca Mau side into the areaand its alkalinity causes a delay in the surface water to turn acid; this delayingeffect is probably marginal.

Earlier reporting by SIWRP and the MDMP suggests that in the past the situationwas even worse. This supports also the probably marginal delaying effect ofalkalinity of the intruding saline water on acidity because prior to the constructionof the sluices a much larger area was affected by saline water intrusion. It isestimated that, in this particular area, saline water intrusion causes a delay in thestart of occurrence of severe acidity in surface water of. at maximum some two tothree weeks.

Conclusionr

In the Quan Lo Phung Hiep area, a trend can be observed that the increasedflushing of the canal network combined with the improved drainage conditionsthrough the operation of sluice gates, negate the effects of excavation in acidsulphate soils and the reclamation of these soils for agriculture or aquaculture.Although extensive development took place, surface water quality tends toimprove gradually.

Saline water intrusion only plays a very limited role in delaying the beginning ofsevere acidic surface water conditions.

MDWRDP, Feasibility Study UpdateAnnex 1, Environmental Impact Assessment and Environmental Action Plan, August 1998 App.C.4

The Socialist Republic of Vletnam/MARD/CPOMekong Delta Water Resources Development Project

Quan Lo Phung Hiep, Main and Secondary Canal excavatlon works 11988 - 1998)

200 - r

IMain Canals: 1S9.3 ktm |__ 1_~i_ 175 Secondary Canals: 876.3 km _______ |

Total length: 1,045. k m | 150

I 126r

3100

~75

25

1988 1989 1990 1991 1992 1993 1994 1995 1996 1997 1998Year (proposed)

ONon-Pyritle Soils OPotential Acid Sulphate Soils WActive Acid Sulphate Soils

MDWRDP. Feasibility Study UpdateAnnex I, Environmental Impact Assessment and Environmental Action Plan, August 1998 App.C.5

The Socialist Republic of VietnemlMAFRD/CPOMekong Delts Water Resources Development Project

Quan Lo Phung Hiep, Cumulative pH Distribution Pattern12 stations

100% -- *--

sw~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~r4 '9XWXX-/-

00

+1993 1_996 199_

MDWRDP, Feasibility Study UpdateAnnex 1, Envffonmantal Impact Assessment and Environmental Action Plan, August 1998 App.C.8

The Socialist Republic of Vietnam/MARD/CPOMekong Delta Water Resources Development Prolect

Quan Lo Phung Hiep, Cumulative pH Distribution Patternphase I & It. excluding shrimp area's In phase It I stations: CMI, 2. 3. 4, 12, 13

100% ___

.3~~~~~~~~~~~~~~~~~~~~~~~~~~~

80% _ _ _ __ _ _ _

40% ___

20%

0%~~~~~~~~~~0

3 3.5 4 4.5 6 s.5 8 6.5 7 7.58

pt(

L41993 .--. 6 1995 1997



Quan Lo Phung Hliep, Cumulative Aluminium Distribution Patternphase I & II, excluding shrimp area's In phase 11i stations: CM1, 2. 3. 4. 12, 13

100% __ _ _ ___ _ _ _

j 80% . _ _ _ _ _ _

160%

140% _ _ _ _

20% -os -I _ __'_

0 0.05 0.1 0.16 0.2 0.26 0.3 0.35 0.4 0.45 0.5Aluminium Concentrations (ppml_1 993 ¢ _~-.01 995 1 997

MDWRDP, Feasibility Study UpdateAnnex 1, Environmental Impact Assessment and Environmental Action Plan, August 1998

The Socialist Republic of Vietnam/MARD/CPOMekong Delta Weter Resources Development Project

Quan Lo Phung Hiep, Cumulative pH Distribution Patternphase ll, Including shrimp area's In phase 11 stations: CM5, 6, 7, 8, 9. 14

100 __ _ ...

I 0

.3

20

I3 3.6 4 4.5 5 5.8 6 6. 7 7.

pH+ 1993 -,-1995 + 1997


The Socialist Republic of Vietnem/MARD/CPCIMekong Delta Water Resources Development Project

Quan Lo Phung Hiep, Cumulative Aluminium Distribution Patternphase Ill, Including shrimp area's In phase 11I stations: CM5. 6. 7. 8, 9. 14

100 -.

I _ _ _ _ __ _ _ . _

20

20 ............................. 1 - - =

0 0.05 0.1 0.15 0.2 0.25 0.3 0.35 0.4 0.45 0.5Aluminium Concentrations (ppml

+ 1993 * --- 1995 - 1997

MDWRDP, Feasibility Study UpdateAnnex 1, Environmental Impact Assessment and Environmental Action Plan, August 1998 App.C. 10


APPENDIX D: IMPACT ASSESSMENT METHODOLOGY

The major assessment summary in this section will be a cross impact matrix, with theproject activities as rows, and the major environmental resources as the columns. Thismatrix will be completed for each of the major seasons of the year dry and wet. Anexample matrix is provided below.

Each entry in the matrix represents a potential environmental issue. One of six possibleassessments is possible for any one issue; the basis for assessment will be defined interms of the time scale of effect, the spatial scale over which the effect may occur, andthe magnitude of the effecz'i:

PosIve - the effect of the given project activity will be to improve the condition andintegrity of the environrmental resource. For example, the provision of groundwater welswill improve the quality of drinking water in the project areas

No Impact - there is no impact of the given project activity on the environmentalresources. This assessment would be made if the project activity is to be spatially ortemporally removed from the environmental resource

insignficant - There is an impact of the given project activity on the environmentalresource, but it is assessed to be too negligible to require intervention in the form of eithermitigation or monitoring. This type of impact would occur under at least one of threefollowing conditions: the time scale of the impact is shorter than the life span or timescale of the environmental resource; the area which the impact may occur is smaller thanthe area over which the environmental resource occurs; or the magnitude of the impact issmall relative to the abundance or quality of the environmental resource.

Signifcant and Unmigabe huact - There is an impact of te given project actvity tnthe environmental resource, it is assessed to be sufficiently large that mitigationintervention is desirable, but there are no mitigation measures available or thereeffectiveness is uncertain. Monitoring would almost certainly be required and monitoringactivities would need to be specified and costed. This type of assessment would occurunder the following conditions:

* any one of:- the time scale of the impact is equal to or longer than the life span or time scale of

the resource of concem- the area over which the impact may occur is equal to or larger than the area over

which the resource of concern occurs- the magnitude of the impact is equal to or larger relative to the abundance or quality

of the resource of concem- the resource of concem has international or global significance, (e.g. an endangered

species or intemational waterway)

* and any one of the following:- there are no known mitgation measures- it is uncertain whether the significant impact can be effectively mitigated

35 It is important to note that the assessmenrit of impacts will be conservative

MDWRDP, Feasibility Study UpdateAnnex I, Environmental Impact Assessment and Environmental Action Plan, August 1998 App.D.1


Significant and Mitigable impact -The impact is Significant, as described above, but it canbe effectively mitigated. Again, monitoring would be required and monitoring activitieswould need to be specified and costed. These impacts would form a major part of theEnvironmental Management Plan for the Project.

Unknown knpact - This would occur under one of the following cases: the presence ofthe project actvity is uncertain; the occurrence of the resource within the Sub-projectarea is uncertain; the time scale of the impact is unknown; the spatial scale over whichthe impact may occur is unknown; or the magnitude of the impact can not be predicted.Monitoring might be required; if it is it will be specified and costed.

After presenting the matrix, the detailed rationale for the issues will be presented in textformat, supplemented by figures, charts, tables, and maps. Where possible, the rationalefor the assessment will be quantitative. We will use the following information sources:data and information from the project site itself; data and information from similar sitesand locations in the Mekong Delta; and interviews with technical specialists.

MDWRDP, Feasibility Study UpdateAnnex I. Environmental Impact Assessment and Environmenta Action Pian, August 1998 App.D.2

environmental impact assessment and environmental … · 8.1.2.1 project impacts on terrestrial...

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