evaluation of the middle rio grande conservancy district ... · 23.12.2002 · prohibits storage...
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1877 Broadway, Suite 703, Boulder, Colorado 80302-5245 • (303) 939-8880
Evaluation of the Middle Rio Grande Conservancy District Irrigation System and Measurement Program Volume I Main Text
S.S. PAPADOPULOS & ASSOCIATES, INC. Boulder, Colorado
December 2002
1877 Broadway, Suite 703, Boulder, Colorado 80302-5245 • (303) 939-8880
Evaluation of the Middle Rio Grande Conservancy District Irrigation System and Measurement Program Volume I Main Text Prepared for: New Mexico Interstate Stream Commission Prepared by:
S.S. PAPADOPULOS & ASSOCIATES, INC. Boulder, Colorado
December 2002
NEW MEXICO INTERSTATE STREAM COMMISSION COMMISSION MEMBERS BATAAN MEMORIAL BUILDING, ROOM 101 STATE CAPITOL RICHARD P. CHENEY, Chairman, Farmington POST OFFICE BOX 25102 HOYT PATTISON, Vice-Chairman, Clovis SANTA FE, NEW MEXICO 87504-5102 THOMAS C. TURNEY, PE., Secretary, Santa Fe PALEMON A. MARTINEZ, Valdez (505)827-6160 JOHN S. BULSTERBAUM, Deming FAX:(505)827-6188 PHILIP R. GRANT, Albuquerque HAROLD HOUGHTALING, Jr., Lake Arthur NARENDRA N. GUNAJI, Las Cruces PHIL H. BIDEGAIN, Tucumcari
December 23, 2002 Dear Interested Party: This letter is intended as a preface to this report prepared for the Interstate Stream Commission by its expert contractor. The report summarizes the most comprehensive study of the Middle Rio Grande Conservancy District (MRGCD) since the 1950s, when studies conducted by the U.S. Bureau of Reclamation led to the rehabilitation of the MRGCD as part of the Middle Rio Grande Project authorized by the U.S. Congress in the Flood Control Acts of 1948 and 1950. The main purpose of this report is to determine how the efficiency of the MRGCD can be improved. The report attempts to determine where and why inefficiencies exist in the MRGCD, what steps would be required to improve the efficiency, which is equivalent to reducing the quantity of water diverted per irrigated acre, and the locations and priorities for efficiency improvements. The New Mexico Interstate Stream Commission determined the need for this study and funded it. Its context includes accountability issues, as explained below, and the fact that as New Mexico enters what may be an extended drought cycle, available water supplies within the fully appropriated middle Rio Grande are dwindling while both human and non-human water demands are increasing. The study was performed and the attached report was prepared by Interstate Stream Commission contractor S.S. Papadopulos and Associates, Inc., of Boulder, Colorado. Dr. Ramchand Oad, Professor of Irrigation Engineering in the Department of Civil Engineering of Colorado State University, was a subcontractor and assisted in the investigation and the preparation of the report. The New Mexico Interstate Stream Commission, which is authorized by statute to investigate, develop, conserve and protect the waters of the state of New Mexico, thanks MRGCD for its cooperation in the investigations that are reported herein. The MRGCD provided a review of the final draft of the report to which the Interstate Stream Commission and its contractor responded (these comments and responses are Appendix J). MRGCD did not participate in the analyses and preparation of the report. The Interstate Stream Commission extends its appreciation and gratitude to the MRGCD for making its staff and records available to the project team during the course of this project. The MRGCD has been criticized in recent years as being very inefficient in its use of the waters of the middle Rio Grande that it is entitled to use under New Mexico water law. That criticism stems in part from the extended failure of the MRGCD to complete a Proof of Beneficial Use
Interested Party December 23, 2002 Page 2 (PBU), which is a requirement of state water law. Specifically, the MRGCD has not complied with a State Engineer directive to document, in a PBU submitted to the Office of the State Engineer, the quantity of water that it has put to beneficial use under its circa 1930 permits #620 and #1690. The MRGCD provides irrigation water to substantially less acreage than it historically has claimed the right to irrigate: 53,926 acres that predate the establishment of the MRGCD, 26,859 acres that the MRGCD claimed in its 1930 survey but were not irrigated due to high groundwater tables, and 42,482 “new” acres—new as of 1930—that it intended to develop and irrigate. MRGCD is obligated, as part of the PBU process, to document the maximum irrigation use under its permits. The quantity of water that MRGCD diverts is very large compared to the acreage that it irrigates—two or more times as much water per acre as the other irrigation and conservancy districts in New Mexico. No other irrigation district in New Mexico attempts to provide unlimited access to water to its members while having no mechanisms to measure or estimate its water deliveries to its members. It is enlightening to compare the operations of the MRGCD with that of the Elephant Butte Irrigation District (EBID) on the lower Rio Grande in southern New Mexico. EBID diverts from three river diversion dams to four major canals. The MRGCD diverts from three river diversion dams and directly from Cochiti Reservoir to six major canals. In both EBID and MRGCD, surface returns to the Rio Grande of excess diversions through “wasteways” and drain flows return significant amounts of diverted water to the river. A memorandum comparing and contrasting the river diversion accounting methods employed by EBID and the MRGCD is provided in the report in Appendix A. It concludes that EBID diverts on average about six acre-feet per acre of irrigated land while the MRGCD diverts on average between eight and 12 acre-feet per acre of irrigated land. While there are differences in the irrigation infrastructure of the two districts, the major difference between them is that EBID carefully monitors and accounts for its deliveries of water to its members. MRGCD does not. EBID’s member irrigators must order their irrigation deliveries from EBID far in advance, must be ready to take the water when it is delivered, and are limited to an annual allotment of irrigation water. MRGCD’s member irrigators have no such requirements or restrictions. It is clear that the MRGCD can be more efficient. The drought year of 2002, one of the worst hydrologic droughts on record on the middle Rio Grande, and the operations of the MRGCD in response to that drought, provided clear evidence that greater efficiencies are achievable and sustainable. A key to the efficiencies achieved by the MRGCD in 2002 was the unprecedented cooperation on water operations during the drought between the MRGCD, the Interstate Stream Commission, the Bureau of Reclamation, the US Army Corps of Engineers, the US Fish and Wildlife Service, the City of Albuquerque and the six middle Rio Grande Pueblos. Given the trends of lower water supply and increased water demand in the middle Rio Grande, continued effective cooperation is essential. The Interstate Stream Commission expects the water supply available to the MRGCD in 2003, and probably in the years that follow, to be much less than the MRGCD has experienced recently. In 2002, MRGCD used more than 180,000 acre-feet of releases of water from
Interested Party December 23, 2002 Page 3 upstream reservoirs to meet its irrigation demands. That storage is now depleted and under requirements of the Rio Grande Compact, will not be refilled for use in 2003. Article VII of the Rio Grande Compact, which went into effect on July 2, 2002 for the first time in 23 years, now prohibits storage of native Rio Grande basin waters in the MRGCD’s El Vado Reservoir. This compact storage prohibition will continue until “usable” stored water in Elephant Butte and Caballo Reservoirs—water that is legally available and obligated to meet downstream water demands in New Mexico, Texas, and Mexico—increases to more than 400,000 acre feet. As long as Article VII of the Rio Grande Compact remains in effect, the MRGCD will not be allowed to store water in El Vado Reservoir for its later irrigation uses after the snowmelt runoff season is over. [Note that this limitation historically has not applied to water storage by the United States to guarantee sufficient water supply for the six middle Rio Grande Pueblos’ prior and paramount water rights. The United States has informed the Rio Grande Compact Commission that it will do so again in 2003.] Historically, Article VII storage limitations have persisted for many years. Consequently, the MRGCD will need to redouble its efforts at improving its efficiency if it is to stretch its available water for its members’ uses. We hope that a number of the recommendations contained in this report can be implemented in a timely manner so as to help the MRGCD rise to meet this significant challenge. Finally, any discussion of the operations and efficiencies of the MRGCD must consider the complex cultural setting within which the MRGCD operates. The MRGCD incorporates numerous pre-existing acequias and serves six Pueblos. Prevalent within the social heritage associated with these Pueblos and former acequias is the philosophy that all irrigation ditches must run full all the time. This philosophy extends to claims that the District and its individual irrigators need not be accountable for either the quantities of water diverted nor the amounts of water delivered to the MRGCD’s irrigator members. That philosophy is at odds with the New Mexico Constitution, New Mexico water law, Reclamation law, and concepts of water conservation and advancement of the public welfare. In addition, the recent practice of the Pueblos has been to irrigate primarily during daylight hours and to require continuing diversions after normal irrigation demand has ceased. Since the Pueblos are at the head of most of the MRGCD’s river diversions, such practices make efficient irrigation in downstream locations more difficult. In March 2001 the State Engineer wrote to the MRGCD and to the Bureau of Reclamation (Reclamation) regarding the MRGCD’s legitimate irrigation diversion requirements (Appendix A of the report). The State Engineer stated his preliminary finding that the MRGCD should not need more than 7.2 acre-feet of diversion per acre of irrigated land per year. Amounts greater than 7.2 acre-feet of diversion per acre of irrigated land per year may be considered wasteful. The letter asked the MRGCD for any information it may have that would explain or clarify its irrigation diversion requirements. It asked Reclamation to determine the proper maximum diversion for the six middle Rio Grande Pueblos that are located within the MRGCD and are served by its facilities so that the State Engineer could take this information into account in determining the maximum allowable diversions for non-Pueblo users. Neither the MRGCD nor Reclamation has provided a written reply to the State Engineer’s letter as of the issuance of this report.
Interested Party December 23, 2002 Page 4 The steps that should be taken, based on this report, to improve water management within the MRGCD include both short-term (1-3 years) and longer-term activities. In the short-term, operational improvements that can significantly reduce the District’s river diversion demands, perhaps as early as next year, include:
• providing training to appropriate District water operations staff in the principles of irrigation scheduling and rotation;
• using that training to develop and implement consistent rotation methodologies and standard operating procedures within MRGCD divisions and between divisions;
• improving coordination between the District and the Pueblos regarding irrigation scheduling and rotation; and
• implementing selected infrastructure improvements. In addition, it is essential to definitively establish the quantity of irrigated acreage in the District and its associated consumptive use water rights. This is necessary to determine the legal limits of MRGCD’s river diversions. Longer-term activities include continued improvement of the District’s water measurement program and evaluation of the data gathered in the program; installation of automated gates and water metering instrumentation at the Isleta and San Acacia Diversions and at key control points throughout the district; and concrete lining of particular canal reaches. Longer-term steps also include establishing accountability for and limits to irrigation deliveries to irrigated land and other uses served by the MRGCD. Please direct any comments or questions regarding this report to the Interstate Stream Commission’s Albuquerque District Office at 505 764-3880. Sincerely,
/s/ Norman Gaume Norman Gaume, P.E. Director
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EXECUTIVE SUMMARY
Background and Purpose
The Middle Rio Grande Conservancy District (MRGCD) was formed in accordance with the New Mexico Conservancy Act of 1923, in response to deterioration of the irrigation systems and flooding of irrigated and other lands in the Middle Rio Grande Valley. Between 1925 and 1935, the MRGCD constructed six major diversion structures, as well as canals headings, and many miles of distribution channels, drains, river levees, and main irrigation canals. The MRGCD extends along the Rio Grande valley over a distance of approximately 150 miles, from Cochiti Dam south of Santa Fe, to the north boundary of the Bosque del Apache National Wildlife Refuge (BdA).
The MRGCD irrigation system integrates a number of pre-existing “acequias” (community irrigation districts), as well as irrigation systems for the pueblos of the Middle Rio Grande valley irrigation system. Many of the practices governing irrigation in earlier times, both by Indians and by Spanish settlers continue today. This history has led to operational and structural complexity within the district.
In recent years, considerable pressure has fallen on the MRGCD to decrease its water diversions from the Rio Grande, and to allow more water to remain in the river for other uses. This pressure has stemmed from increasing and competing water demands and interest in the preservation of habitat associated with the river, especially for endangered species. Some have asked whether it would be feasible to improve efficiency through modification of water delivery infrastructure or operations, or through improvements at the farm level, and still meet farm demands.
The New Mexico Interstate Stream Commission (NMISC) funded this comprehensive evaluation of the MRGCD irrigation system and measurement program with the goal of better understanding water delivery, water use, and irrigation efficiency in the District. Better understanding in these areas will suggest opportunities for improving irrigation efficiency within the District.
This comprehensive evaluation of conditions in the MRGCD involved the following processes:
• Characterization of the physical aspects of water supply;
• Characterization of the physical aspects of water demand;
• Analysis of the water delivery operations and infrastructure;
• Overview-level analysis of water accounting and system efficiency; and,
• Identification of potential areas for improvement.
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Water Supply, Demand, Operations and Infrastructure
The MRGCD diverts water from the Rio Grande, the Low Flow Conveyance Channel (LFCC) and drains within the Rio Grande valley. Water diverted by MRGCD originates as native flow of the Rio Grande and its tributaries, including the Rio Chama. In addition, the MRGCD has a contracted right to 20,900 acre-feet annually from the San Juan-Chama Project. MRGCD stores water in El Vado Reservoir, with a present storage capacity of about 180,000 acre-feet. New Mexico State Engineer Permits 0620 and 1690 provide for a farm delivery requirement of 3.0 acre-feet per irrigated acre annually.
The MRGCD is divided into four divisions: Cochiti, Albuquerque, Belen, and Socorro. The MRGCD’s conveyance system operates from gravity flow in mostly unlined ditches. Drains collect groundwater and farm runoff. Water in drains and tailwater from conveyance channels is eventually returned to the river through wasteways or delivered to a downstream division.
Ditchriders are responsible for the distribution of water to irrigators within their service areas. The ditchrider evaluates water delivery and water use conditions through physical monitoring and through communication with irrigators. Generally, canals and laterals are operated full to provide continuous-flow water-delivery service from March 1 through October 31. However, during years that the MRGCD experiences water shortages, water saving through measures such as farm-delivery rotation is practiced.
This study identified four water-scheduling procedures in the MRGCD service area, through observation of the actual operational procedures of the ditchriders during the 2001 irrigation season. These four procedures are:
(1) Irrigation event scheduling (2) Pre-season irrigation scheduling (3) Free-flow irrigator scheduling (4) Complete absence of scheduling
Ditchriders may employ a combination of these procedures depending primarily on the size of irrigated parcel, the irrigator density, local conditions and presence of pueblo lands. They may also change their water-scheduling procedure during drought. MRGCD ditchriders manage water demand by qualitatively assessing the relationship between water supply and demand, accepting or denying water delivery requests, and by physically locking water delivery infrastructure. MRGCD ditchriders typically use one or more of the following criteria to deny or accept a water delivery request:
(1) Number of irrigators scheduled for requested time (2) Number and/or size of turnouts open at requested time (3) An understanding of additional ditchrider service area demand (4) An intuitive sense of the water volume and head in the delivery system
Historically, the MRGCD has gaged major diversions to the irrigation conveyance system and select drain returns and mid-canal points. Beginning in 1997, the MRGCD embarked on an expanded monitoring program (using MRGCD labor and equipment and federal and state
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funding for supplies and equipment) with the goal of measuring additional diversion points within the irrigation system and measuring all outfalls and drain return flows. As of the end of irrigation year 2002, most of the major diversions from and returns to the river are gaged in the three lower divisions (Albuquerque, Belen, and Socorro). The overall adequacy and accuracy of the MRGCD metering system has improved dramatically in the past five years.
The system was designed with a capability to irrigate up to approximately 90,000 acres of land. The average irrigated acreage shown on USBR records (Crop Production and Water Utilization Data), including pueblo land, for the period 1991 to 1998 is approximately 53,400 acres. Recent efforts have been initiated by the MRGCD and others to assess and improve the accuracy of methods for quantifying irrigated acreage. However, according to the NMISC, the recent remote sensing effort (IKONOS survey) conducted by the MRGCD and NMISC was unsuccessful at defensibly determining irrigated acreage for a significant portion of the MRGCD.
The MRGCD crop demand can be estimated by multiplying the assumed acreage by the assumed district-weighted consumptive irrigation requirement (CIR). On the low end, assuming an irrigated acreage of 53,000 acres, and a CIR of 2.0 acre-feet per acre (derived from the modified Blaney-Criddle method), the crop consumptive demand is 106,000 acre feet. On the high side, assuming an irrigated acreage of 63,000 acres and a CIR of 3.0 acre-feet per acre (derived from yield-adjusted Penman method), the crop consumptive demand is 189,000 acre-feet. Most likely, the present MRGCD CIR falls within the lower half of this range. Clearly, it would be useful to narrow the range of this uncertainty.
The Net Supply reported in USBR records, equal roughly to the sum of river diversions at the four diversion dams, has averaged approximately 600,000 acre-feet per year over the 1990s decade. Of course, this figure does not represent the District’s consumptive use, as much of this water returns to the river system via drains and wasteways. And, some of this water returns to the river above downstream diversion dams and comprises part of the downstream diversions at these dams.
Total river diversions in 2001 were 492,000 acre-feet. This number reflects the total amount of water diverted from the river as reflected in MRGCD gage measurements (including water eventually returned to the river further downstream). This value is approximately 100,000 acre feet less than the average over a number of years in the 1990s and reflects recent MRGCD efforts to improve the overall system efficiency. The 2001 total river diversions are in the range typical for the 1980s. Operations in 2001 and previous years in the 1980s indicate that the MRGCD can operate with river diversions less than 500,000 acre-feet per year. Furthermore, past records indicate that considerably lower diversions have occurred in the past; and, evaluation of the system water budget suggests that it is possible to meet system demands with diversions below 400,000 acre-feet per year, given the present condition of the conveyance system and infrastructure. Further reductions should be possible with improvements in operations or infrastructure, although further improvements will likely require funding for capital improvements, enhanced maintenance and additional staffing.
Evaluation of irrigation efficiencies indicates that the Belen and Socorro divisions have the highest efficiency. A lower efficiency in the Albuquerque Division reflects urbanization impacts. The efficiency of the Cochiti Division is significantly lower, due to the provision of
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water 24 hours a day to satisfy pueblo customs. Provisional results from this study suggest that 24-hour scheduling, low acreage density and long canal reaches contribute to lower efficiencies.
Recommendations
This study recommends actions to build on MRGCD’s recent program of improvements to enhance irrigation efficiency and to support water management. Recommendations are summarized below in the areas of measurement and evaluation; and, operations and infrastructure. Finally, a list of recommended actions for the near-term period is provided, to focus immediate efforts.
Measurement and Evaluation • Construct additional gages for improved system monitoring:
o At remaining ungaged division inflow and outflow points, o At key division sub-zone inflow and outflow points, o At major tailwater inflows to drains,
• Identify channel capacity at the head and tails of all major canals and drains; • Install a network of shallow piezometers and monitor to evaluate changes in
groundwater storage contributing to drain flows; • Quantify canal seepage losses in major canals sections; a program of permanent
gage installations and seepage runs for this purpose is proposed; • Quantify river losses in key reaches throughout the District; • Develop links between the river water budget and the irrigation system water
budget for evaluation of how irrigation changes will impact the flow in the river; and,
• Definitively establish the quantity of irrigated acreage in the District and associated consumptive use.
Infrastructure and Operations
• Initiate rotational water delivery at locations in the district where it is feasible; • Create an Irrigation Advisory Service (IAS); • Enforce the creation and management of community ditches and limit the number
of new turnouts; • Identify mitigation measures to lessen effects of arroyo flooding, improve existing
crossings, and improve policy governing the construction of crossings; • Initiate concrete lining of selected canal reaches; and, • Collaborate with municipalities to encourage the use of agricultural water for
urban outdoor uses and to manage the effects of urbanization on the irrigation system.
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Near-Term Actions
• Conduct a comprehensive field measurement program over the next two irrigation seasons to include:
o Measure all ungaged inflow points to the system, including diversions from drains, to assist in the design of new flow monitoring stations;
o Conduct seepage runs along canal sections that are believed to have significant seepage losses to aid in the selection of locations for piping or channel lining;
o Conduct seepage runs along main canal sections to characterize the magnitude and variation of canal losses for water budget purposes;
o Evaluate infrastructure suitability for supporting a rotational water delivery schedule (identify channel capacity at key control points);
o Identify canal crossings that should be replaced to improve system operation;
o Update maps of lateral service areas and irrigated lands, incorporating ditchrider and field-checked observations.
• Conduct a series of workshops by agricultural experts to train MRGCD personnel in the implementation of operational improvements, particularly rotational water delivery.
• Conduct a provisional accounting analysis of 2002 irrigation season flow data; utilize 2002 and 2001 data to refine accounting assumptions.
• Building from the accounting analysis, ditchrider input gained in workshops, and field data, begin to prepare decision-support models for evaluating and optimizing operations within districts and sub-zones.
• Develop plans for installation of automated gates and metering instrumentation at the Isleta and San Acacia diversions, as well as key control points throughout the district.
In summary, it should be recognized that significant improvements have been made in the
MRGCD irrigation and measurement system in recent years. These improvements are beginning to manifest in improved efficiencies and an ability to satisfy farm demand with reduced river diversions. This study suggests areas for continued improvements to further support optimized water use in this region.
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TABLE OF CONTENTS Page EXECUTIVE SUMMARY ES-1 LIST OF FIGURES v LIST OF TABLES vi LIST OF APPENDICES vii REPORT 1.0 INTRODUCTION 1
1.1 Study Objectives 1 1.2 Study Approach and Project Team 2 1.3 Report Organization 2
2.0 BACKGROUND 4
2.1 MRGCD History 4 2.2 Sources of MRGCD Water Supply 5 2.3 Diversity of Uses 7
3.0 PHYSICAL ASPECTS OF THE WATER SUPPLY 8
3.1 Physical Configuration of District 8
3.1.1 MRGCD Organization and Water Delivery 10 3.1.2 Schematic Diagrams of Conveyance Channels 12 3.1.3 Lateral Service Areas 12 3.1.4 Ditchrider Service Areas 14
3.2 Flow Measurement Program 15
3.2.1 History of Metering Program 15 3.2.2 MRGCD’s Planned Metering Program 16 3.2.3 Condition and Adequacy of Existing Gages 20
and Metering Program
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3.3 Review of Flow Records 24
3.3.1 USBR Water Distribution Reports 24 3.3.2 MRGCD Gaging Records 26
3.3.2.1 Historical 26 3.3.2.2 Irrigation Season 2001 27
3.3.3 Water Supply at the Division Level 29
4.0 PHYSICAL ASPECTS OF WATER DEMAND 31 4.1 Crops and Cropping Patterns 32
4.1.1 USBR Crop Census Reports 32 4.1.2 NMSU Agricultural Experiment Station Reports 34 4.1.3 USBR Land Use Trend Analysis 36 4.1.4 IKONOS Satellite Imagery Vegetation Classification, 38
Summer 2000 4.1.5 Comparison of Irrigated Agriculture Acreage Estimates 38 4.1.6 Other Irrigation Uses 39
4.2 Crop Consumptive Use 40
4.2.1 Blaney-Criddle Approach (USBR Assessment) 40 4.2.2 Penman Approach (ET Toolbox) 42
4.3 Crops and On-Farm Demand 43 5.0 DESCRIPTION OF WATER DELIVERY OPERATIONS 45
5.1 Information Sources 45 5.2 Planning and Water Scheduling 45
5.2.1 Division Manager Position 45 5.2.2 Ditchrider Position 46 5.2.3 Implementation of Scheduling 48
5.2.3.1 Irrigation Event Scheduling 49 5.2.3.2 Pre-season Irrigation Scheduling 50 5.2.3.3 Free-Flow Irrigator Scheduling 51 5.2.3.4 Complete Absence of Scheduling 51 5.2.3.5 Determinant Factors for Water Scheduling 52
Procedures
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5.3 Water Delivery to Users 53
5.3.1 General Delivery Patterns 53 5.3.2 Delivery Practice 54
5.4 Management of Water Demand to Users 55 5.4.1 Matching Supply and Demand 55 5.4.2 Acceptance and Denial of Water Delivery Requests 56
6.0 WATER ACCOUNTING ANALYSIS 60
6.1 Purpose 60 6.2 Accounting Analysis Template for 2001 62 6.3 Delineation of Sub-Division Zones 63
7.0 EVALUATION OF OPERATIONS AND INFRASTRUCTURE 65
7.1 Water Delivery Patterns 65 7.1.1 Rotational Water Delivery 65 7.1.2 Water Delivery Recommendations 68
7.2 Management of Demand 69
7.2.1 General Management Procedures 69 7.2.2 Management of Demand through Rotational Water 69
Delivery 7.3 Irrigation Advisory Service for Users 71
7.3.1 Extent of On-Farm Involvement by the MRGCD 71 7.3.2 Irrigation Extension Opportunities to Promote Efficient 73
On-Farm Use 7.4 Urbanization Concerns 74
7.4.1 Increased Number of “Weekend Farmers” and 75 Free-Flow Irrigators
7.4.2 Increased Number of Farm Turnouts and Community 76 Ditches
7.4.3 Increased Maintenance and Repair Requirements 77 7.4.4 Positive Aspects of Urbanization 77
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7.5 Infrastructure Concerns 78
7.5.1 Reducing Conveyance Losses 79 7.5.2 Canal Crossings 80 7.5.3 Flooding by Arroyos 81 7.5.4 Control of Irrigation 81
8.0 FEASIBILITY AND IMPLEMENTATION OF IMPROVEMENTS 83
8.1 Rotational Water Delivery 83
8.1.1 Justification 83 8.1.2 Initial Planning 83 8.1.3 Actual Implementation 84 8.1.4 Policy Support 85 8.1.5 Infrastructure Requirements 86
8.2 Management of Demand 87 8.3 Irrigation Advisory Service 88 8.4 Urbanization 90 8.5 Infrastructure 92
9.0 CONCLUSIONS AND RECOMMENDATIONS 94
9.1 Analysis of MRGCD Irrigation System and Measurement 94 Program
9.2 Cochiti Division: Observations and Recommendations 96 9.3 Albuquerque Division: Observations and Recommendations 98 9.4 Belen Division: Observations and Recommendations 99 9.5 Socorro Division: Observations and Recommendations 100 9.6 Next Steps 102
REFERENCES 104 FIGURES TABLES APPENDICES
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LIST OF FIGURES
1.1 Location of the MRGCD
2.1 Simplified Schematic of the MRGCD System 2.2 Ditchrider Service Areas, Cochiti Division 2.3 Ditchrider Service Areas, Albuquerque Division 2.4 Ditchrider Service Areas, Belen Division 2.5 Ditchrider Service Areas, Socorro Division 3.1 Irrigation Season 2001 River Diversions 6.1 Accounting Zones, Cochiti Division 6.2 Accounting Zones, Albuquerque Division 6.3 Accounting Zones, Belen Division 6.4 Accounting Zones, Socorro Division
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LIST OF TABLES 3.1 Lateral Service Areas 3.2 Summary of Ditchrider Service Areas 3.3 Existing and Planned Gaging Stations for Monitoring Key MRGCD Irrigation System
Flows, Cochiti Division 3.4 Existing and Planned Gaging Stations for Monitoring Key MRGCD Irrigation System
Flows, Albuquerque Division 3.5 Existing and Planned Gaging Stations for Monitoring Key MRGCD Irrigation System
Flows, Belen Division 3.6 Existing and Planned Gaging Stations for Monitoring Key MRGCD Irrigation System
Flows, Socorro Division 3.7 Recommendations for Improvements to Specific Gages or Locations 3.8 Summary of MRGCD Water Distribution Data Reported to USBR 3.9 Comparison of MRGCD Reported Net Supply to Composite Diversions 3.10 2001 Monthly Discharge by Division
4.1 Summary of Historic Data Regarding Irrigated Acres within the MRGCD 4.2 MRGCD Crop Census Reports – Summary of Acreage in Crop Categories 4.3 List of Land Use Classes for Estimating Irrigated Acreage 4.4 Irrigated Areas between Cochiti and Bosque del Apache National Wildlife Refuge 4.5 Comparison of Reported Irrigated Acres
6.1 Division Characteristics 6.2 Acreage Distribution Factors by Division and Accounting Zone 6.3 General Description of Accounting Zones 6.4 Irrigation Density by Division and Accounting Zone 7.1 Advantages and Concerns Related to Rotational Water Delivery 7.2 Approximate Percentage of MRGCD Lands Devoted to Different Land Use Practices
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LIST OF APPENDICES
APPENDIX A Documents Referenced in NMISC Cover Letter
A-1 Memorandum from Spronk Water Engineers to New Mexico Interstate Stream Commission, 5/20/02
A-2 Letter from New Mexico State Engineer T. Turney to S. Shah & S. Hansen, March 23, 2001
APPENDIX B MRGCD System Diversion Structures and Conveyance Channels B-1 Profiles of El Vado Dam, Cochiti Dam, and MRGCD Irrigation
Diversion Structures B-2 Schematic Diagrams of Conveyance Channels APPENDIX C Mapped Lateral Service Areas APPENDIX D Monitoring Systems within the MRGCD
D-1 Profiles of Gages for Monitoring MRGCD Irrigation System Flows D-2 USGS Gage Specification Sheets D-3 MRGCD Virtual Gage Records on USBR ET Toolbox Webpage
APPENDIX E Sample Data and Historic Memos of Crop and Water Allocation Reports E-1 Sample Water Utilization Records from Bureau of Reclamation E-2 Sample Crop and Water Data from Recent Reports by MRGCD
and Bureau of Reclamation, by Division and District Totals E-3 Historic Memos Regarding Preparation of Allocation Reports from
Bureau of Reclamation
APPENDIX F MRGCD Discharge Records F-1 Annual Flow Record at Gages with Long-Term Record F-2 2001 Monthly Record at Select Gages F-3 2001 Daily Discharge Record APPENDIX G Crop Records
G-1 MRGCD Crop Census Reports, 1956 – 1999 (years missing 1966 - 1981)
G-2 Irrigated and Dry Cropland Acreages in New Mexico by County
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APPENDIX H MRGCD Ditchrider Profiles and System Operational Documents H-1 MRGCD Ditchrider Profiles H-2 System Operational Documents
APPENDIX I Accounting Analysis Details APPENDIX J Responses to MRGCD Comments
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1.0 INTRODUCTION
1.1. Study Objectives
The Middle Rio Grande Conservancy District (MRGCD) operates an irrigation and
drainage system in the Middle Rio Grande region of New Mexico, extending along the Rio
Grande valley over a distance of approximately 150 miles, from Cochiti Dam south of Santa Fe,
to the north boundary of the Bosque del Apache National Wildlife Refuge (BdA) (Figure 1).
In recent years, considerable pressure has fallen on the MRGCD to decrease its water
diversions from the Rio Grande and to allow more water to remain in the river for other uses.
This pressure has stemmed from increasing and competing water demands and interest in the
preservation of habitat associated with the river, especially for endangered species. Some have
asked if it would be feasible to improve efficiency through modification of water delivery
infrastructure or operations, or through improvements at the farm level, and meet farm demands
with reduced river diversions.
The New Mexico Interstate Stream Commission (ISC) funded this comprehensive
evaluation of the MRGCD irrigation system and measurement program with the goal of better
understanding water delivery, water use, and irrigation efficiency in the District. Better
understanding in these areas may suggest opportunities for improving irrigation efficiency within
the District.
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1.2. Study Approach and Project Team
This comprehensive evaluation of conditions in the MRGCD involved the following
processes:
• Research o Compilation and review of published data and reports o Compilation and review of unpublished data and reports o Field observation of diversion structures, gages, canals, drains and farms o Interviews with MRGCD staff at all levels
• Characterization of the physical aspects of water supply • Characterization of the physical aspects of water demand • Analysis of the water delivery operations and infrastructure • Overview-level analysis of water accounting and system efficiency • Identification of potential areas for improvement
This work was conducted by a project team including: S.S. Papadopulos & Associates,
Inc.; Dr. Ramchand Oad, agricultural engineer, Colorado State University; John P. Borland,
hydrologist; and, Ms. Rachel Barta, graduate student in agricultural engineering, Colorado State
University. Considerable time was spent both in the field and in the office with MRGCD
personnel to gain understanding of the District. The assistance of the MRGCD staff is gratefully
acknowledged, without their cooperation this study would not have been possible. The
conclusions of this report are those of the project team and may not represent the opinions of the
District.
1.3. Report Organization
This report is organized generally according to the process steps described above.
Section 2 contains general background information on the MRGCD. Sections 3 and 4 describe
the physical aspects of the water supply and water demand. Section 5 describes the water
delivery operations at both the district and the division level. Information at the division level
was gained through extensive field visits and interviews with MRGCD staff. Section 6 describes
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in general terms the results of a quantitative analysis of water accounting and efficiency within
the District. Section 7 evaluates operations and infrastructure, including water delivery patterns,
management of demand and irrigation assistance. Section 8 provides a detailed discussion of
potential areas for improvement to MRGCD operations. Section 9 provides conclusions and
recommendations.
Comprehensive supporting material, gathered during the course of this study, is provided
in the appendices. Appendix A contains documents referenced in the report Forward. Appendix
B provides profiles of diversion structures and detailed schematic diagrams showing the primary
conveyance channels within each division of the District and gage locations. Appendix C
contains provisional maps of lateral service areas. Appendix D describes the monitoring systems
within the MRGCD and contains a profile sheet for each gage within the District, documenting
gage condition and other attributes observed during a field survey of the monitoring system.
Appendix E provides example records of historical flows. Appendix F contains discharge
records for the MRGCD gages. Appendix G contains various crop records for the District.
Appendix H contains profile sheets for most ditchrider areas, documenting conditions observed
during field visits, and system operational documents. Appendix I contains details of the water
accounting analysis. Appendix J contains responses to the MRGCD comments on the draft
report.
2.0 BACKGROUND
2.1 MRGCD History
Irrigation has been practiced for centuries in the Middle Rio Grande valley of New
Mexico. Many of the practices governing irrigation in earlier times, both by Indians and by
Spanish settlers, are continued into the present day. The MRGCD was created in the early part
of this century through conglomeration of a number of pre-existing “acequias” (community
irrigation districts), as well as irrigation systems for the pueblos of the Middle Rio Grande
valley. This history has lead to operational and structural complexity within the district.
The Middle Rio Grande Conservancy District (MRGCD) was formed in accordance with
the New Mexico Conservancy Act of 1923, as amended, as a political subdivision of the State of
New Mexico, with all the powers of a public or municipal corporation. Petitions for the
organization of the MRGCD were originally filed in the District Court of the Second Judicial
District, County of Bernalillo in 1923. The Court officially entered a successful decree of
organization in 1925 and approved the Official Plan of the MRGCD (Burkholder, 1928) in 1928.
The MRGCD was formed in response to deterioration of the irrigation systems and
flooding of irrigated and other lands in the Middle Rio Grande Valley. Between 1925 and 1935,
the MRGCD constructed six major diversion structures, as well as canals headings, and many
miles of distribution channels, drains, river levees, and main irrigation canals. El Vado Dam and
Reservoir was constructed in 1935 on the Rio Chama near Tierra Amarilla to provide
conservation storage.
In 1950, Congress authorized the Middle Rio Grande Project, to rehabilitate the MRGCD
facilities as well as to control sedimentation and flooding on the Rio Grande. The U.S. Bureau
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of Reclamation (USBR) planned and funded the rehabilitation of El Vado Dam, rehabilitation of
irrigation and drainage works, and river channel maintenance. Diversion structures originally
constructed by the MRGCD and rehabilitated by the USBR include the Isleta and San Acacia
diversion structures. The U.S. Army Corps of Engineers constructed reservoirs and levees for
flood control, and replaced the MRGCD’s original Cochiti diversion structure with a larger
flood-control dam (which the MRGCD also uses for irrigation diversions) and reservoir. From
1951 to 1977, a system of Kellner jetty-jack fields was installed along the river to protect levees
and to aid in flood control and channel stabilization. Extensive rehabilitation work was
performed on canals, laterals, drains, and acequias by the USBR between 1953 and 1961. The
MRGCD took over operation and maintenance of the system from the USBR in 1975. In 1999,
the MRGCD completed repayment of USBR Middle Rio Grande Project contract obligations.
2.2 Sources of MRGCD Water Supply
The source of irrigation water for the MRGCD is surface water. In some instances,
individual farmers use private groundwater wells as either a primary or supplemental water
supply. SSP&A personnel have observed a significant number of irrigation wells in the field,
particularly in the Socorro Division, but it appears that many of these irrigation wells are not
presently in service. The use of groundwater within the MRGCD is not quantified, and is not a
part of this study. This discussion pertains to the surface water sources that constitute the
District supply.
The MRGCD diverts water from the Rio Grande, the Low Flow Conveyance Channel
(LFCC) and drains within the Rio Grande valley. Water diverted by MRGCD originates as
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native flow of the Rio Grande and it’s tributaries, including, the Rio Chama (the major tributary
to the Rio Grande in New Mexico), and San Juan-Chama Project water (transmountain
diversion).
A portion of the water used by the MRGCD is stored in El Vado Reservoir, which was
constructed by the MRGCD in 1935 with a total storage capacity of 198,110 acre-feet, since
reduced by sedimentation to approximately 180,000 acre-feet. The MRGCD also has use of
2,000 acre-feet of storage in Abiquiu Reservoir, for San Juan-Chama Project water.
The MRGCD’s 1930 water rights applications (OSE permit application Nos. 1690 and
0620; 1930a and 1930b) to the New Mexico Office of the State Engineer (OSE) were for storage
of water in El Vado Reservoir and irrigation of 123,267 acres. The acreage referenced in permit
application No. 0620 included 80,785 acres of pre-MRGCD lands for which the points-of-
diversion were to be consolidated and which were to be served with MRGCD facilities, and
42,482 acres of lands that the MRGCD expected to recover and render irrigable through the
creation of drainage works. These acres include 22,734 acres of Pueblo land (OSE permit
application No. 1690 and 0620, 1930a and 1930b). The system was designed with a capability to
irrigate up to approximately 90,000 acres of land. The present irrigated acreage is not well
quantified. The average irrigated acreage reflected on USBR Form 7-2045, Crop Production
and Water Utilization Data, including Pueblo land, for the period 1991 to 1998 is approximately
53,400 acres (Section 4.1). The MRGCD estimates that the present irrigated acreage is closer to
73,000 acres.
El Vado Reservoir storage rights (OSE permit application No. 1690, 1930a) were
assigned to the U. S. Bureau of Reclamation (USBR) by MRGCD in 1963. The reservoir is
6
owned by the MRGCD, except for the outlet works and emergency spillway, which are owned
by USBR. It is currently operated by the USBR under an agreement with the MRGCD. The
District specifies the releases from this reservoir as needed to augment expected native flows of
the Rio Grande. Typically, the District utilizes the native flow of the Rio Grande during spring
run-off, and concurrently, attempts to fill El Vado Reservoir on the Rio Chama. When native
flow of the Rio Grande becomes insufficient for the District’s diversion needs, releases are made
from El Vado Reservoir to augment flows. “Insufficient” water is a function of the districts
water demands and required deliveries. Deliveries require a minimum head availability to
effectively irrigate lands.
Upstream of the District’s diversion structures, water ultimately used by the MRGCD
passes through the Cochiti Reservoir in “run-of the-river” fashion. Cochiti Reservoir was
authorized primarily for flood control purposes and is not available to the District for water
storage or for re-regulation of El Vado releases or flood flows.
2.3 Diversity of Uses
The MRGCD, stretching from Cochiti Dam to the northern boundary of the Bosque del
Apache National Wildlife Refuge, encompasses not only irrigated agricultural lands but also
pueblo lands, community ditch associations, independent acequias, and urban centers. The
competing demands of these different entities increases the complexity inherent in operation of
the District by imposing additional constraints on water deliveries. For example, water must be
provided 24-hours a day to satisfy pueblos needs. Such constraints must be taken into
consideration in evaluating District efficiencies.
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8
3.0 PHYSICAL ASPECTS OF THE WATER SUPPLY
3.1 Physical Configuration of District
The MRGCD is divided into four divisions: Cochiti, Albuquerque, Belen, and Socorro.
Each division is served by main canals that begin at diversion structures at the head of the
division (Figure 2.1). The MRGCD divisions obtain water from the diversion structures
described below:
• The Cochiti Division obtains water from canals with headings at Cochiti Dam • The Albuquerque Division diverts water from the Angostura Dam (diversion weir) at
Algodones • The Belen Division diverts water from the Isleta Dam (diversion weir) at Isleta • The Socorro Division diverts water from the San Acacia Dam (diversion weir) at San
Acacia and, when supplies from inter-divisional flows from the Belen Division and diversions from San Acacia are insufficient to supply the entire division, from three locations on the LFCC: the Lemitar Check Structure in Lemitar, the 1200 Check Structure in Socorro, and the Neil Cupp Check Structure between Socorro and San Antonio.
In addition to river diversions, the MRGCD obtains water through diversions from
various drains throughout the District. Inter-divisional flows, consisting of tail-water returns or
drainflows, occur in some locations where drains from one division feed directly into canals of
an adjacent downstream division. These inter-divisional flows are conveyed through drains and
are eventually diverted into the subsequent downstream canal for re-use in the District. The
following drains supply the Albuquerque, Belen, and Socorro Divisions: Algodones Riverside
Drain, Barr-Chical, Isleta Drain, and Unit #7 Drain. Although these drains were originally
constructed for the purposes of draining water-logged areas and providing a control on
groundwater levels, many now constitute an important element of the divisional supply.
The MRGCD’s conveyance system operates from gravity flow in mostly unlined ditches.
Conveyance channels within the MRGCD consist of main canals, secondary canals, laterals, and
9
acequias. Water is delivered to users through diversions from main canals to secondary canals or
to laterals, and eventually to small ditches and acequias. These in turn feed water to farm
turnouts and community ditches. While most water users receive water from the laterals and
acequias, some users receive water directly from the main canal. A network of drains collects
groundwater and farm runoff. Water in drains and tailwater in the downstream portions of
conveyance channels is eventually returned to the river through wasteways or delivered to the
downstream division. In some areas, channels that may have been designed as drains now are
dry, or function as canals, due to the lowering of the water table in certain regions. Also, some
drains are used as conveyance channels in their lower reaches, since at that point they are higher
than the river.
Several other water users rely on MRGCD diversion and conveyance facilities, including
the La Joya Acequia Association, four New Mexico Department of Game and Fish refuges (the
Belen Waterfowl, Casa Colorado, Bernardo and La Joya Waterfowl Areas), the U.S. Fish and
Wildlife Service (USFWS) Sevilleta National Wildlife Refuge (Sevilleta), and the USFWS
Bosque del Apache National Wildlife Refuge (BdA). BdA, the largest of these water users, is
located just downstream of the MRGCD and diverts water both from MRGCD canals carrying
water diverted at San Acacia, as well as from the LFCC and other drains collecting return flow
from the MRGCD. In addition, many community or private ditches receive water from the
MRGCD conveyance system; however, MRGCD does not maintain or operate these community
ditches. These ditches are either descendents of historic acequia associations that predate the
MRGCD, or are the result of subdivided farmland. They service small-scale agriculture, and are
most common in the Albuquerque and Belen Divisions.
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The conveyance system in the MRGCD is primarily of earthen construction. Concrete
lined canals exist in few areas where bank stabilization and water seepage problems are
prevalent. Although pipe networks are not extensive in the MRGCD, some small sections of the
conveyance system are siphoned below roadways, arroyos, other conveyance channels, and the
river.
After water is conveyed through canals and laterals, it is delivered to the farm through a
turnout structure, often with a check structure in the lateral canal. Each irrigator in the MRGCD
either owns one or (if the size or configuration of the irrigated parcel warrants it) more
turnout(s), or shares a turnout with one or more neighboring properties. Most MRGCD turnouts
are steel screw and handle infrastructure, although some wooden turnouts still exist. Check
structures are used to decrease flow velocity and increase head in the lateral canal so that water
can be diverted at upstream turnout head gates. For many irrigators, water delivery is not
possible unless downstream check structures are closed. The physical condition of conveyance
channels in specific areas is discussed more fully in Section 5.
3.1.1 MRGCD Organization and Water Delivery
Organizationally, the MRGCD delivers water to users through services and administration
provided at a Central Office and four Division Offices. The MRGCD Central Office in
Albuquerque provides many central services, including the management of service charges to
irrigators in the District. The four field Division Offices manage the physical delivery of water.
Each Division Office includes administrative, field maintenance, and water operation services.
Administrative services in each division include a Division Manager and clerical operator. Field
maintenance services vary within each division but generally consist of labor foremen, field
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supervisors, mower operators, various equipment operators, and general laborers. While
administrative and field maintenance operations are important components of the MRGCD
service, emphasis in this study was placed on the water operation services provided by
ditchriders. Ditchriders are responsible for the distribution of water to irrigators within their
service areas. The ditchrider evaluates water delivery and water use conditions through physical
monitoring, or “riding”, the ditches, canals, drains, and wasteways within their designated
service area and through communication with irrigators. The ditchrider controls check structures
and head gates, using local knowledge of the distribution system and the irrigator’s needs to
deliver available water within the service area.
Ditchriders control water delivery manually and do not meter individual farm turnouts
(although they do estimate water delivery based on time required for irrigation). Generally, to
provide continuous-flow water-delivery service throughout the irrigation season, the MRGCD
operates with the system’s various main canals and laterals full, from March 1 through October
31. However, during years that the MRGCD experiences water shortages, water saving
measures such as farm-delivery rotation are practiced. Flow measurement is used for
informational purposes. Meter-based automated control of diversions is not employed, although
some trials of automatic wasteway gates are in progress.
The MRGCD also conducts other activities necessary to ensure adequate water
operations, including maintenance of the conveyance and drainage system (excluding private
community ditches). Irrigation season maintenance includes vegetation control through mowing
and some herbicide application, canal and drain dredging to remove excessive silt or debris, bank
stabilization, debris and trash removal, right–of-way upkeep, and emergency repairs. Non-
irrigation season maintenance includes turnout or check structure repair/construction, dredging,
12
concrete lining, and large-scale construction or maintenance projects, including the installation
and repair of gaging stations. Continual maintenance and repair of infrastructure in the MRGCD
is strongly emphasized both during and after the irrigation season. However, maintaining good
working condition in some channels is problematic at times. These problems vary, but include
damage by gophers and breaches from heavy storms or flooding, and vandalism. The MRGCD
is also concerned with road crossings and fence structures within their conveyance and drainage
system, which can be installed by landowners within the district. Improperly constructed
structures can obstruct flows within the district’s canals and drains.
3.1.2 Schematic Diagrams of Conveyance Channels
A generalized schematic of the diversion dams, primary canals, and return flow points to
the river is provided in Figure 2.1. More detailed schematic diagrams of conveyance channels,
drains, and wasteways, which have been developed as part of this study, are provided in
Appendix B-2. The location of MRGCD and U.S. Geological Survey (USGS) gages are
identified on these schematics. These schematics have been developed through several iterations
involving the following steps:
• Delineation of channels from available maps • Consultation with MRGCD staff • Field checks at selected locations • Review of draft schematics by MRGCD staff • Revision of provisional schematics
Continuing field verification will likely result in future revisions and improvements to the
schematics.
3.1.3 Lateral Service Areas
As a first step in understanding the routing and distribution of water within MRGCD
divisions, maps were developed of lateral service areas, the land area served by each lateral canal
13
within the district. This project was conducted in coordination with the MRGCD Geographical
Information System (GIS) staff. The project resulted in GIS shapefiles delineating areas served
by specific laterals, as well as the compilation of detailed data tables describing the parcels
served by individual laterals (note – these tables are in the custody of the MRGCD; parcel data
retained by the MRGCD has not been made public). The mapped lateral service areas are
identified in Table 3.1 and are shown, along with the metadata describing the delineation of the
lateral service areas, in Appendix C.
The lateral service areas were delineated following a set of rules, outlined in the above-
referenced metadata, that were designed to achieve a first-order approximation of the areas
served by particular laterals. The primary data sources used to delineate the service areas were
ditchrider records of irrigated lands, which include the names of the laterals serving specific
parcels. Some inference or interpretation was required for parcels not bearing the above
information in records, or for parcels for which descriptive errors were known or suspected. In
these cases, areas could logically be assigned to a lateral service area by guidelines including
continuation of irrigation patterns evidenced by other surrounding parcels or by evaluation of
land topography, canal elevations, or other features. A conservative approach was taken to this
process – where there was doubt whether a given parcel is served by a lateral, it was assumed to
be included. Therefore, the areas delineated as serving laterals may be biased high. The lateral
service areas mapped by this methodology include not only irrigated lands, but also other non-
irrigated areas, for example urbanized areas, roads or parks
Work conducted under a separate project, by MRGCD in cooperation with the ISC, has
identified a number of differences between the number of acres and crop type reported by the
ditchriders and similar information developed through aerial photography or remote-sensing
14
interpretation (Strech, D.W. and T.S. Matthews, 2001). MRGCD staff has determined that some
of these differences are attributable to inaccuracies in ditchrider reports and ditchrider-identified
lands, due particularly to the presence of several community ditches. The MRGCD has therefore
initiated a program of ditchrider interviews and field checks to begin to eliminate some of these
inaccuracies. Maps of lateral service areas and associated lands may be revised as this work
progresses.
3.1.4 Ditchrider Service Areas
In similar fashion to the delineation of lateral service areas, ditchrider service areas have
been mapped using MRGCD records of irrigated parcels assigned to ditchriders. These areas are
summarized on Table 3.2 and are mapped by division on Figures 2.2 through 2.5. Although the
mapped areas are provisional, and should be improved with field checking, they are believed to
provide a reasonable approximation of the extent and layout of the ditchrider areas.
The number of ditchriders in each division is:
Cochiti Division: 3 ditchriders (not including ditchriders on Pueblo land) Albuquerque Division: 12 ditchriders Belen Division: 10 ditchriders Socorro Division: 4 ditchriders The number of ditchriders assigned to each division is dependent on division area, as well
as the number of irrigators. Larger divisions and those with a higher irrigator density require a
greater number of ditchriders. The service area of each ditchrider is unique, in the context of
physical characteristics such as acreage and irrigator density. While some ditchriders service as
many as 300 irrigators who water mostly residential lawns, gardens, and pastures in the valley in
Albuquerque, other ditchriders serve comparatively fewer irrigators who irrigate thousands of
acres of alfalfa and pasture in Socorro and Valencia counties.
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3.2 Flow Measurement Program
Typically, within an irrigation district, water measurement of diversions, return flows,
and mid-system flows are desired for a number of reasons. These reasons may include:
• Monitoring of diversions and farm delivery for evaluation of water rights issues • Matching supply to demand • Maximizing system efficiency or otherwise improving operations • Understanding hydrologic water budgets • Assessment of fees
In the MRGCD, metering has been conducted for many years at selected locations and
recently the metering program has been significantly expanded. The following sections describe
metering in the historical period, or time prior to the recent program expansion. Following a
description of the metering locations, an evaluation of the metering program undertaken as part
of this study is described. The metering evaluation was conducted to assess the condition of
existing gages and the sufficiency of the planned gage network.
3.2.1 History of Metering Program
Historically, the MRGCD has gaged major diversions to the irrigation conveyance system
and select drain returns and mid-system conveyances. For the period of 1974 to 1995, records
generally consist of handwritten tables of estimated daily flows (supported by manual
measurements) at 13 to 15 stations. The MRGCD believes that similar records might exist, in
warehoused boxes, for the years prior to 1975. In addition, the USGS operates three gages at
MRGCD canal headings. The stations with recorded measurements between 1974 and 1995
(some with only partial records) are listed by division on Tables 3.3 through 3.6. The MRGCD
does not measure flow to individual farms or fields, and we have found no records indicating that
it ever has.
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3.2.2 MRGCD’s Planned Metering Program
Beginning in 1997, the MRGCD embarked on an expanded monitoring program with the
goal of measuring additional diversion points within the irrigation system and measuring all
outfalls and drain return flows. This program was initiated in cooperation with the USBR, using
Federal funding, and was continued in cooperation with the ISC and the OSE using State of New
Mexico funding. Additionally, the MRGCD is implementing an electronic data storage and
retrieval (telemetry) system. The implementation plan includes outfitting USGS gages to
provide consistent and real time data retrieval. Additional monitoring stations that have been
installed or are scheduled for installation are also included in Tables 3.3 through 3.6.
Recommendations for future expansion of the metering program beyond that presently proposed
are provided in Section 8.0.
The metering expansion program initiated by the MRGCD includes the installation of
additional control structures and meters, especially of flows returning to the Rio Grande. The
program calls for providing new and existing gages with radio transmission equipment to
automatically transmit the collected data to the MRGCD office. Because of the costs and time
required to complete this undertaking, the gaging stations are being installed using a phased
approach, starting with the Albuquerque Division, followed by the Belen, Socorro, and the
Cochiti Divisions, in that order. As of the end of irrigation year 2002, all of the major diversions
from and returns to the river are gaged in the three lower divisions (Albuquerque, Belen, and
Socorro). Metering of the Cochiti Division has not yet been initiated. The gaging stations
constructed in the lower three divisions are equipped with either a pressure transducer or a shaft
encoder, and transmit gage heights via a radio transmitter every 30 minutes to the main MRGCD
office in Albuquerque.
17
The gages that were installed and operational as of May 2001 have been evaluated as part
of this study. The following gages are not included, since their construction was not complete at
the time of our survey:
• 240WW: 240 Wasteway • NBLWW: New Belen Wasteway • LP2DR: Lower Peralta Drain #2 • SFRDR: San Francisco Drain • STYWW: Storey Wasteway
Presently, the MRGCD plans to discontinue use of the Barr-Chical Canal, eliminating the need to
monitor this inter-division flow between the Albuquerque and Belen divisions.
The current phase of the MRGCD metering program includes the construction of eight
new gages in the Socorro Division, and focuses on points in the system where irrigation return
flows enter the Rio Grande or the Low Flow Conveyance Channel (LFCC). These gages were
installed and brought on-line during the 2002 irrigation season. Labor and supervision for the
construction of these new gages in the Socorro Division was provided by the MRGCD. These
sites include the following:
• San Acacia Wasteway • Escondida Wasteway off Socorro Main Canal • Socorro Wasteway • Brown Arroyo Wasteway • Socorro Riverside Drain at north boundary of the Bosque del Apache • Socorro Main Canal South at north boundary of the Bosque del Apache • San Antonio Ditch at north boundary of the Bosque del Apache • Elmendorf Drain at north boundary of the Bosque del Apache
The construction of these gages in the Socorro Division nearly completes the metering of
diversions and return or tailwater flows within the MRGCD between Angostura Dam and the
BdA.
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The only remaining ungaged return flow points are approximately 10 to 14 locations in
the Cochiti division (MRGCD), the Isleta Drain Outfall (MRGCD), and the return flow from the
La Joya Acequia (non-MRGCD). The flow of the Isleta Drain from the Albuquerque Division
into the New Belen Acequia in the Belen Division is an ungaged interdivisional flow. The Lower
San Juan Riverside Drain, which is a significant contributor of return-flow from the Belen
Division to the Rio Grande, might also be a point worth considering for a new gage. The
existing gage on this drain is located about 2 miles above the outfall at the Bernardo cross-
section, near Highway 60. Since it is located so far from the outfall, it does not explicitly
represent return flow to the river, although the MRGCD estimates that the flow at the outfall is
very similar to the flow at the gage (i.e., the MRGCD believes that this 2–mile reach of drain
does not have significant gains or losses). If a siphon is built at Bernardo to carry water from the
Lower San Juan Riverside Drain on the east side to the Unit 7 Drain on the west side, the
MRGCD has indicated that it will move the gage to the siphon, and also gage the siphon
wasteway.
Ungaged diversion points include diversions from drains throughout the system, as well
as three LFCC diversions in the Socorro Division:
• Lemitar Diversion (LEMDV) • Socorro Diversion (12HDV) • Neil-Cupp Diversion (NCPDV)
Hydraulic heads (water elevations) on either side of these diversion structures are highly
variable, and as a result, measuring flows at the three diversion points is difficult. Metering of
these diversions is not included in the current phase of MRGCD’s gage construction program.
Plans for the Socorro Division metering also include a provision for updating of USGS gages to
19
transmit data to the MRGCD on an improved real-time basis (presently the MRGCD can only
obtain these data with the 4–hour USGS transmission schedule).
In equipping new gaging locations, the MRGCD considers the stability of the current
channel or existing control structures (previous metering stations, gates, etc.), ratings at these
stations (if available), and the amount of flow at the station versus costs associated with
construction of a new control. If deemed appropriate, the MRGCD designs new control
structures that would establish a stable and realistic stage-discharge relationship using the
USBR’s WinFlume program for long-throated flumes and broad-crested weirs, and then
constructs these structures within the canal reach to be monitored. The WinFlume program also
provides a theoretical rating for each new structure.
After the control is established, a gage, consisting of either a pressure transducer or a
shaft encoder, is installed, and equipped with a solar-powered radio transmitter so that the gage
reading at the station can be relayed to the MRGCD office every 30 minutes. Through the use of
rating curves, these gage heights can be converted into stream flow data at the MRGCD office.
At four gaged wasteway sites, the MRGCD has installed spillway gates with the
capability of automated control. These gates can be operated remotely from the MRGCD central
offices in Albuquerque. However, they are currently being configured for operation by
ditchriders, through the entry of a setpoint to control upstream water levels, in order to meet the
needs of irrigators. The sites include the Sandia Lakes Spillway, the Central Avenue
(Weedracks) Spillway, the Lower Peralta Drain, and the Madron Heading (which
measures/controls the 2nd Lower Peralta Drain Outfall). The control gates at these sites have also
been calibrated for flow measurement.
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3.2.3 Condition and Adequacy of Existing Gages and Metering Program
The condition and adequacy of existing gages has been evaluated as part of this study.
Recommendations for future expansion of the gage network are provided in Section 8.0. The
evaluation of existing gages included:
• Field visits to all gaged locations • Preparation of a gage report for each location visited, identifying
o Gage type and condition o Quality of gaged section and control structure o Gaging problems that may be associated with the section
• Evaluation of the suitability of the gage network
John P. Borland, hydrologist and member of the SSP&A project team, accompanied by
David Gensler, MRGCD Hydrologist, visited each gaged location. Visits were conducted
between April 30, 2001 and May 18, 2001. At each site, the following observations were made:
gage type and condition; quality of the gaged section; working condition; probable accuracy; and
gaging problems.
The results of the evaluations of individual gages are provided on gage profile sheets in
Appendix D. The gage profile sheets include a description of the gage characteristics, quality
attributes, photographs, and a rating curve if available. Recommendations for changes to the
structure or operation of individual gages are made within the profiles, and are summarized in
Table 3.7.
The following general comments are provided regarding the condition and adequacy of
gages:
• The overall adequacy of the MRGCD metering system has improved dramatically in the past five years, with the expansion of the gaging network;
• The accuracy of gaged data has improved over the past five years, with the addition of concrete controls supporting stage/discharge relationships; and
21
• The ability to trouble-shoot problem areas is substantially improved with the nearly real-time transmission of data, allowing a means of checking the operation of a station at 30-minute intervals. The following general recommendations are provided for improving the gaging network
and monitoring capability within the District:
Cochiti Division Gages: Gaging needs in this Division are not yet satisfied. Design and implementation of monitoring in this division should be pursued, and the MRGCD has plans to begin this work in 2003 or 2004.
Prior to selection of sites for gages in the Cochiti Division, discharge measurements should be made at the twelve sites identified by the MRGCD as those that would quantify the Cochiti system. These include the “wetfield discharges,” where water that has leaked beneath the Cochiti Dam is collected via subsurface tile-drains and discharged to an MRGCD drain, wasteways where flow is returned to the Rio Grande, and points where water passes into the Albuquerque Division. Most of these locations have relatively minor flows and a series of discharge measurements could assist in determining which of these sites are worth the effort of installing and maintaining a gage. These sites include the following:
• Island Lateral Wasteway • Seguro Wasteway • Peña Blanca Riverside Drain Outfall • Cochiti Eastside Main Canal Wasteway to Galisteo Creek • Seguro Feeder Wasteway • Upper Santo Domingo Acequia Wasteway • Lower Santo Domingo Acequia Wasteway • Borrego Wasteway • Sili Main Canal Wasteway • Santo Domingo East Riverside Drain Outfall • Santo Domingo West Riverside Drain Outfall • San Felipe Drain
Belen Division Gages: It was recommended to the MRGCD that it finish installation and repair of gages. This was completed during the 2002 irrigation season. It was also recommended that it implement preventative measures to protect solar panels and transmitters from vandalism. The MRGCD reports that this effort is underway.
Socorro Division Gages: It is noted that the installation and monitoring of gages on the Rio Grande and the LFCC at the North Boundary of the Bosque del Apache (by the USGS or the State of New Mexico, for example) would be of great benefit to the MRGCD, since it would allow a complete accounting of surface water in the Rio Grande valley as it leaves the MRGCD system.
Discharge Measurements for Rating Curves: Most of the new control structures were designed using the Bureau of Reclamation’s WinFlume program for long-throated flumes and broad-
22
crested weirs. This program provides a theoretical rating for each new structure. Once these theoretical ratings have been verified by discharge measurement it is not necessary to continue measurements at these sites every-other-week, as is now being done. The MRGCD may consider making less frequent discharge measurements at these sites. For measurements in smooth, straight channels, especially those locations with long-throated concrete flumes, it is not necessary to adhere to the protocol of the USGS (Techniques of Water-Resources Investigations of the United State Geologic Survey: Discharge Measurements at Gaging Stations; Book 3, Chapter A8). Whether these protocols are followed at a given location should be left to the discretion of the MRGCD hydrologist.
Frequency of gage height measurements: Reviewing the gage height measurements received from the gaging stations is recommended in order to ascertain if any of the sites should collect gage height more frequently than every 30 minutes. Gaging stations that have very little change in gage height during the day should remain at the 30-minute interval; however, the MRGCD might consider collecting data at 15-minute intervals at those gages that are constantly changing during the day, if this increase in monitoring frequency is practicable. This would provide a better record of flow at the gaging stations and may assist in system operations. Data Transmission: The quality of the product could be improved if the current radio transmitter system were expanded to include a redundancy feature, so that each data transmission includes the previous measurement, or the previous two measurements, in addition to the current measurement. This will help prevent loss of data due to intermittent data transmission failures (such as during thunderstorms), since if a transmission were missed, it would be picked up on the next transmission. [Note – the MRGCD has indicated that it is presently working on adding this redundancy feature to its data transmission.] Rating Curves: At the end of each irrigation season, the MRGCD should review the rating curve for each station. If plotting measurements made during the irrigation season does not continue to define the existing rating, a new rating should be developed based on the plotted measurements. [Note – the MRGCD has indicated that this recommendation is currently being implemented.] Vandalism: Vandalism continues to be a major problem, particularly in the Belen Division. Solar panels have been stolen and others destroyed by gunfire. The MRGCD has indicated its belief that this vandalism is at least in part a result of resentment of many valley residents to gaging. However, gaging is actually a benefit to irrigators in the valley and to the MRGCD. It would seem that the MRGCD would benefit from – and may even bear some responsibility for - educating the community about the benefits to irrigators of gaging. Gaging allows the district to more effectively manage its available supply to maintain a fair distribution of water among its constituents. Training: Staff may benefit from attending training sessions in data collection and computation presented by the U.S. Bureau of Reclamation and the USGS. These sessions could help make their data collection efforts consistent with those of other agencies in the area, and also possibly give the MRGCD ideas of ways to make its data collection and handling more efficient. [Note – the MRGCD has indicated that this recommendation is currently being implemented.]
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Data handling and processing: The efficiency of data handling and processing, which is now performed using a number of Microsoft Excel spreadsheets, could benefit from the use of a water data collection computer package. There are several water data collection computer packages currently on the market that are suitable for evaluation, i.e., HYDRON, a package currently being used by Los Alamos National Labs for its data collection program. Staff load: With the expansion and addition of gaging stations in Belen, Socorro, and Cochiti Divisions, an additional staff member may be needed in the future to assist with measurements and data collection and handling. [Note – the MRGCD has indicated that this recommendation is currently being implemented: Staff in the Belen Division have assumed responsibility for operations and maintenance of the gages in their division, and the Socorro Division will soon assume responsibility for the gages in their division (many of which are recently installed).]
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3.3 Review of Flow Records
Available records of historic and recent flows have been compiled and are reviewed in
this section. Flow records include USBR water distribution reports and MRGCD gage records.
MRGCD gage records represent primary data. The USBR water distribution reports combine the
gage data with estimates of ungaged flows to characterize the canal system water budget on a
monthly and annual basis.
Other entities have utilized these information sources for various analyses, and in the
process, have generated related secondary data sets. For example, the URGWOM modeling
group has filled missing daily data in the historic MRGCD gaged record to fulfill modeling
needs (USBR, 2000). The New Mexico Office of the State Engineer has performed calculations
with USBR estimated quantities to characterize elements of the irrigation system (Wilson, 1997).
Similarly, other studies reference the MRGCD gage data or USBR reports. Discussion in this
section is limited to the MRGCD records and the USBR reports, and does not address use of this
information by others or the development of secondary data sets.
3.3.1 USBR Water Distribution Reports
A summary of several components of the MRGCD irrigation system flow budget is
reflected in water distribution reports, prepared by the USBR on an annual basis. These records,
prepared for each division within the MRGCD, include net supply (gaged diversions to major
canals with adjustments), estimated main canal waste (operational spills, carriage water, etc.),
estimated loss (defined as evaporation, phreatophyte consumption and seepage to groundwater)
and estimated deliveries to farms. Table 3.8 summarizes the MRGCD water distribution data as
reflected in USBR reports. Examples of these data reports are provided in Appendix E. USBR
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memoranda documenting the procedures for obtaining the reported quantities have been found
for the years 1956 through 1964, 1966 and 1974; these are also included in Appendix E.
The memoranda indicate that of the reported water quantities, the net supply is based on
gaged measurements (with adjustments for relevant ungaged flows); quantities other than net
supply are estimated. The reported quantities and their measurement or estimation procedures
are noted below.
Net Supply: Supply to the irrigation system or division. Documentation of which river diversions are included or adjusted is provided on the annual USBR memoranda. Typically, this quantity includes the summation of flow recorded at gages at canal headings and, addition or subtraction of gaged or estimated interdivisional flow (depending on gage location). It is not known if the diversions from the LFCC in the Socorro Division are included in the calculation of net supply.
Wasteway Returns (Canal or lateral waste): Significant flow back to the river occurs via wasteways, sometimes close to the main diversion point. The quantity of these and other wasteway flows have not been historically metered. Review of the USBR memoranda suggests that, typically, lateral waste was assumed to be 10% of the flow to laterals. Main canal waste was determined as a residual term in a water balance including net supply, waste, losses and farm delivery. Monthly distribution of this term is as follows:
“…the main canal waste was distributed by assuming, from information provided
by O&M Division, that there was a 50% waste in March, a 25% waste in April, and the remainder would be distributed in equal percentages during the rest of the months.” (R.W. Fife, March 25, 1957).
Memoranda for some later years (for example, 1974) indicate that this procedure was varied for the Cochiti division, where waste was assumed also to be 50% of flow in April.
Losses: Canal and lateral losses were estimated as a percentage of flow. The USBR memorandum prepared by R.W. Fife (1957) provides the following discussion:
“The main canal and lateral losses were assumed to be as follows: Cochiti
division, 50% of the diversions; Albuquerque and Belen divisions, 30%; Socorro division, 20%. These losses were broken down approximately equal between the main canals and the laterals on the assumption that the seepage losses would be greater per mile in the main canals, but the greater mileage of laterals would result in the lateral losses being approximately equal to the main canal losses on an acre-foot basis.”
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Farm Delivery: Farm delivery within the MRGCD was estimated. The estimation procedure is not explicitly discussed in most of the early USBR memoranda. However, a March 8, 1957 memoranda from Charles H. Clark, on the topic of water use, estimates a farm delivery “based on the number of and estimated depth of water per irrigation application for the representative crops grown within each irrigation branch”. Later memoranda reference that an estimated farm delivery was furnished by the Irrigation Division (Shaffer, 1959, 1960).
Review of the available USBR memoranda suggest that the procedures for estimating
water distribution data were developed prior to and during the late-1950s by the USBR Irrigation
Division and Hydrology Division. Procedures for estimating ungaged quantities appear to be
based on observation and professional judgment. These procedures appear to have been
followed in later years, as “rules-of-thumb”, with exceptions described in some years due to
unusual supply or distribution conditions.
3.3.2 MRGCD Gaging Records
3.3.2.1 Historical
Annual values derived from the historical flows recorded on MRGCD handwritten
spreadsheets for the period 1974 to 1995 are shown graphically in Appendix F-1. Total gaged
flows associated with river diversions for each division have been quantified from these records
by summing the diversion at canal headings, and subtracting gaged inter-division flow, where
available, as described below:
Cochiti Division: Sum of Sili Main Canal and Cochiti Eastside Canal Albuquerque Division: Sum of Albuquerque Main Canal and Atrisco Feeder, minus the
Algodones Drain Belen Division: Sum of Chical Lateral, Cacique Acequia, Peralta Main Canal,
Belen Hi Line Canal and Chical Acequia Socorro Division: Gaged flow at the Socorro Main Canal (in the historic period,
gaged flow in the Socorro Main Canal included ungaged flow from the Unit 7 Drain, and does not strictly represent river diversions)
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The flows calculated above are shown graphically for each division in Appendix F-1 for
the post-1975 period. This procedure results in quantification of a somewhat different entity
than the net supply reported on the USBR water distribution data reports, at least according to
procedures described in USBR memoranda in the 1957 to 1975 period. Documentation of
USBR calculation procedures in the post-1975 period has not been found, but likely followed the
earlier procedures. The USBR net supply reflects estimates of ungaged flows providing supply
to a division. Table 3.9 shows a comparison of the USBR reported net supply and the
summation of gaged flows described above for the post 1975 period during which MRGCD gage
records were available.
3.3.2.2 Irrigation Season 2001
Records for the 2001 irrigation season have been compiled from the expanded metering
network operated by the MRGCD. Although these records do not provide a complete accounting
for the system, and the data are affected by some weaknesses and uncertainties, they enable a
more detailed accounting of the water budget in the Albuquerque and Belen divisions for the
2001 season than has been available previously.
Table 3.10 provides the average monthly discharge in 2001, by division, for individually
gaged canals, drains and wasteways. Where adequate data exist for a division, Table 3.10
provides summation of total river diversions, the division supply (river diversions plus inter-
division inflow), total river return flow; and the division outflow (river returns plus inter-division
outflow). Records for individual gages and for river diversions are provided graphically in
Appendix F-2 and in tables in Appendix F-3. The tables provided in Appendix F-2 identify daily
gaged flows and, in some cases, estimates made by the MRGCD hydrologist. These data were
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tabulated by the MRGCD and were provided to this project team in January and February 2002.
Missing data were estimated by MRGCD to complete the daily record (identified in bold
on the Appendix F-3 tables). For example, missing data occurred at gages constructed during the
season, or gages that were inoperable. MRGCD made such estimates based on one or several of
the following methods (David Gensler, personal communication, February 5, 2002):
• Extrapolating from previous long-term records (for example, if a gage was inoperable all season, average the previous 5 years data);
• Fill missing daily data by averaging the daily values immediately prior to and following the missing day(s);
• Fill missing days by including a hand-gaged value with averaging as noted above; • Estimation by visual observation.
Figure 3.1 shows monthly river diversions for each division, calculated as the total
amount of water actually diverted from the river. In the Socorro Division, this calculation is
more accurate than in the past due to the presence of the new Unit 7 Drain gage that allows
subtraction of the inter-divisional flow from the Belen Division that is intercepted by the Socorro
Main Canal above its gage. In 2001, efforts were made in the Belen Division to maximize the
flow of the Unit 7 Drain, in order to minimize diversions at the San Acacia Dam. Under these
conditions, approximately 79% of the flow in the Socorro Main Canal was comprised of direct
inter-divisional flow from Belen via the Unit 7 Drain. Without the gaged record at the Unit 7
Drain, the river diversions at San Acacia in 2001 could not be accurately quantified. In past
years, although not known precisely, it is believed that the Unit 7 Drain did not typically
comprise such a large percentage of the Socorro Main Canal flow.
A small amount of inter-divisional flow occurs from the Albuquerque to the Belen
Division via the Barr-Chical Canal. In past years, very little flow has come through this canal
into the Belen Division -- water has backed up into the canal from the Isleta Dam and become
29
stagnant. However, on May 28, 2001, the gates were opened and an area at the intake pipes was
cleared of debris. From May 28 through the end of the irrigation season, the flow was estimated
by MRGCD to be approximately 30 cfs.
3.3.3 Water Supply at the Division Level
Inspection of records suggests that the water supply of the individual divisions of the
MRGCD comes from two sources:
• direct diversion from the river; and • inter-divisional flow (tail water from the upstream division – except in the Cochiti
Division).
Additionally, in the Socorro Division, the supply includes water diverted at three
locations from the Low Flow Conveyance Channel (LFCC). According to the system gage
measurements and estimates provided by the MRGCD, the total direct diversion from the river
for the 2001 irrigation season was approximately 492,000 acre-feet, with 102,000, 126,000,
233,000 and 31,000 acre-feet directly diverted at Cochiti Dam, Angostura Dam, Isleta Dam, and
San Acacia Dam, respectively.
The division supply can be calculated by summation of river diversions, interdivisional
inflow and other sources – based on gage records (of the river diversions and interdivisional
flows) and estimates of the water from other sources. The division supply for the Albuquerque
Division was approximately 160,000 acre-feet, including the interdivisional inflow from the
Angostura Drain. The division supply for the Belen Division was approximately 241,000 acre-
feet, including a small estimated ungaged contribution from the Barr-Chical lateral. The division
supply at the upstream end of the Socorro Division was approximately 112,000 acre-feet,
including the interdivisional flow through the Unit 7 Drain and not including diversions from the
LFCC at the Lemitar, Socorro (1200) and Neil Cupp diversion structures. Inclusion of estimated
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diversions from these structures results in an estimated total division supply of approximately
139,000 acre-feet for the Socorro Division.
Significant amounts of water are returned to the river (or LFCC) via drains and
wasteways throughout all divisions. The return flows are not yet quantified in the Cochiti or
Socorro divisions. In the Albuquerque Division, gaged return flow was approximately 180,000
acre-feet in 2001 (including the non-irrigation season months). Similarly, in the Belen Division,
gaged return flow was approximately 96,000 acre-feet.
Water returning to the river includes direct surface water returns from the irrigation
system (operational spills, tailwater); indirect sub-surface returns from the irrigation system
(intercepted percolation from water applied to farms and intercepted seepage from canals);
intercepted seepage from the riverbed; intercepted groundwater recharge; overland run-off and
inflow from uncontrolled arroyos; and, net effects of changes in groundwater storage. The
individual contributions of these components to the total return flow are difficult to distinguish.
Therefore, while the difference between division supply and return flow represents a composite
depletion (or accretion) for the sum of components, this difference does not represent the
irrigation system consumptive use. Analysis of the 2001 irrigation flow records and inferences
related to the irrigation system budget will be addressed in Section 6.0.
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4.0 PHYSICAL ASPECTS OF THE WATER DEMAND
Speaking broadly, the water demand is the amount of water needed to satisfy irrigation
uses. The irrigation system water demand includes a number of components, some of which are
fixed and some of which can be reduced through improved practices. Discussion and
quantification of water demand is often obfuscated by inconsistent definitions of the system
components under consideration. The demand may be conceptualized as applying to a whole
system, or to system components; for example, one may speak of system demand, canal heading
demand, on-farm demand, or crop demand.
The crop demand typically is referred to as the consumptive irrigation requirement
(CIR), or the crop consumptive use minus the amount of water satisfied by precipitation or
available soil moisture. The on-farm demand typically is referred to as the farm delivery
requirement (FDR). The FDR includes water to satisfy the CIR; water consumed by incidental
on-farm depletions; water necessary to adequately deliver water from the farm headgate to the
crops; and, excess water for soil flushing. Some portion of the FDR is not consumptively used
and is returned to the surface or groundwater system, or both. The canal heading demand, or,
canal diversion requirement, includes water to satisfy the FDR for lands along the canal; water
for additional consumptive uses, for example, riparian evapotranspiration (ET) or open-water
evaporation from the conveyance system; water necessary to maintain adequate head within the
system or meet other operational needs such as sluicing; water that seeps from canals; minus,
return flows that, in some areas, may accrue to the canal. Finally, the irrigation system demand,
or, total river diversion requirement, is the sum of the canal heading demand, minus any return
flows that accrue to the delivery system, for example, drain flow returned to downstream canals.
The irrigation system demand is a function of the consumptive irrigation requirement, or, crop
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demand, and delivery (off-farm) and irrigation (on-farm) efficiency. The efficiency terms reflect
the amount of water circulated within the irrigation system beyond that consumptively used by
crops.
Water demand and irrigation efficiency are difficult to quantify. In the MRGCD, uncertainty
exists both in the total number of acres irrigated in a given season, in the consumptive use
requirements for irrigated crops, and in the quantity and disposition of diverted, but non-
consumptively used water. However, significant work has been conducted in the Middle Rio
Grande valley by several entities to assess demand-related parameters, particularly over the last
decade. This body of work is used to characterize the physical aspects of the MRGCD on-farm
water demand in this section.
4.1 Crops and Cropping Patterns
This section describes historic and more recent sources of information on numbers of
crops irrigated and cropping patterns within the MRGCD. The historic sources include USBR
crop census records and compilations prepared by New Mexico State University. More recent
information sources include a land use assessment conducted by the USBR in 1992-1994; and, a
satellite imagery-based vegetation classification conducted by the MRGCD and the ISC in 2001.
The information provided by these documents and studies are described in the following
sections.
4.1.1 USBR Crop Census Reports
The MRGCD produces Crop and Water Utilization Data reports (a.k.a., crop census
reports) annually, and, until 1999, was required as part of Middle Rio Grande Project to submit
these reports to the USBR. The crop distribution data presented in these reports from 1956
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through 1999 are summarized on Tables 4.1 and 4.2. Table 4.1 identifies the irrigated lands
(harvested cropland and pasture, unharvested cropland and acres set aside for soil building),
fallow or idle lands, and the total of these categories, representing lands in irrigation rotation.
The average acreage reported over the period 1991 through 1998 is:
Irrigated lands: 53,355 acres Fallow or idle lands: 10,567 acres Total lands in irrigation rotation: 63,901 acres Table 4.2 breaks down the harvested cropland and pasture acreage into eight reported
crop categories, including cereals, forage, miscellaneous field crops, vegetables, seeds, fruits,
nuts and others. Tables providing additional detail from these records are provided in Appendix
G-1 (tables G 1-1 through G 1-9). Similar reports from prior to 1956 are reported to exist, but
are not available from either the MRGCD or the USBR. The crop census reports also provide
the acreage in other categories of service, not in irrigation rotation, to derive a total classification
for all irrigable lands in service. These other categories of service include: dry cropped; idle,
fallow or grazed; farmsteads, roads, ditches, drains; urban and suburban residential, commercial
and industrial lands. The sum of lands in irrigation rotation and lands not in irrigation rotation
is reported as total irrigable area for service. The total irrigable area for service is reported as
121,680 acres from 1956 through 1965. A similarly derived quantity, total irrigable area, is
reported for years 1983 through 1998 and is 89,711 acres.
The acres irrigated does not vary substantially, as reflected in the available crop census
reports over the period 1956 and 1998; the acreage for the years shown on Table 4.1 varies from
about 50,000 to 58,000 acres, with an average of 54,557 acres. However, there is a significant
difference in reported acreages for total area in irrigation rotation, reflected primarily in the
number of fallow or idle lands reported in this category. Furthermore, there is a substantial
34
difference in the total irrigable service area in records prior to 1965 and after 1983. This
difference primarily is accounted for in the number of idle, fallow or grazed acres included in the
lands not in irrigation rotation.
Presently, the crop census reports are prepared based on a compilation of crop
distribution data from ditchrider logs (Doug Strech, MRGCD GIS Manager, personal
communication, 2001). However, there are some indications (Annabelle Gallegos, MRGCD
Librarian, personal communication, 2000; Bob Lansford, formerly of NMSU Agricultural
Experiment Station, personal communication, 11/15/2001) that in the past, the reports were
based on data obtained by a consortium arranged by the New Mexico State University (NMSU)
Agricultural Experiment Station and reported in Agricultural Experiment Station Technical
Reports (Landsford et. al., 1993, 1996; Landsford, 1997). When and how the data compiled by
NMSU might have been incorporated into the crop census reports, and the year in which the
method switched to reliance on ditchrider logs, is not known. New methods of crop census
reports may not comply with USBR requirements.
4.1.2 NMSU Agricultural Experiment Station Reports
The reports prepared by the consortium arranged by the New Mexico State University
Agricultural Experiment Station are titled "Sources of Irrigation Water and Irrigated and Dry
Cropland Acreages in New Mexico, by County, [years]", and were produced for multi-year
periods from 1970 through 1996 (Landsford et. al., 1993, 1996; Landsford, 1997). These reports
form the basis of crop acreages reported by county by the New Mexico State Engineer Office
(Wilson and Lucero, 1997). The crop-distribution data obtained from these reports for the
counties in which MRGCD is located is provided in Appendix G-2. The data are divided by
county, rather than by irrigation district, or division of irrigation district. Although irrigated
35
acreages falling within the MRGCD are not strictly identifiable from these reports, they do
provide an indication of the primary crop types as well as trends through time in crop types and
irrigated acreages in this region. Idle and fallow lands are grouped in these tabulations. Total
irrigated cropland includes the idle and fallow lands. Total acres irrigated exclude the idle and
fallow category. For the years 1992 and 1993, respectively, the total acres irrigated are
reported as 59,850 and 61,570 acres. The total irrigated cropland for both years is reported at
77,710 acres.
The information provided in the Agricultural Experiment Station reports was developed
as described in the following paragraphs (Landsford, personal communication, 11/15/2001). As
part a NMSU Agricultural Experiment Station study, air photos were obtained. The project team
used these photos, which were taken by the Soil Conservation Service (now the Natural
Resources Conservation Service), as a basis for a summer-long project in which they field
checked the entire Rio Grande (Lower, Middle, and Upper) and Pecos River Valleys, cataloging
the crops. The results of this survey were published in the early 1970s in NMSU Water Institute
Reports (a series). The original mapping data have not been made available, and may no longer
exist.
After that first complete survey, annual reports were prepared from these basic data along
with records of documented changes since 1969. The project team would send out annual
questionnaires to the county agents. These questionnaires would list the crop distribution from
the previous year within that county, and provide locations to note changes to the listed acreages.
The county agents would distribute these questionnaires to the federal agricultural agencies
operating in the county. The team would also collect data on land use within the Pueblos from
the Bureau of Indian Affairs (BIA), which has its own crop census. Annual meetings were then
36
held in each county to compile all available data on the changes in cropping patterns, etc. and to
modify these reports. These meetings would typically last 2 to 3 hours. They would typically be
attended by:
• NMSU Ag Experiment Station • NMSU Department of Agricultural Statistics • NM Department of Agriculture / National Agricultural Statistics Service (a joint
state/federal agency, which performs surveys and provides data) • Other interested parties, including representatives of irrigation districts • Local representatives, such as from irrigation districts
In addition, Earl Sorensen of the OSE provided OSE summaries of the total irrigated
acres, by county. These tallies were developed as part of a State Water Plan. The tallies from
each county meeting were put into a computer program, which tabulated the data from each
county into one large database.
4.1.3 USBR Land Use Trend Analysis
The USBR conducted a land use trend analysis (LUTA) in the Middle Rio Grande Valley
(Bell et al., 1994). This study, performed between 1992 and 1994, provides an assessment of
land use in the Albuquerque basin, which extends from Cochiti down to San Acacia (and
therefore includes three of the four MRGCD divisions), and land use changes through time over
the past half century. In the LUTA, assessments were made of the distribution of land uses in the
valley in 1935, 1954/55, the mid 1970s, and 1992/93. The report concludes the following
regarding agricultural land use:
“The maximum acreage of all agricultural classes combined, with the exception of idle agriculture, occurred in the 1970s (63,827 acres)… There was a 5 percent increase in the combined agricultural classes between 1935 (48,976 acres) and 1992/93 (51,266 acres). During the same period, idle agriculture doubled from 7,908 acres. The combined residential and urban land use classes increased by 80,326 acres … in the 58-year LUTA period of analysis study.”
37
For the 1992/93 Assessment, aerial photography and 1992 Landsat TM satellite imagery
were interpreted in coordination with a program of field verification, and the resulting land use
distribution was compiled into a GIS database. Land use classification for 1992/93 included 33
land use classes; classification for the historic period (which could not be field checked) included
22 land use classes. Table 4.3 identifies the land use classes for the 1992/93 Assessment and
shows those selected for quantifying irrigated lands for this study. Among the land use classes
for agriculture are fallow agriculture, defined as “agricultural lands not currently planted, but
undergoing active land treatment (plowed or disked); and, idle agriculture, defined as
“agricultural lands abandoned for more than one year, as evidenced by invasion of weeds and
shrubs”.
Crop acreage characterizations for this study were calculated from the existing GIS
LUTA (land use/land cover) dataset that has been made available by the New Mexico Resource
GIS (NMRGIS) website (http://rgis.unm.edu, September 2001), as maintained by the
Environmental Data Analysis Center (EDAC). The coverages from the 1992/93 LUTA
assessment have been extended to include a new study area boundary, which incorporates lands
downstream of San Acacia and areas outside the MRGCD boundary. Acreage summaries
provided by this dataset reflect the extended study area. Additionally, the land use classification
scheme is built on the same 33 land use classes derived in the 1992/93 study.
Table 4.4 shows the sum of irrigated, fallow, idle and irrigated plus fallow lands by
county and by Division, based on the revised LUTA dataset. The total of irrigated plus fallow
lands identified in the GIS data equals 63,651 not including Pueblo Lands. An additional 14,786
acres are identified as idle agriculture.
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4.1.4 IKONOS Satellite Imagery Vegetation Classification, Summer 2000
A Middle Rio Grande Vegetation Classification project was conducted as a joint effort
between the MRGCD and the NMISC in 2001, using IKONOS satellite imagery from the
summer of 2000 (Strech, D.W. and T. S. Matthews, 2001). This project attempted to develop a
standardized vegetation classification system and to assess the utility of using remote-sensed
information for MRGCD water management. Agriculture crops were divided into crop classes.
Due to similar reflective responses, a class identified as fallow and barren lands included idle and
fallow fields, arroyos, empty urban lots and barren ground such as dirt roads and vacant fields (a
much broader class than the fallow or idle lands identified in previous projects, described above).
The project team noted some difficulty in classification resulting in inconclusive results.
Additional field research and refinement of procedures was recommended to improve crop
classification by this methodology.
4.1.5 Comparison of Irrigated Agriculture Acreage Estimates
Table 4.5 compares the irrigated acreage reported in the information sources discussed
above. The USBR and NMSU estimates relate to acres of specific irrigated crops, and exclude
the idle and fallow category. The NMSU estimate may include some acreage beyond the
MRGCD boundary. The LUTA estimate (revised RGIS from EDAC) includes the fallow
category, but not the idle lands. While reports are not strictly comparable, they approximate the
actively irrigated acreage within the MRGCD. The reported quantities vary between 52,000 and
63,000 acres. One estimate, not discussed above, is a 1992 unsupervised satellite classification
reported in the LUTA report. This estimate yielded 58,782 for irrigated agriculture and 10,600
acres for fallow agriculture. The combination of these two classes is 69,382 acres. Because this
39
classification does not include an idle agriculture class, the idle lands may have been included in
the fallow category, resulting in the higher number.
4.1.6 Other Irrigation Uses
In addition to irrigation of croplands within the MRGCD, other water users rely on the
MRGCD diversion and conveyance facilities. These include the La Joya Acequia Association,
the four New Mexico Department of Game and Fish refuges (the Belen Waterfowl, Casa
Colorado, Bernardo and La Joya Waterfowl areas) and the USFWS Bosque del Apache National
Wildlife Refuge. Water use by the La Joya Acequia Association and the Bosque del Apache
National Wildlife Refuge is briefly described below.
The La Joya Acequia is located east of Bernardo in Socorro County. The following
information is reported in a Draft Environmental Assessment (U.S. Army Corps of Engineers,
2001):
The acequia is 8.9 miles long and provides irrigation water to 1,350 acres of farmland. The La Joya Acequia is the only communal acequia system between Albuquerque and Elephant Butte Reservoir…. The heading structure at Highway 60 withdraws water from another ditch, the Lower San Juan Canal, managed by the MRGCD. The return flows from the acequia empty into the river via the Bernardo Arroyo about two miles south of the village of La Joya. … The acequia association is authorized to divert 36 cubic feet per second for three acre-feet per acre per year….. about 800 acres will be utilized during the 2001 irrigation season.
The Bosque del Apache holds License No. 2, dated July 30, 1956, with a priority date of
January 4, 1906, for a diversion of 97 cubic feet per second for “… protecting, production of
feed, resting, and propagation of wildlife…”. Licensed operations include ponding of water,
conservation and production of habitat and crop production, consisting of small grains, corn and
alfalfa. The originally permitted place of use was 4,139 acres within approximately 12,500 acres
in the floodplain area of the BdA. In 1999, the BdA received a permit from the OSE to expand
40
its place of use to 8,239 acres. The BdA points of diversion for surface water presently include
conveyance channels at the downstream end of the MRGCD and the LFCC. As a condition of
approval, the OSE limited consumptive use to 8,691 acre-feet per year.
4.2 Crop Consumptive Use
The primary mechanism for consumptive use of water by the MRGCD is
evapotranspiration (ET) by crops irrigated within the District. The USBR and others have
conducted work to quantify this parameter within the Middle Rio Grande valley. Two USBR
projects yielding regional estimates of crop ET are described in this section. For the MRG Water
Assessment (King and Wan, 1997), the modified Blaney-Criddle method was employed. For the
ET Toolbox (USBR website: www.usbr.gov/rsmg/awards/ettoolbox.html), the Penman method is
used.
The calculation of ET by the modified Blaney-Criddle method yields lower estimates of
ET than are reflected in the Penman calculations within the ET Toolbox. These methods and
results are briefly discussed below. Differences in the calculated ET by these two methods
underscore the uncertainty in quantification of this parameter.
4.2.1 Blaney-Criddle Approach (USBR Assessment)
The original Blaney-Criddle method (Blaney and Criddle, 1962) calculates crop
consumptive irrigation requirements based on air temperature, daylight, and a consumptive use
factor for each crop considered in a particular region. The SCS Modified Blaney-Criddle
method adds a climatic factor to the consumptive use factor, separating the temperature factor
from the crop coefficient (SCS, 1970).
41
For the MRG Water Assessment, a project was undertaken to calibrate the SCS Modified
Blaney-Criddle crop coefficients based on locally measured ET data for the Middle Rio Grande
region; and, to adjust the calibrated crop coefficients to reflect actual field production water use
based on seasonal ET predicted by crop water-production functions (King and Wan, 1997). The
crop coefficients were calibrated based upon results from lysimeter studies of crop ET conducted
in the region. A scaling factor was developed through the use of a crop water-production
function. The function is assumed to be a linear relationship between crop ET and crop yield
under both non-stressed and stressed soil moisture conditions.
The function can be expressed as:
Based on this assumption, the crop coefficients can be adjusted to provide a better estimation of
crop ET (King and Wan, 1997).
The modified Blaney-Criddle method was used in the USBR Middle Rio Grande Water
Assessment to quantify crop evapotranspiration in the Albuquerque Basin, from Cochiti to San
Acacia. For this area, the annual crop net consumptive irrigation requirement for the identified
cropping pattern ranges from 1.5 acre feet per acre in the northern part of the study area to 2.1
acre feet per acre in the southern part of the study area, with a weighted average consumptive
irrigation requirement of approximately 2.0 acre feet per acre (USBR, 1995, Supporting
Document 6). The Assessment study area does not include the Socorro Division of the MRGCD;
ETbaY *+=
waterofdepth in expressed spiration,Evaportran function production of slope theConstant,
function production theofintercept theConstant,kg/ha)in (usually yield Crop
:where
====
ETbaY
42
extension of these calculations further south to include the Socorro Division would likely result
in a slightly higher weighted average consumptive irrigation requirement.
4.2.2 Penman Approach (ET Toolbox)
The modified Penman method for estimation of potential ET (King and Bawazir, 2000) is
a physically-based model incorporating the following factors: net radiation, soil heat flux, slope
of the vapor pressure vs. temperature curve, psychrometric constant, saturation vapor pressure,
actual vapor pressure, air temperature and wind speed. Some of these factors are estimated or
derived empirically. Actual ET for a particular crop is derived through use of an empirically
determined crop coefficient, typically derived under ideal conditions where growth isn’t limited
by physiological factors.
The USBR has developed a web-based tool, the ET Toolbox, to calculate and display real
time calculated ET for crops and riparian vegetation for a study area extending from Cochiti to
Elephant Butte. The ET project region is divided into 4km x 4km cells that correspond to the
National Weather Service grid developed for the Hydrologic Rainfall Analysis Project (HRAP).
Within each grid cell the water requirement is determined based upon land use classifications
and vegetation types derived from the 1992 LUTA. ETp is calculated by applying the modified
Penman method to weather data collected in the region and utilizing crop coefficients determined
through lysimeter studies conducted at New Mexico State University. The ET Toolbox also
reports an “estimated daily consumptive use” for each cell by subtracting the daily rainfall as
estimated by the National Weather Service Stage III Multi-Sensor (radar and gage) hourly
precipitation measurements from the calculated consumptive use requirement (ETp) (ET Toolbox
documentation, www.usbr.gov/rsmg/awards/ettoolbox.html). For the study area, the weighted
average annual crop consumptive use for the 1985 to 1998 period is 3.9 acre-feet per acre, based
43
on the 1992 LUTA crop classification. The effective rainfall must be subtracted from the crop
consumptive use to obtain the consumptive irrigation requirement. The Penman-derived
consumptive use will overestimate actual consumptive use in situations where crop consumption
is limited by water availability, plant vigor, or other factors. An approximation of CIR, derived
from the Penman method with the computed consumptive use reduced by 30% to represent a
typical yield below the assumed ideal yield, and the effective rainfall assumed to be 50% (or
about 4 inches per year) of the total rainfall, results in a weighted-average crop consumptive
irrigation requirement of 2.4 acre-feet per acre. However, yield in the MRGCD has not been
researched as part of this project, and the above 30% reduction assumption may not represent the
present, or the optimum yield for the District. If one assumes a more favorable yield of 85% for
the District (i.e., a yield-adjustment of 15%), then the computed CIR would be approximately 3.0
acre-feet per acre per year.
4.3 Crops and On-Farm Demand
The MRGCD crop demand can be estimated by multiplying the assumed acreage by the
assumed district-weighted consumptive irrigation requirement. Discussion in the above sections
indicates the uncertainty in estimation of these factors. On the low end, assuming an irrigated
acreage of 53,000 acres, and a CIR of 2.0 acre-feet per acre, the crop consumptive demand is
106,000 acre feet. On the high side, assuming an irrigated acreage of 63,000 acres and a CIR of
3.0 acre-feet per acre, the crop consumptive demand is 189,000 acre-feet. Most likely, the
present MRGCD CIR falls within the lower half of this range.
The on-farm demand will equal the crop CIR divided by the on-farm efficiency.
Quantification of the on-farm efficiency is not within the scope of this study, and published
44
studies on this topic have not been found for the MRGCD study area. However, an on-farm
efficiency in the range of 50%, or, perhaps, 60% in the Belen and Socorro divisions, would not
be an unreasonable assumption. Assuming an on-farm efficiency of 50%, and a district-wide
CIR of 130,000 acre-feet per year, the farm delivery demand is estimated at about 260,000 acre-
feet per year. Continued research to support quantification of the on-farm efficiency, the
weighted-CIR and the irrigated acreage is needed to improve the estimation of this key factor of
the irrigation system water budget.
45
5.0 DESCRIPTION OF WATER DELIVERY OPERATIONS
5.1 Information Sources
This description of water delivery operations was developed through interviews, field
visits and observation, and review of documents relevant to MRGCD operations. Field visits and
interviews were conducted over a period of three months during the summer of 2001, and
involved intensive interaction with ditchriders and other MRGCD personnel, and personnel of
other relevant organizations. Twenty ditchriders and several other MRGCD personnel, including
Division Managers and Field Supervisors, were interviewed. It is important to note that these
interviews do not include all ditchriders in the MRGCD.
Field observations consisted of a detailed tour of each ditchrider area and an informal
discussion concerning operations, infrastructure, and on-farm water use within the ditchrider
service area. These discussions were informal in the sense that although a general set of
interview questions were kept in mind, interviews were open to the specific concerns and
characteristics of each ditchrider area.
A document entitled “Policies and Procedures of the MRGCD” attached in Appendix H-2
(MRGCD, document JBDPP94.001) was key to this evaluation, as it sets forth the operating
policies with respect to water delivery and other related District functions.
5.2 Planning and Water Scheduling
5.2.1 Division Manager Position
All MRGCD division managers, with the exception of the Belen Division, were
interviewed as part of this study. Division managers direct water delivery operations, collaborate
46
with central office administration, prepare annual budget and finance reports for their respective
divisions, and supervise field operations, repairs, and maintenance. MRGCD division managers
are in constant communication with both field and central office personnel. In some divisions,
division managers delegate additional responsibility to water masters, ditchrider supervisors, and
field supervisors. Water masters and ditchrider supervisors manage water delivery operations
among ditchriders, while field supervisors oversee field maintenance and repair operations as
well as personnel.
5.2.2 Ditchrider Position
The ditchrider fulfills a critical function in the planning and scheduling of water
deliveries. Each ditchrider is responsible for the distribution of water among the users in his
assigned area. In the MRGCD, a ditchrider position appears to be a desirable position, since
most have held their jobs for many years. This position is considered socially prestigious
because the ditchriders are responsible for the service or delivery of water to the District’s
constituents, the water users. The relationship between the ditchrider and the irrigators is a very
important component of the ditchrider position, as expressly stated in the “Policies and
Procedures of the MRGCD” (MRGCD, document JBDPP94.001): “The ditchrider holds a key
position and will at all times maintain close contact with the farmer or water user. There shall be
no partiality shown in distribution of water regardless of personal feeling, race, creed,
relationship, political, or social standing or previous grievances” (Item J).
The job of a ditchrider is very demanding. During the irrigation season (March 1 through
October 31), ditchriders are required to be on call at all times, and are accessible via pager, cell
phone, and CB radio in their MRGCD trucks. In fact, many MRGCD ditchriders reside, and
sometimes irrigate, within their service areas. Ditchriders also attend to emergencies including
47
ditch breaks, ditch clogs, leaky gopher holes, drastic alterations in water levels. Perhaps the
biggest concern for ditchriders are the monsoon rains that occur mid-summer in New Mexico.
During such events, arroyos (natural floodways) running perpendicular to MRGCD canals bring
unwanted sediment and water; often overflowing and breaking ditch banks. Because such rains
occur frequently and unexpectedly, ditchriders must be available at all times to make necessary
changes in the conveyance system (such as opening wasteways).
MRGCD ditchriders are required to “ride” the ditches, canals, acequias, drains, and
wasteways in their service area several times a day, seven days a week. They are relatively
independent, scheduling rounds according to the time that works best for the rider and the water
users. The purpose of these rounds is to monitor water use, open and close check structures or
canal head gates as needed for irrigation, inform and communicate with irrigators, and monitor
the physical system for ditch breaks or clogs.
In addition to the responsibilities of water delivery and system monitoring, a ditchrider is
responsible for collecting a significant amount of data in ditchrider logs. The “Policies and
Procedures of the MRGCD” (MRGCD, document JBDPP94.001) state:
Each ditchrider will keep a record in a bound book (ditchrider's log) furnished for the purpose of showing water use by ditches. The record will show water users in proper sequence on each ditch, the date water was started and shut off, and whether irrigation was completed. Notes shall be made of any special cases of delivery, wasting of water, turning off at night, or violations of regulations and instructions regarding distribution or use of water. Each violation will be promptly reported to the Division Manager, and each such report will be noted in the record book. (Item I)
Ditchrider logs are three ring binders containing a page for each land parcel irrigated in a
ditchrider service area (sample pages provided in Appendix H-2, Attachments 1 and 2). These
ditchrider logs give the District office a written record of irrigator water delivery and use. The
data are critical field checks for lands reported irrigated and the assessments charged to water
48
users. The ditchrider logs also serve to support the on-going GIS mapping within the MRGCD,
and a way to monitor a ditchrider’s performance. With such information, the District office has
been able to match irrigated parcels with a particular water delivery structure in a GIS interface.
Although a significant amount of data is collected in the ditchrider logs, there are many
inaccuracies. Recent ditchrider interviews by the GIS staff, as well as improved mapping, are
resolving some of these inaccuracies, and should improve future ditchrider record keeping. The
MRGCD has stated that its contract with its ditchriders requires better bookkeeping.
5.2.3 Implementation of Scheduling
In theory, ditchrider water scheduling procedures are guided by the “Policies and
Procedures of the MRGCD” (MRGCD, document JBDPP94.001). Under the Water Distribution
section of this document, water users are required to schedule for water delivery with the
ditchrider at an established time, and not use water until specifically permitted. These policies
are as follows:
• No irrigation deliveries will be made except with the express permission of the ditchrider (Item E).
• The water user shall notify the ditchrider as far in advance as possible of his need for water, and the ditchrider will advise the water user as far in advance as possible when the water will be available (Item H).
• A ditchrider shall establish a definite time, preferably around mealtime, when water users may call to place orders for water and obtain information. In case ditchrider is not available the irrigator may call appropriate division office for assistance (Item K). In practice, the water scheduling and delivery methods differ significantly in each
ditchrider area. Since the characteristics of each ditchrider area are unique, it has been important
for the District to allow the ditchriders a considerable amount of local control and authority.
Thus, the local control has yielded scheduling methods that presumably work best in each
49
ditchrider service area. The ditchrider profiles summarize water-scheduling procedures for each
ditchrider interviewed (Appendix H-1).
In theory, the MRGCD ditchriders are responsible for scheduling and delivering water to
the users. In practice, they are given the autonomy to delegate operation of the check structures
and turnout gates to save their time and effort. In practice, therefore, water users may operate
their turnouts and necessary check structures. The ditchriders believe this is a cost-saving way of
system operation. They point out that user operation of turnouts is only done in accordance with
the scheduling policy or when users are given permission by the ditchrider (MRGCD, document
JBDPP94.001).
This study identified four water-scheduling procedures in the MRGCD service area,
through observation of the actual operational procedures of the ditchriders. These four
procedures are:
1. Irrigation event scheduling 2. Pre-season irrigation scheduling 3. Free-flow irrigator scheduling 4. Complete absence of scheduling
Ditchriders may employ a combination of these procedures depending primarily on the size of
irrigated parcel, the irrigator density, the nature of the lateral from which water is delivered, and
presence of Pueblo lands. They may also change the water-scheduling procedure in their area
during drought, as a drought management procedure. Each scheduling procedure and the reasons
for its use are discussed below.
5.2.3.1 Irrigation Event Scheduling
Irrigation event scheduling may be defined as a scheduling procedure whereby a
ditchrider requires irrigators to request water delivery for every irrigation event throughout the
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irrigation season. This scheduling procedure requires not only a request for water by the user,
but the “express permission of the ditchrider” to proceed with irrigation (Item 1E; MRGCD,
document JBDPP94.001). To aid in this scheduling process, most ditchriders will “establish a
definite time” when users are allowed to schedule for their irrigation events. For example, some
may require requests for water only the night before the desired delivery, while some may
require requests between one and seven days in advance of the desired delivery (Appendix H-1).
This scheduling procedure allows for a considerable amount of user flexibility, and a promise of
timely water deliveries in accordance with user’s schedules. However, it requires considerable
effort on the part of the ditchrider. In event scheduling, the ditchrider and irrigator must
continually communicate to ensure adequate delivery in a timely manner.
5.2.3.2 Pre-season Irrigation Scheduling
Pre-season scheduling can be defined as a scheduling procedure by which the water user
and the ditchrider enter into an agreement prior to the irrigation season, establishing the
frequency and duration of all irrigation events in an irrigation season. For example, an
agreement could be established such that a particular irrigator is to water every other Thursday
and Friday, day and night, for the entire irrigation season. When pre-season irrigation
scheduling is established, there is usually little contact between the user and the ditchrider during
the irrigation season, unless problems arise. Although this scheduling procedure is not
particularly common in MRGCD, it is practiced in some ditchrider areas. Pre-season scheduling
enables the ditchrider to know where water use is occurring on a given day, thereby simplifying
their work. It is harder, however, to appease user’s needs because pre-season scheduling reduces
51
the user’s flexibility to water at optimal times, and therefore some ditchriders find it more
difficult.
5.2.3.3 Free-Flow Irrigator Scheduling
Free-flow irrigator scheduling is used to provide water to small-scale agriculture users
who neither significantly affect the water head in the canals nor use water for long periods of
time. While some ditchriders designate certain times free-flow irrigators are allowed to use
water, other ditchriders allow free-flow irrigators to use water at their convenience. This
scheduling procedure is considered beneficial to both MRGCD ditchriders and the irrigators
using free flow, since it reduces communication needs and saves ditchrider time for other duties.
In areas where a large number of free-flow irrigators reside, only a small number of these
irrigators may actually know who the MRGCD ditchrider is in their service area. This practice is
beneficial to irrigators since they are allowed to use water at their convenience; most small-scale
irrigators choose to irrigate on weekends.
5.2.3.4 Complete Absence of Scheduling
There are two instances where either irrigation scheduling is not required or does not
always occur. The first case is that of the six pueblo’s lands within the MRGCD boundaries; the
pueblos hold prior and paramount water rights for irrigation, and take for their lands as much
water as they desire at any time. However, a large portion of the water routed through pueblo
lands returns back to the river or irrigation system drains and canals.
The second instance where scheduling does not occur is when irrigators do not follow the
policies and procedures of the MRGCD. Although the “Policies and Procedures of the
MRGCD” (MRGCD, document JBDPP94.001) explicitly state, “no irrigation deliveries will be
made except with the express permission of the ditchrider” (Item 1E), the interpretation of this
52
policy is not taken literally by all irrigators, and violations are quite common. In these situations,
most ditchriders will first give verbal warnings to the irrigator and make written record of the
event. In instances where a water user continues to take water without scheduling, some
ditchriders will lock the farm turnout and unlock it for the irrigator when he/she schedules for the
next event. In the most extreme instance, if an irrigator continually takes water without
scheduling, and especially if he/she vandalizes turnout locks in order to do so, the irrigator will
be denied the use of water for the remainder of the irrigation season. Although this is a standard
regulation understood by most ditchriders, none of those interviewed have had to deal with such
extreme cases.
5.2.3.5 Determinant Factors for Water Scheduling Procedures
The size of irrigated parcel, the density of irrigators in an area, the nature of the lateral or
canal used for water delivery, and the presence of pueblo lands are some of the reasons for
employing particular scheduling procedures. On the Socorro Main Canal where ditchriders have
large-scale agriculture and low-irrigator density, event scheduling or pre-season scheduling is
used to ensure adequate and equitable delivery to all users. This practice is typical of many large
canals in the Albuquerque, Belen, and Socorro Divisions. In areas of small-scale agriculture and
high-irrigator density, the free-flow method of irrigation, which is primarily unscheduled and
unregulated, is used to facilitate water delivery to multiple users.
The operational and physical nature of the canal or lateral used for water delivery also
plays a role in the scheduling procedure used. For example, in the Albuquerque Division, the
Herrera Ditch runs on an intermittent basis, making it necessary for the users to schedule with
the ditchrider to unlock headgates or, in this example, turn on the pump that supplies that
particular canal. In some canals in the Albuquerque Division, the physical nature of the canal is
53
such that both large-scale and small-scale irrigators may require a check structure to be dropped
to provide adequate water pressure or head for water delivery. In this case, most ditchriders
require users to schedule for water delivery, regardless the size of their irrigated parcel, to ensure
equitable delivery to all users on a canal.
The presence of pueblo land in a ditchrider area will also govern the scheduling
procedure used. In areas where there is a pueblo presence, a ditchrider may attempt to develop a
scheduling system among the pueblo irrigators. For example, on a particular lateral in the
Albuquerque Division, water is delivered to non-pueblo irrigators at the head and tail of the
lateral, as well as pueblo irrigators in the middle of the lateral. Although the ditchrider requires
his non-pueblo irrigators to schedule, he cannot require his pueblo irrigators to schedule.
Because this scheduling situation has been problematic for this ditchrider and the tail end water
users, he has attempted to develop a scheduling procedure for the pueblo to follow (Appendix
H-1). However, this scheduling procedure is not currently in use.
5.3 Water Delivery to Users
5.3.1 General Delivery Patterns
Water delivery patterns used by the MRGCD ditchriders include aspects of both on-
demand delivery and delivery rotation. On-demand water delivery is defined as the distribution
of water to users, made available within a few days of a water delivery request (Sagardoy et al.,
1986). Rotational water delivery refers to access to water on a by-turn basis, and can consist of
turns among laterals and/or turns within laterals. Rotation among laterals is defined as a water
delivery pattern in which lateral canals receive water by turns, allowing water use in some
54
laterals while the others are closed. Rotation within laterals is a water delivery pattern in which
water use is distributed in turns among water users. In other words, it is a rotation among users
in a head to tail fashion, within a particular lateral. It is possible to have both rotation among
laterals and rotation within the laterals in a single ditchrider service area.
5.3.2 Delivery Practice
Although water delivery in the MRGCD contains aspects of the patterns discussed above,
water is not distributed to users strictly as outlined. The actual operating practice, in most
locations, is to run all main and lateral canals at near full capacity, so that all demand within the
system can be met most of the time. The water delivery is on-demand, made possible by keeping
the available water supply in the canals always greater than the perceived demand. Although the
MRGCD may divert a large amount of water from the river, the unused portion is returned to the
river, and much of it is re-diverted downstream.
Ditchrider interviews tend to support the observation that at most locations within the
MRGCD and at most times, the supply is greater than the demand, and water delivery is on-
demand, with few denials for water delivery requests. During times when demand is greater than
supply, a rotational water delivery pattern is used, to better match the supply with an enforced
demand. This enforced demand is the result of rotational delivery because the ditchrider, not the
water user, controls the time water will arrive at the farm turnout. Typically, ditchriders at the
tail end of the irrigation system experience low supply situations first. For example, in dry years,
Ditchrider 310 has had to consolidate water flow into few canals by implementing a rotation
among laterals. In addition to rotation among laterals, Ditchriders 302, 306, and 310 have been
known to implement rotation within laterals.
55
According to interviews, there have been instances where a division, such as Belen or
Socorro, has had to implement some aspects of a rotational water delivery pattern. Ditchrider
interviews have shown that, although rotational delivery patterns have been required in the past,
such events typically occur only during the later part of an irrigation season in extremely dry
years. Although a strict rotational delivery pattern is not often used in the MRGCD, some
ditchriders choose to incorporate aspects of a rotational delivery pattern even when supply is
greater than demand.
5.4 Management of Water Demand to Users
In addition to planning, scheduling, and conveying water to users, ditchriders must
effectively manage water demand. MRGCD ditchriders manage water demand by qualitatively
assessing the relationship between water supply and demand, accepting or denying water
delivery requests, and by physically locking water delivery infrastructure.
5.4.1 Matching Supply and Demand
Ideally, an irrigation enterprise will attempt to match its water supply with the water
demand of the users, as closely as possible. In general, this requires quantitative water
measurements at the irrigation operation and user levels, and managerial capabilities to
administer and enforce both supply and demand. In situations where these do not exist, it is very
difficult, if not impossible to closely match supply and demand.
Aside from measuring water diversions at the four main diversion weirs on the river,
there is little attempt in the MRGCD to quantify water supply. Exceptions to this include some
laterals, such as the Bernalillo and the Corrales main canal in the Albuquerque Division.
56
Although recently there has been a significant effort to install new meters throughout the
District, these have been placed primarily in areas of return flow to the Rio Grande (Section 3).
Water demand may be defined as the amount of water delivered and used at the farm
level (Section 4). MRGCD does not attempt to measure the amount of water used at the farm,
primarily because the water users are assessed annually on an acreage basis. This amount is
currently $28 per year per acre, regardless the quantity of water used (Appendix H-2,
Attachments 3-1 to 3-5). A water user may request water delivery as often and for as long as they
feel is necessary to fulfill their irrigation water requirement. Therefore, water delivery requests
and water use are not limited in time or in volume. However, water use is still subject to the
approval of the ditchrider, in the general sense that water should be beneficially used.
Although the technical and managerial capabilities of quantitatively matching supply and
demand in the MRGCD are not in place, there is still an attempt to qualitatively match supply
and demand through operations such as “wasting” and alterations in water delivery and
scheduling procedures. For example, in situations where supply may be greater than demand, a
ditchrider may attempt to match supply and demand by releasing supply through “wasteways”
that return water to drains, and then diverting that water from the drains for use downstream.
In situations where demand is greater than supply, the MRGCD may change water
delivery procedures from on-demand to scheduled, rotational delivery. This rotational delivery
procedure is used to reduce demand by limiting requests in time and quantity to better match
supply.
5.4.2 Acceptance and Denial of Water Delivery Requests
The term “management of demand to users” is primarily used in this report to explain the
criteria that the ditchriders use to accept or deny a request for water delivery. As described, the
57
only scheduling procedure employed by the ditchriders that requires a request for water delivery
is irrigation event scheduling. However, ditchriders employ other criteria when managing water
demand or accepting/denying irrigation requests. For example, before a ditchrider can accept a
request for a certain time, he has to consider whether he has large-scale irrigators under pre-
season scheduling, which may prohibit the unscheduled user from receiving water at the
requested time. A ditchrider may also know from experience when pueblo irrigators tend to
irrigate or when a large number of free-flow irrigators use water. In addition, a ditchrider has to
consider other ditchrider service areas located downstream of his, which depend on his outflow
for their supply. These other criteria may affect a ditchrider’s decision to accept or deny a water
delivery request.
MRGCD ditchriders typically use one or more of the following criteria to deny or accept
a water delivery request:
1. Number of irrigators scheduled for requested time 2. Number and/or size of turnouts open at requested time 3. An understanding of additional ditchrider service area demand 4. An intuitive sense of the water volume and head in the delivery system
For example, when an irrigator requests delivery on a certain lateral, the ditchrider may
have a standard number of scheduled irrigators or open turnouts that he may allow at any given
time. If the request does not conflict with this standard, the ditchrider will give permission to
irrigate. If the request does conflict, the ditchrider will usually advise the user of the most
appropriate alternative time for water delivery. Most experienced ditchriders have a very good
understanding of how much time users need to irrigate their parcels. With this experience, a
ditchrider can determine when water will be available to fulfill another request for water
delivery. While some ditchriders keep a formal schedule on a calendar or in a notebook, other
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ditchriders know in their head who is irrigating at a given time and when those irrigation events
will be complete.
Some ditchriders may not keep track of either the number of scheduled irrigators or
opened turnouts on a lateral or canal, but will base acceptance or denial of a request on their
intuitive sense of the conveyance system. For example, because a ditchrider knows the nature of
the irrigations occurring during the requested time and can physically view the water level in the
lateral or canal, he will know from experience and intuition whether or not he can accept the
request. Such expertise is developed over many years of experience.
In accepting or denying a water delivery request, an MRGCD ditchrider will consider the
demand requirements of the ditchrider service areas downstream. Because most ditchrider
service areas are hydraulically connected through conveyance infrastructure, the ditchriders
maintain a constant communication network with each other in addition to water masters and
division managers. If a particular ditchrider feels that his supply is inadequate for his current
water demand, he may contact the ditchriders upstream and request more water. These upstream
ditchriders may respond by decreasing the number of scheduled irrigators in their area or
increasing water head to the downstream ditchrider’s service area by decreasing it elsewhere in
the system. Also, ditchriders will use physical indicators on their canals to insure adequate
delivery to ditchriders below. For example, ditchrider 201 knows there is enough water for the
Corrales area when two-inches of water flows over the spillway. While the management of
demand between ditchrider service areas may be systematic, most management is achieved
through inter-ditchrider experience and communication.
For the most part, a ditchrider will only deny a water delivery request if he feels there is
not an adequate supply of water to ensure delivery to his other users or to provide adequate water
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to the ditchrider service areas below. A lack of adequate water supply may be a short-term result
of intense water use by other irrigators in the area, or a longer-term condition resulting from
drought. Ditchriders will also deny water delivery requests from those users that: (1) are
delinquent in the payment of their MRGCD assessments, and (2) do not maintain their
community ditches, field ditches, or laterals. These guidelines are set forth in the “Policies and
Procedures of the MRGCD” (MRGCD, document JBDPP94.001) as follows:
• No water will be delivered to water users who are delinquent in the payment of Conservancy District Assessments (Item B).
• In the interest of the water user welfare and efficient water distribution, ditchriders will not be required to deliver water to silt-laden and weed-clogged community ditches, field ditches and laterals (Item C).
Although these guidelines are set forth by the District for all ditchriders, some ditchriders may
enforce them more than others. It is unknown to what extent these policies and procedures are
enforced within the MRGCD.
Aside from managing demand in an operational manner, an MRGCD ditchrider may
employ physical demand management tools. A ditchrider can physically regulate water use or
demand by locking turnouts and check structures as needed. As mentioned, in the event of a user
failing to schedule for water, a ditchrider may lock a turnout to prevent an irrigator from taking
water without scheduling. In other situations, a ditchrider may lock check structures to enforce
scheduling and prevent vandalism to the irrigation system or harm to other users. For example,
Ditchrider 203 implements a schedule such that users in the upper half of a lateral receive water
Sunday through Wednesday, and those in the lower half receive water Thursday through
Saturday. To prevent users at the upper half of the canal from taking the lower half’s water, he
will lock check structures, making it physically impossible for an irrigator to take water out of
turn.
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6.0 WATER ACCOUNTING ANALYSIS
6.1 Purpose
A quantitative analysis that accounts for the distribution, use and return flow of water in
the MRGCD system (water accounting analysis) is needed to characterize off-farm (conveyance)
efficiency and on-farm efficiency; to understand how changes in delivery and use might serve to
improve efficiency; and, to understand how changes might impact other inter-related elements of
the hydrologic system (i.e., shallow groundwater conditions and river flows). A complete
quantitative water accounting analysis requires the following information:
• Location and quantity of river diversions • Conveyance losses • Water demand in irrigated areas • Direct (surface) return flows from irrigated areas via drains and wasteways • Subsurface return flows from irrigated areas intercepted by drains • Indirect diversions (drain diversions or internal diversions) • Quantification of other water intercepted by the irrigation conveyance system through
surface or subsurface flow (bank storage, groundwater recharge, uncontrolled overland or tributary inflow, river seepage)
An analysis of how efficiency might be improved also requires knowledge of channel and farm
conditions, and some inference regarding minimum efficiency levels required for adequate water
delivery to farms, adequate application on farms, and adequate soil flushing.
Data collection programs within the MRGCD address many of the data areas noted
above; and recently, data coverage has increased significantly. However, the quantification of all
elements required for a complete water accounting is a monumental task. Many elements cannot
be measured directly. Some elements can be obtained indirectly, but not without extensive effort
and cost. Thus, even with the recent expansion in data programs, significant data gaps remain.
Given the existing data gaps, it is not yet possible to conduct a definitive or complete
water accounting analysis. Regardless, there is value in setting up a framework, or template, for
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such an analysis, and to populate the template with “best estimates”, or, “placeholder” values.
The utility of such an analysis includes the following:
• Data gaps are readily identified; • Sensitivity analyses can be performed to identify areas where data collection would be
more helpful for understanding the irrigation system water budget; • “What if” scenarios can be conducted to explore system relationships and make
inferences regarding various conditions and trends. • Using ranges of values for system variables, ranges of responses to operational changes
can be explored. For these reasons, a spreadsheet-based template for a water accounting analysis has been
constructed as part of this study. The accounting template is based on a simple mass balance
model, incorporating assumptions concerning water delivery, on-farm efficiency, crop acreage,
CIR and water demand for the four MRGCD divisions. This water accounting template is used
with existing data and estimates of unmeasured parameters to explore the bounds of the irrigation
system water budget. Where data are unavailable or uncertain, assumptions are made to create
“placeholder” values in the analysis. Ranges of values can be substituted for the placeholder
values to better understand possible outcomes and to evaluate the sensitivity of system outcomes
to various factors. Clearly, given data gaps, this analysis is not the “last word” on conditions in
the MRGCD. This effort provides a starting point for quantification and improvement of water
delivery and use within the District. Characterizations emerging from such analyses can be
compared to field observations and ditchrider/District knowledge, to explore opportunities and
constraints for irrigation system improvements; and, to identify data gaps in the irrigation system
budget.
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6.2 Accounting Analysis Template for 2001
The accounting analysis template has been populated, to the extent possible, using data
collected in the 2001 irrigation season and various assumptions for unmeasured parameters.
Using gaged data, estimates for ungaged flows, and other information regarding the physical and
functional characteristics of the divisions, a “base-case” and “sensitivity” analyses provide some
insight into the irrigation water budget for the four divisions. These analyses and underlying
assumptions are described in Appendix I. The 2001 accounting analysis is considered
provisional, due to the large number of assumptions made in the absence of data in several areas.
The accounting analysis describes the farm water budget, the canal water budget and the
irrigation budget for each division. Table 6.1 summarizes some of the division characteristics
used in this analysis. From this analysis, the off-farm efficiency, representing the water
delivered to farms divided by the division water supply, is provisionally estimated at 0.19, 0.39,
0.57 and 0.46 for the Cochiti, Albuquerque, Belen and Socorro divisions, respectively.
Sensitivity analyses illustrating the range of influence of selected assumptions on the calculated
off-farm efficiencies are described also in Appendix I. Over a reasonable range for most
assumptions, general conclusions drawn from the “base case” are applicable.
This exercise, although provisional, suggests that there is a difference in efficiency
throughout the divisions. The Belen and Socorro divisions reflect the highest efficiency. The
lower efficiency in the Albuquerque Division reflects the presence of urbanization The
significantly lower efficiency of the Cochiti Division is due, in part, to the provision of water 24
hours a day to satisfy pueblo customs. The efficiency in the Socorro Division is generally of the
same magnitude as that for the Belen Division, with the exception of the first month of the
irrigation season, which is impacted by imprecise data on the monthly distribution of water use
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within the Bosque del Apache. These provisional results suggest that 24-hour scheduling, low
irrigation acreage density, and long canal reaches contribute to lower efficiencies. Additional
work is recommended to further refine the assumptions employed in the template and to improve
the quantification of the irrigation and farm budgets, particularly as additional data become
available.
6.3 Delineation of Sub-Division Zones
In developing the template, the feasibility of extending the accounting analysis to smaller
units than the four MRGCD divisions was examined. Inspection of the divisions indicated the
presence of sub-areas of divisions which are hydrologically isolated or distinct, such as where
constrictions at the upstream and downstream ends of the sub-area limit the number of canals
and drains connecting them to adjacent areas. Estimates of acreage within each division and
within sub-areas have been developed using the land classifications from the GIS LUTA dataset
that has been made available by the New Mexico Resource GIS (NMRGIS) website and
maintained by the Environmental Data Analysis Center (EDAC), including Indian land defined
by the BLM, cropped areas within the MRGCD’s division, and fallow lands. These acreage
amounts, and ratios (distribution factors) relating division and sub-area acreage to total irrigated
acreage are provided on Table 6.2. While the configuration of the sub-areas suggests that an
accounting analysis could logically be extended to smaller areas, the lack of flow quantification
between the areas limits the utility of such an analysis at this time. Regardless, maps of the
proposed sub-areas and some presentation of their characteristics are provided (Figures 6.1
through 6.4), as they may be helpful in developing future monitoring programs and analyses to
support water delivery decisions.
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The zones shown on Figures 6.1 through 6.4 were developed by grouping lateral service
areas, or areas receiving water from a specific lateral system or waterway. In this process,
ditchrider zones were used to group lateral service areas because of the likelihood that a
ditchrider tends to work a service area(s) with identifiable inflow points, and where delivery
service to irrigated lands occurs on a small scale systems basis. Next, those areas were further
grouped based on spatial distribution and urban/rural characteristics. Table 6.3 identifies the
primary inflow channels for each zone and describes the physical location by river mile (RM)
and nearby landmarks. Table 6.4 shows the irrigation density for each zone, calculated as the
ratio of the irrigated area to the zone area.
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7.0 EVALUATION OF OPERATIONS AND INFRASTRUCTURE
Five operational and structural concerns have been evaluated for the purposes of making
recommendations for improving the efficiency of water delivery and use in the MRGCD. These
concerns include:
• water delivery patterns; • management of demand; • irrigation assistance service to users; • urbanization; • infrastructure.
7.1 Water Delivery Patterns
In general, MRGCD’s water delivery approach optimizes water conveyed to users by
increasing supply to the point that it is greater than demand (Section 3.0 and 4.0). Operationally,
this practice is more cost effective than trying to match supply and demand because it requires
less management, planning, monitoring, and financial resources. Evidence of significant return
flow to the river supports the observation that MRGCD diverts, and conveys water through its
system, such that supply is generally greater than demand. Therefore, on a system level,
efficiency could be increased by better matching supply and demand through a reduction in
diversions. The ability to divert less water, while ensuring the same or adequate delivery to
users, is dependent upon the water delivery patterns employed in the irrigation system.
7.1.1 Rotational Water Delivery
As discussed in Section 5, several water delivery patterns are employed by the MRGCD,
including on-demand delivery and some aspects of rotational delivery. Rotational water delivery
is a more efficient way to distribute water among users than on-demand delivery because water
deliveries to users can be made with smaller diversions. Since the primary water delivery pattern
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currently employed in the MRGCD is on-demand delivery, there is speculation that rotation
could be used to a greater extent. To better understand the water delivery practices in the
MRGCD, reasons for employing or not employing rotation must be evaluated.
In general, rotational water delivery is only used in the MRGCD in times of drought.
However, some ditchriders choose to implement some aspects of rotational water delivery for the
entire irrigation season. These full-time practices are typically rotation among laterals and
rotation among check structures. Rotation within laterals (among farmers) is only practiced in
situations where water supply is much less than the demand, since this method requires
additional organization and management. For example, during one dry season, ditchrider 301
required three additional ditchriders to maintain a strict rotation. Ditchrider interviews have
shown many reasons for employing or not employing a rotational delivery pattern. Table 7.1
lists some of the advantages of, and arguments against, a rotational water delivery pattern, from
the perspective of MRGCD ditchriders.
Advantages of rotational water delivery in the MRGCD include enabling ditchrider to
better control where water deliveries are occurring and how often users receive water throughout
the irrigation season. In a rotation, ditchriders communicate to water users when and how often
they can irrigate (rather than waiting for the irrigators to call to schedule particular water
delivery times). This artificially creates a water scarcity, encouraging efficient water use.
Several ditchriders have pointed out that the needed knowledge and infrastructure for a
rotation are already in place in the MRGCD, since it is District policy to practice rotation in dry
years. For instance, the Belen Division was on a rotational water delivery schedule starting June
25th of the 2001 season. The purpose of the rotation was to supply additional water to the
Socorro Division by increasing interdivisional flows in the Unit #7 Drain and river return flows
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in the Lower San Juan Drains (which discharge to the river at the lower end of the Belen
Division). Although this mandatory rotation was used to increase supply for the Socorro
Division, it was not used to decrease total Isleta diversions for the Belen Division. However,
rotational water delivery could also be used to satisfy user demand under reduced diversion from
the river.
Concerns expressed by the MRGCD against rotational water delivery include the lack of
adequate labor, management, planning, technical, and financial resources. Strict rotation
requires a significant investment of resources, and those resources may not be currently available
at the MRGCD. Ditchrider concerns include the social acceptance among water users of
rotational delivery. Currently, most water users in the MRGCD schedule for water use at the
times most convenient to them and most beneficial to their crops. If a strict rotation schedule
were implemented in the MRGCD, and particularly if the rotation system is not well designed,
many users may not receive water at the time they deem most optimal, and this may have a
detrimental affect on their crops.
In ditchrider areas servicing both pueblo and non-pueblo irrigators, it may not be possible
to implement rotational delivery because delivery practices cannot be enforced within pueblo
lands. The independent control over irrigation scheduling and water use that the pueblos
maintain adds a significant operational complexity to the MRGCD system. It also limits the
flexibility of the MRGCD to implement operational improvements, since the pueblos are
embedded within the system, not separate from it. The limits the pueblos impose on MRGCD
operational flexibility have a ripple effect through much of the system.
Additionally, site-specific concerns that might limit implementation of rotational delivery
have been expressed. These concerns include the characteristics of individual canals; some
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lateral canals may be extremely long or service too many users to implement an efficient rotation
system. Similarly, fluctuations in the canal water levels, as a result of rotation among laterals,
may encourage noxious weed growth and canal breaks. Although these concerns are valid and
important, they are site-specific and can be addressed on a case-by-case basis.
Overall, ditchriders tend to either fully support or not support the use of rotational water
delivery in the MRGCD. Those ditchriders who do make regular use of such practices generally
agree that more planning is necessary in their jobs, but once implemented and accepted among
users, rotation is effective and preferred to other water delivery procedures. In fact, they believe,
rotation would be possible in a majority of the District if sufficient start-up manpower and
support were provided.
7.1.2 Water Delivery Recommendations
It is a recommendation of this study, based on ditchrider interviews and observations and
an evaluation of ditchrider recommendations and concerns, that the MRGCD increase use of
rotational water delivery procedures. It is likely that MRGCD diversions can be decreased for
most conditions, while still fully supporting the current water demand, by employing rotational
water delivery procedures. It is recognized that site-specific concerns throughout the MRGCD,
particularly difficulty in scheduling or inability to schedule rotational water delivery within the
pueblos, may influence the feasibility of implementing rotation through the entirety of the
District. It is advised that MRGCD carefully study implementation methods for rotational water
delivery within the MRGCD, including field-testing in selected areas.
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7.2 Management of Demand
7.2.1 General Management Procedures
In some irrigation systems, demand is managed through a volumetric quantification of
water use and a subsequent service charge for that use. These systems include most irrigation
systems in northern Colorado, as well as the Elephant Butte Irrigation District in New Mexico.
In the MRGCD, service charges for water use are based on the land area being irrigated, rather
than the volume of water used to irrigate that land. Therefore, there is a disconnect between
service charges and the amount of water actually delivered on-farm. This payment structure
does not provide an incentive for conservative water use.
In irrigation systems such as the MRGCD, where charges to users are not based on the
amount of water used, the only option to promote efficient water use is to limit user’s access to
water, based on certain criteria. In a rotational water delivery, for example, water is only
available for use when the service canal is in operation or when water is physically at the farm
turnout. Most irrigation systems overseas (Egypt and Pakistan, for example) use this principle to
manage demand. Since volumetric water control may not be feasible in MRGCD in the near
future, managing demand through rotational water delivery is likely a more feasible option.
7.2.2 Management of Demand through Rotational Water Delivery
Rotational water delivery limits user access to water (1) by conveying water
intermittently in secondary canals and laterals and (2) by delivering water to turnouts and check
structures at a monitored, scheduled time. As mentioned, the current MRGCD practice is to keep
all canals flowing full most of the time. This allows users to take water at will, and since users
are not charged on a volume basis, there is little incentive for efficient use. Ditchrider interviews
clearly show that unauthorized water use in the MRGCD is a significant concern in many areas.
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Although MRGCD policies discourage unauthorized use of water through the right to sanction
users, most ditchriders believe enforcement of these policies is too expensive and difficult to
manage effectively. Rotational water delivery is recommended as a means of promoting
efficiency by limiting water access to users.
Currently, the following factors limit water use in the MRGCD:
• A natural limit to the amount of water crops can use before experiencing a reduction in yield;
• Sanctions that the MRGCD can impose on users who over-irrigate; • System-wide limits to water availability.
MRGCD ditchriders believe that although there is not a quantitative limit to the amount of water
that irrigators can use, a good irrigator would not use water in an unreasonable or wasteful
manner. In theory, a “good” irrigator knows there is a maximum limit to water that can be
applied to a field before a reduction in crop yield occurs. Although the ditchriders believe that
most irrigators practice good irrigation techniques, some farmers do have poor irrigation
practices; some ditchriders believe that the yield-reducing limit is not enough of a concern to
prevent these farmers from excessively using water.
Over-irrigation, according to the MRGCD, occurs when a water user applies excess water
to the point that it flows off the irrigator’s land. In situations where excess irrigation water spills
onto adjacent land or onto a roadway, the MRGCD has the right to sanction or deny water
delivery to the user. However, although some ditchriders interviewed spoke of frequent over-
irrigation in their service areas, these policies are not enforced consistently. Most ditchriders
appear reluctant to report instances of over-irrigation because there is not a mechanism to
document its occurrence. The seeming inconsistency with which sanctions are used in the
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MRGCD to limit over-irrigation calls for a more efficient means of limiting water use or
managing demand.
7.3 Irrigation Advisory Service for Users
The MRGCD has limited involvement with on-farm water use, beyond water delivery to
the farm turnouts. According to most MRGCD personnel, their jurisdiction ends at the field or
farm turnout. While ditchriders communicate with irrigators for the purpose of water delivery,
they are not directly involved in how irrigators utilize delivered water.
Although MRGCD legal jurisdiction ends at the turnout, it is recommended that the
District encourage efficient on-farm practices by providing an irrigation advisory service (IAS).
An IAS would provide irrigators with irrigation extension opportunities, including (1) advice to
farmers on how to improve their irrigation practices and (2) assistance to farmers in improving
farm layout.
Presently, some of the functions of an IAS are served by the NRCS. The NRCS has cost
sharing programs to support on-farm efficiency improvements, and has supported laser leveling
of fields and lining of on-farm canals throughout the district (especially, in recent years, in the
Socorro Division). The MRGCD Engineering Department currently refers irrigators to the
NRCS for this kind of service.
7.3.1 Extent of On-farm Involvement by the MRGCD
Currently, the MRGCD does not have a formal IAS for water users. The extent of on-
farm involvement includes informal advice offered by ditchriders, information concerning other
extension opportunities available, and free turnout installation for those users making on-farm
improvements. Ditchriders with considerable experience in the MRGCD will often help
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irrigators with their on-farm practices by sharing knowledge and giving advice. For example, in
ditchrider 205’s area, several irrigators experienced insufficient yields despite watering their
alfalfa at least once a week. When these irrigators expressed concern to the ditchrider, he
suggested they water every two weeks; when implemented, this improved the irrigator’s yields.
Similarly, ditchriders share ideas with water users about what on-farm practices are working or
not working for other irrigators in the area. They may suggest that water users laser level their
fields to increase yield and decrease the amount of time it takes to irrigate. However, ditchriders
are concerned they do not often have time to deal with on-farm issues and that they may not be
seen as sources of professional advice because on-farm concerns are not their primary
responsibility.
On-farm improvements, including laser leveling fields and lining or adding new on-farm
ditches, results in faster and more efficiently water application to fields. However, these on-farm
improvements often necessitate increasing the size of the original field turnout. Because faster
on-farm water increases MRGCD water deliver efficiency, the Socorro Division Manager
encourages on-farm improvements by upgrading turnouts at no cost to the water user. For these
turnout upgrades, the MRGCD often work directly with the NRCS for coordination and design
purposes.
Most ditchriders interviewed expressed the opinion that the District should have greater
on-farm involvement. On-farm improvements, especially laser leveling, significantly affect local
water delivery. Often, as a result of these on-farm improvements, irrigators decrease their
watering times significantly, allowing ditchriders to schedule that unused water elsewhere. The
limited involvement of MRGCD at the farm level, the concerns of ditchriders, and the belief that
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many on-farm practices can be improved, support the need for an irrigation assistance service in
the MRGCD.
7.3.2 Irrigation Extension Opportunities to Promote Efficient On-Farm Water Use
Many water users in the MRGCD, primarily in the Socorro Division, use extension
opportunities provided by the local Soil and Water Conservation District (SWCD) and the
USDA NRCS. These extension opportunities include the NRCS Cost-Share program assistance,
NRCS EQIP program, and funds available through the SWCD Mill Levy. These programs
primarily provide financial and technical assistance to irrigators for improving physical farm
layout, such as laser land leveling and concrete lining on-farm ditches. They also provide
technical advice such as prediction of water requirements for particular crops in particular soils.
The assistance programs have been beneficial for many irrigators in the MRGCD, but the
programs are limited by financial resources and cannot meet the needs of the entire District. A
summary of the NRCS extension program in Socorro is listed in the References, Socorro Soil
and Water Conservation District, 2000.
Although current irrigation extension opportunities help improve on-farm efficiency from
a physical perspective, they do not include services that directly relate to farmer irrigation
practices and operations. These services could include information on subjects such as irrigation
scheduling, best water application methods, optimal cropping patterns, weather forecasting,
fertilizer application, and new irrigation technology. Such information could be shared with
users through extension agents, free literature, and demonstration projects. Although the New
Mexico State University Experiment Station has several demonstration plots within the District,
it does not provide information or support to water users within the district. Many ditchriders
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believe irrigators could benefit from education on irrigation practices and operations. For
example, ditchrider 301 has an irrigator who monitors the soil moisture in his alfalfa fields to
determine the optimal time for irrigation and as a result has the healthiest alfalfa in the area.
Efficient water use such as this is highly encouraged by ditchriders because it simplifies their
jobs.
Although MRGCD legal responsibility ends at the farm turnout, as the entity responsible
for water delivery to the agricultural sector, the District should be concerned with the efficiency
of water use at the farm. It is recommended that the MRGCD provide an irrigation assistance
service including education and assistance in both physical farm layout and irrigation practices.
In addition to improving on-farm efficiency, an irrigation assistance service would lessen the
burden on the MRGCD ditchriders to provide these services.
7.4 Urbanization Concerns
Urbanization in the MRGCD service area has been occurring since District formation
(MRGCD Water Policies Plan, 1993). Table 7.2 shows the distribution of District lands, for
select years, devoted to different land use practices, including urbanization. The data show that
the proportion of urban land in the Middle Rio Grande valley has increased over time, and that
the proportions of cultivated lands and grass and brush have both decreased. While a decrease in
grass and brush land primarily reflects an increase in newly developed urban lands, a decrease in
cultivated land reflects a shift from agriculture to urban land use. In addition to losing ground to
urbanization, agricultural land has also changed in character. Urbanization has primarily
transformed large-scale agriculture into a more diverse, small-scale agriculture. A former forty-
acre parcel of alfalfa in the Albuquerque Division may now consist of eight five-acre parcels,
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where people irrigate small gardens, residential lawns and horse pastures. As a result, water
consumption has probably increased, since small urban plots are generally planted with high
water-use vegetation, and generally have associated domestic water use (from a municipal
supply or private well) in addition to irrigation. Although this change has been slow, it has
significantly affected the operations of the MRGCD by increasing:
• the number of “weekend farmers” and free-flow irrigators • the number of farm turnouts and community ditches • the required maintenance and repair of water conveyance structures
Ditchriders interviewed in this study believe these factors result in less efficient water use
in the irrigation system. It is recommended that MRGCD policy more fully address urbanization
concerns.
7.4.1 Increased Number of “Weekend Farmers” and Free-Flow Irrigators
The shift from large-scale to small-scale agriculture that has occurred in the more urban
portions of the MRGCD has transformed the type of water users in these areas. Ditchriders call
the urban, small-scale irrigators, “weekend farmers,” because most work weekday jobs in the
city and irrigate on the weekends. Ditchriders believe that, because these irrigators do not rely
on income generated from their crop and do not farm as a full-time vocation, they are less likely
to use water efficiently. One ditchrider spoke of a weekend farmer who continually over-
irrigates his residential lawn, flooding the adjacent road. Since the yield in the residential lawn is
not reduced (the lawn does not die), there is no incentive for this user to use water more
efficiently. Similarly, no incentives exist to laser level small plots or irrigate at the optimal time
for crops because income is not generated from many of these parcels.
In areas where the number of “weekend farmers” has increased, the MRGCD has had to
change water delivery and scheduling. While the ditchrider service areas have remained the
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same, the number of irrigators has considerably increased in the Albuquerque and Belen
Divisions. Unable to manage all irrigators, many of these ditchriders have increased the use of
free-flow irrigation scheduling and water delivery. As mentioned, free-flow irrigation saves time
for the ditchrider, but it also reduces the amount of control the ditchrider has. It is difficult for a
ditchrider to prevent inefficient water use in densely populated areas. In addition, since most
urban users desire irrigation on the weekends, many ditchriders find it difficult to implement a
scheduled system of water delivery.
7.4.2 Increased Number of Farm Turnouts and Community Ditches
When large parcels of land are subdivided adjacent to MRGCD canals, new landowners
apply for an MRGCD turnout to irrigate their gardens, pastures and lawns. Generally,
application for turnouts are, and the cost of turnout and installation is born by the irrigator.
MRGCD policy (MRGCD, document JBDPP94.001; see Appendix H-2) governing installation
and replacement of farm turnout states, “farm turnouts will be installed on the basis of one
turnout per ownership or farm unit up to 40 acres in size.” Consequently, the number of turnout
structures has increased in urbanized areas. There does not appear to be a policy governing how
many turnouts the MRGCD will allow when land is subdivided adjacent to the irrigation system.
Because there is concern regarding less efficient water use in urbanized areas, it is recommended
that policy be implemented to control significant increases in turnout density.
MRGCD policy does address the subdivision of lands along preexisting lateral channels.
When such land is subdivided, on-farm laterals become community ditches, and are not within
the jurisdiction of the MRGCD. No policies are outlined regarding how these community
ditches should operate within or relate to the MRGCD water delivery system. Policy does not
require community ditch users to organize, communicate, and plan for water deliveries. The lack
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of restrictions on community ditches in the MRGCD has given rise to many problems. While
some community ditches have formed associations, created a formal water schedule within the
ditch, and hired professional irrigators, most operate with little organization (Ditchrider 205 and
206). It is not uncommon to find unkempt community ditches in the Albuquerque Division,
where not all irrigators receive water in the same rotation (Ditchrider 208). Community ditch
users may request water delivery at separate times, requiring the MRGCD to supply water to the
ditch individually for each user. This lack of organization in some community ditches
contributes to less efficient water use. It is recommended the MRGCD develop policies and
guidelines for water user associations within community ditches.
7.4.3 Increased Maintenance and Repair Requirements
The urbanization of agricultural land increases maintenance and repair requirements in an
irrigation system. In the MRGCD, an increase in urbanization has been coupled with an increase
in recreational use, as well as trash dumping and vandalism, along canal banks and right-of-
ways. The time required for additional maintenance and repairs in urban areas decreases the
effort the MRGCD personnel can place elsewhere in the District. These additional pressures
contribute to a decreased emphasis on efficiency issues in the MRGCD.
7.4.4 Positive Aspects of Urbanization
Although urbanization has and continues to be a major concern, positive aspects of urban
water use should be emphasized because it is a significant and unique aspect of the MRGCD. In
supplying raw canal water for urban uses, the MRGCD provides benefits to urban irrigator and to
the urbanized centers, in the form of cheaper, non-treated water. The use of irrigation water in
urban lawns and gardens is an efficient form of exchange between the urban and agricultural
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sectors because it re-allocates unused agricultural water and decreases the demand for treated
city water.
In several communities in Colorado and Utah, irrigation ditch companies and city
governments have cooperated to transfer excess ditch water for use in urban lawn irrigation. The
MRGCD is already encouraging the use of canal water for urban irrigation; further study of areas
of potential collaboration between the MRGCD and neighboring city centers is recommended.
More stringent guidelines and policies should be implemented to control the negative aspects of
urbanization in the MRGCD, however, so that this collaboration can be fully optimized. It is
recognized that implementation of tighter control may not be immediately feasible due to legal
and financial constraints.
7.5 Infrastructure Concerns
Infrastructure concerns, though a subject of this study, have been given comparatively
less attention than operational concerns. Infrastructure concerns tend to be more site-specific,
and will not have as great an impact as operational improvements in improving system-wide
efficiency and performance. Still, several general recommendations regarding infrastructure are
presented which could improving the efficiency of the MRGCD. A detailed list of site-specific
infrastructure concerns and proposed remedies are presented in Appendix D. General MRGCD
infrastructure concerns include:
• Canal leakage / conveyance losses • Canal crossings • Canal damage due to seasonal flooding of natural floodways (arroyos)
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7.5.1 Reducing Conveyance Losses
Piping and lining of some conveyance infrastructure in the MRGCD is recommended to
improving District efficiency, particularly for extended stretches of canal where little or no
irrigation occurs and for canals with significant water loss and bank instability. Where feasible
and appropriate (for example, where gradients are sufficient and sediment loads and flow
variations are favorable, and where there are high losses from earthen canals) conveyance of
water through pipes or lined canals, as opposed to earthen canals, can increase water savings and
decrease maintenance requirements. Although initial cost may be significant, benefits include
operational and physical efficiency.
Some MRGCD officials maintain that the seepage from earthen canals is beneficial as a
source of groundwater recharge and as a source of water for riparian growth. Assessment and
comparison of these benefits to other benefits associated with decreased river diversion have not
been evaluated in this study. However, fostering these processes are not the primary goal of an
irrigation system. In the context of meeting irrigation goals in a water-short basin, unnecessary
seepage is inefficient, if not wasteful.
Many of the earthen canals in the MRGCD system appear to not be subject to excessive
seepage, but there are some canal reaches that would benefit from lining or replacement by
pipes. This study identified the following canal reaches that might benefit from lining or piping::
• San Juan Main Canal (Ditchrider 301), • Belen Highline Canal (Ditchrider 304), • Gun Club Lateral (Ditchrider 211), • Several canals in Cochiti Division, • Canals throughout the system with persistent gopher hole problems (see Appendix D
for details).
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In addition, there are general ditchrider concerns about structural issues in canals in ditchrider
areas 209 and 404. It is recommended that further study address these concerns, which include
water seepage, canal siltation, bank stabilization, gopher holes, and extended canal stretches that
it may be feasible and beneficial to replace by pipe.
7.5.2 Canal Crossings
More rigorous enforcement of policy governing canal crossings in the MRGCD is
recommended. Inadequately designed canal crossings in the MRGCD limit water conveyance
capacity, increase debris clogs in conveyance infrastructure, and increase system maintenance
requirements, all of which decrease efficiency. Current MRGCD policy regarding canal, lateral,
levee and drain crossings include the following (MRGCD, document JBDPP94.001):
• No crossing may be constructed without prior written approval of the Conservancy District and the Bureau of Reclamation. Such approval shall be in the form of a license. Licenses for construction of new crossings will be issued only after the responsibility for maintenance has been clearly established.
• A license for the construction of a crossing over District facilities may be granted in the event of definite inconvenience or hardship imposed by severance or as a result of District or Bureau construction, real estate transactions or developments which result in loss of access detrimental to land use through no fault of the applicant.
• Request for licenses to construct new crossings must be submitted in writing to the Chief Engineer of the Conservancy District. No construction will be permitted until controlling elevations have been established or checked in the field by a representative of either the District or the Bureau.
Although MRGCD policy requires licensure and design approval for crossings placed
along their conveyance system by other parties, observed canal crossings within the system
suggest that the implementation of this policy has not been adequate. For example, the Sandia
Lateral includes five private canal crossings that limit the carrying capacity of the canal. This is
problematic for Ditchrider 202 because he is often unable to provide sufficient water to satisfy
the Pueblo Prior-and-Paramount water rights on this lateral. Crossings along the Alameda
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Lateral are problematic for Ditchrider 204. This 19-mile long lateral includes 195 crossings,
many of which continually trap debris and clog the conveyance system. Although all crossings
are licensed by the MRGCD, criteria for adequate placement and construction of crossings have
changed over time. It is recommended that current crossings that limit the capacity and flow of
water in MRGCD conveyance infrastructure be removed and that future crossing licensure be
more stringent. Future study is recommended for identifying additional inefficiencies within the
MRGCD as a result of canal crossings.
7.5.3 Flooding by Arroyos
Many arroyos (natural floodways) run perpendicular to the MRGCD conveyance system.
During monsoon rains, sediment and water from the arroyos can flood the canals, causing ditches
to overtop their banks or breach. This can result in significant water loss, siltation, decreased
conveyance capacity, and increased maintenance and repairs for the MRGCD. Infrastructure
changes, including piping/lining of canals, canal siphons under arroyos, and retention basins, are
recommended for decreasing losses caused by arroyo flooding. Much of this infrastructure is
already in place in the MRGCD, particularly in the Cochiti Division. However, in other areas,
required infrastructure is inadequate or absent. Further characterization of the required system
improvements needed to minimize arroyo flooding impacts is recommended.
7.5.4 Control of Irrigation
The MRGCD should give serious consideration to methods of controlling the timing of
water use. Efficiency in an irrigation system is decreased when ditchriders do not have rigid
control over water use. If the MRGCD does not have the ability to control the irrigation times of
its irrigators, it cannot effectively implement rotational water delivery (or any other form of
scheduled water delivery).
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The MRGCD will need to develop methods to gain this control – probably through
education, as well as structural improvements. Steel screw-type check structures and turnouts
can be locked, but problems are caused to this system when these locks are cut. Also, the
MRGCD feels that these structures give them less flexibility, due to their underflow design.
Wooden check structures, which are still common in the district, have an overflow design,
which, the district says, makes them somewhat self-regulating. However, to operate the wooden
check structures, boards are placed in the check to raise the level of water in the canal; and they
are removed at the irrigator’s own wooden stop-log turnouts, so water will flow onto his field.
This is typically done by the irrigator himself, and therefore the MRGCD doesn’t have control
over when and for how long this is done. The MRGCD will need to determine the most
appropriate combination of check structure and turnout design and education to gain effective
control over irrigation within its system.
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8.0 FEASIBILITY AND IMPLEMENTATION OF IMPROVEMENTS
This section addresses the feasibility and general implementation needs of the previous
recommendations for improvements to system operations and infrastructure (Section 7). The
following topics, in general, will be addressed for each recommendation:
1. How would the recommendation be implemented? 2. What organization and policy changes would be required for implementation? 3. What are the economic implications of implementation? 4. What additional physical infrastructure will be required for implementation? 5. How are other irrigation systems following similar practices?
8.1 Rotational Water Delivery
8.1.1 Justification
Water should be delivered to users within the MRGCD according to a rotational water-
delivery procedure; this is the most feasible way of creating scarcity within the system, thereby
promoting more efficient water use. Charging for water on a volumetric basis could also create
this scarcity, but this approach is not deemed practical or feasible at this time. Also, its
implementation may have some conflicts with current water-rights law (this would require
further investigation).
8.1.2 Initial Planning
The first step in implementing rotational delivery is determination of water requirements
at the lateral and farm level. Crop water requirements depend on soil type, size of irrigated
parcel, on-farm efficiency, conveyance water loss, canal capacity, and crop type. Prior to the
irrigation season, farm characteristics within the service area should be inventoried to predict
seasonal volumetric water demand. Similarly, seasonal volumetric demand at the lateral level
should be determined by summing all farm requirements and anticipated conveyance losses in
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the lateral. Consideration must be given to canal capacity, and its ability to deliver the required
demand.
Once the anticipated seasonal demand is quantified, it should be related to water supply
for the purposes constructing a rotational delivery schedule, such as seen in the sample rotational
delivery schedules shown in Appendix H. A rotation schedule typically includes alternating
points of delivery to laterals and farm turnouts on a weekly basis. In constructing rotational
delivery schedules, consideration must be given to the required timing (frequency and duration)
and volumetric demand of water deliveries. For example, the schedule must consider that some
crops require water weekly (chili), while other crops require water bi-weekly (alfalfa). Similarly,
the likely duration of irrigation events must be considered, since these durations will differ
significantly with farm size, soil type, land level, and crop.
In locations identified as suitable for rotational delivery, organization, policy, and
economic modifications may be necessary. Pre-season planning is used to determine the
volume, frequency, and duration of water requirements, as well as a schedule and points of
delivery. Although initially expensive and time consuming to create, rotational delivery
schedules can be used year to year with few pre-season modifications. Typically performed by
an agricultural engineer, the initial rotational delivery process will require constant
communication and feedback from division managers, ditchriders, and water users. It is essential
that the central administration, division managers, and ditchriders communicate the rotational
delivery process and the resulting seasonal schedules to water users.
8.1.3 Actual Implementation
During the irrigation season, management and monitoring of water deliveries, and
system-wide communication of this information, is critical to system operation. For instance,
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during strict rotation (among and within laterals), Ditchrider 301 requires the assistance of three
additional ditchriders. Currently, MRGCD ditchriders are on-duty 24 hours a day, seven days a
week, making it difficult to further monitor and manage the system for rotational water delivery.
The Elephant Butte Irrigation District (EBID), in the Lower Rio Grande, employs three
ditchrider shifts for every service area, allowing constant monitoring and management of the
irrigation system. Even though the EBID delivers water to users on-demand, monitoring at all
times is insurance against illegitimate water use. In a sense, rotational delivery reduces the need
for monitoring, particularly among laterals, because water cannot be used illegitimately if there
is no water in the lateral. Conversely, rotation within laterals may require more monitoring,
because users on the upper end will have water flowing past the turnout throughout the rotation.
From an organizational perspective, a shift to either form of rotational water delivery will require
additional ditchrider time and financial support.
8.1.4 Policy Support
In addition to implementing rotational water delivery in practice, the MRGCD must have
appropriate policy to support such practice. The following policies regarding rotation presently
exist in the MRGCD (MRGCD, document JBDPP94.001; see Appendix H-2):
• Water will be delivered to ditches at the upper end of each division and will be supplied progressively toward the lower end of the division. Irrigation will be completed in each area before transferring the water to another area, provided inter-division water rationing and rotation are not required (Item 1d).
• In a similar manner, irrigation deliveries will be started at the upper end of each ditch, and each tract served by that ditch will be irrigated progressively downstream upon request from the water users. No irrigation deliveries will be made except with the express permission of the ditchrider (Item 1e).
• During the periods of water shortage, it is essential that water users irrigate both day and night on a seven-day schedule to utilize available supplies. Failure to do so will be construed to indicate no further need for water (Item 1f).
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• Water users who work outside their farms will, if possible be advised in advance as to when water is scheduled for delivery to their farm so that they can make arrangements for labor that may be required (Item 1g). Policy 1d and 1e set forth the general requirements for rotational water delivery,
progressive water delivery toward the lower end of each division and of each ditch. The
MRGCD has a responsibility to inform irrigators of scheduled water deliveries, and water users
are required to irrigate at their allotted time, or an indication of “no further need for water” will
be construed (1g). This allotted time includes day and night, seven days a week (1f). In theory,
it is feasible for the MRGCD to implement rotation because essential policy is already in place.
In practice, rotational water delivery requires enforcement and support of these policies.
According to New Mexico State Statutes, conservancy districts have the right to change the
manner in which irrigation waters are distributed to users. N.M.S.S. 73-14-50 states, “the method
and manner of distribution and allocation may be altered and changed as often as is deemed
requisite. The decision [decisions] of said board of directors, as determined from time to time,
shall be expressed in rules and regulations to be adopted and published…”
8.1.5 Infrastructure Requirements
MRGCD is capable of implementing rotational water delivery because much of the
needed infrastructure, such as check structures in the lateral canals, presently exists. This is true
in the Belen and Socorro Divisions, where rotation has been implemented under low supply
conditions. As mentioned, rotation requires “quantification” of supply and demand; however,
this does not have to be on a volumetric basis. Water supply and demand can be quantified in
units of time, thus eliminating any need for lateral metering technology. However, a rotational
delivery system can be operated more efficiently when water is measured volumetrically on the
lateral scale.
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8.2 Management of Demand
Because charges for water delivery in the MRGCD are based on acreage, and do not
change according to the quantity of water used, there is little accountability for water use. Water
service charges on a volumetric basis create a sense of accountability, but involve an extensive
implementation process. The following recommendations have been presented as a feasible
means of promoting scarcity and efficiency through the management of water demand:
1. Limit water access to users through rotational delivery 2. Use crop and land characteristics as a basis for determining frequencies and
durations of irrigation events Implementation of rotational water delivery can be used to manage water demand with
few additional requirements. However, determination of demand throughout the irrigation
season is prerequisite to any change in water delivery. Guidelines for determining the
appropriate frequency and duration of irrigation events are developed from on-farm
characteristics and theoretical requirements for irrigation events. Although the process of
gathering this information is expensive and timely, it is the same as that required for rotational
water delivery. Rotational water delivery justifies water service charge on acreage basis,
because it limits user access to water, much like a volumetric water service charge would.
The recommendations above require few policy, organization, and infrastructure changes,
and are therefore quite feasible. Policy governing water service charges based on land are
already in place. New Mexico State Statutes affirm, “class ‘A’ property, shall embrace irrigable
lands in the district and shall be assessed and levied against annually as herein provided at a
uniform rate per acre” (N.M.S.S., 73-18-6A). Organization and economic requirements are the
same as those required for rotational water delivery, including significant planning, managing,
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and monitoring. As with rotation, initial data collection and evaluation require additional labor
resources, both in the field and central office.
8.3 Irrigation Advisory Service
It is recommended the MRGCD provide an irrigation advisory service (IAS) including
education and assistance in both physical farm layout and irrigation practices. With few
irrigation advisory opportunities currently available within the area served by the MRGCD,
implementation of IAS will require considerable effort. However, on-farm advisory programs
can significantly improve practices within irrigation systems. Implementation should include the
following services and resources:
1. Advice to farmers on how to improve irrigation practices • Irrigation Scheduling • Best water application methods • Weather forecasting • Fertilizer application • Optimal cropping patterns
2. Assistance to farmers in improving farm layout • New irrigation technology • On-farm conveyance systems • Turn-out/diversion systems • Land preparation
An IAS provides the services and resources suggested above by managing demonstration
plots for new technology and providing hands-on demonstrations, providing on-line and
telephone services for weather forecasting and irrigation scheduling, distributing free educational
literature, and providing extension agents for on-farm consultations. In addition to providing on-
farm services, the IAS must actively promote and encourage farmer participation in IAS projects
for them to be affective. The Food and Agriculture Organization of the United Nations (FAO)
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states the basic philosophy of an IAS, “is that farmers become responsible for the execution of
improvements . . . with some technical guidance and financial incentives provided by the
administration” (Sagardoy et al., 1986). While technical guidance is provided by IAS staff,
financial incentives include breaks on annual service charges or a continuation of free turnout
installation for on-farm improvements.
MRGCD will need to consider how best to organize for irrigation assistance to their
users. The IAS may choose to be organizationally involved with on-going extension efforts of
the NRCS and SWCD. If financial incentives for IAS participation are offered to water users,
these incentives should be a matter of policy. These incentives can be directly related to water
service charges, because improvements from IAS result in greater efficiency and less water use.
Economic implications of an IAS may be significant. While the primary function of the
IAS is the “service” aspect, or transfer of knowledge by staff, it may be necessary to physically
demonstrate and provide these services. It is financially burdensome to demonstrate and promote
new irrigation technologies, because the District must cover the cost of implementation. It is
recognized the MRGCD may not be financial capable of supporting IAS programs, and may
need external financial assistance. Little physical infrastructure will be required for an IAS to be
implemented, aside from demonstration plots within the District.
IAS is used in many irrigation systems in the U.S. and abroad. The Northern Colorado
Water Conservancy District supports the Irrigation Management Service (IMS). With six full-
time employees and six college-interns, the IMS “assists area farmers and turf managers without
charge in practical application of irrigation principles and technologies to improve water
management and conservation on a voluntary basis,” for 1.5 Million acres (not all of which is
irrigated). The IMS support the following efforts and concerns (among others): Best
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Management Practices for agriculture, canal automation, drip irrigation, surge valve loan
program, salinity, soil testing, landscape/turf water management and conservation, and
weather/evapotranspiration data.
8.4 Urbanization
In evaluating the effects of urbanization, the intent is not to limit use of raw water for
urban landscape irrigation, but rather to encourage greater collaboration between the MRGCD,
urban users, and municipal governments. Supporting these relationships will lessen the negative
impacts of urbanization on the irrigation system. In this section, general implementation
concerns will be addressed for the following recommendations:
1. Limit the number of turnouts in new subdivisions 2. Explore avenues for cooperation between the MRGCD and municipal governments to
encourage the use of raw water for urban landscaping (“dual systems”). 3. Require Water User Associations (WUA’s) for new subdivisions in order to decrease
MRGCD’s maintenance and repair burden
When new subdivisions are built on existing agricultural land, the number of turnouts in
the MRGCD irrigation system should not be increased. Subdivisions requesting access to
irrigation water should be encouraged by the MRGCD, but should be allowed to access water
from existing turnout structures only. New water users in subdivisions should form Water User
Associations (WUA’s) along their community ditch (often the original farm lateral from the
existing turnout). The purpose of WUAs is to manage and organize water users in order to
equitably share the resources and the responsibilities for system maintenance and repairs. The
Grand Valley Irrigation Company has created the Landowner’s Guide to Incorporating
Irrigation Ditches and Laterals (Bertrand, et. al 1996), and sets forth the following two basic
steps in forming WUA’s: (1) gathering information and organizing the lateral with the other
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landowners, and (2) managing the lateral for the future benefit of the landowners. The MRGCD
should encourage the formation of these organizations through similar educational opportunities
as the Grand Valley Irrigation Company, because community ditch organization decreases
operational problems, maintenance, and the number of turnouts. In addition to adopting new
policy to support these WUA’s, the MRGCD should implement the existing policy that limits the
number of turnouts the District can approve.
The MRGCD should collaborate with municipal governments to encourage raw water use
for urban landscape irrigation. Implementation is quite feasible because the MRGCD already
operates a dual water use system by providing to urban water users in the Albuquerque and
Belen Divisions. However, this collaboration is informal and not managed between the two
entities. As mentioned, communities in Colorado and Utah are in the process of creating formal
relationships, whereby urban users receive raw water from irrigation districts and companies.
The MRGCD is ahead of this process, because much in the direction of implementation has
occurred. Only formal management is needed to continue successful operation and encourage
future opportunities.
The implementation of WUA’s and dual systems is a feasible means of decreasing
additional maintenance and repair in the irrigation system as a result of urbanization. As
WUA’s, community ditches will be required to maintain and repair their ditches, decreasing
problems for the MRGCD. Also, the revenue generated from additional urban users in a dual
systems program can pay for the increases in maintenance and repair costs that result from their
existence. The negative impacts of urbanization can be decreased by implementing associations
among urban water users through WUA’s and between the MRGCD and municipal governments
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through dual systems programs. Further study is needed to fully understand the implementation
process in these areas.
8.5 Infrastructure
Present infrastructure is generally adequate for water conveyance and distribution among
users in the MRGCD. However, opportunities exist for infrastructure improvement for the
purposes of water conservation. It is feasible to make some general improvements to the
infrastructure in the MRGCD. The general areas of concern are:
• Lining of canals and the use of pipe for water conveyance, where feasible and beneficial • Canal crossings • Seasonal flooding of arroyos • Irrigation control
In general, full-scale lining of irrigation canals is not necessary. However, in limited
areas it may be beneficial to line or pipe sections of canal. Before implementation,
comprehensive study is needed to identify areas where lining or piping might be beneficial, and
where system gradients are sufficient to make concrete-lining of canals or piping feasible. When
financial resources are available, the MRGCD does concrete-line unstable and water losing
sections of canal. Because they currently line canals, it appears MRGCD has the capability of
improvement, but not necessarily the financial resources.
The MRGCD should enforce existing policy concerning canal crossings. In theory,
policy changes need not be implemented; in practice it will be necessary to improve existing
crossings (such as by replacing them with bridge or box culverts, which allow more effective
flow) as well as better manage future policy regarding the approval of canal crossings. Financial
resources will be needed both to improve existing problems and to create a more rigid approval
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policy for canal crossings. The approval process should include definite design criteria that do
not limit the carrying capacity of canals or restrict water flow.
The MRGCD should explore structural and operational alternatives for lessening the
negative impact on the irrigation system caused by natural floodways (arroyos). Structural
improvements in the Cochiti Division concerning these arroyos, should be implemented
elsewhere in the MRGCD. The designs used in the Cochiti Division are feasible elsewhere in
the District, but will required additional financial resources. The MRGCD should consider
operational alternatives for controlling arroyo flooding similar to that used by the Elephant Butte
Irrigation District (EBID). The EBID irrigation system layout is similar to the MRGCD, in that
arroyos run perpendicular to canals and laterals. The EBID electronically meters water flow in
major arroyos to track peak discharges and times of arrival to the irrigation system. During a
storm event, discharge is relayed to the main office via telemetry where automated wasteways
are opened or ditchriders are contacted to make adjustments in the conveyance system.
Although relatively new, the arroyo-tracking program has been helpful for the EBID because
they have advanced information to assist them in making decisions about flooding events. Even
though initial costs for arroyo-tracking programs are high, benefits result from lowered
maintenance and repair costs.
Finally, the MRGCD should give serious consideration to methods of controlling the
timing of water use. Efficiency in an irrigation system is decreased when ditchriders do not have
rigid control over water use. If the MRGCD does not have the ability to control the irrigation
times of its irrigators, it cannot effectively implement rotational water delivery (or any other
form of scheduled water delivery). The MRGCD will need to develop methods to gain this
control – probably through education, as well as structural improvements.
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9.0 CONCLUSIONS AND RECOMMENDATIONS
9.1 Analysis of MRGCD Irrigation System and Measurement Program
Metering in the MRGCD irrigation system has seen marked improvements over the past
five years, with most major division inflows and outflows presently gaged, or expected to be
gaged within the next year. However, significant data gaps remain that make evaluation of
irrigation system efficiency and recommendations for improved water management subject to
uncertainty. Despite these uncertainties, an estimated irrigation system water budget has been
prepared using data and estimates for the 2001 season. Observations from this analysis and
inspection of historic records support the following general conclusions:
River Diversions: Total river diversions in 2001 were 492,000 acre-feet. This number reflects the total amount of water physically diverted from the four river diversion points (regardless of its origin, or whether it is returned to the river further downstream or rediverted). This value is approximately 100,000 acre feet less than the average over a number of years in the 1990s and reflects recent MRGCD efforts to improve the overall system efficiency. The 2001 total river diversions are in the range typical for the 1980s. This year’s operation and previous years in the 1980s indicate that the MRGCD can operate with river diversions less than 500,000 acre-feet per year. Furthermore, past records indicate that considerably lower diversions have occurred in the past; and, evaluation of the system water budget suggests that it may be quite possible to meet system demands with diversions below 400,000 acre-feet per year, given the present condition of the conveyance system and infrastructure. Further reductions may be possible with improvements in operations or infrastructure, although these will require funding for capital improvements, enhanced maintenance or additional staffing.
Off-Farm Efficiency: The off-farm efficiency is greatest in summer months, when crop demand is highest with respect to supply. The Belen and Socorro divisions have the greatest efficiency of the four divisions. The Cochiti Division has a very low efficiency, in part due to 24-hour scheduling to satisfy pueblo customs. The efficiency of the Albuquerque Division suffers due to impacts of urbanization. District Consumptive Use: District consumptive use is estimated to be in the range of 150,000 acre-feet. Significant uncertainty in this number stems from lack of precise definition of the number of irrigated acres, and from uncertainty in the consumptive irrigation requirement, or, CIR. Numerous sources of information on these parameters have been reviewed; variability in derived estimates among different sources reflects the difficulty in estimation of these parameters. Better quantification of the consumptive use would be extremely helpful in evaluating the irrigation water budget and evaluating water savings opportunities.
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Total River Returns: Total river returns for the 2001 season were estimated at approximately 280,000 acre-feet, for the Albuquerque and Belen Divisions. Cochiti river returns, ungaged, may bring the total river returns to a quantity on the order of 300,000 acre-feet (very little of Socorro Division outflow returns to the river – outflow from this Division is primarily to the LFCC, and to the downstream BdA). District Net Water Use: With total river diversions of 492,000 acre feet and estimated LFCC diversions of 27,000 acre feet, the district supply (interdivisional flows are not included in this quantity) is estimated at 519,000 acre feet for the 2001 season. With estimated river returns of 300,000 acre feet, the net water use plus Socorro Division outflow is approximately 219,000 acre feet. The net water use cannot be isolated from this lumped quantity until the Socorro Division outflow becomes gaged, and, therefore, is unknown for 2001. This outflow is presently being gaged, and therefore this quantity should be quantifiable for 2002, when those gage records become available. However, non-irrigation system related drain inflows will be imbedded in this term (i.e., arroyo inflow, changes in groundwater storage, river seepage); and may vary from year to year in the degree of their influence on the water budget-derived net water use. Until the Socorro outflow can be isolated from the net water use term, and until at least several years of data are obtained to support evaluation of the non-irrigation system contributions to this term, the net water use will not be a meaningful reflection of the irrigation system consumptive use.
Ratio of Composite Division Supply to District Supply: The composite division supply, defined as the sum of the supply to all four divisions (river diversions, LFCC diversions and interdivision flows), has been calculated based on gage records and estimated parameters to be approximately 642,000 acre-feet per year. The ratio of the composite division supply to the District supply is 1.24, indicating that division return flows comprise a significant portion of supplies to downstream divisions. This operational approach provides flexibility in operation to the District, may help alleviate supply-demand problems in difficult locations, and reduces the amount of river diversions needed at downstream locations. On the other hand, carrying excessive water in the irrigation conveyance system could potentially have an adverse impact on river flow conditions in upper reaches, and it modifies the distribution and magnitude of conveyance losses. Whether such modification is favorable or unfavorable to overall basin water supply conditions has not been evaluated as part of this study.
Recommendations for improvements in measurement and evaluation programs, at the
District level, to support better water management and evaluation of impact of operational
changes on efficiency include:
• Construct additional gages for improved system monitoring: o At remaining ungaged division inflow and outflow points, o At key division sub-zone inflow and outflow points, o At major tailwater inflows to drains;
• Identify channel capacity at the head and tails of all major canals and drains;
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• Install a network of shallow piezometers and monitor to evaluate changes in groundwater storage contributing to drain flows;
• Quantify canal seepage losses in major canals sections; • Quantify seepage losses in key reaches of the Rio Grande throughout the District; • Develop links between the river water budget and the irrigation system water budget, and
vice versa, for evaluation of how irrigation changes will impact the flow in the river; • Definitively establish the quantity of irrigated acreage in the District and associated
consumptive use.
The above recommendations will take time to implement. As products from such efforts become
available, assessment of operational efficiencies will be improved, and solutions will be more
readily identified. For example, “gaming” with the accounting analysis spreadsheet indicates
that potentially, river diversions could be significantly decreased from those at present.
However, such analyses are not meaningful without better identification of constraints, i.e.,
channel capacities, head, gradient and seepage rates.
In the interim, a number of operational improvements have been identified in previous
sections of this study that can be implemented while data collection and analysis continues.
These include:
• Initiation of rotational water delivery at locations in the district where it is feasible, • Creation of an Irrigation Advisory Service (IAS), possibly with assistance from Federal
agencies that currently provide IAS services, • Enforcement of the creation and management of community ditches and limits on the
number of new turnouts, • Infrastructure improvements, including mitigation measures to lessen the effects of
arroyo flooding, improvements of existing crossings, and new policy governing the construction of crossings.
• Collaboration with municipalities to encourage the use of agricultural water for urban uses and to manage the effects of urbanization on the irrigation system.
9.2 Cochiti Division: Observations and Recommendations
The Cochiti Division is relatively small in terms of total irrigated acreage, containing
about 6% of the total District irrigated area. This division diverts a significant amount of water
97
into two major canals (approximately 100,000 acre-feet in 2001). Interdivision outflow from
this division to the Albuquerque Division is relatively large, through the Algodones Drain. Other
significant division outflows are believed to occur through ungaged drain returns. The estimated
off-farm efficiency for this division is low (estimated at 19% under the 2001 provisional water
accounting analysis). Characteristics of the Cochiti Division contributing to lower efficiencies
include:
• The irrigation density is low, at approximately 26%. The number of acres served per canal mile is consequently relatively low, at about 39 acres per canal mile.
• Nearly 84% of the irrigated lands in this division are Pueblo lands. Pueblo customs regarding 24-hour availability of supply require larger diversions to the division.
Quantitative evaluation of conditions in this division is difficult due to the lack of data on key
inflow and outflow parameters. These include drain and tailwater returns to the Rio Grande, and
flows into and out of pueblo lands. Additionally, canal seepage losses are not known. The
USBR estimated a high rate of canal loss in this division (50% of flow); field studies are needed
to further evaluate this supposition.
General recommendations for improvement in the monitoring system include (other
specific recommendations are contained elsewhere in this report):
• Perform field measurements and/or temporary gage installations within the division to determine which locations are worth measuring and can be feasibly measured. These potential monitoring locations include:
o wetfield discharges (intercepting seepage from Cochiti Dam), o tailwater returns and drain flows to the river o outflow points to the Albuquerque Division o midstream points at the entrance to or exit from hydrologic sub-zones which can
be used to enhance system operations
Recommendations for improvement of operational conditions include:
• Continue flood and sediment control programs to abate the effects of arroyo flooding, • Evaluate lining of canals or piping of reaches of major canals where little irrigation
occurs, where feasible.
98
9.3 Albuquerque Division: Observations and Recommendations
The Albuquerque Division contains approximately 21% of the total District irrigated
area. This division diverts a significant amount of water from the river into two major canals
(approximately 160,000 acre-feet in 2001). Interdivision inflow from the Cochiti division to the
Albuquerque Division is also relatively large, through the Angostura Drain. Interdivision
outflow to the Belen Division, through the Barr-Chical Lateral and the Isleta Drain, is
unmeasured. The off-farm efficiency for this division is estimated at 39% with assumptions
made in the 2001 provisional water accounting analysis. Characteristics of the Albuquerque
Division include:
• The irrigation density is low, at approximately 29%, due to urbanization. • The number of acres served per canal mile is about 64 acres per canal mile.
Urbanization in the Albuquerque area causes numerous water delivery challenges.
Quantitative evaluation of flow conditions in this division is significantly improved with
the recent construction of gages at nearly all return flow points. However, additional monitoring
needs include the interdivisional outflow points. Canal seepage losses are not well understood.
The USBR estimated a rate of canal loss in this division of 30% of flow; field studies are needed
to further evaluate this supposition.
General recommendations for improvement in the monitoring system include (other
specific recommendations are contained elsewhere in this report):
• Construct gages on the Isleta Drain and Barr-Chical Lateral at the outflow locations, • Evaluate canal seepage losses through field measurement and/or temporary gage
installation. Recommendations for improvement of operational conditions include:
• Increased maintenance and repair of walking ditches (those without vehicle access),
99
• Evaluate lining of canals or piping of reaches of major canals where little irrigation occurs, seepage appears significant, and where bank stabilization is a problem,
• Evaluate means of improving inadequate crossings that limit channel capacity, • Evaluate feasibility of implementing a rotational water delivery schedule, • Address specific identified canal deficiencies.
It is recognized that small farm economic and quality of life issues must be considered in the
implementation of these recommendations.
9.4 Belen Division: Observations and Recommendations
The Belen Division contains approximately 54% of the total District irrigated area. This
division diverts a significant amount of water from the river into five major canals
(approximately 230,000 acre-feet in 2001). Interdivision inflow from the Albuquerque Division
occurs through the Isleta Drain and the Barr-Chical Lateral. Significant interdivision outflow to
the Socorro Division is feasible through the Unit 7 Drain (approximately 88,000 acre-feet in
2001). The estimated off-farm efficiency is greatest in this division (estimated at 57% with
assumptions made in the 2001 provisional water accounting analysis). Characteristics of the
Belen Division include:
• The irrigation density is relatively high, at approximately 54%, • The number of acres served per canal mile is about 106 acres per canal mile.
Quantitative evaluation of flow conditions in this division is significantly improved with
the recent construction of gages at nearly all return flow points. However, canal seepage losses
are not well understood. The USBR estimated a rate of canal loss in this division of 30% of
flow; field studies are needed to further evaluate this supposition.
General recommendations for improvement in the monitoring system include (other
specific recommendations are contained elsewhere in this report):
100
• Construct a gage on the San Juan Riverside Drain at its return to the river (note: If a siphon is built at Bernardo, it would be more appropriate to wait and install the gage at the siphon),
• Evaluate canal seepage losses through field measurement and/or temporary gage installation.
Recommendations for improvement of operational conditions include:
• Increased flood and sediment control for arroyo flooding in highline canals, • Evaluate lining of canals or piping of reaches of major canals where seepage appears
significant, and where bank stabilization is a problem (example: Belen Highline Canal) • Evaluate water logging conditions along San Juan Main Canal, • Evaluate feasibility of implementing a rotational water delivery schedule, • Address specific identified headgate deficiencies.
9.5 Socorro Division: Observations and Recommendations
The Socorro Division contains approximately 19% of the total District irrigated area.
The conveyance system also serves lands within the Bosque del Apache. Of the total division
supply in 2001 (112,000 acre feet), only 31,000 acre feet were diverted from the river, with the
remainder supplied from the Unit 7 Drain interdivision flow from the Belen Division. The off-
farm efficiency was estimated at 46% with the assumptions made in the 2001 provisional water
accounting analysis (including the Bosque del Apache water use). Characteristics of the Socorro
Division include:
• The irrigation density is high, at approximately 67%, • The number of acres served per canal mile is about 88 acres per canal mile.
Quantitative evaluation of flow conditions in this division is difficult at this time, due to
lack of metering at all outflow points. Canal seepage losses are not well understood. The USBR
estimated a rate of canal loss in this division of 20% of flow; field studies are needed to further
evaluate this supposition. Preliminary field studies were conducted on the Socorro Main Canal
in summer 2001 (SSPA, 2002), but further work is needed to quantify canal loss rates.
101
General recommendations for improvement in the monitoring system include (other
specific recommendations are contained elsewhere in this report):
• Construct gages to monitor all LFCC diversions to the irrigation system, • Evaluate canal seepage losses through field measurement and/or temporary gage
installation. • Evaluate the possibility of abandoning Socorro Ditch, where it passes through the City of
Socorro, since it has been observed to have very few irrigators using it.
Recommendations for improvement of operational conditions include:
• Evaluate lining of canals or piping of reaches of major canals where seepage appears significant, or, reaches are long with few irrigators (Socorro Main Canal from San Acacia to San Lorenzo Settling Basin and Socorro Ditch are candidates for evaluation)
• Evaluate feasibility of implementing rotational scheduling.
Finally, there has been discussion among some entities of the feasibility of removing the San
Acacia Dam to allow unrestricted passage for the endangered silvery minnow. In the past year,
diversions from this dam were significantly reduced over previous years diversions. It is
possible that with careful evaluation of efficiency issues in this division, improved efficiency
would reduce the need for river diversions. Some have suggested that with such reduction,
possibly combined with increased diversion in the Belen Division, it might be possible to meet
the needs of the Socorro Division without the San Acacia Dam. The feasibility of such a
solution has not been evaluated quantitatively as part of this study, due to lack of data regarding
channel capacities, channel losses, gradients, and Socorro Division outflow. However, there are
a number of considerations that would make such a change difficult1. In addition to significant
1 MRGCD notes that there would be significant operational problems associated with this change. The seasonal distribution of supply and demand significantly impacts the feasibility of this option. Flows in drains arriving at San Acacia do not increase to a point sufficient to supply the Socorro Division until the Belen Division irrigators have been operating for several weeks, causing increases in shallow groundwater and fueling drain flows. Additionally, the Socorro Division is south, and warmer; generally requiring irrigation water in the spring before irrigators in Belen initiate irrigation. Finally, ditch breaks and thunderstorms in Belen can cause cessation of diversions at Isleta, causing insufficient water to operate Socorro Division without river diversion.
102
operational challenges, such a change in infrastructure could bring adverse environmental
impacts in upstream reaches of the Rio Grande. A recommendation on this topic is beyond the
scope of this study.
9.6 Next Steps
This study recommends infrastructure and operational changes to improve the efficiency
of the MRGCD irrigation system. Many of the recommended changes will require design work,
development of plans, time and additional funding. Focusing efforts in the near-term on specific
actions is recommended to assist the MRGCD in improving District efficiency. Theses actions
include:
• Conduct a comprehensive field measurement program over the next two irrigation seasons to include:
o Measure all ungaged inflow points to the system, including diversions from drains, to assist in the design of new flow monitoring stations;
o Conduct seepage runs along canal sections that are believed to have significant seepage losses, to aid in the selection of locations for which piping or channel lining could significantly decrease channel losses; evaluate canal slope and sediment load in the reaches determined to have high losses;
o Conduct seepage runs along main canal sections to characterize the magnitude and variation of canal losses for water budget purposes;
o Evaluate infrastructure suitability for supporting a rotational water delivery schedule (identify channel capacity measurements at key control points);
o Identification of canal crossings that should be replaced to improve system operation;
o Update maps of lateral service areas and irrigated lands, incorporating ditchrider and field-checked observations.
• Conduct a series of workshops by agricultural experts for the MRGCD to train MRGCD personnel in the implementation of recommended operational improvements, particularly rotational water delivery. The MRGCD has indicated that its ditchriders could benefit greatly from this training, and supports this recommendation. Also, input from the ditchriders in these workshops could aid greatly in the development of a decision support system for management of system operation.
• Conduct a provisional accounting analysis of 2002 irrigation season flow data, utilize this with 2001 data to refine accounting assumptions, as possible.
103
• Building from the accounting analysis, ditchrider input gained in workshops, and field data, begin to prepare decision-support models for evaluating and optimizing operations within districts and sub-zones.
• Develop plans for installation of automated gates and metering instrumentation at the Isleta and San Acacia diversions, as well as key control points throughout the district.
• Initiate concrete lining of particular canal reaches for which this step has been deemed feasible and beneficial.
Completion of these steps will provide a starting point from which future programs can build.
Efficient operation within the MRGCD will require both continuation and augmentation of
existing programs, but is inarguably a goal worthy of investment.
104
REFERENCES Bell, A.D., K.R. Blaney, K.J. Oliver, and R.E. Miller, 1994. Middle Rio Grande Water Assessment: Middle Rio Grande land use trend analysis geographic information system data base; Middle Rio Grande Water Assessment, Supporting Document No. 13, U.S. Bureau of Reclamation (Published by USBR, 1997). Bertrand, et al., 1996. Landowner’s Guide to Incorporating Irrigation Ditches and Lateral. Blaney, H. F. and W. D. Criddle, 1962. Determining Consumptive Use and Irrigation Water Requirements, Technical Bulletin 1275. US Department of Agriculture, SCS, Washington, D.C. Burkholder, J.L., 1928. Submitting a Plan for Flood Control, Drainage and Irrigation of the Middle Rio Grande Conservancy District. Report of the Chief Engineer, Middle Rio Grande Conservancy District. Clark, Charles H., 1957. Water Use – Middle Rio Grande Project, New Mexico. Memorandum from acting project manager to Regional Director, Amarillo, TX, Attention 5-430. March 8, 1957. Fife, R. W., 1957. Preparation of Monthly Water District Report, Form 7233. Memorandum, U.S. Department of the Interior, Bureau of Reclamation. Files, Albuquerque, NM, March 25, 1957. King, Phillip J. and A. S. Bawazir, 2000. Riparian Evapotranspiration Studies of the Middle Rio Grande. NM State University, Technical Completion Report, Project No. 1-4-23955. King, Phillip J. and L. Wan, 1997. Middle Rio Grande Water Assessment: Determination of soil conservation service modified Blaney Criddle crop coefficients in New Mexico; Middle Rio Grande Water Assessment, Supporting Document No. 5, U.S. Bureau of Reclamation. Lansford, Robert R., et al., 1993. Sources of irrigation water and irrigated and dry cropland acreages in New Mexico, by county and hydrologic unit, 1991-1993. Agricultural Experiment Station Technical Report No. 21, College of Agriculture and Home Economics, New Mexico State University, Las Cruces, NM. Lansford, Robert R., et al., 1996. Irrigation water sources and cropland acreages in New Mexico, 1993-1995. Agricultural Experiment Station Research Report, College of Agriculture and Home Economics, New Mexico State University, Las Cruces, NM. Lansford, Robert R., 1997. Trends in irrigated and dryland acreages in New Mexico, 1970-1994. Agricultural Experiment Station Research Report No. 713, College of Agriculture and Home Economics, New Mexico State University, Las Cruces, NM. Middle Rio Grande Conservancy District (MRGCD). Policies and Procedures of the Middle Rio Grande Conservancy District. Document No. JBDPP94.001. Middle Rio Grande Conservancy District (MRGCD) Board of Directors, 1993. Middle Rio Grande Conservancy District Water Policies Plan. New Mexico Office of the State Engineer, 1930a. Water Rights Permit Application No. 1690. Approved August 20, 1930. New Mexico Office of the State Engineer, 1930b. Water Rights Permit Application No. 0620. Approved January 8, 1931. New Mexico State Statues 73-18-6A.
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Sagardoy, J. A., A. Bottrall and G.O. Uittenbogaard, 1986. Organization, operation and maintenance of irrigation schemes – FAO irrigation and drainage paper 40. FAO – Food and Agriculture Organization of the United Nations Rome, 1986. Shaffer, L. E., 1959. Preparation of Monthly Water District Report, Form 7-233. Memorandum, U.S. Department of the Interior, Bureau of Reclamation. Files, Albuquerque, NM, Feb. 17, 1959. Shaffer, L. E., 1960. Preparation of Monthly Water District Report, Form 7-233. Memorandum, U.S. Department of the Interior, Bureau of Reclamation. Files, Albuquerque, NM, Feb. 14, 1960. Socorro Soil & Water Conservation District, July 31, 2000. Irrigation Improvement Practices within the Socorro Soil & Water Conservation District, USDA Natural Resources Conservation Service, USDA Farm Services Agency, Middle Rio Grande Conservancy District, and NMSU Cooperative Extension Service Soil Conservation Service (SCS) Division, April 1967, revised September 1970. Irrigation Water Requirements. US Department of Agriculture, SCS Technical Release No. 21. S.S. Papadopulos & Associates, Inc. 2000. Middle Rio Grande Water Supply Study. Prepared under contract to the Army Corps of Engineers and the Interstate Stream Commission. Strech, D. W. & T. S. Matthews, August 15, 2001. Middle Rio Grande Vegetation Classification – Summer 2000. Joint Project between MRGCD, NM Office of the State Engineer, and Interstate Stream Commission. U. S. Army Corps of Engineers, 2001. Draft Environmental Assessment and Finding of No Significant Impact for Conveyance Treatment for La Joya Acequia, Soccorro County, New Mexico. U.S. Army Corps of Engineers, Albuquerque District, Albuquerque, NM. U.S. Bureau of Reclamation, 1995. Middle Rio Grande Water Assessment: Estimates of consumptive use requirements for irrigated agriculture and riparian vegetation; Middle Rio Grande Water Assessment, Supporting Document No. 6, U.S. Bureau of Reclamation. U.S. Bureau of Reclamation, U.S. Army Corps of Engineers, U.S. Geological Survey, et al., 2000. Upper Rio Grande Water Operations Model Physical Model Documentation: Technical Review Committee Draft. Technical Review Committee draft of the Upper Rio Grande Water Operations Model (URGWOM) physical model. U.S. National Resources Committee, 1938. The Rio Grande joint investigation in the Upper Rio Grande Basin in Colorado, New Mexico, and Texas, 1936-1937; regional planning part VI, U.S. National Resources Committee, Regional Planning U.S. Government Printing Office. Wilson, B.C. and A. A. Lucero, 1997. Water Use by Categories in New Mexico Counties and River Basins, and Irrigated Acreage in 1995. New Mexico State Engineer’s Office, Technical Report 49.
peralta m ain cana l
.-,40
.-,25
(/60
(/60
(/380
"!6
"!47
"!44
Bosque del ApacheNational Wildlife Refuge
Cochiti Division
Albuquerque Division
Belen Division
Socorro Division
Rio Gra
nde
JemezReservoir
CochitiReservoir
Elephant ButteReservoir
xz
xz
xz
Socorro
Tome
Albuquerque
Rio Salado
Rio
Puerco
Figure 1.1 Location of the MRGCD
0 10 20 Miles
N
EW
S
MRGCD BoundaryReservoirRio Grande Tributary
RoadInterstateN.M.U.S.
SILN5 CCCN5
CTDN5
Cochiti Dam
OTWN5
CMCCN
SFPN5Angostura Diversion
ALGDR
ALBCN
ATFCN
SNFDR
Jemez River JECN5
Corrales Siphon
BERCN
ALBDR
ARSDR
SANWW
CORWW
LCRDR
UCRDR
CORCN
ATRDR
Atrisco Siphon
CENWW
ABQN5
ARECN
ATDCN
ARMCN
Isleta DiversionBELCN CHICN
CHACNCACCNPERCN
PERWW
240WW
ISLDN
LP1DR
LP2DR
BELDR
NBLWW
FD3WW
SABDR
STYWW
LSJDR
San Acacia Diversion
RFBN5Rio Puerco SFRDR
UN7DR
SOCCNSocorro
Main CanalNorth SNAN5
San Juan Feeder Canal
Salas Arroyo
San Felipe Siphon
ESCWWLEMDVSOCDV
SOCWW
BRNWW
NCPDV
SOCDR
9MILE
Brown Arroyo
LFC
C
SMFN5SMCN5
Figure 2.1 Simplified Schematic of MRGCD System
02/11/02
.-,25
"!22
"!16
MRGCD Division Boundary
Ditchrider Service Area101102103
RoadsInterstateN.M.U.S.
Hydrologic Features
0 1 2 3 Miles
N
EW
S
Cochiti Division
Figure 2.2 Ditchrider Service Areas, Cochiti Division
Delineated service areas areprovisional pending field verification
"!44
(/66
.-,25
.-,40
MRGCD Division Boundary
Ditchrider Service Area103201202203204205206207208209210211212
RoadsInterstateN.M.U.S.
Hydrologic Features
0 3 6 Miles
N
EW
S
Albuquerque Division
Figure 2.3 Ditchrider Service Areas, Albuquerque Division
Delineated service areas areprovisional pending field verification
"!6
"!47
"!47
"!314
"!45
(/60
.-,25
Figure 2.4 Ditchrider Service Areas, Belen Division
Belen Division
Delineated service areas areprovisional pending field verification
N
EW
S
0 3 6 9 Miles
MRGCD Division Boundary
Ditchrider301302303304305306307308309310
RoadsInterstateN.M.U.S.
Hydrologic Features
(/60
(/380
.-,25
Figure 2.5 Ditchrider Service Areas, Socorro Division
MRGCD Division Boundary
Ditchrider Service Area401402403404
RoadsInterstateN.M.U.S.
Hydrologic Features
0 2 4 Miles
N
EW
S
Socorro Division
Delineated service areas areprovisional pending field verification
Fig
ure
3.1
Irri
gat
ion
Sea
son
200
1 R
iver
Div
ersi
on
s
0
10,0
00
20,0
00
30,0
00
40,0
00
50,0
00
60,0
00
70,0
00
80,0
00
Jan
Feb
Mar
Apr
May
Jun
Jul
Aug
Sep
tO
ctN
ovD
ec
Mo
nth
Diversion (acre-feet)
Soc
orro
Div
isio
n
Bel
en D
ivis
ion
Alb
uque
rque
Div
isio
n
Coc
hiti
Div
isio
n
.-,25
"!22
"!16
Figure 6.1 Accounting Zones, Cochiti Division
MRGCD Division Boundary
Accounting Zone12345
Hydrologic Features
RoadsInterstateN.M.U.S.
0 1 2 3 Miles
N
EW
S
Cochiti Division
"!44
(/66
.-,25
.-,40
Figure 6.2 Accounting Zones, Albuquerque Division
Albuquerque Division
N
EW
S
0 3 6 Miles
MRGCD Division Boundary
Accounting Zones12345
RoadsInterstateN.M.U.S.
Hydrologic Features
"!6
"!47
"!47
"!314
"!45
(/60
.-,25
MRGCD Division Boundary
Accounting Zones1234
RoadsInterstateN.M.U.S.
Hydrologic Features
0 3 6 9 Miles
N
EW
S
Belen Division
Figure 6.3 Accounting Zones, Belen Division
(/60
(/380
.-,25
Socorro Division
N
EW
S
0 2 4 Miles
MRGCD Division Boundary
Accounting Zones1234
Hydrologic Features
RoadsInterstateN.M.U.S.
Figure 6.4 Accounting Zones, Socorro Division
Table 3.1 Lateral Service Areas
Cochiti Division
Service Area Name Service Area Acreage
ALGODONES ACEQUIA SA 541COCHITI MAIN CANAL SA 8,408COCHITI MAIN CANAL SA (UNUSED) 296LEYBA LATERAL SA 61MAJADA LATERAL SA 104RIVERA LATERAL SA 453SAN FELIPE DITCH SA 687SANTA ANA LATERAL SA 32SANTA ANA LATERAL SA 17SILI MAIN CANAL SA 4,161SILI MAIN CANAL SA (UNUSED) 993YESO LATERAL SA 279
Albuquerque Division
Service Area Name Service Area Acreage
ALAMEDA LATERAL SA 2,386ALBUQUERQUE MAIN CANAL SA 2,424ARENAL ACEQUIA SA 1,116ARENAL MAIN CANAL SA 3,826ARMIJO ACEQUIA SA 1,605ATRISCO ACEQUIA SA 461ATRISCO LATERAL SA 84BARELAS DITCH (ABANDONED) SA 3,017BARR MAIN CANAL SA 3,253BERNALILLO ACEQUIA SA 1,269BOSQUE LATERAL #1 SA 686BOSQUE LATERAL #2 SA 525BUTTE LATERAL SA 224CHAMISAL LATERAL SA 1,830CORRALES ACEQUIA SA 1,344CORRALES MAIN CANAL SA 1,916DERAMEDERA ACEQUIA SA 420DURANES LATERAL SA 2,137GALLEGOS LATERAL 1,000GRIEGOS ACEQUIA SA 1,564GRIEGOS LATERAL SA 834GUN CLUB LATERAL SA 1,088INDIAN LATERAL SA 2,109MERCANTILE LATERAL SA 77MIRABEL LATERAL SA 17NICHOLS LATERAL SA 35PAJARITO ACEQUIA SA 1,843PAJARITO LATERAL SA 1,803PUEBLO ACEQUIA SA 668SAN JOSE LATERAL SA 449SANDIA ACEQUIA SA 2,027SANDIA INTERIOR DITCH SA 780SANDOVAL LATERAL SA 1,026SANTA ANA ACEQUIA SA 456SUMMERFORD LATERAL SA 179
Table 3.1 Lateral Service Areas
Belen Division
Service Area Name Service Area Acreage
ARROYOS LOWER ACEQUIA 1,305ARROYOS UPPER ACAQUIA 424BELEN GRANT # 1 LATERAL 396BELEN GRANT # 2 LATERAL 815BELEN HIGHLINE CANAL 5,557BELEN NEW ACEQUIA 3,581BELEN NEW WASTEWAY 350BELEN OLD ACEQUIA 520BELEN RIVERSIDE LATERAL 34BOSQUE - SMITH LATERAL 258BROUGHT LATERAL 165CALDWELL LATERAL 389CASA COLORDO DITCH OR SAIS LATERAL 1,169CHICAL LATERAL 797CHICAL LATERAL EXTENSION 508CITY OF BELEN (NO IRRIGATED PLOTS WITHIN) 606ENRIQUE LATERAL 251GABALDON LATERAL 620GARCIA # 1 LATERAL 1,188GARCIA EXTENTION ACEQUIA 6,069GARCIA UPPER ACEQUIA 878HARLAN HENDERSON LATERAL 2,213HELLS CANYON LATERAL 2,021HUNING LATERAL 1,408JACKSON ACEQUIA 478JARAL # 1 LATERAL 874JARALES NEW ACEQUIA 113JARALES OLD ACEQUIA 2,465LA CONSTANCIA LATERAL 1,858LA JOYA ACEQUIA 1,175LAS CERCAS ACEQUIA 1,148LAS NUTRIAS LATERAL 1,012LOS CHAVES ACEQUIA 1,275LOS CHAVES LATERAL 154LOS LUNAS ACEQUIA 1,501MIDDLE UPPER ACEQUIA 664OTERO LATERAL 2,184PERALTA ACEQUIA 930PERALTA MAIN CANAL 6,272RINCON ACEQUIA 159SABINAL # 1 LATERAL 1,116SAN FERNANDEZ #4 ACEQUIA 115SAN JUAN ACEQUIA 453SAN JUAN MAIN CANAL 2,999SANCHEZ ACEQUIA 129SAUSAL LATERAL 1,071TIBO FEEDER? 136TOME ACEQUIA 1,322VALENCIA ACEQUIA 919VALLEJOS LATERAL 286
Table 3.1 Lateral Service Areas
Socorro Division
Service Area Name Service Area Acreage
ALAMILLO ACEQUIA 442APODOCA LATERAL 255CHAMBRON LATERAL 404FLORIDA LATERAL 443ISLA LATERAL 308JARAL ACEQUIA 445LEMITAR ACEQUIA 321LEMITAR LATERAL 959LEMITAR WASTEWAY 987LUIS LOPEZ #1 ACEQUIA 221LUIS LOPEZ #2 ACEQUIA 595MORTON LATERAL 151MOSLEY LATERAL 483POLVADERA ACEQUIA 668RINCONADA ACEQUIA 216SAN ACACIA FEEDER 42SAN ACACIA LOWER DRAIN 92SAN ANTONIO ACEQUIA 1,508SAN ANTONIO LATERAL 578SARRACINO LATERAL 60SOCORRO ACEQUIA 1,522SOCORRO CENTER MAIN C. 1,772SOCORRO N. MAIN CANAL 2,122SOCORRO SOUTH MAIN C. 2,406VASQUEZ LATERAL 417(UNNAMED) 0.1
Table 3.2 Summary of Ditchrider Service Areas
MRGCD Ditchrider NumberAcreage within Ditchrider Area
101 1,189102 621103 446201 816202 1,824203 4,623204 2,442205 3,685206 4,234207 2,059208 1,871209 3,886210 3,366211 3,975212 2,219301 2,806302 5,184303 5,619304 4,646305 3,913306 7,397307 4,572308 6,288309 9,245310 6,845401 1,539402 5,858403 4,745404 6,589
MRGCD DIVISIONAcreage within Ditchrider Area
COCHITI (100's) 2,256ALBUQUERQUE (200's) 34,998BELEN (300's) 57,688SOCORRO (400's) 18,731
Table 3.3 Cochiti DivisionGage Name Gage ID Operator Gage Purpose Period of Record
Cochiti East Side Main Canal CCCN5 USGS Canal Heading 1954 - present
Sili Main Canal SILN5 USGS Canal Heading 1954 - present
Approximately 10 - 14 return flow points -------- --------- Returns to River TBD
Cochiti Main at San Felipe CMCCN MRGCD mid-reach (1954) 1974 - present
Table 3.4 Albuquerque DivisionGage Name Gage ID Operator Gage Purpose Period of Record
Albuquerque Main Canal ALBCN MRGCD Canal Heading 1974 - present
Atrisco Feeder Canal ATFCN MRGCD Canal Heading 1974 - present
Algodones Riverside Drain ALGDR MRGCD Return from Cochiti Div. 1974 - present
Arenal Main Canal ARECN MRGCD Central Ave. X-Section 1974 - present
Armijo Acequia ARMCN MRGCD Central Ave. X-Section 1958 - present
Atrisco Ditch ATDCN MRGCD Central Ave. X-Section 1958 - present
Albuquerque Riverside Drain @ Central Avenue ALBDR MRGCD Central Ave. X-Section 1954 - present
Corrales Main Canal CORCN MRGCD Secondary Canal 1974 - present
Upper Corrales Riverside Drain UCRDR MRGCD Drain to River 2001 - present
Corrales Main Canal Wasteway CORWW MRGCD Wasteway to River 1997 - present
Central Avenue Wasteway CENWW MRGCD Wasteway to River 2000 - present
Atrisco Riverside Drain ATRDR MRGCD Drain to River 1997 - present
Lower Corrales Riverside Drain LCRDR MRGCD Drain to River 2000 - present
Albuquerque Riverside Drain ARSDR MRGCD Drain to River 1997 - present
Sandia Lakes Wasteway SANWW MRGCD Wasteway to River 2000 - presentBernalillo Acequia BERCN MRGCD Secondary Canal 2001 - present
Existing and Planned Gaging Stations for Monitoring Key MRGCD Irrigation System Flows
1This gage also forms the basis for estimating return flow to the river from this drain.2 Diversions from the Low Flow Conveyance Channel gaged intermittently by USGS.3 MRGCD has a new gage here beginning 2001. TBD - the installation date has not yet been established.
Existing and Planned Gaging Stations for Monitoring Key MRGCD Irrigation System Flows
Table 3.5 Belen DivisionGage Name Gage ID Operator Gage Purpose Period of Record
Belen Highline Canal BELCN MRGCD Canal Heading 1974 - present
Peralta Main Canal PERCN MRGCD Canal Heading 1974 - present
Chical Lateral CHICN MRGCD Canal Heading 1974 - present
Chical Acequia CHACN MRGCD Canal Heading 1974 - present
Cacique Acequia CACCN MRGCD Canal Heading 1974 - present
Lower San Juan Riverside Drain LSJDR MRGCD Bernardo X-Section1 1974 - present
Isleta Drain Outfall ISLDR ---------- Drain to River TBD
Barr-Chical Canal BCHCN ---------- Return from Alb. Division 1997; 2002 planned
Peralta Main Wasteway PERWW MRGCD Wasteway to River 1999 - present
Feeder #3 Wasteway FD3WW MRGCD Wasteway to River 2000 - present
240 Wasteway 240WW MRGCD Wasteway to River 2002 planned
Belen Riverside Drain BELDR MRGCD Drain to River 2000 - present
New Belen Acequia Wasteway NBLWW MRGCD Wasteway to River 2002 planned
Lower Peralta Riverside Drain #1 LP1DR MRGCD Drain to River 2001 - present
Lower Peralta Riverside Drain #2 LP2DR MRGCD Drain to River 2002 planned
Sabinal Riverside Drain SABDR MRGCD Drain to River 2001 - present
Storey Wasteway STYWW MRGCD Wasteway to River 2002 planned
San Francisco Riverside Drain SFRDR MRGCD Drain to River 2002 planned Unit 7 Drain UN7DR MRGCD Return to Socorro Division 2001 - present
Table 3.6 Socorro DivisionGage Name Gage ID Operator Gage Purpose Period of Record
Socorro Main Canal SOCCN USGS/MRGCD3 Canal Heading 2001 - present
San Acacia Wasteway SNAWW MRGCD Wasteway to LFCC 2002 planned
Escondida Wasteway off Socorro Main Canal ESCWW MRGCD Wasteway to LFCC 2002 planned
Socorro Wasteway SOCWW MRGCD Wasteway to LFCC 2002 planned
Brown Arroyo Wasteway BRNWW MRGCD Wasteway to Brn. Arroyo 2002 planned
Socorro Riverside Drain at Bosque del Apache SOCDR MRGCD end of MRGCD reach 2002 planned
Socorro Main Canal South at Bosque del Apache SMSCN MRGCD end of MRGCD reach 2002 planned
San Antonio Ditch at Bosque del Apache SADCN MRGCD end of MRGCD reach 2002
Elmendorf Drain at Bosque del Apache ELMDR MRGCD end-reach 2002 planned
Lemitar Diversion LEMDV MRGCD Diversion from LFCC2 TBD
Socorro Diversion SOCDV MRGCD Diversion from LFCC2 TBDNeil-Cupp Diversion NCPDV MRGCD Diversion from LFCC2 TBD1This gage also forms the basis for estimating return flow to the river from this drain.2 Diversions from the Low Flow Conveyance Channel gaged intermittently by USGS.3 MRGCD has a new gage here beginning 2001. TBD - the installation date has not yet been established.
Table 3.7 Recommendations for Improvements to Specific Gages or Locations
Gage or Location Recommendation Rationale
Sandia Lakes and Central Avenue
Wasteways
Replacement of the radial gates with Langemann Weir Gates. Also: Should take discharge measurements, to define the rating curves for the gates.
Gives a much better picture of the amount of flow leaving the system within the Albuquerque Division, than previously available.
Algodones DrainFind a way to improve the record being collected.
There is presently no correlation between stage and discharge.
Corrales Main Canal Relocate the gaging station.Backwater problems at the present location.
Peralta Main CanalReview the rating curve and measurements.
This gage is a concrete structure, but manually measured points have a lot of scatter around the theoretical curve.
Cacique AcequiaReview the rating curve for the end of 2001 irrigation season.
Evaluate whether or not backwater conditions were as prevalent in 2001, as they were in 2000.
Table 3.8 Summary of MRGCD Water Distribution Data Reported to USBR(values reported in acre-feet)
Year* Net Supply Waste Transportation Losses Delivered to Farms1976 550,110 179,190 195,310 175,6101979 547,726 178,586 209,878 159,2621980 513,465 169,363 205,306 138,7961981 475,590 154,160 189,740 131,6901982 434,790 129,580 155,820 149,3901983 465,330 135,290 159,300 170,7401984 525,883 171,360 192,920 148,4101985 468,930 187,860 163,540 117,5301986 565,950 221,220 203,110 141,6201987 588,670 176,300 205,670 205,6701988 596,650 172,760 223,470 200,4201989 567,650 187,300 198,670 181,6801990 506,730 167,990 177,310 162,3301991 554,450 185,900 192,120 176,4301992 599,890 210,030 204,200 185,6601993 609,050 213,160 200,970 194,9201994 606,030 219,120 209,570 177,3401995 617,530 214,920 203,970 198,6401996 618,419 216,447 204,079 197,8941997 653,872 228,855 215,778 209,2391998 679,266 237,744 224,158 217,3651999 612,120 214,242 202,000 195,589
Average 561,732 189,608 197,131 174,374
NOTE: For comparison purposes, 1936 diversions are reported as 619,989 in Table 72, Rio Grande JointInvestigation, 1938 for 59,159 irrigated acres.
*Records prior to 1975 and 1977-1978 were not located for this study, but should be available in USBRarchived files.
Source of Information:1983, 1985 - 90, 1992-99: Monthly Water Distribution Reports1991: Monthly Water Distribution and Annual Operation and Maintenance Costs1976, 1979-82, 1984: 19__ Summary Statistics, Vol. 1, Water, Land and Related Data, USBR
Table 3.9 Comparison of MRGCD Reported Net Supply to Composite Diversions(values reported in acre-feet)
YearNet Supply
Reported to USBRComposite MRGCD
Diversions1976 550,110 - - -1979 547,726 - - -1980 513,465 - - -1981 475,590 - - -1982 434,790 385,7421983 465,330 451,2661984 525,883 470,7511985 468,930 442,1411986 565,950 564,7621987 588,670 549,0401988 596,650 418,3401989 567,650 431,5511990 506,730 517,1441991 554,450 570,2101992 599,890 - - -1993 609,050 600,1091994 606,030 603,3961995 617,530 613,0711996 618,419 590,2441997 653,872 - - -1998 679,266 - - -1999 612,120 - - -
Tab
le 3
.10
2001
Mon
thly
Dis
char
ge b
y D
ivis
ion
(val
ues
repo
rted
in a
cre-
feet
)
Stat
ion
Cod
e1T
ype
of fl
owD
ata
Sour
ceA
nnua
l Tot
alJa
nF
ebM
arA
prM
ayJu
nJu
lA
ugSe
pO
ctN
ovD
ecIn
ter-
divi
sion
al fl
ow fr
om le
akag
e be
low
Coc
hiti
Dam
-N
MN
MN
MN
MN
MN
MN
MN
MN
MN
MN
MN
MN
MSI
LN5
Can
al h
eadi
ngU
SGS
36,3
720
04,
069
4,10
14,
668
4,53
94,
587
4,54
94,
242
4,06
91,
549
0C
CC
N5
Can
al h
eadi
ngU
SGS
65,5
160
05,
822
7,55
58,
547
8,18
47,
932
8,17
08,
118
8,35
22,
835
0
CO
CD
VT
otal
Riv
er D
iver
sion
(SIL
N5
+ C
CC
N5)
CA
LC
101,
888
00
9,89
111
,656
13,2
1512
,723
12,5
1912
,719
12,3
6012
,422
4,38
40
CO
CSU
PD
ivis
ion
Supp
ly (S
ILN
5 +
CC
CN
5 +
leak
age)
-N
MN
MN
MN
MN
MN
MN
MN
MN
MN
MN
MN
MN
M
CO
CR
RT
Tot
al R
iver
Ret
urns
-N
MN
MN
MN
MN
MN
MN
MN
MN
MN
MN
MN
MN
MA
LG
DR
Inte
r-di
visi
onal
flow
to A
lb.
MR
GC
D34
,160
1,39
01,
270
3,78
04,
126
3,65
23,
516
3,31
63,
294
3,16
73,
561
1,67
01,
418
CO
CO
UT
Tot
al o
utfl
ow fr
om C
ochi
ti
Div
isio
n (I
nter
-div
isio
nal f
low
to A
lb +
R
iver
Ret
urns
)-
NM
NM
NM
NM
NM
NM
NM
NM
NM
NM
NM
NM
NM
ALG
DR
Inte
r-di
visi
onal
flow
fr C
ochi
tiM
RG
CD
34,1
601,
390
1,27
03,
780
4,12
63,
652
3,51
63,
316
3,29
43,
167
3,56
11,
670
1,41
8A
LBC
NC
anal
hea
ding
MR
GC
D79
,614
00
7,34
38,
635
10,0
9410
,462
10,6
129,
911
9,70
910
,110
2,73
90
ATF
CN
Can
al h
eadi
ngM
RG
CD
80,8
431,
370
1,23
86,
705
8,30
310
,325
10,0
819,
999
9,69
49,
235
9,35
62,
995
1,54
2B
ERC
NSe
cond
ary
cana
lM
RG
CD
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
CO
RC
NSe
cond
ary
cana
l hea
ding
MR
GC
DN
AN
AN
AN
AN
AN
AN
AN
AN
AN
AN
AN
AN
AA
LBD
RC
entra
l Ave
. Cro
ss-s
ectio
nM
RG
CD
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
ATD
CN
Cen
tral A
ve. C
ross
-sec
tion
MR
GC
DN
AN
AN
AN
AN
AN
AN
AN
AN
AN
AN
AN
AN
AA
RM
CN
Cen
tral A
ve. C
ross
-sec
tion
MR
GC
DN
AN
AN
AN
AN
AN
AN
AN
AN
AN
AN
AN
AN
AA
REC
NC
entra
l Ave
. Cro
ss-s
ectio
nM
RG
CD
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
UC
RD
RD
rain
to ri
ver
MR
GC
D23
,279
918
880
3,30
72,
936
3,10
62,
275
2,16
02,
984
2,78
31,
931
NA
NA
LCR
DR
Dra
in to
rive
rM
RG
CD
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
ATR
DR
Dra
in to
rive
rM
RG
CD
30,9
662,
876
2,55
84,
175
2,98
63,
827
2,90
82,
917
3,23
12,
809
2,68
0N
AN
AA
RSD
RD
rain
to ri
ver
MR
GC
D61
,837
4,45
43,
195
6,33
87,
918
7,60
56,
064
6,90
37,
243
6,24
35,
875
NA
NA
SAN
WW
Was
tew
ay to
rive
rM
RG
CD
31,0
053,
320
2,50
681
529
781
71,
425
1,73
33,
153
2,08
62,
253
8,33
74,
263
CO
RW
WW
aste
way
to ri
ver
MR
GC
D3,
901
6923
545
518
623
554
572
281
316
397
2N
AC
ENW
WW
aste
way
to ri
ver
MR
GC
D29
,527
3,70
54,
158
2,81
460
11,
881
911
504
1,06
671
32,
600
5,97
64,
599
AN
GD
V
Tot
al R
iver
Div
ersi
on (A
LB
CN
+
AT
FCN
- A
LG
DR
)M
RG
CD
312
6,17
70
010
,267
12,8
1116
,767
17,0
2717
,296
16,3
1015
,776
15,9
064,
017
0
AL
BSU
PD
ivis
ion
Supp
ly
(A
LB
CN
+
AT
FCN
)C
AL
C16
0,45
81,
370
1,23
814
,047
16,9
3720
,419
20,5
4320
,611
19,6
0518
,943
19,4
675,
734
1,54
2
AL
BR
RT
Tot
al R
iver
Ret
urns
(UC
RD
R +
L
CR
DR
+ A
TR
DR
+ A
RSD
R +
SA
NW
W +
CO
RW
W +
CE
NW
W)6
CA
LC
180,
516
15,3
4113
,321
17,9
9315
,257
17,8
5914
,137
14,7
8817
,959
14,9
4815
,736
14,3
158,
862
Inte
r-di
visi
onal
flow
to B
elen
2-
NM
NM
NM
NM
NM
NM
NM
NM
NM
NM
NM
NM
NM
AL
BO
UT
Tot
al o
utfl
ow fr
om A
lb. D
ivis
ion
(Int
er-d
ivis
iona
l flo
w to
Bel
en +
Riv
er
Ret
urns
)-
NM
NM
NM
NM
NM
NM
NM
NM
NM
NM
NM
NM
NM
C O C H I T I A L B U Q U E R Q U E
Tab
le 3
.10
2001
Mon
thly
Dis
char
ge b
y D
ivis
ion
(val
ues
repo
rted
in a
cre-
feet
)
Stat
ion
Cod
e1T
ype
of fl
owD
ata
Sour
ceA
nnua
l Tot
alJa
nF
ebM
arA
prM
ayJu
nJu
lA
ugSe
pO
ctN
ovD
ec
Inte
r-di
visi
onal
flow
fr A
lb.2
MR
GC
DN
MN
MN
MN
MN
MN
MN
MN
MN
MN
MN
MN
MN
MC
HA
CN
Can
al h
eadi
ngM
RG
CD
3,47
90
017
542
754
961
445
252
842
728
920
0C
AC
CN
Can
al h
eadi
ngM
RG
CD
9,27
50
021
61,
164
1,27
21,
308
1,20
61,
253
1,16
41,
515
177
0B
ELC
NC
anal
hea
ding
MR
GC
D10
5,83
90
010
,781
13,4
3215
,138
16,5
5115
,708
12,9
3111
,080
9,87
334
50
CH
ICN
Can
al h
eadi
ngM
RG
CD
18,1
020
010
52,
238
2,84
03,
061
2,98
92,
309
2,76
21,
766
310
PER
CN
Can
al h
eadi
ngM
RG
CD
104,
398
00
4,64
414
,424
15,6
8117
,462
16,0
8913
,501
13,2
789,
013
306
0L
SJD
RB
erna
rdo
Cro
ss-s
ectio
nM
RG
CD
71,7
892,
877
2,61
55,
630
8,56
08,
920
7,91
37,
510
8,15
08,
118
9,87
11,
623
0L
P1D
RD
rain
to ri
ver
MR
GC
D26
,496
1,22
975
41,
110
2,38
02,
459
3,90
93,
900
3,80
34,
251
2,32
637
50
LP2
DR
Dra
in to
rive
rM
RG
CD
11,8
882,
459
2,57
885
329
730
729
730
730
729
759
52,
717
873
BEL
DR
Dra
in to
rive
rM
RG
CD
15,0
832,
459
2,11
01,
528
743
585
569
477
615
595
1,12
33,
333
946
SAB
DR
Dra
in to
rive
rM
RG
CD
9,03
31,
249
2,61
81,
507
297
307
297
307
307
297
615
1,22
90
PER
WW
Was
tew
ay to
rive
rM
RG
CD
26,3
320
03,
003
3,46
04,
246
4,29
74,
398
3,67
53,
253
00
0FD
3WW
Was
tew
ay to
rive
rM
RG
CD
7,62
10
02,
464
1,17
398
41,
188
613
369
436
316
790
ISL
DV
Tot
al R
iver
Div
ersi
on (C
HA
CN
+
CA
CC
N +
BE
LC
N +
CH
ICN
+ P
ER
CN
- B
arr
Chi
cal L
ater
al)
MR
GC
D3
233,
406
00
15,9
2131
,686
35,4
8038
,817
34,6
0028
,678
26,9
2620
,612
687
0
BE
LSU
PD
ivis
ion
Supp
ly (C
HA
CN
+ C
AC
CN
+
BE
LC
N +
CH
ICN
+ P
ER
CN
)C
AL
C24
1,09
30
015
,921
31,6
8635
,480
38,9
9536
,444
30,5
2228
,711
22,4
5687
80
ISL
RR
T
Tot
al R
iver
Ret
urns
(LP
1DR
+
LP
2DR
+ B
EL
DR
+ S
AB
DR
+ P
ER
WW
+
FD
3WW
)C
AL
C96
,453
7,39
78,
059
10,4
658,
350
8,88
910
,558
10,0
039,
076
9,13
04,
976
7,73
21,
818
UN
7DR
Inte
r-di
visi
onal
flow
to S
ocor
roM
RG
CD
87,9
562,
314
1,44
77,
081
10,1
1110
,335
9,45
010
,357
11,2
2111
,528
11,1
482,
044
919
BE
LO
UT
Tot
al o
utfl
ow fr
om B
elen
Div
isio
n (I
nter
-div
isio
nal f
low
to S
ocor
ro +
Riv
er
Ret
urns
)C
AL
C18
4,40
89,
711
9,50
617
,546
18,4
6219
,224
20,0
0820
,360
20,2
9820
,658
16,1
249,
776
2,73
7
UN
7DR
Inte
r-di
visi
onal
flow
fr B
elen
MR
GC
D87
,956
2,31
41,
447
7,08
110
,111
10,3
359,
450
10,3
5711
,221
11,5
2811
,148
2,04
491
9SO
CC
N4
Can
al h
eadi
ngU
SGS
111,
948
00
10,5
5912
,878
14,7
0214
,991
15,2
7514
,155
14,6
8814
,700
00
SNA
DV
Tot
al R
iver
Div
ersi
on (S
OC
CN
- U
N7D
R)
MR
GC
D3
30,7
170
03,
478
2,76
64,
367
5,54
24,
918
2,93
33,
160
3,55
20
0
SOC
SUP
Div
isio
n Su
pply
(SO
CC
N +
L
EM
DV
+ 1
2HD
V +
NC
PD
V)5
-N
MN
MN
MN
MN
MN
MN
MN
MN
MN
MN
MN
MN
M
SNA
RR
TT
otal
Riv
er R
etur
ns-
NM
NM
NM
NM
NM
NM
NM
NM
NM
NM
NM
NM
NM
Out
flow
to B
osqu
e de
l Apa
che
NW
R-
NM
NM
NM
NM
NM
NM
NM
NM
NM
NM
NM
NM
NM
SOC
OU
T
Tot
al o
utfl
ow fr
Soc
orro
Div
isio
n (O
utflo
w to
Bos
que
del A
pach
e N
WR
+
Riv
er R
etur
ns)
-N
MN
MN
MN
MN
MN
MN
MN
MN
MN
MN
MN
MN
M
S O C O R R OB E L E N 1 Sta
tion
code
s re
pres
entin
g ca
lcul
ated
tota
ls h
ave
been
ass
igne
d by
SS
PA
for t
he p
urpo
se o
f thi
s st
udy.
2 Inte
r-di
visi
onal
flow
from
Alb
uque
rque
to B
elen
div
isio
ns is
com
pris
ed o
f flo
w in
the
Bar
r Chi
cal L
ater
al a
nd Is
leta
Dra
in.
3 For
mul
as p
rovi
ded
for R
iver
Div
ersi
on to
tals
are
as
calc
ulat
ed b
y D
avid
Gen
sler
of t
he M
RG
CD
.4 D
ata
for S
OC
CN
is re
porte
d fro
m th
e U
SG
S g
age
due
to o
pera
tiona
l pro
blem
s w
ith th
e M
RG
CD
gag
e.5 L
EM
DV
-- L
FC
C d
iver
sion
at L
emita
r; 1
2HD
V --
LF
CC
div
ersi
on a
t Soc
orro
(120
0); N
CP
DV
-- L
FC
C d
iver
sion
at N
eil C
upp
6 Thi
s to
tal d
oes
not i
nclu
de a
sm
all,
unga
ged
quan
tity
from
the
Low
er C
orra
les
Riv
ersi
de D
rain
(LC
RD
R).
NM
-- N
ot M
easu
red
NA
-- M
RG
CD
QA
/QC
'd d
ata
was
una
vaila
ble
at ti
me
of re
port
est -
- val
ues
estim
ated
by
MR
GC
DU
SG
S --
Dat
a ob
tain
ed fr
om N
ew M
exic
o U
SG
SM
RG
CD
--
Dat
a ei
ther
obt
aine
d fr
om M
RG
CD
QA
/QC
'd d
ata
set,
or
calu
late
d by
MR
GC
D a
nd re
porte
d he
re (m
ay in
clud
e es
timat
es)
CA
LC --
Div
isio
n S
uppl
y, T
otal
Riv
er R
etur
ns a
nd T
otal
Ret
urn
valu
es
calc
ulat
ed a
ccor
ding
to fo
rmul
as p
rovi
ded
Table 4.1 Summary of Historic Data regarding Irrigated Acres within the MRGCD
1956 49,442 3,429 595 53,466 13,879 67,3451957 52,185 1,635 298 54,118 11,530 65,6481958 51,638 2,601 117 54,356 10,428 64,7841959 51,076 3,186 38 54,300 9,820 64,1201961 48,784 3,956 407 53,147 34,434 87,5811962 48,480 2,268 226 50,974 36,779 87,7531963 46,810 4,051 264 51,125 37,211 88,3361964 51,904 2,626 159 54,689 33,227 87,9161965 54,158 2,982 593 57,333 30,384 88,117
1982 54,242 117 54,359 14,902 69,2611983* 55,994 250 56,244 13,812 70,0561984 56,967 265 57,232 12,945 70,1771985 58,158 275 58,433 11,648 70,0811986 57,796 285 58,081 11,821 69,9021987 55,271 290 55,561 14,246 69,8071988 57,058 283 57,341 12,343 69,6841989 55,931 400 56,331 12,549 68,8801990 53,736 400 --- 14,481 --1991 57,058 283 57,341 12,343 69,6841992 57,234 295 57,529 12,241 69,7701993 52,281 2,329 54,610 14,511 69,1211994 53,457 300 53,757 15,000 68,7571995 49,718 0 49,718 5,087 54,8051996 52,163 0 52,163 5,335 57,498
1997 50,593 0 50,593 9,742 60,2351998 51,126 0 51,126 10,273 61,399
(Source: USBR Crop Census Reports, 1956 - 1965 and 1982 - 1998)
*After 1983 Cropland not harvested and soil building is one category
Cropland Not Harvested
Harvested Cropland and Pasture
YearTotal Area in
Irrigation Rotation
Fallow or Idle Lands
Acres Irrigated
Soil building
Tab
le 4
.2 M
RG
CD
Cro
p C
ensu
s R
epor
ts- S
umm
ary
of A
crea
ge in
Cro
p C
atag
orie
s
Yea
rsC
erea
lsF
orag
eV
eget
able
sSe
eds
Fru
its
Nut
sO
ther
1956
9,83
534
,831
1,56
61,
065
201,
174
01,
033
49,5
2449
,524
8249
,442
1957
10,1
6136
,535
2,09
51,
330
861,
095
01,
213
52,5
1552
,515
330
52,1
8519
588,
937
37,7
461,
748
1,31
550
1,18
40
1,08
452
,064
52,0
6442
651
,638
1959
9,57
235
,161
2,69
11,
429
8796
80
1,33
851
,246
51,2
4617
051
,076
1961
5,28
938
,331
2,25
393
710
382
30
1,22
248
,958
48,9
5817
448
,784
1962
4,90
737
,791
2,36
51,
195
5976
80
1,44
848
,533
48,5
3353
48,4
8019
633,
889
38,8
522,
131
987
1237
90
872
47,1
2247
,122
312
46,8
1019
643,
989
43,2
802,
086
786
098
20
951
52,0
7452
,074
170
51,9
0419
653,
493
46,3
062,
198
1,01
699
510
01,
161
54,7
8354
,783
625
54,1
58
1982
3,88
848
,407
095
093
367
060
654
,311
54,3
1169
54,2
4219
833,
246
50,4
648
1,11
783
413
062
555
,956
56,0
7985
55,9
9419
843,
292
51,4
290
1,08
665
423
076
757
,062
57,0
6295
56,9
6719
853,
432
52,2
260
1,22
070
451
090
958
,308
58,3
0815
058
,158
1986
4,51
650
,271
201,
493
9549
10
1,06
057
,946
57,9
4615
057
,796
1987
4,46
048
,591
111,
404
9047
60
980
56,0
1255
,446
175
55,2
7119
884,
918
49,2
3515
1,49
995
436
01,
010
57,2
0857
,208
150
57,0
5819
894,
077
51,0
7727
1,71
50
620
01,
341
58,8
5756
,831
300
55,9
3119
901,
364
49,6
2238
1,35
90
463
01,
224
54,0
7054
,070
334
53,7
3619
914,
918
49,2
3515
1,49
995
436
01,
010
57,2
0857
,208
150
57,0
5819
924,
907
49,3
7015
1,52
195
336
01,
165
57,4
0957
,409
175
57,2
3419
936,
512
39,8
460
2,62
948
351
02,
895
52,2
8152
,281
052
,281
1994
052
,970
089
60
301
019
054
,357
54,3
57-9
0053
,457
1995
048
,482
081
10
266
015
949
,718
49,7
180
49,7
1819
960
50,7
040
631
021
645
835
52,4
3152
,423
260
52,1
6319
970
49,4
900
707
024
222
743
51,2
0451
,183
590
50,5
9319
980
49,5
870
565
020
30
771
51,1
2651
,126
051
,126
Sour
ce:
Cro
p U
tiliz
atio
n an
d Pr
oduc
tion
Rep
orts
Yea
rs 1
956
to 1
999,
yea
rs m
issi
ng 1
966
to 1
981
Not
e:1-
Cal
cula
ted
sum
of a
crea
ge fo
r 8 c
rop
cata
gori
es s
how
n.2-
Rep
orte
d su
m o
f acr
eage
from
Cro
p C
ensu
s re
port
s.(d
iffe
renc
es in
tota
l cal
cula
ted
and
repo
rted
not
ed fo
r yea
rs: 1
983,
198
7, 1
989,
199
6, 1
997,
& 1
999)
3- T
otal
Har
vest
ed C
ropl
and
and
Past
ure
as re
port
ed in
Cro
p C
ensu
s re
port
s eq
uals
tota
l (re
port
ed) m
inus
acr
es m
ultip
le c
ropp
ed.
Mis
cella
neou
s F
ield
Cro
ps
Tot
al H
arve
sted
C
ropl
and
and
Pas
ture
Acr
es
Mul
tipl
e3
Cro
pped
Tot
al,1
Cal
cula
ted
Tot
al,2
Rep
orte
d
Table 4.3 List of Land Use Classes for Estimating Irrigated Acreage
-X- Irrigated Crops and Fallow Lands
O Other Land Use Categories
Alfalfa -X-Pasture Grasses -X-Sorgum/Sudex -X-Wheat -X-Corn -X-Chile Peppers -X-Grapes -X-Fallow Ag -X-Idle Ag OResidential OResidential - dense OUrban Residential Irrigated OParks & Golf Courses OUrban Vacant OCommercial/Industrial ORiparian Woodland OSaltcedar ORiparian Shrub OMarsh Veg ODesert Scrub OPinion Juniper OArroyo - Desert Scrub OOpen Water OMisc. Grasses OSand/Gravel Pit OFeeding Farms -X-Melons -X-Tree Fruit -X-Nursery Stock -X-Oats -X-Beans -X-Misc. Fruit -X-Misc. Vegetables -X-Bosque O
Land Use (Vegetation) Classification
Table 4.4 Irrigated Areas between Cochiti and Bosque del Apache National Wildlife Refuge
Crop Acres (Class 1-7, 26-33)
Fallow Agriculture Acres (Class 8)
Idle Agriculture Acres (Class 9)
Crop and Fallow Agriculture Acres
Sandoval 7,338 670 3,867 8,008Bernalillo 8,786 505 2,631 9,292Valencia 28,136 323 5,097 28,460Socorro 17,532 359 3,191 17,892
61,793 1,858 14,786 63,651Note: Acreages include irrigation activities outside the MRGCD lateral service area boundary
Crop Acres (Class 1-7, 26-33)
Fallow Agriculture Acres (Class 8)
Idle Agriculture Acres (Class 9)
Crop and Fallow Agriculture Acres
Cochiti 3,743 386 2,413 4,130Albuquerque 12,318 789 4,067 13,107Belen 33,948 543 7,061 34,492Socorro 11,783 140 1,244 11,923
61,793 1,858 14,786 63,651Note: Acreages include irrigation activities outside the MRGCD lateral service area boundaryTOTAL
County
TOTAL
Division
Table 4.5 Comparison of Reported Irrigated Acres
USBR Census Report, Harvested Cropland and Pasture, 1992 57,234USBR Census Report, Harvested Cropland and Pasture, 1993 52,281NMSU Ag. Exp. Station Reports, Total Acres Irrigated, 1992 59,850NMSU Ag. Exp. Station Reports, Total Acres Irrigated, 1993 61,570Revised RGIS from EDAC, Irrigated Crop plus Fallow 63,651
Table 6.1 Division Characteristics
Cochiti Albuquerque Belen Socorro
Irrigation Density1 0.26 0.29 0.54 0.67Irrigation Acreage Factor2 0.06 0.21 0.54 0.19Acres Served per Canal Mile3 39 64 106 88
DivisionCharacteristic
1 Ratio of number of irrigated acres over total acres in lateral service areas2 Ratio of acres in division to total acres in district3 Irrigated acres divided by mapped canal miles
Table 6.2 Acreage Distribution Factors by Division and Accounting Zone
Cochiti Division
Sub-Divison ZoneTotal Area of Irrigation within
Accounting Zone (acres) Excluding Idle Lands
Acreage Distribution Factors
1 1,253 0.022 870 0.013 1,126 0.024 526 0.015 234 0.00
All Sub-Divisions 4,009 0.06
Albuquerque Division
Sub-Divison ZoneTotal Area of Irrigation within
Accounting Zone (acres) Excluding Idle Lands
Acreage Distribution Factors
1 2,838 0.052 1,584 0.033 2,212 0.044 4,451 0.075 1,816 0.03
All Sub-Divisions 12,902 0.21
Belen Division
Sub-Divison ZoneTotal Area of Irrigation within
Accounting Zone (acres) Excluding Idle Lands
Acreage Distribution Factors
1 12,925 0.212 8,659 0.143 7,205 0.124 5,024 0.08
All Sub-Divisions 33,813 0.54
Socorro Division
Sub-Divison ZoneTotal Area of Irrigation within
Accounting Zone (acres) Excluding Idle Lands
Acreage Distribution Factors
1 757 0.012 4,114 0.073 2,517 0.044 4,339 0.07
All Sub-Divisions 11,726 0.19
MRGCD 62,450Note: Acreages include irrigated crop classes and fallow acres that fall within the MRGCD lateral service area boundary
Table 6.3 General Description of Accounting Zones COCHITI DIVISION
ZONE INFLOWS UPSTREAM BOUNDARY LOCATION
Zone 1 Inflows ~RM 232.6
Sile Main Canal Downstream of Cochiti Dam
Zone 2 Inflows ~RM 232.6
Cochiti East Side Main Canal Downstream of Cochiti Dam
Zone 3 Inflows ~RM 224.5
Cochiti East Side Main Canal
*Note: wasteway into Galisteo Creek does not flow into Zone 3 but flows out of Zone 2
South of Galisteo Creek North of Santo Domingo Pueblo
Zone 4 Inflows ~RM 214.0
Algodones Lateral
Angostura Lateral (aka. Cochiti East Side Main Canal)
*San Felipe Siphon @ RM 214.3
South of Arroyo Tongue Across the Rio Grande from San Felipe Pueblo Approx. 0.6 RM south of San Felipe Bridge
Zone 5 Inflows ~RM 214.0
Southwest San Felipe Ditch South of San Felipe Pueblo on west side of Rio Grande
Table 6.3 General Description of Accounting Zones ALBUQUERQUE DIVISION
ZONE INFLOWS UPSTREAM BOUNDARY LOCATION
Zone 1 Inflows ~RM 209.7
Algodones Riverside Drain
Santa Ana Acequia
Algodones Acequia
Beginning of MRGCD Albuquerque Division North of Angostura Arroyo (Las Huartas Creek)
Zone 2 Inflows ~RM 190.9
Corrales Main Canal
Corrales Siphon
Near Rio Rancho North of Arroyo de Las Lomatas Negras
Zone 3 Inflows ~RM 195.0
Albuquerque Riverside Drain
Albuquerque Main Canal
Waterway – Unknown
Sandia Acequia
North of AMACA North Diversion Channel approx. 0.8 RM Northern edge of Mora, R.’s, Ditchrider #2, service boundary
Zone 4 Inflows ~RM 184.0 – 183.0
Atrisco Siphon
Isleta Drain
Arenal Main Canal
Near Central Avenue Bridge in City of Albuquerque
Zone 5 Inflows ~RM 180.2
Albuquerque Riverside Drain
Barr Main Canal
Barelas Ditch
South of Bridge Blvd Bridge approx. 1 RM North of AMAFCA South Diversion Channel approx 3.5 RM Northern edge of Trujillo, J.’s, Ditchrider #10, service boundary
Table 6.3 General Description of Accounting Zones BELEN DIVISION
ZONE INFLOWS UPSTREAM BOUNDARY LOCATION
Zone 1 Inflows ~RM 169.3
Peralta Main Canal Isleta Diversion Dam South of Isleta Bridge on East side of Rio Grande
Zone 2 Inflows ~RM 169.2
Belen Highline Canal
Isleta Drain
Isleta Riverside Drain (begins)
Isleta Diversion Dam South of Isleta Bridge on West side of Rio Grande
Zone 3 Inflows ~RM 150.5
Belen Hiline Canal
New Belen Acequia
Garcia Acequia
Santa Fe Ditch
Upper Arroyos Acequia
Old Jarales Acequia
Lower Belen Riverside Drain
North of NM 6 on West side of Rio Grande North of NM 6 & US 85 intersection
Zone 4 Inflows ~RM 145.0
San Juan Feeder Canal North of San Juan Wasteway (LP2DR) South of NM 47 & AT&SF Railroad intersection
Table 6.3 General Description of Accounting Zones SOCORRO DIVISION
ZONE INFLOWS UPSTREAM BOUNDARY LOCATION
Zone 1 Inflows ~RM 116.2
Socorro Main Canal
LFCC San Acacia Diversion Dam
Zone 2 Inflows ~RM 113.6
Polvadera Acequia
Socorro Main Canal
Lemitar Riverside Drain
LFCC
East of San Lorenzo Settling Basin at arroyo/wash North of Chamisal
Zone 3 Inflows ~RM 104.8
Socorro Main Canal
McAllistar Drain
Lemitar Riverside Drain
LFCC
North of Escondida Bridge at Arroyo de La Parida Pueblito on east side of Rio Grande
Zone 4 Inflows ~RM 94
Luis Lopez Acequia #2
Socorro Main Canal
Socorro Riverside Drain
LFCC
At Brown Arroyo South of Wasteway near Brown Arroyo
Table 6.4 Irrigation Density by Division and Accounting Zone
Cochiti Division
Sub-Divison Zone
Area of Zone (acres)
Total Area of Irrigation within Accounting Zone (acres)
Excluding Idle Lands
Irrigation Density
1 5,608 1,253 0.222 2,805 870 0.313 3,991 1,126 0.284 2,611 526 0.205 687 234 0.34
All Sub-Divisions
15,701 4,009 0.26
Albuquerque Division
Sub-Divison Zone
Area of Zone (acres)
Total Area of Irrigation within Accounting Zone (acres)
Excluding Idle Lands
Irrigation Density
1 7,519 2,838 0.382 4,499 1,584 0.353 14,930 2,212 0.154 14,159 4,451 0.315 3,702 1,816 0.49
All Sub-Divisions
44,809 12,902 0.29
Belen Division
Sub-Divison Zone
Area of Zone (acres)
Total Area of Irrigation within Accounting Zone (acres)
Excluding Idle Lands
Irrigation Density
1 20,177 12,925 0.642 16,273 8,659 0.533 17,863 7,205 0.404 8,018 5,024 0.63
All Sub-Divisions 62,331 33,813 0.54
Socorro Division
Sub-Divison Zone
Area of Zone (acres)
Total Area of Irrigation within Accounting Zone (acres)
Excluding Idle Lands
Irrigation Density
1 1,634 757 0.462 5,554 4,114 0.743 4,403 2,517 0.574 5,825 4,339 0.74
All Sub-Divisions 17,417 11,726 0.67
MRGCD 140,259 62,450Note: Acreages include irrigation activities within the MRGCD lateral service area boundary
Table 7.1 Advantages and Concerns Related to Rotational Water Delivery
Advantages Concerns
Greater ditchrider control of water delivery
Cropping patterns: types and practices Weather patterns
Limits irrigator water use through creation of scarcity
Inconvenient: users expect to irrigate when best for them
Labor requirements
Has already been implemented in water short situations
Decreased support for riparian corridor along canals
Pre-season planning and management requirements
General
Most required infrastructure is already in place
Lack of technical infrastructure System layout
Guarantee of equitable water delivery to all users
Concern for lack of adequate water for tail-end of system
Reduced diversions may impact water pressure or head for delivery
More feasible in large scale agriculture than small-scale
Increased weed growth in drying canals
Too many irrigators in urbanized areas: free-flow irrigators
Prevents users from taking water out of turn
Canal characteristics: length, number of users, capacity
Alterations in schedule due to: repairs, maintenance, emergencies
Site Specific
Provides water to Pueblo at a prescheduled time
Pueblo delivery requirement
Water level fluctuations: gophers and erosion
Table 7.2 Approximate Percentage of MRGCD Lands Devoted to
Different Land Use Practices
Year 1938 1954 1975 1986 Cultivated 51% 56.3% 54.9% 48%
Grass & Brush 34.5% 26.5% 19.4% 15.4% Bosque 12.7% 9.3% 8.3% 10.2%
Urban 1.7% 7.9% 17.4% 26.4% Total 100% 100% 100% 100%