Environmental Flows Assessment

• Objective Based Flow-Setting

– In certain cases, people intend to have specific pre-defined ecological, economical and social objectives for the river.

• Scenario Based Flow-Setting

– if water managers are able to understand and make decision on water allocations and scenarios for trade offs in managing and balancing the water demands/requirements.

Building Block Methodology

• Building Block Methodology – one of the most comprehensive methodology

– Bottom up approach

– Much detailed and can be tailored to suit local conditions

– Most frequently used holistic methodology

– Rigorous and well documented

Building Block Methodology

• Flexible to accommodate other local aspects, like religious and spiritual requirements (hence applicable for Indian rivers)

• Functions well in data-rich and data-poor situations

• Links to external stakeholders and public participation processes

• Applicable to regulated and non-regulated river regimes

• Moderate to highly resource intensive

Building Block Methodology

Stage A: Scoping Stage B: Preparation for theAssessment

Task 1: Initiate EFA assessment (level of detail, define methodology)

Task 8: Define reference conditions

Task 7: Ecological and Social Importance and Sensitivity

Task 9: Define present ecological status

Task 10: Define environmental objectives

Stage C: EFA Setting workshop

Stage E: Implementation and compliance monitoring

Task 2: Constitution of theassessment team

Task 3: Zone the study area

Task 4: Habitat integrity

Task 5: Site SelectionTask 6: Surveys and measurementsBiological SurveysHydraulic survey Hydrological analysis

Geomorphological surveyWater Quality analysisSocial survey

Stage D: NegotiationTask 1: Hydrological yield analysisTask 2: Scenario analysisTask 3: Decision

7

RequiredHabitats

ActivitiesProcesses

HydraulicsDepth

VelocityWidth

Substrate

HydrologyCubic metres per second of

Water required

ObjectivesGANGA EFA: Promote the

sustainable use of water resources in the Ganga to:

- Ensure ecological integrity-Provide livelihoods

- Maintain sacred values

Flow IndicatorsFish, Dolphins,

Invertebrates, Algae, Religious rites, Livelihoods,

Channel processes

• Zone I: Upper Reach (Gangotri to Rishikesh)

• Zone II: Reference zone(U/S of Garhmukteshwar to Narora)

• Zone III: Middle Reach(Narora to Farrukhabad)

• Zone IV: Lower Reach (Kannuaj to Kanpur)

Rishikesh

Kannauj

Narora

9

Zone 1 Gangotri to Rishikesh

Zone 3 Narora to

Farrukhabad

Zone 2 U/S of Garhmukteshwar

to Narora(Reference Zone)

Zone 4 Kannauj to

Kanpur

1. Hydrology

- Identify and review previous hydrological modeling studies and assessment of their usability

- To set up model and calibrate under existing conditions of land and water use

- Examine the feasibility of different ways of modeling the past ‘natural’ and present-day flows, using observed flow data

Components

2. Fluvial Geomorphology and hydraulic modeling for maintaining sustainable flows

- Analysis of sediments in the river, and the assessment of the effects that will result from different flow regimes

- Analyse the channel and floodplain morphology in terms of the geomorphic features, and their stability

- Generate the cross section and longitudinal profile for hydraulic modelling

3. Habitat preferences of selected Aquatic species

– Assess present condition in terms of the difference between the reference condition and survey results

– Describe measured depths, average velocities and substratum types most commonly associated with sensitive species and families, and/or with maximum biodiversity

Components

4. Economic and Livelihood objectives for Maintaining Sustainable Flows

- Evaluate livelihood activities and its implications on environmental flows of the river

5. Assessment of Cultural & Spiritual in stream flow required for Maintaining Sustainable Flows

– Representation of the river in mythology, folklore, folk art and popular literature and art

– Historical evidence of civilizations along the river, and its influence on society

– Cultural, Religious, spiritual importance of the Ganga, with focus on rituals and festivals

6. Water Quality and Pollution

– Generation of data on water quality parameters that is not available from any sources, but considered essential by the water quality group (samples from 30 locations)

– Assessment of various types of pollution loads in different stretches/sub-stretches

Components

Arriving at E-Flows

STEP 1: Hydrology and Hydraulics Cross Sections for each zone

STEP 2: Flow motivationsFlow recommendations based on requirements of biodiversity, Livelihoods, Culture/Spiritual needs, Geomorphology

Maintenance Flows

The Maintenance Flows are for "normal" years, not very wet or not very dry, here one would expect all the ecological functions and processes:

fish breeding floodplain wetlands full sediment transport etc.

Maintenance Flows would be equaled or exceeded during 70 years out of 100; however flows would be lower for 30 years out of 100 or in other words, 70% probability on the flow duration curve.

For a long-term E-Flow, the water volume required would be at maintenance recommendations or higher for 70% of the time, and between drought and maintenance for 30% of the time.

STEP 3: Calculating critical flows

Critical flows• Kaudiyala:

– January maintenance flow: fluvial geomorphology

– August maintenance flow: biodiversity• Kachla Ghat & Bithoor:

– August flows (both during maintenance and drought years): cultural and spiritual

• Almost half of the critical flow recommendations were influenced by biodiversity requirements

STEP 4: Calculating annual E-Flows requirements

– Driest and wettest months under maintenance and drought conditions (January – driest month and August – wettest month)

– E-Flows values were calculated, based on inputs from working groups, by hydrologist for other months of the year by means of interpolation

– Monthly flow volumes for each month of the year for low-flow and high-flow components calculated

Arriving at E-flows

Results: Zone 1, Maintenance Flows

0

2000

4000

6000

8000

10000

12000

14000

1 2 3 4 5 6 7 8 9 10 11 12

Months

Flow

Vol

ume,

MCM

maintenance low maintenance high natural total

Site -Kaudiyala

72% MARE-Flows: 72% of Mean Annual Runoff

Present day flows could not be calculated, as flow release data from the Tehri Dam was not available

Results-Zone 3: Narora–Farrukhabad Maintenance Flows

0

2000

4000

6000

8000

10000

12000

14000

1 2 3 4 5 6 7 8 9 10 11 12

Months

Flow

Volu

me,

MCM

maintenance low maintenance high natural total Present

Site –Kachla Ghat 45% MAR

E-Flows requirement: 45% of MAR

Present day flows does not meet E-Flows requirement during the lean season

Results - Zone 4: Kanauj- Kanpur Maintenance Flows

0

2000

4000

6000

8000

10000

12000

14000

16000

18000

1 2 3 4 5 6 7 8 9 10 11 12

Months

Flow

Volu

me,

MCM

maintenance low maintenance high natural total Present

Site EF4 – Bithur

47% MARE-Flows: 47% of MAR

Present day flows not meeting E-Flows requirements for lean months

• Access to observed long term hydrological data, is critical for assessing flows and this would have considerably increased the confidence in the environmental flow assessment.

• Further calibration and verification of the existing rated cross-sections, and the establishment of additional cross-sections, would also increase confidence in the flow recommendations

• Relationships between indicator fish, invertebrates and flow would allow more precise flow recommendations

• More precise relationships between water quality parameters and flow would have allowed the prediction of the effects of recommended flows on water quality to be assessed

Key Issues

E-flows

• Not a one time flow; Regime of flows • Assess E-flows using a holistic approach:

hydrology, hydraulics, fluvial geomorphology, water quality, socio-cultural-spiritual, biodiversity and livelihood

• Need to be an integral part of the EIA & CIA – Bottoms up-project, sub-basin to basin level; – Existing projects – Trade-off analysis

• Need to place it in the context of river basin management plan

E-flows

• Implementation & monitoring– Joint monitoring– Whether required releases are being made– Impacts

• Adaptive process needed in E-flows assessment and implementation

• The EF process should be embedded in a framework of inclusive stakeholder understanding and participation, and preferably within a broader context of IWRM

Partners

Facilitation: Prof Jay O’Keeffe, (formerly UNESCO-IHE, Netherlands) & Dr Vladimir Smakhtin, IWMI Biodiversity: Prof Prakash Nautiyal, Garhwal UniversityCultural/Spiritual: Prof Ravi Chopra, People’s Science InstituteLivelihoods: Prof Murali Prasad, IIT KanpurGeomorphology: Prof Rajiv Sinha, IIT KanpurWater Quality: Prof Vinod Tare, IIT KanpurHydraulics: Prof A K Gosain, IIT DelhiHydrology: Dr Vladimir Smakhtin, Dr Luna Bharati,

IWMI

THANK YOU

Building Block Methodology

Assessment Method

Basis Cost/time Conf-idence

Example

Look-up tables Hydrology Small Low Tennant

Time Series models Hydrology Small/Medium Low IHA

Rated X-Section models

Hydraulics Medium Medium Intermediate (SA)

Habitat Models Hydraulics/Ecology High Medium IFIM

Regional Hydrology/Ecology High (initial) Medium ELOHA/Desktop

HolisticHydraulics/Ecology/Geomorph./Social/

Water QualityHigh High BBM/DRIFT/

Benchmarking

Different EF Assessment Methodologies

Desktop (Half-Day)

Over 200 methodologies