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Environmental Flows Assessment Objective Based Flow-Setting –In certain cases, people intend to have specific pre-defined ecological, economical and social.

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Presentation on theme: "Environmental Flows Assessment Objective Based Flow-Setting –In certain cases, people intend to have specific pre-defined ecological, economical and social."— Presentation transcript:

1 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.

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3 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

4 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

5 Step 4: Identify critical components (building blocks) of the flow regime that govern environmental conditions (e.g. dry and wet season base flows, and different-sized high flows and floods) Step 3: Use flow-dependent indicators (e.g. dolphins, gharial, turtles, fish, invertebrates, floodplain vegetation), non-consumptive human requirements, as well as water quality metrics and sediment transport, to identify water depths, velocities, river widths, and substrate types that will provide required habitats and conditions. Such hydraulic requirements can then be converted to hydrological (flow) requirements Step 2: Assess a modified flow regime that will meet those objectives Step 1: Use a stakeholder consultation process to set objectives for the environmental condition of the river Building Block Methodology

6 Stage A: Scoping Stage B: Preparation for the Assessment 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 the assessment team Task 3: Zone the study area Task 4: Habitat integrity Task 5: Site Selection Task 6: Surveys and measurements Biological Surveys Hydraulic survey Hydrological analysis Geomorphological survey Water Quality analysis Social survey Stage D: Negotiation Task 1: Hydrological yield analysis Task 2: Scenario analysis Task 3: Decision

7 7 Required Habitats Activities Processes Hydraulics Depth Velocity Width Substrate Hydrology Cubic metres per second of Water required Objectives GANGA EFA: Promote the sustainable use of water resources in the Ganga to: - Ensure ecological integrity -Provide livelihoods - Maintain sacred values Flow Indicators Fish, Dolphins, Invertebrates, Algae, Religious rites, Livelihoods, Channel processes

8 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 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

10 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

11 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

12 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

13 Arriving at E-Flows STEP 1: Hydrology and Hydraulics Cross Sections for each zone

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

15 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.

16 STEP 3: Calculating critical flows

17 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

18 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

19 Arriving at E-flows

20 Results: Zone 1, Maintenance Flows Site -Kaudiyala 72% MAR E-Flows: 72% of Mean Annual Runoff Present day flows could not be calculated, as flow release data from the Tehri Dam was not available

21 Results-Zone 3: Narora–Farrukhabad Maintenance Flows Site –Kachla Ghat 45% MAR E-Flows requirement: 45% of MAR Present day flows does not meet E-Flows requirement during the lean season

22 Results - Zone 4: Kanauj- Kanpur Maintenance Flows Site EF4 – Bithur 47% MAR E-Flows: 47% of MAR Present day flows not meeting E-Flows requirements for lean months

23 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

24 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

25 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

26 Partners Facilitation: Prof Jay O’Keeffe, (formerly UNESCO-IHE, Netherlands) & Dr Vladimir Smakhtin, IWMI Biodiversity: Prof Prakash Nautiyal, Garhwal University Cultural/Spiritual:Prof Ravi Chopra, People’s Science Institute Livelihoods: Prof Murali Prasad, IIT Kanpur Geomorphology: Prof Rajiv Sinha, IIT Kanpur Water Quality: Prof Vinod Tare, IIT Kanpur Hydraulics:Prof A K Gosain, IIT Delhi Hydrology:Dr Vladimir Smakhtin, Dr Luna Bharati, IWMI

27 THANK YOU

28 Building Block Methodology

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30 Assessment Method BasisCost/timeConf- idence Example Look-up tablesHydrologySmallLowTennant Time Series modelsHydrologySmall/MediumLowIHA Rated X-Section models HydraulicsMedium Intermediate (SA) Habitat ModelsHydraulics/EcologyHighMediumIFIM RegionalHydrology/EcologyHigh (initial)MediumELOHA/Desktop Holistic Hydraulics/Ecology /Geomorph./Social/ Water Quality High BBM/DRIFT/ Benchmarking Different EF Assessment Methodologies Desktop (Half-Day) Over 200 methodologies


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