Ministry of Environment and Forests

Eflows in India: Groping in Darkness

Eflows in India: Groping in Darkness

– Dr. Latha Anantha

It is becoming increasingly evident that ‘rivers’ do not figure anywhere in the entire e flows discourse and assessments going on at Government level in India. We have so many different types of e-flows assessments being tried out.

Multiple agencies, but where are the flows? At least 69 hydro power projects are in various stages of development in Alaknanda – Bhagirathi sub basins of the Ganga (as per IMG records). Four different e-flow regimes based on different approaches have been put forward by the four different agencies. While AHEC (Alternate Hydro Electricity Centre) has used Mean Annual Flows (MAF), WII (Wildlife Institute of India) has resorted to Mean Seasonal Runoff (MSR) for different seasons based on the needs of the fishes. CWC (Central Water Commission) has resorted to ad-hoc e flows of 20 % of daily flows. IMG (Inter-Ministerial Group) has come out with its own recommendation of percentage of daily inflows for different seasons  going upto 50 % for winter season from December – March where winter flows are very low.

The beautiful Nyamjangchu River, Tawang, Arunachal Pradesh, now threatened by the 780 MW Nyamjangchu Hydel Project and very  low eflows recommendation Photo courtesy: Tenzing Rab Monpa
The beautiful Nyamjangchu River, Tawang, Arunachal Pradesh, now threatened by the 780 MW Nyamjangchu Hydel Project and very low eflows recommendation Photo courtesy: Tenzing Rab Monpa

While admitting that Building Block Methodology (BBM) is the most comprehensive holistic methodology, IMG report claims (without basis) that since it is time consuming and since it has not been tried out in any large river basin, interim e-flows recommendations be done so that hydro power development is not held up for want of environmental decisions. Mind you, this is the case with all the rivers where hydro power projects are being planned.  While many of the project developers and EIA agencies claim that they follow BBM methodology, it is evident that none of these fulfill the requirements of a comprehensive BBM methodology. So who cares about the rivers here?

NIH workshop on Oct 2-3, 2013 without MoEF! The National Workshop on Environmental flows organized by the National Institute of Hydrology (NIH), Roorkee along with UK based Centre for Ecology and Hydrology (CEH) during 2-3 Oct 2013 only reinforced my conviction that what is going on in the name of e flows assessment is indeed not for any goodwill for the rivers. The workshop was conspicuous by the absence of MoEF officials whose main mandate is protecting river ecosystems and life in rivers. Were they not invited or did they decide not to participate? It was mostly dominated by technical persons and organisations who believe that rivers are for the exploitation by humans alone mostly through mega projects. The workshop agenda was set on the oft repeated dictum that e flows should be integrated into water resources development, without any will for such integration.

Ganga, completely dry downstream Bhimgouda Barrage, Haridwar Photo: Parineeta, SANDRP
Ganga, completely dry downstream Bhimgouda Barrage, Haridwar Photo: Parineeta, SANDRP

E-flows are for rivers In India e flows is just a formality to fulfill the requirements of the environmental clearance process. Ironically, resource persons from countries outside India with ample experience on e flows assessment pointed out that the intention was to find ways to ‘limit’ or mitigate the impacts of development. If the agenda had been set with the intention that e flows should be part of river conservation and not just to fulfill the development agenda then we would have some hope for rivers.

Developers don’t want any e-flows Project developers are clearly unhappy with even the meager allocation in the name of e flows. The dam builders like the NHPC, Uttaranchal Jal Vidyut Nigam Ltd. and Tehri Hydro Power Corporation claimed that they are actually releasing more water than they are ‘asked to’! This is indeed ridiculous. Even what they are ‘asked to’ release does not amount to e-flows and is not based on any comprehensive assessment or community validation! And there is clear evidence that they are not releasing even that (e.g. NHPC’s Teesta V or Tehri). Then where does the question of reducing e-flows allocation below dams arise? They even went to the extent of recommending that in those rivers where tributaries join the dry stretch below the dam, can’t e flows allocation be reduced and can’t the tributary contribution added as e flows? Can’t e flow releases be used for power generation by installing dam toe power houses? For them e flows is mere ‘cumecs’ (Cubic meters per second) of water to be released and nor do they understand that each tributary and the main stem of the river have their own ecological niches & functions; and social and cultural dependencies which are linked to the flows in each of these.

Dhauliganga before the disaster, with zero water flow downstream from the dam, killing a perennial river. Source: Author
Dhauliganga before the June 2013 disaster, with zero water flow downstream from the dam, killing a perennial river. Source: Emmanuel Theophilus

The presentations made by NIH Roorkee, CIFRI (Central Inland Fisheries Research Institute), GBPIHED (GP Pant Institute of Himalayan Environment and Development) and AHEC for proposed hydro power projects in the Himalayas and the North East India revealed that none of the studies had carried out consultations with river dependent communities and did not follow the BBM principles either.

CIFRI-NIH’s flawed assessment of Teesta IV HEP e-flows Teesta IV HEP proposed in Sikkim is presently under the scanner since many groups have raised the genuine concern with the MoEF (Ministry of Environment and Forests), EAC (Expert Appraisal Committee), FAC (Forest Advisory Committee) and the NBWL (National Board of Wild Life) that if implemented it would mean the death of the last free flowing stretch of the main Teesta river. The ToR (Terms of Reference) of the study commissioned by MoEF says, “An estimation to be made for environmental flows downstream for sustenance of aquatic environment and for downstream uses, considering details of streams joining the river below the proposed dam site with their approximate distance from the dam site, their nature (whether perennial or seasonal) etc. A detailed environmental flows study shall be carried out through the premier institutions such as Central Inland Fisheries Research Institute (CIFRI), Barrackpore and National Institute of Hydrology (NIH), Roorkee for biological and hydrological components”.


The consultants took just 7.5 km length of the river from dam axis to the existing downstream project Teesta V which is immediately downstream. The study carried out in 2009- 2010 period has prescribed a minimum discharge of 10 cumecs (Cubic Meters per second) from the dam during the lean period and 40 cumecs for wet season for aquatic life is also prescribed. The ToR has two objectives namely e flows for the sustenance of aquatic environment and for downstream uses, but the sampling parameters in the presentation does not reflect the fulfillment of these objectives.

Teesta V HEP Photo: Tehelka
Teesta V HEP Photo: Tehelka

Since the Teesta V is already commissioned, the impact below the dammed and flow regulated stretch of Teesta V on the aquatic environment and downstream uses would have given useful comparisons. The study seems to have ignored the e flows for downstream uses of communities even in the 7.5 km stretch. The study though claimed to have used the BBM methodology, it is doubtful if all the relevant building blocks have been considered. The study carried out in 2009-10 does not seem to be uploaded in public domain to date.

E-flows for all projects do not make sense? Most shockingly, the chief consultant for the Ganga River Basin Management Plan now being formulated by a consortium of IITs (Indian Institutes of Technology) Dr Vinod Tare was of the opinion that all projects to release e flows does not make sense. He said it is important to seek balance and generate power as well. Now this is problematic. Let us face it that in Indian conditions we are working on e-flows under data and information deficient conditions. We are still far away from understanding a river system in its complexity along with its basin characters, eco- hydrological interactions and land use changes.

Lack of Eco-hydrological understanding Even NIH engineers and other experts agreed during discussions that we lack reliable hydrological data and have absolutely very little ecological data base on our rivers to arrive at proper recommendations for e-flows. MoEF and NGRBA (National Ganga River Basin Authority) has meanwhile accepted BBM methodology (as in the NGRBA Report; Code – 022_GBP_IIT_EFL_SOA_01_Ver 1_Dec 2011) as the most robust assessment approach to e-flows and they also say it needs to be worked upon.

The report says, ‘The BBM methodology is found to be robust with high confidence level. However, specific flow recommendations are difficult to justify at this stage, and will have to be worked out afresh. The major uncertainties centered on the hydrological and hydraulic models due to lack of availability of reliable data’. In BBM all blocks are equally important as they interact with each other. Against such a scenario, Dr Tare needs to think twice before making such statements! They can be used by dam developers to lobby for reduced or even no flows.

What about e-flows from existing dams? Another missing element from e-flows at the NIH workshop that is bothersome was the lack of interest by the experts and the various authorized institutions in allocating e flows below already dammed rivers. They say it will be a tough job and would not be possible politically. However, ultimately e-flows is a social and political choice with trade offs and negotiations inbuilt into it. Does that imply that we can leave heavily dam ravaged rivers like the Mahanadi, Krishna, Cauvery, Narmada, Tapi, Sabarmati, Godavari, Teesta, Sutlej, Ravi, Beas, Chenab, Periyar and the like to die without allowing them at least their long overdue minimum flows leave alone e flows ? It is high time the Government took interest and started engagement and studies in arriving at and allocating e flows below dammed rivers.

The same Baspa, bone dry, about 5 kms downstream Baspa Dam. Photo: SANDRP Partners
The same Baspa, bone dry, about 5 kms downstream Baspa Dam. Photo: SANDRP Partners

Future challenges After two days of debate and disagreements, I came out of the workshop with the following thoughts at the top of my mind.

Several institutions in this country with expertise in ecology and hydrology and with necessary infrastructure who could have made efforts to put in place comprehensive e-flows assessment process are working for dam developers and serving as experts in EIA studies giving green signals to ill conceived hydro electric projects and dams based on inadequate e-flows recommendations. The level of dilution of science and ethics this can lead to is mind-boggling and with disastrous consequences for our rivers. For example e-flows and minimum environmental flows are being used as synonyms by many institutions including CWC. An interesting and dangerous recommendation from CWC at the workshop is; ‘If feasible, a separate storage of water in the upper reaches of a river basin maybe created for environmental needs which will help in augmenting flows during lean season and satisfy the e-flows demands particularly for Himalayan rivers’. So in future all river basins with dam cascades could be recommended with e-flows reservoirs!

What about compliance, MoEF? While e-flows have become mandatory for hydro power projects in this country, it is surprising and shocking that MoEF is yet to ensure compliance and to take up comprehensive and fundamental assessment of e-flows in sample river basins on its own which is its primary mandate. It is high time MoEF develops a ToR for e-flows from its conception to implementation to monitoring. E-flows assessment presently being carried out lacks proper objectives and mostly excludes communities from its purview or assessment. There is vagueness about what constitutes downstream in e-flows assessment. Even for the e flows assessment carried out in River Ganga for the NGRBA has there been any effort to implement the same? Has the MoEF ever tried to seek inputs on e flows from outside the government organisations or from the several groups working tirelessly for conservation of rivers?

Will NIH exercise have credibility? NIH in collaboration with many institutions proposes to take up sample river basins in India and put in place eco hydrological models for e flows. The absence of MoEF and members of the Expert Appraisal Committee on River Valley Projects at this workshop organized by a MoWR institution speaks for itself how e-flows will be realized if the mandatory ministry does not take a pro active role.

Some of the gaps and challenges in e flows assessment in Indian context include: lack of reliable data, lack of understanding of eco- hydrological linkages, river aquifer interactions, pollution related aspects (how to quantify and relate to flow releases), e-flow releases for flood plains, lack of resource allocation, lack of valuation of ecosystem services and societal – cultural value of rivers, multiple institutions working against each other’s interests (MoWR vs MoEF), Peaking induced flashiness, scientific and acceptable ways to compute e-flows and lastly but most importantly, effective implementation and monitoring.

Experts from other countries pointed out that rather than numbers it is better to have distribution ranges for e flows under Indian conditions with complex dependencies. They also made an important comment that uncertainty and risk factors never get integrated into our e-flows estimations. In India land use changes are also not accounted in e flows calculations.

We have a very long way to go.

Dr. Latha Anantha (

SANDRPs post on NIH Eflows workshop:

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