Ministry of Environment and Forests · Ministry of Water Resources

MoWR report on “Assessment of E-Flows” is welcome, needs urgent implementation

A three member committee set up by the Union Ministry of Water Resources, River Development and Ganga Rejuvenation (MoWR for short) has submitted a report in March 2015, which makes welcome recommendation on “Assessment of Environment Flows”. These recommendations on Environmental Flows (E-Flows) need to be implemented immediately for better health of our rivers. The committee members include Dr Vinod Tare of Indian Institute of Technology Consortium (IITC), senior officials of Union Ministry of Environment, Forests and Climate Change (MoEF for short, it was represented by Dr Shashi Shekhar, Special Secretary in MoEF) and MoWR (represented by Dr Amarjeet Singh, Additional Secretary, MoWR). Sushri Uma Bharti, Union Water Resources Minister[1] and even the recent meeting of National Ganga River Basin Authority (NGBRA) on March 26, 2015[2], headed by the Prime Minister referred to this committee.

What is E-flows and E-flows assessment? The committee concludes that “E-flows Assessment (EFA) is an important step in determining the River Health Regime (RHR)… Achieving a specific RHR may warrant (i) certain policy decisions to set boundary conditions for planned actions (e.g. irrigation and hydropower projects that are at planning stage), and/or (ii) reversal of trends in ongoing activities (e.g. hydropower projects and water diversions schemes that  are operational). The time line, resource, resource requirements and challenges faced are expected to be different and may have to be based on strategic planning (e.g. Ganga River Basin Management Plan).”

The MoWR committee “recommends adoption of this description of the E-flows”: “E-Flows describe the temporal and spatial variations in quantity and quality of water required for freshwater and estuarine systems to perform their natural ecological functions (including material transport) and supports the spiritual, cultural and livelihood activities that depend on them.” The committee report also emphasises that the E-flows are not only about water flows: “However, maintenance of the water-sediment balance is also an essential condition. It is desired that E-flows should carry suspended load and bed load in approximately the same proportions as present in virgin flow.”

It is noteworthy that the 32 page report is not about EFA or RHR only of Ganga River but rivers of India in general, which is also welcome. The report gives seven examples of EFA, which are all in upper Ganga Basin since the IITC report on GRBMP, just recently submitted was available with the committee. In fact all these seven examples are taken from the “Mission 1: Aviral Dhara” document of the GRMBP 2015 of IITC.

It defines E-flows as: “E-Flows are a regime of flow in a river that mimics the natural pattern of river’s flows… E-Flows refer to the quality, quantity and timing of water flows required to maintain the components, functions, processes, and resilience of aquatic ecosystems that provide goods and services to people.”

The report has taken note of the recommendations of the various earlier reports on Ganga and also the latest report of the IITC. It also refers to somewhat discredited BK Chaturvedi committee report and strangely does not even refer to the report of the Wildlife Institute of India report on Cumulative Impact Assessment on Ganga Basin. Since WII provides one of the more credible reports on Ganga Basin, the MoWR report should have mentioned it.

The Methodology for assessment of MER The committee has come up with recommendations about how to estimate E-Flows, Minimum Environment Requirement (MER) in Rivers, depending on River Health Regime. The report strongly recommends the Building Block Method (BBM) for assessment of E-Flows as “robust and scientifically most suitable”. The methodology suggested by the committee involves identification of keystone species for the river stretch for which E-flows is to be assessed, after defining the river cross section and generating stage-discharge curve. The report defined Keystone specie as: “A species that has disproportionately large effect on the environment relative its abundance.” In case of Upper Ganga basin, the report identifies two keystone species at different locations, namely Snow Trout and Golden Mahseer.

The methodology then asks for assessment of temporal variations in depth of flow required for survival (minimum depth) and natural growth (spawning season depth). It also requires assessment of water required for longitudinal (upstream downstream) connectivity and lateral connectivity with the floodplains for the historically observed number of days during monsoon season. The flow depths for any given flow will be different at different locations, for example the depths will be greater at pools than that at the riffles. To ensure that the minimum flow depth is available at the entire stretch under assessment, the flow depth is assessed at riffles. This assessment provides Minimum Ecological Requirements (MER).

For Upper Ganga Basin examples, the report assesses that the river requires lateral connectivity for at least 18 days during monsoon. For each of these depths, water flow requirements are assessed at average and at 90% dependable flow regime.

River cross section at E-Flows site (Source: GRBMP report Mission 1)
River cross section at E-Flows site (Source: GRBMP report Mission 1)

E-flows Hydrograph The report says that “The E-Flows are obtained by mimicking the trend in daily 90% dependable flow using the MEF for non monsoon season as the E-Flows for non-monsoon period.” The higher figure between the flow required for spawning season and the maximum E-flows during non monsoon season is specified as minimum monsoon flow. “The E-Flows for monsoon period are obtained by mimicking the trend in daily 90% dependable flow using the minimum monsoonal flow”, report says, at the same time ensuring that lateral connectivity for the historical average number of monsoon days is assured. However, the methodology for EFA given in the report in para 3.2 is not very clear.

River Health Regime The report divides the rivers into five health regimes: Pristine, Near Pristine, Slightly Impacted, Impacted and Degraded. Here is how it defines these regimes.

  • Flow regime inferior than the MER would render the river in Degraded Most rivers in India (except possibly those in North East and some Himalayan tributaries in upper reaches) are already degraded since we are not maintaining even minimum flows.
  • Flow regime that is better than MER but below the E-Flows will make the river Impacted.
  • Flow regime higher than E-Flows but below 90% dependable flow will make the river slightly impacted.
  • Flow regime better than E-Flows but below the average flows will mean river is in Near Pristine
  • If flow regime matches the average flows in the river, than it is considered in Pristine

The above description of River Health status is only with respect to hydrological quantities, we need similar classification for river water quality, geomorphology and biology, but the MoWR committee does not go into these definitions. MoWR should possibly ask the same committee to take this remaining task too.

The committee has stated that the river needs to have Environment flows higher than the MER to allow the rivers to continue to perform its basic functions. It says on page 9, while starting to assess the e flows requirements at seven sites along the Upper Ganga by way of illustration, that “E flows at the sites selected consider the ecological and geo-morphological requirements, which in turn, ensure the minimum ecosystem goods and services of the river (including the cultural, spiritual and livelihood requirements that depend on these).

E-flows Assessment along Upper Ganga Basin by MoWR Committee and IITC’s GRBMP:

E-flow sites along Upper Ganga (Source: GRBMP Mission 1 document)
E-flow sites along Upper Ganga (Source: GRBMP Mission 1 document)
Site MER in Wet period as % of AVF MER in Dry period as % of AVF E-flows in wet period as % of AVF E-flows in dry period as % of AVF
Ranari, Dharasu/ Bhagirathi 32.59 32.96 46.13 53.12
U/s of Devprayag/ Bhagirathi 29.00 20.48 37.96 29.04
D/s of Rudraprayag/ Alaknanda 31.71 19.3 46.19 38.16
D/s of Devprayag/ Ganga 43.21 29.98 61.47 59.00
U/s of Rishikesh/ Ganga 53.00 30.23 67.29 50.23
At Rishikesh/ Ganga 55.83 31.72 70.55 52.55
D/s of Pashulok Barrage, Rishikesh/ Ganga 27.99 30.99 37.43 58.42

Note: AVF: Average Virgin Flow

The committee goes on to recommend that the rivers must have E-flows and not just MER, which is welcome. It can be seen from the table above that at most sites (only exception is site no 7), the dry season E-flows as % of AVF is lower than wet season E-flows. However, the river is in greater stress in dry season, and possibly would need greater % of AVF releases in this season. Secondly, the whole assessment given here is basically for keystone species and it is assumed that the requirements for keystone species will be also take care of all the other social, cultural, ecological needs of the river. That assumption may not always hold good and there should be an assessment if the E-flows for keystone species will satisfy these other river requirements. Lastly, it should be noted that the WII report recommends greater depths for adult and juvenile species of snow trout and golden mahseer than what is assumed by IITC[3]. It should be noted that WII is the credible, specialist agency on these matters and hence recommendation of the WII in this regard should be followed.

However, leaving aside these qualifications, the MoWR report is most welcome and needs urgent adoption and implementation.

E-flows is not a luxury but a necessity for the people and society The MoWR committee says, “The objective of –E-flows is to recognise the physical limit beyond which a water resource suffers irreversible damage to its ecosystem functions, and systematically balance the multiple water needs of society in a transparent and informed manner. E-flows are one of the central elements in water resources planning and management for sustainable development.” That element has been completely absent from India’s water resources planning and management, and earlier we bring that element into the decision making and implementation, better it will be for everyone.

E-flows are practical It can be easily argued that the implementation of these E-flows recommendations are neither impractical nor will the implementation have disruptive impact on our water needs and uses. There are many reasons for this assertion, the biggest one is that since agriculture is our biggest user of water and since groundwater is the lifeline of agriculture water requirement, groundwater recharge and sustainable use should be our biggest priority. Secondly, there are methods like System of Rice Intensification and Sustainable Sugar Initiative that can reduce our agriculture water requirement hugely, similar is the case for appropriate cropping pattern. As far as Urban and Industrial water use is concerned, in the interest of the cleaner rivers, it is even more important that there is treatment and recycle of maximum about of effluents from these sources, nearest to the source of such effluents. Lastly, if we take up rainwater harvesting more seriously, the demands on rivers would automatically reduce. To implement these set of steps, we will need much greater social and political will, it is the lack of will that is the biggest impediment in the path of better future for our rivers.

Implications of the Report Such E-flow assessment exercise as described in this MoWR report has NOT be done for any of the dam or hydropower project anywhere in India or in Ganga basin or in Uttarakhand as part of the decision making process for hydropower projects, dams and irrigation projects.

This is also true for the projects under consideration in the Supreme Court now. Hence all the projects must go through this exercise as recommended by this report. Without such assessment and implementation, there is no possibility for the river to perform its minimum functions and no possibility of Ganga Rejuvenation, promised by the current government from day one. Hence the Supreme Court should direct that the projects follow these recommendations to achieve e flows recommended in this report. We hope the government, including the Ministry of Environment and Forests and also the Ministry of Water Resources, who are part of this report, will make their submissions to the court on these lines. The conflict between the two ministries that the Attorney General hinted in the Supreme Court on April 13, 2015 seems to be misleading considering this joint report from two ministries.

However, this report has much greater significance beyond the Supreme Court case, beyond the Uttarakhand and Ganga Basin. It holds significance for all Indian Rivers and the government needs to start implementing these recommendations immediately.

Implications in the context of Uttarakhand None of the existing hydropower projects in Uttarakhand are releases e-flows. Firstly, the government and the apex court should immediately mandate that there is an independent credible assessment (by an agency like Wildlife Institute of India or the Expert Body headed by Dr Ravi Chopra or even the three member team that gave this MoWR report) of the Eflow releases from existing dams and how it can be made possible through gate operations. This may mean some reduction in generation, which can be made good through tariff adjustments as provided in the Electricity Act of 2003. However, this will mean a huge advantage for the rivers, the communities residing on the river banks, for the groundwater levels and for the fisheries and other biodiversity.

For future hydropower projects, they should be mandated to release the lean season E-flows through a gap in the dam wall (as mandated by the IIT Consortium for providing longitudinal connectivity) and additional flows in spawning and monsoon seasons through operation of the gates.

As far as under construction projects are concerned, for projects whose dam wall has not been constructed above river bed level, they should be asked what is required for future projects, that is e-flow releases through a combination of longitudinal connectivity and gate mechanism. All the 24 projects now under review by the apex Court fall in this category as the dam wall in these projects have not been constructed beyond riverbed level to the best of our information. For projects whose dam wall has been constructed above river bed level, they may be asked to see if it is possible to still provide longitudinal connectivity.

Himanshu Thakkar, SANDRP (

POST SCRIPTThe report of MoWR reviewed above can be downloaded from eflows MoWR Report.

END NOTES: [1] According to the 4th meeting of the NGBRA held on 27th October, 2014, chaired by Susri Uma Bharti, “The Additional Secretaries of MoWR, RD & GR and MoEF&CC will review the recommendations of these reports and will submit their report for the implementation of Environmental Flow… It was informed that the Ministry has set up a committee of Additional Secretaries with support from the convener of the IIT consortium to go through the recommendations of the previous committees as well as the report of the IITs and expedite the decision on the environmental flow.”

[2] PIB PR on this meeting:

[3] Adult and Juvenile Mahseer need depths higher than 0.75 meters (Adults: depths greater than one meter, Juveniles: shallow, ranging 0.75- 1.5 mts), see Table 7.6 of WII report.

39 thoughts on “MoWR report on “Assessment of E-Flows” is welcome, needs urgent implementation

  1. See this para “E-Flows are a regime of flow in a river that mimics the natural pattern of river’s flows… E-Flows refer to the quality, quantity and timing of water flows required to maintain the components, functions, processes, and resilience of aquatic ecosystems that provide goods and services to people.”, it is a highly hypothetical in nature and mis-leading. It appears this report presents a theoretical exercise leading no where with little practical utility. In rivers frequency of occurrence of floods follow a natural rhythmic variation. Nowhere this issue was neither discussed nor linked in their assessment. This in fact plays the vital role. Though the report says “temporal and spatial variations” With out such analysis this report has little use but such reports mislead governments and people.

    Dr. S. Jeevananda Reddy
    Formerly Chief Technical Advisor – WMO/UN & Expert -FAO/UN
    Fellow, Andhra Pradesh Akademy of Sciences
    Convenor, Forum for a Sustainable Environment
    Tel. (040)23550480 [Hyderabad, India]


  2. Minimum flows, environmental flows and river health would be largely dependent on health and features of contributing watersheds as well. Thus, identifying sensitive watersheds, particularly fisheries sensitive watersheds based on certain critical attributes like erosion potential, forest cover, urban index, water quality status or index, drainage density, confluence density, sinuosity (meandering) index, rate of agri. chemicals use per ha, % area degraded, road density, fishing intensity, socio-economic importance of the watersheds etc. accounting ecological, stressors and social metrics become imperative for categorical management.
    Here, we need to fast develop expertise on river management using bio-physical interventions, database, working strategies and approaches involving all possible stakeholders and organisations. This sort of interest will also benefit interlinking of rivers (ILR) as well.
    The ICAR-Indian Institute of Soil and Water Conservation (ICAR-IISWC, formerly CSWCRTI), Dehradun is developing interests on this line of works and has recently initiated a research project on classification of fisheries-sensitive watersheds.


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