ENSURING ENVIRONMENTAL FLOWS IN INDIAN RIVERS

Above: Dead river Yamuna at Mawi (Panipat) in Haryana (Photo by Yamuna Jiye Abhiyaan)

Guest Blog by: Manoj Misra (yamunajiye@gmail.com)

A perennial river that does not flow is no river. This is because flow enables a river to fulfil its various ecological functions of which completion of the water and nutrient cycles; maintenance of aquatic and riparian flora and fauna and recharge of ground water through aquifer action is the most evident and critical. The recharged ground water also helps meet a number of human dependencies like irrigation and drinking water supplies.

On this World Water Day (March 22) 2015, following the 6th meeting of the Yamuna Review Committee held under chairperson ship of Union Water Resources Minister Sushri Uma Bharti (See Annexure for the PIB Press Release about it) on March 20, 2015, this blog shows how it is possible to achieve environment flows in Yamuna River. Hope all the concerned state governments including that of Delhi headed by Arvind Kejriwal, Union Water Resources Minister and the National Green Tribunal that made an order in this regard, will take due note of this.

The state of the Yamuna has reached a boiling point as eleven members of the Yamuna Muktikaran Abhiyaan have started a fast unto death on March 21, 2015 in Delhi, charging Union Water Resource Minister Uma Bharti that “she only made hollow promises. She barely knew about the issue”. This group has been marching to Delhi every year since last three years and have felt cheated by the authorities each time. They decided to end the protest action on March 22, 2015 under some rather vague promise by the government that within two months Yamuna river will be brought under Environment Protection Act, 1986.

What flow in a river is not just water but also sediment and many of its biota element. As a matter of fact, the first charge on a river’s water and sediment is that of the sea, where the river’s mouth (often in form of a multichannel delta) forms the unique brackish water ecosystem (marked by mangrove vegetation) and the sediment provides stability to the coast line. The second charge is that of the ground water aquifers, the third of the river’s biodiversity and only then of anyone else including us humans and other non riverine life forms.

Against the above, on display today almost everywhere is an indiscriminate drying through increasing diversion of river water, capture of sediments behind dams and barrages and consequent break in riverine longitudinal and lateral continuities & connectivities. This is nothing short of a river-cide.

The above unacceptable scenario can be reversed only through a resumption of riverine connectivities based on legally ensured environmental flows (of both water and sediments) in them, while still allowing for permissible levels of diversion of river water to meet basic human needs.

Minimal interference Let us not forget that the waters flowing in a river belongs to none else but the river and all life forms that form a part of its ecological processes as characterised by its longitudinal, lateral and vertical continuities. Any disruption in such continuities is against nature and the river dependent natural processes. It is also an irrefutable fact that water flowing down a river to the seas is an age old natural phenomenon that completes the earth sustaining natural “water cycle” and any talk of such water having been ‘wasted’ is unscientific and unwarranted.

As a matter of fact all flow in a river with all its natural spatial and temporal variations constitutes its environmental flow and hence the effort should be to ensure a minimal interference (a term often used by the noted river and water expert Sri Ramaswamy Iyer) with its flow. In any case there can be no justification on any ground whatsoever to divest a river of all its flow during some part of the year as if a river were a pipeline whose flow could be put on and off at will?

Still in view of human dependencies having been created on waters diverted from a river there is a case to arrive at a comfortable ‘minimum’ whereby the basic needs of both the river (as an ecosystem) and of those dependent on its waters could reasonably be met.

Researchers have laboured hard to arrive at a number of formulas to estimate minimum environmental flows in rivers. At last count these numbered some 200 different methods. But majority of these lead to uneven percentages whose implementation and validation remains a challenge and which are then often contested on the ground.

Thumb rule[1] According to Professor Gary Jones (Australia) a river remains healthy as long as no less than 70 % of its waters in different seasons remain in the river. In extreme cases, this figure could go down to 50% but no less.

INDIAN RIVERS Indian rivers are largely monsoonal. They carry high to very high flows during the monsoon period and soon taper down to low and sometimes just to aquifer fed base return (influent) flows.

Himalayan Rivers Perennial Himalayan rivers are predominantly glacier fed, with their rain fed tributaries often being seasonal. This property invests in them a uniqueness which must be factored in when we talk of ensuring environmental flows in them.

Unique features of Himalayan Rivers Like other rivers in the country Himalayan rivers have their high to very high flows during the three monsoon months of July, August and September. But unlike the peninsular rivers, the glacier fed Himalayan rivers have their minimum flows in the winter months of December, January and February, when frozen glaciers release little water. Flow in them begins to rise once the winter snow on the high hills begins to melt with the summer heat.

Thus it is the critical winter period when flow would be defined as the ‘low’ in case of glacier fed Himalayan rivers and to which all dependent ecological processes would have adapted over the millennia. It thus also automatically qualifies to be termed as its ‘minimum’ environmental flow.

Barrages and Dams Dams hold water & sediment in reservoirs behind them, while barrages divert waters away from the rivers. In both instances the result is a break in both longitudinal connectivity of the river as well as wide changes in the lateral connectivity of the river both in the upstream and the downstream of the structures.

It is well known that both dams and barrages have a design limitation above which they can neither hold water nor divert waters into their feeder canals. And then at least in the case of barrages the feeder canals are closed and the river flows unhindered down its course.

In our understanding one of the key reason of river demise is lack of any such mandatory low level threshold, when again the canals would be closed and the river again allowed to flow unhindered. This would be done in the interest of the river and not for any design defined structural limitation.

Principles Thus the first principle of river rejuvenation shall be to provide for a minimum level below which again there shall be no diversion of water from a structure. That is to say that a barrage shall have a design ‘high’ (structure design limitation) as well as a stipulated ‘low’ (minimum environmental flow) above and below which respectively the structure shall not come into operation.

Second principle of river rejuvenation shall be based on the fact that a river needs utmost care in its severest lean period so that its ecological abilities are not gravelly and almost irreversibly compromised. This shall require the provision of an unhindered flow during such ‘lean’ period which shall be designated as its “no diversion” period.

Third principle of river rejuvenation shall be that in order to prevent pollution of the rivers, no water once diverted from a river shall be released back in the river in any form (treated or untreated). Such extracted waters should continue to be recycled and reused to meet essential non potable human uses including irrigation, habitation and the industrial needs.

Peninsular Rivers In case of peninsular rivers the key difference from the glacier fed Himalayan rivers is the ‘lean period’ when natural flows are at their lowest.  Such period shall obviously be the peak summer months for peninsular rivers as against the winter months for the Himalayan rivers.

The principles as mentioned above for river restoration shall otherwise hold equally true for the peninsular rivers.

Moreover, what applies to the main river stem applies equally to its tributaries.

RIVER YAMUNA – A CASE STUDY

A barrage cum dam at Hathnikund (HKB), some 230 km upstream of Delhi is the most critical structure which has sounded an almost death knell for the Yamuna river. This is because resulting from an unreasonable inter-state MOU (1994) the flow in the river downstream of the barrage has been limited to mere 160 cusecs (cubic feet per second), which by no stretch of imagination can be called its minimum environmental flow. Such deliberate drying of a river is not justified on any grounds.

It is a matter of record that the design limitation of the barrage (HKB) requires closing of its canals and a free flow of the river once the water exceeds 70,000 cusec at HKB. (Source: Flood data acquired through use of RTI from the Haryana Irrigation department).

An analysis of the average flow data in the river at Hathnikund (and prior to 2002 at Tajewala barrage, which was decommissioned when new Hathnikund barrage was commissioned) since 1961 indicates an average daily flow of 3500 cusec during the lean season months of December, January and February. This thus in all fairness is the ‘minimum’ environmental flow to which all ecological processes related to the river Yamuna are naturally adapted and to deprive the river of even this level of flow cannot be justified under any circumstances. To presently allow a mere 160 cusec in the river against the winter lows of a daily average of 3500 cusec is a travesty.

Even if we resort to Prof. Jones thumb rule of 70% water in the river for a healthy river then in case of river Yamuna a minimum of say 2500 cusec (around 70 cumec) should remain in the river at all times. There can be no case to divert part of this or any lesser flow in the river at any time.

SUGGESTION

  1. a) No diversion of waters from the river is made during the “lean” period from 15 Dec – 15 Feb.
  2. b) As waters in the river increases with snow melt and rainfall in the catchment in the higher reaches, then diversion in following proportions could be made so that neither the river nor the dependent realistic human needs suffer:
Total water in the river Water d/s of the structure Water diverted into canals Comment
2500 cusec 2500 cusec Nil Min Env Flow in the river (70% of the av lean season flow)
3000 cusec 2500 cusec 500 cusec Diversion of water in excess of min env flow
4000 cusec 2500 cusec 1500 cusec Diversion of water in excess of min env flow
5000 cusec 2500 cusec 2500 cusec 50% in river and 50% diverted (since the river is heavily burdened)
6000 cusec 3000 cusec 3000 cusec 50% in river and 50% diverted
8000 cusec 4000 cusec 4000 cusec 50% in river and 50% diverted
10000 cusec 5000 cusec 5000 cusec 50% in river and 50% diverted
15000 cusec 7500 cusec 7500 cusec 50% in river and 50% diverted
30000 cusec 21,000 cusec 9,000 cusec Design limitation of the canals permit maximum of 7500 cusec in WYC and 1500 cusec in EYC
50,000 cusec 41,000 cusec 9,000 cusec DO
70,000 cusec 70,000 cusec NIL Design limitation of the canals and the HKB require river to flow free
70,000 cusec + 70,000 cusec + NIL Design limitation of the canals and the HKB require river to flow free.

Western Yamuna Canal (WYC) and Eastern Yamuna Canal (EYC) are the two canals that originate at the Hathnikund Barrage (HKB).

c) Off river reservoirs be created at suitable locations along the river to harness allocated portions during the high flow period in the river to meet the human needs during the above no diversion lean season period of the river (see the sub section below with title Off river reservoirs). This practice is being followed in many countries & cities where flow in rivers are naturally limited.

Lessons and learning from the Yamuna flood of 2010 River Yamuna experienced high to very high floods beginning late August till late September 2010.

Accordingly it is a matter of record that the river Yamuna remained free flowing (all barrage gates open) downstream of the barrage at Hathnikund (HKB) for more than a month from 22 August 2010 till 3 October 2010 (43 days). This implies that there was no diversion of any water during the same period from the river, into either the Western Yamuna Canal (WYC) or the Eastern Yamuna Canal (EYC).

The above points to the fact that all the river water dependent water access and use systems from the Hathnikund barrage (HKB) have already a provision of more than a month of reserve water storage. Thus with little augmentation it is very much possible to provide for free river flows as suggested during its lean period from 15 December – 15 February for river rejuvenation.

Off Channel reservoirs It is suggested that each riparian city of river Yamuna may invest in creation of an adequately sized  reservoir on the side of the river (off river) in flood plain where an allocated portion of the river Yamuna’s high flows during the monsoon months could be collected for later use.

This practice shall on one hand given full handle to the city in question to manage its own water supplies (thereby preventing inter-state water conflicts) as also offset any need of construction of dams (presumably for water supply) on the river or its tributaries in its higher reaches in the states of Uttarakhand and Himachal Pradesh.

City of London – an example City of London in UK manages its water supplies in the form of off channel reservoirs created on the bank of river Thames. Water from river Thames during high flows in winter months is collected for later use.

Off Channel Reservoirs along Thames River

Off Channel Reservoirs along Thames River

NCT of Delhi

NCT of Delhi can create a number of off channel reservoirs in river Yamuna flood plain in its Zone P II located in a north-south direction so that water transfer could be easily affected using gravity since north is at a higher elevation than the south.

Possible sites of off channel reservoirs along Yamuna River in Delhi

Possible sites of off channel reservoirs along Yamuna River in Delhi

Similarly placed off-river reservoirs could be created by cities likeYamuna nagar, Karnal, Panipat, Sonepat and Faridabad in Haryana and Saharanpur, Baghpat, NOIDA, Mathura, Agra and Etawah in UP.

While such locations within the flood plain of the river could be easily located, wherever such reservoir might still require land from a farmer or other land holder, the latter may be mandatorily made a partner in the enterprise with his piece of land taken by the city managers on a long term lease and a lease amount (adjusted with inflationary changes) paid in perpetuity to the lessor in form of a payment for ecological services (PES) that the city dwellers/ water users must be made to contribute as a cess.

END NOTES:

[1] http://ewater.com.au/archive/crcfe/freshwater/publications.nsf/827558d21061a2f2ca256f150011f4da/2673f6a120c6c3a9ca256f0b001b7a3e/$FILE/Science%20behind%20e-flows%20-%20GJones%20260303.pdf

[2] http://indianexpress.com/article/cities/delhi/to-save-yamuna-yamuna-muktikaran-abhiyaan-begins-fast-unto-death/

ANNEXURE

http://pib.nic.in/newsite/PrintRelease.aspx?relid=117564

Ministry of Water Resources21-March, 2015 18:08 IST

Government Committed to Ensure e-flow of Yamuna Says Uma Bharti 
Union Minister for Water Resources, River Development and Ganga Rejuvenation Sushri Uma Bharti has said that an inter-ministerial committee constituted under the chairmanship of the Additional Secretary of her Ministry to suggest measures to tackle pollution in Yamuna and to ensure e-flow of the river will submit its interim report within a week. This was stated by the Minister while chairing the 6th meeting of Upper Yamuna Review Committee held here yesterday. Referring to the sentiments of people agitating for pollution free Yamuna the Minister said this committee will also go through the reports of Ravi Chopra committee, Chaturvedi committee and IIT consortium.Referring to the order of NGT to ensure e-flow of river Yamuna the Minister requested the states of UP, HP, Uttarakhand, Haryana and Delhi to send their suggestions to the Union Environment Ministry within a week so the Ministry could submit it before the Principal Committee of NGT. Sushri Bharti said that urgent steps will have to be taken to stop the flow of pollutants from Hindon river and Shahdara drain into river Yamuna.Chief Minister of Haryana Shri Manohar lal Khattar, Delhi CM Shri Arvind Kejriwal, irrigation Ministers of UP and Rajasthan and senior officials of HP and Uttarakhand attended the meeting.Samir/
(Release ID :117564)

One Comment on “ENSURING ENVIRONMENTAL FLOWS IN INDIAN RIVERS

  1. Pingback: No amount of cleaning can cure the Yamuna unless it is liberated at Hathnikund barrage - The Caravan

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