Countries like Bhutan, Nepal, parts of Tibet and parts of India like Sikkim have some lovely Buddhist traditions linked to the nature. On the edges of forests, overlooking valleys and atop majestic mountains flutter tiny colorful prayer flags.Inside Dzongs, fixed prayer wheels spin by the tug of a pious hand. While spinning and fluttering, the prayers are supposed to be disseminated in the universe, reaching every sentinel being.
But there is a third kind of fascinating prayer wheel. It worships not only the creator, but also flowing water. Today, as naturally flowing waters become rarer, it is strangely reassuring to see these wheels spinning away, as the stream pushes the small wooden turbines round and round. These wheels are more fascinating for their symbolic significance: In these regions where water wheels worship the flow, the same flow is being harnessed for generating money and power: Hydropower. In Bhutan, the 10,000 MW + hydropower initiative supported by India and financial institutions like ADB & other foreign players will dam almost all of the big river systems in the country.
In fact, institutions like ADB are so over-enthusiastic in pushing hydropower in Bhutan ( ADB is ‘administering‘ Hydropower grants to Bhutan from countries like Norway and Japan) that they see Bhutan’s strong environmental conservation practices as ‘hurdles’ in this development. ADB says: “Bhutan’s strong environmental conservation policies have affected the pace of implementing power projects because of the time required to complete procedures such as environmental impact assessments, public consultations, forestry clearances, and road planning.”
What follows is a short photo feature on Water Wheels in Bhutan as well as the hydropower development in the Punatsangchu Basin, through the 1200 MW Punatsangchu I HEP. Just a few kilometers downstream is the proposed intake and dam of Punatsangchu II which is also underway.
Bhutan is the only country in the world which measures its development not only in terms of GDP, but through Gross National Happiness (GNH), which is an aggregate of a number of things, including environmental conservation and preservation of culture.
Let us hope that this dense hydropower development does not affect the Bhutanese tenets of happiness…
Majestic three- tiered prayer wheels in Paro, on way to Tiger’s Nest Monastery Photo: SANDRPA tiny water wheel in agricultural fields of Paro Photo: SANDRPOne more water wheel on way to Taktsang Monastery Photo: SANDRPA water prayer wheel in a village near Paro Photo: SANDRPA water wheel on a flowing stream in a dense forest, on way to Phobjikha Valley Photo: SANDRPThe wooden wheel blades Photo: SANDRPA roadside Prayer wheel with steel blades Photo: SANDRPA roadside water wheel on way to Thimpu Photo: SANDRPOn way to Thimpu Photo: SANDRPOn way to Taktsang Monastery Photo: SANDRPCascade of three water wheels in Phobjikha Valley Photo: SANDRPDifferent ways of using the flow: A storehouse for Apples and other seasonal fruits, built on the top of a stream, which acts like a natural AC Photo: SANDRPFresh fruits, preserved in a storehouse on the stream! Photo: SANDRP
HYDROPOWER IN BHUTAN
At the same time, huge, unprecedented hydropower developing is also challenging the tiny nation. Much of it is pushed by India.
Planned, underconstruction and commissioned hydropower projects may cover all the river systems in Bhutan. Photo: Down to Earth from CEA
In 2006, India and Bhutan signed an agreement to “facilitate and promote development and construction of hydropower projects and associated transmission systems as well as trade in electricity, through both public and private sector engagements”. Under this agreement, India has agreed to minimum imports of 5,000 MW of hydropower capacity by 2020. The agreement will be valid for a period of 60 years and can be extended. In addition to this agreement, a protocol between India and Bhutan was signed in 2009 through which India will develop 10,000 MWs of hydropower in Bhutan for export of surplus power to India by 2020. This has been going on through a mix of soft loans and grants. This also means services for Indian engineering and design consultants like WAPCOS and Indian developers & contractors like L and T, NHPC, Gammon India, JP Associates, BHEL, SJVN, THDC, Tatas, HCC, Jindal, etc.[1] Indian companies like NHPC, WAPCOS are also involved in Detailed Project Reports, while other Indian companies are bagging the construction and equipment contracts.[2]
Already, three hydro projects funded and built by India are operating in Bhutan which include 336 MW Chukha, 60 MW Kurichu and 1020 MW Tala HEP. Under-construction projects funded mainly by India include 1200 MW Punatsangchhu HE Project Stage-I, 1020 MW Punatsangchu Stage II and 720 MW Mangdechu HEP. News reports indicate that Bhutan and Indian government have together identified 10 HEPs with a total capacity of 11,576 MW by 2020 for development. In addition the country has about 16 operating HEPs[3].
Punatsangchu I Project, 130 mts high dam, envisages submergence of 673 acres of Reserve forest land, 78 acres of private land (involving 116 land owners) and 6 acres of Institutional Land (2 institutions) till the end of April 2013 for the project construction. Punatsangchu II project with 80 mts high dam, involves 479 acres of reserve forest land, 14 acres of private land (involving 17 land owners) and 5 acres of Institutional Land (3 institutions) till the end of April 2013 for the project construction.
In 2014, India and Bhutan also signed an agreement for 2120 MW hydropower capacity through four projects which include 600 MW Kholongchu project, 180 MW Bunakha project (with 230 MW downstream benefits from Tala, Chukha and Wangchu HEPs), 570 MW Wangchu project, and 770 MW Chamkarchu-I project.[4]
Following are some pictures from Punatsangchu I Site.
Riparian farming on a tributary of Punatsangchu Photo: SANDRP
Coffer dam and diversion of PSHP I Project Photo: SANDRPDam Axis of PSHP I Photo: SANDRP
Diverted River, dry and without flows Photo: SANDRPHuge muck disposal next to the river bank near the intake chambers Photo: SANDRPL and T India is the contractor for construction of Diversion Tunnel, Dam, intake and Desilting Chambers Dam Wall Photo: SANDRPGammon India is contractor for 7.48 kms Head Race Tunnel. Bharat Heavy Electricals and HCC are also contractors in PSHP I Photo: SANDRPStretch of Punatsangchu River that will be diverted through the tunnel when the dam is commissioned Photo: SANDRPBaso Chhu River, entirely dried as it is diverted for the 66 MW BasoChhu Power Project of Druk Green Photo: SANDRPThe Six symbols of Longevity celebrated in Bhutan ( also Tibet). Photo: At Punakha Monastery, SANDRP
In almost all Dzongs, as well as hotels and homes rests a picture of Six Symbols of Longevity ( see picture above), all of them are interlinked, hold symbolic significance and are supposed to be auspicious.
They include Man, Animals, Birds ( The Black Necked Cranes, incidentally threatened by an Indian Dam: 780 MW Nyamjangchu, close to Bhutanese border), Mountains, Trees and Rivers!
[5] Samir Mehta’s blog on Hydropower Challenges in Bhutan: http://www.internationalrivers.org/blogs/257/bhutan-s-picture-of-gross-national-happiness-blurs
[7] Sector Study of Bhutan’s Hydropower by World Bank: http://documents.worldbank.org/curated/en/2007/12/9425448/bhutan-hydropower-sector-study-opportunities-strategic-options
[8] ADB pushing for Hydropower in Bhutan, also for storage projects, which have huge impacts! http://www.adb.org/features/bhutan-s-hydropower-sector-12-things-know?ref=countries/bhutan/features
At the 10th International Symposium on Ecohydraulics in Trondheim, Norway in June 2014, SANDRP talked with Dr. Thomas Hardy, Past President of the Ecohydraulics Section of the International Association for Hydro-Environment Engineering and Research (IAHR), and The Meadows Center for Water and the Environment Endowed Professor in Environmental Flows at Texas State University.
Dr. Hardy holds advanced degrees (MS and PhD) in both aquatic ecology and civil engineer and has been at the forefront globally, for linking issues related to hydraulics and hydropower with ecosystems. Here he talks about issues like state-of-art mitigation measures being put to use across the world for mitigating impacts of hydropower, evolution of Ecohydraulics and the dangers of “Putting dams at the wrong place”
We see some significant mitigation measures, some of which include decommissioning, for addressing impacts of hydropower coming from over the world. How did this system evolve? What was the role of various actors and did this happen suo motto from the companies?
Since the last two decades, we have recognized the environmental consequences of hydropower. The cost benefits analyses of many projects is getting skewed, we have been witnessing the ecological costs of many of such projects are exceeding their economic benefits. For example, in the 5 dams in a cascade on the Klamath River, the economic value of the salmon fisheries being destroyed was more than the hydropower benefits from the dams. A lot of mitigation measures have come from countries like Norway and countries like US have also seen them, and we are always keeping our eyes open for better solutions.
While it’s accepted that there will be impacts of any intervention, we need to be honest about the scale of the impacts and who pays the price for these impacts.
About the suo motto role of companies, unfortunately, I have not seen very many companies adopting better environmental standards by themselves without consistent pressures and constant monitoring from people and the government. A lot of credit to increased performance of hydropower mitigation measures goes to NGOs, civil society groups, indigenous communities and the citizens themselves for raising these issues with the companies as well as governments to adopt better standards for their rivers. The advent of social media continues to help a lot to this end.
In the US, a lot of changes were also driven by aboriginal communities who protected their fishing rights or riverine ecosystems. For example in the Klamath River, the aboriginal tribes upheld their traditional fishing rights of salmon which were affected by the dams. This led to not only changes in dam operation, but a spurt of work on fish ladders, passes, eflows and decommissioning. Having said that, we have also committed some massive mistakes, the cost of which have been great. The mitigation measures we are trying to put in now are very costly. Making wise decisions about siting dams and including mitigation measures at the level of designing itself is not only effective, but its also comparatively cheaper. In that sense, it is encouraging to see China being more concerned about the impacts of its hydropower on the environment.
It is claimed that Run of the River projects are environmentally better than storage type HEPs. There are some such projects which undertake massive peaking. How can the impacts of massive scale of hydro-peaking be mitigated?
Firstly, if its peaking, its not an ROR. [1]An ROR by definition cannot store water and cannot change the hydrographs of a river on a timescale. If it’s doing that, it’s not an ROR and should not be labelled as such. Period. If anyone is doing that, I would question their motives in being less than truthful. It’s also a matter of wrong green labels to these projects. So we need to remember that RORs do not change the downstream hydrograph and hence cannot peak.
How about the contention that ramping up and down reduces peaking capabilities of the project?
Well, there is no free lunch. There is a cost to doing business, cost of doing good business, and only this will keep it running in the long term. No one would deny that all developmental activities entail environmental costs, but we to understand the range of environmental and social costs, put them on table and then take a wise decision, taking everyone on board.
As for ramping rates affecting peaking operations, power demands do not fluctuate hugely from established patterns on a daily, weekly, or seasonal basis and the companies have a pretty good forecast idea of the range of demand. Based on this, if the peaking is supposedly for 3 hours, up ramping can be started an hour earlier, so that we get the benefits of 3 hours peaking. Same goes for down ramping, you need to coordinate it that way. Of course this will mean some change of efficiency, but like I said, there is no free lunch and surely government and companies are concerned about safety of their people downstream these projects.
Safety concerns of peaking opeartions, apart from the ecological concerns, are very important to consider. In case of the Milner Dam on the Snake River in the US, I actually had a group of students and fishermen stand and then wade in a river and we then worked on the releases from the dam which gave sufficient time for these people to get out of the river. There is no option to safety measures. They are of paramount importance.
When we develop rivers in a cascade, would it help if we maintain free flowing stretches between projects?
Well it’s a relative question, which is all about siting your projects. In the first place, don’t put a dam in the wrong place! That’s most important. After that, placing of other dams will be specific to the ecological uniqueness of that river. But we need guidelines which say at least some percentage of the upper watershed should be conserved and not exposed to impacts like peaking. It may be better to entirely protect the tributaries of a heavily dammed basin, rather than adopting a cut and stitch approach. FERC (Federal Energy Regulatory Commission) is now routinely including impacts of hydropeaking on fish and other organisms like benthic macroinvertebrates while relicensing and also licensing.[2]
Decommissioning of the Glines canyon Dam on the Elwha River From USGS.gov
How is the monitoring mechanism around mitigation measures developed in the US? Do communities have a role to play here?
Monitoring is well developed and an important part of the licensing process. The company can do annual monitoring themselves, or they can outsource this to an external entity. Monitoring advisory Committees are mandatory for projects and this committee includes representatives from the company, wildlife groups, aboriginal groups, regulators, etc. The membership to this committee is pretty flexible. If a group has significant reasons and wants to be a part of the monitoring committee, it can do so. This committee monitors environmental management plans and also guides the company in this process.The issue is about making the companies and government accountable to the society.
There has been a flood of eflows methodologies, Which one would you describe as the state of art methodology at this moment?
ELOHA is robust and well developed for this moment, but there is no one size fits all method, the assessment method depends on the data, time and resources available. The main point is that even eflows entail consensus generation and equitable sharing of resources and here too, the community should be playing a main role.
When the dam building pressures are too high, there is little point in hurrying through studies. In extreme cases, it is wise to put a moratorium on on-going development, try and fathom what we have lost and will be losing, look at the environmental and social consequences of this loss and then decide on the way forward. These things cannot be hurried into.
At places like Columbia River systems, we realize that we have changed the entire river basin, but the mitigation measures have been developed, put in place and are working. So, that’s good. But in other places, we realize that the social, ecological and even economic costs we are paying for developing dams are just not worth the costs. In those cases, we need to bring them down. This has happened too.
Interviewed by Parineeta Dandekar, SANDRP
(The trip was possible due to generous support from Both ENDS)
~~~~~~~~~~~~~~~~~~
[1]Text book definition of ROR: ““Run-of-river” refers to a mode of operation in which the hydro plant uses only the water that is available in the natural flow of the river, “Run-of-river” implies that there is no water storage and that power fluctuates with the stream flow.”
NOTE: Contrast this with the Indian Bureau of Standards definition of ROR, which allows pondage for even weekly fluctuations of demands and then claiming that this “does not alter the river course materially”. This is a blunder as that sort of pondage and resultant peaking hydrograph changes the downstream character of the river completely. even weekly storage and then peaking as ROR!
[2]http://www.northfieldrelicensing.com/NorthfieldRelicensing/Lists/Documents/Attachments/47/20130228-5329(28100604).pdf: The Turners Falls Project is currently operated with a minimum flow release that was not based on biological criteria or field study. Further, the project generates power in a peaking mode resulting in significant with-in day flow fluctuations between the minimum and project capacity on hourly or daily basis. The large and rapid changes in flow releases from hydropower dams are known to cause adverse effects on habitat and biota downstream of the project. Effects on spawning behavior could include suspension of spawning activity, poor fertilization, flushing of eggs into unsuitable habitat due to higher peaking discharges, eggs dropping out into unsuitable substrate and being covered by sediment deposition and/or eggs becoming stranded on de-watered shoal areas as peak flows subside.
June 16, 2014 This is a sad day, reminding us of the Uttarakhand disaster that began on this day a year ago. The disaster was triggered by unseasonal and heavy rainfall in which indicates a clear footprint of climate change. At the same time, the role played by massive infrastructure interventions, including an onslaught of hydropower projects and dams in Uttarakhand’s fragile ecosystem, in magnifying the proportions of this disaster manifold is also undeniable[1]. It is a sign of callousness of our system that till date we do not have a comprehensive report about this disaster that throws light on what all actually happened, which institutes played what role, which institutes failed or succeeded in their assigned role, what were the rehabilitation and resettlement provisions, processes, plans and policies, and what lessons we can learn from this experience.
The lessons from this experience hold significance for the entire Himalayan region.
Uttarakhand and the union government declined to even investigate the role of hydropower projects in the disaster. It was left to the Supreme Court of India, through its order of Aug 13, 2013, to ask the government to set up a committee to assess the role of existing and under construction hydropower projects in the disaster.[2] The apex court also asked governments to stop clearances to all such projects in the state in the meantime. The reluctant Union Ministry of Environment and Forests (MEF) took two more months to set up the committee which was headed by Dr Ravi Chopra.[3]The committee submitted the report in mid April, 2014, but two months later the MEF is yet to put up the report in public domain. Or make it available to the people of Uttarakhand in their language or invite their views. SANDRP had written in detail about the recommendations of the EB, the committee certainly said that the hydropower projects played a significant role in the disaster[4]. Eminent geologist Prof K S Valdiya has also written in Current Science in May 2014 (Vol. 106, p 1-13) that most projects are being built in landslide prone, seismically active area and should not be built there.
It was again left to the Supreme Court on May 7, 2014 to order stoppage of work on the 24 hydropower projects. The Expert Body recommended cancellation for 23 of these projects and change of parameters for one project. There is immense hope in further proceedings in the apex court in coming months, since the results will provide a guide for the whole Himalayan region in Uttarakhand, in other states in India and even for the Himalayan region beyond the border.
At the same time, it is unfortunate to see that the MEF, the Union government and Uttarakhand government seem to have learnt no lessons from the disaster. These bodies have been trying all sorts of manipulations to push massive projects like Lakhwar and Vyasi in Yamuna basin even without Environment Impact Assessment, Cumulative Impact Assessment or public consultations.
Now a new government has taken over at the centre. It is possible sign of things to come that India’s new Prime Minister Shri Narendra Modi has chosen this anniversary day to lay foundation stone for a huge hydropower project in the Himalayan region, read his own statement dated June 14, 2014[1], about his impending trip to Bhutan on June 15-16, 2014: “During the visit, we will lay the Foundation Stone of the 600 MW Kholongchu Hydropower Project[5].” This possibly indicates the thinking of new government on this issue.
The memory and lessons of this unprecedented disaster seem to be fading already. While going through the articles on this disaster in a number of newspapers like Indian Express, Hindu, Tribune, Business Standard, among others, I could find just one article in Business Standard[2] that mentioned the role of hydropower projects in Uttarakhand disaster.
It is very important, in this context to remember the issue. We are here presenting here some photos of the damaged hydropower projects of Uttarakhand in that context. The photos are mostly taken from official sources, namely 582 page annexures to the Ravi Chopra Committee report. Most of the photos have not been in public domain to the best of our information.
Assi Ganga I (4.5 MW in Uttarkashi district): Letter from Regional office of MoEF to Uttarakhand Forest secretary dated 30 March, 2014 says:“The project was heavily damaged in 2013 devastation.” It also says that the project is in Ganga Eco Sensitive Zone and in the zone only projects below 2 MW capacity and serving the needs for the local population are allowed. Hence it says, “…the project should not start without obtaining fresh forest clearance and permission from the Central Govt.”
Assi Ganga II (4.5 MW in Uttarkashi district): Similar letter from Regional office of MoEF says: “The project was heavily damaged in 2013 devastation.” Following photos from the monitoring report of the project speak about the damage this project suffered:
Kaldigarh HEP (9 MW in Uttarkashi district) The project heavily damaged in 2012 floods and it being in Eco Sensistive zone, the report says the project should not be allowed to restart without permission from central govt.
Kotli Bhel 1A HEP (195 MW on Bhagirathi river in Uttarkashi district) The project has not given the final forest clearance. The stage I forest clearance was given on 13.10.2011 and environment clearance on 09.05.2007. The Ravi Chopra Committee report has asked for changes in the project parameters and Supreme Court order of May 7, 2014 has asked for stoppage of work on 24 HEPs, this project is on that list of 24 projects. The regional office report says that work on the project has been started on non forest land, which should now come to stop.
Kaliganga II HEP (6 MW, Rudraprayag district, Mandakini Basin) The Project got forest clearance on March 6, 2007. But project is yet to provide non forest land as required under act. The project is also within 2 km of Kedarnath Wildlife Sanctuary, but has not got clearance either from state wildlife Board or National Wildlife Board. The project construction thus is clearly illegal. Project has now suffered damages in June 2013 disaster, as can be seen from the photos below.
Madhya Maheshwar HEP (10 MW, Rudra Prayag district):
Phata Byung HEP (76 MW, Mandakini river, Rudra Prayag district):
Singoli Bhatwari HEP (99 MW, Mandakini river, Rudra Prayag district):
Bhyunder Ganga HEP (15 MW, Alaknanda river, Chamoli Disrict):
What happened in Uttarakhand a year ago in June 2014 was possibly a warning.
These photos are a reminder that even the hydropower projects are not safe and they will invite not only destruction for themselves, but also for the surrounding areas. Lest we forget the warning.
“We enjoy Pushing Rivers Around” –An early Hydraulic engineer in California (from Patrick McCully’s Silenced Rivers, 1996)
“We can tame the mighty rivers. We are an example of human will and endeavor”
-Sutlej Jal Viduyt Nigam Limited, damming the entire Satluj Basin in India.
“A river flowing to the sea is a waste”- a view held by several water resource developers in India
Welcome to Anthropocene [1],says James Syvitski, a leading oceanographer, geologist and hydrologist from Colorado University who has been studying subsidence of deltas.
Some scientists are now placing Anthropocene, an era marked with human interference with natural systems, at par with geological epochs like Pleistocene and Holocene. It is manifested in many ways. Rivers and associated systems like deltas and floodplains possibly have had to face the maximum brunt of the Anthropocene.
Cutting edge scientists like Prof. Syvitski who study the changes in our deltaic systems seem to reach to a common conclusion: Delta subsidence is now the main driving force for effective sea level rise for many coastal environments. This subsidence is more influential than sea level rise related to global warming and any deltas are sinking much faster than the sea level is rising.
But why are deltas sinking? What is the main reason behind this subsidence which is eating away land and making millions of people more vulnerable?
It has been established that the main reason behind delta subsidence is drastically reducing sediments reaching the delta.Studies estimate that during the past century, there has been a 94% reduction in Krishna’s sediment reaching the delta, 95% reduction from historic load in Narmada, 80% reduction in Indus, 80% reduction in Cauvery, 96% reduction in Sabarmati, 74% reduction in Mahanadi, 74% reduction in Godavari, 50% reduction Brahmani, etc.[2],[3]
But why are sediments not reaching the delta?
Almost unanimous agreement between scientists indicates that the reason behind this drastic decline in sediments is sediment retention by dams and reservoirs in the upstream[4].(Walling and Fang (2003), Vörösmarty et al., 2003; Syvitski et al.,(2005), Erisson et al, (2005), Walling (2008), K Rao et al (2010), H Gupta et al (2012) ). This has been reiterated in IPCC WG II Report, April 2014.[5]
Bhola Island in Bangladesh, eroded by Meghana River. PhotoSrestha Banerjee, Green Clearance Watch
Prof. Syvitski wrote a few words on the issue for SANDRP. He says, “A delta can form only where the sediment volume supplied from a river can overwhelm the local ocean energy (waves, tides, currents). Ocean energy is ceaseless. Engineering of our river systems, largely through the construction of upstream dams and barrages, has reduced this sediment supply. Consequently ocean energy has begun to reduce the size of our deltas, and coastal retreat is presently widespread. Deltas, once the cradle of modern civilizations, are now under threat — some deltas are in peril of lasting only the next 100 years. Sea level is rising due to ocean warming and glacier melting. Incessant mining of groundwater from below a delta’s surface, along with oil and gas extraction, further contribute to our disappearing deltas. At risk are the residences of more than 500 million people, the loss of biodiversity hotspots, major infrastructure (e.g. megacities, ports), and the rice and protein bowls of the world. Every year thousands of people drown due to storm surges and other coastal flooding. Sinking deltas are evidence of the magnitude of the human footprint on our planetary environment. We must learn to do better.” Professor J P Syvitski (U Colorado, Boulder, USA), Chair — International Geosphere-Biosphere Programme (ICSU), Executive Director, the Community Surface Dynamics Modeling System
Large reservoirs trap as much as 80% of the upstream silt. As a result, most rivers are carrying much less sediment, and some rivers (like Krishna, Indus, Nile, and Colorado) transport virtually no sediment! In the last 50 years, the combined annual sediment flux of the large Chinese rivers has been reduced from 1800 million tons (Mt) to about 370 Mt[6]mainly due to frenzied dam building. The impact of dams and reservoirs on sediment retention has been so significant that the resultant reduced sediment load represents a volume of about 730 km3, equivalent to an area of 7300 km2 assuming a 10 m thick bed[7]. Waling (2008) states that about 25 Gt/year of sediment are trapped by large dams each year. IPCC Report (Assessment Report 5, 2014) refers that 34 rivers with drainage basins of 19 million km2 in total show a 75% reduction in sediment discharge over the past 50 years due to reservoir trapping.
Delta Subsidence and Effective Sea Level Rise (ESLR)
While this delta subsidence and sediment retention has several impacts on dense delta population and coastal ecosystems which offer important services, one of the most serious impacts is its direct role in Effective Sea Level Rise. Ericsson and Vorosmarty et al, 2012[8], concluded that decreased accretion of fluvial sediment resulting from sediment retention and consumptive losses of runoff from irrigation (also due to dams) are the primary determinants of ESLR in nearly 70% of studied deltas.
More and more scientists are concluding that climate related sea level rise has a ‘relatively minor influence on delta conditions’, as compared to anthropogenic reasons. As seen above, there is an almost unanimous agreement that dams are the most important factor influencing contemporary land-ocean sediment fluxes.[9] Globally, greater than 50% of basin-scale sediment flux in regulated basins is potentially trapped in artificial impoundments of approximately 45,000 reservoirs (with dams 15 m high) (Vörösmarty et al., 2003; Syvitski etal., 2005) and sediment delivery to deltas has been reduced or eliminated at all scales.[10]Other reasons for delta subsidence include flow diversion by dams, sediment compaction due to groundwater abstraction, oil and gas exploration and mining, etc,.[11]
Deltas, formed by centuries of accretion of rich sediment, are one of the most fertile and densest populated regions across the world. It is estimated that close to half a billion people live on or near deltas, often in megacities.[12] Although constituting a mere 5% of the total landmass, coastal regions sustain almost three-quarters of the world’s population and yield more than half of global gross domestic product (Vorosmarty et al.,2009).
The direct impacts of ESLR and delta subsidence include inundation of coastal areas, saltwater intrusion into coastal aquifers, increased rates of coastal erosion, an increased exposure to storm surges, etc. These threats have implications for hundreds of millions of people who inhabit the deltaic as well as the ecologically sensitive and important coastal wetland and mangrove forests.
Already, some studies are ringing alarm bells. It is estimated that if no mitigation measures are undertaken and sediment retention continues, then by 2050, more than 8.7 million people and 28,000 km2 of deltaic area in 33 deltas studied including Ganga-Brahmaputra, Indus, Krishna and Godavari could suffer from enhanced inundation and increased coastal erosion. In addition, a larger population and area will be affected due to increased flood risk due to storm surges[13]. Conservative estimates state that delta area vulnerable to flooding could increase by 50% under the current projected values for sea-level rise in the 21st century and this could increase if the capture of sediment upstream persists and continues to prevent the growth of the deltas.[14]
The Intergovernmental Panel on Climate Change (IPCC) projects that sea level will rise by another 21 to 71 cm by 2070, with a best estimate of 44 cm averaged globally. This will further compound impacts of delta subsidence and sediment trapping.
It has been estimated that even in the case of debilitating floods, sediment has not reached rivers in the deltas.[15]In 2007–08 alone Ganges, Mekong, Irrawaddy, Chao Phraya, Brahmani, Mahanadi, Krishna and Godavari flooded with more than 100,000 lives lost and more than a million habitants displaced. Most of the deltas that suffered from floods did not receive a significant input of sediment, and this lack of sediment can be attributed to upstream damming.[16] Some studies demonstrate that storage of sediment-laden water of major flood events leads to huge sediment trapping behind mega dams.[17]
Above: Global distribution of ESLR under baseline for each of the 40 deltas studied by Ericsson et al, 2006.From Ericsson et al, 2006
Fluvial Sediments and Deltas in India
Rivers are not only conduits of water. They are a complex, moving systems carrying sediment, nutrients, organisms, ecosystems, energy, material and cultures in their wake.
There are three kinds of sediments: suspended, bed load and wash load. Here we are referring to mainly the suspended sediments in the rivers. Sediments play a significant role in the river geomorphology, defining the river channel, its shape and structure. Sediment deposits form alluvial floodplains, deltas, levees, beaches, ox bow lakes and lagoons and creeks. The sediment load and composition changes according to the river, the geological landscape it flows in, its length, flow, structure, etc. While much of the sediment is deposited by the river on its banks, the delta of the river is primarily formed of rich sediments. Through this deposition, the river may form distributaries at its mouth, like in case of Ganga, Brahmaputra or Mahanadi systems. Ganga-Brahmaputra Delta, shared by India and Bangladesh is one of the largest delta systems in the world, spanning more than 100,000 km2[18]carrying more than one billion tonnes of sediments annually.[19]
Deltaic populations in shared rivers of India, Bangladesh and Pakistan: Population of Ganga-Brahmaputra-Meghana Delta is more than 147 million people with a population density of more than 200 people per km2 (520 people per square mile), making it one of the most densely populated regions in the world . The Krishna Godavari twin deltas supports 9·26 million people inhabiting the 12,700 km2 area at 729 persons per km2, which is more than double the country’s average.[20] Cauvery delta supports 4.4 million people[21] while the Mahanadi Delta too supports millions. Only two districts of Cuttack and Jagatsinghpur have a population more than 3.7 million. (Census 2011) in addition, the contribution of deltas to economics, food production, transport, ecosystem services etc., is immense, making it a very valuable ecosystem which deserves protection. Indus Delta in Pakistan supports more than 900,000 people.
Deltas in Peril: Impact of damming on deltas in India
1. Krishna-Godavari Delta: In 2010, a team led by K Nageswar Rao of Dept of Geo Engineering, Andhra University, carried out an assessment of the impacts of impoundments on delta shoreline recession in Krishna and Godavari Delta.[22] The study revealed a net erosion of 76 km2 of area along the entire 336-km-long twin delta coast during the 43 years between 1965–2008 with a progressively increasing rate from 1·39 km2 per year 1965 and 1990, to 2·32 km2 per year during 1990–2000 and more or less sustained at 2·25 km2 per year during 2000–2008.
For Krishna, flows as well as suspended sediments in the delta have nearly reached zero. Suspended sediment loads decreased from 9 million tons during 1966–1969 to negligible 0·4 million tons by 2000–2005. Syvitski et al in their 2009 assessment place Krishna in the category of “Deltas in Greater Peril: Virtually no aggradation and/or very high accelerated compaction.”
In the case of the Godavari delta, there has been almost a three-fold reduction in suspended sediment loads from 150·2 million tons during 1970–1979 to 57·2 million tons by 2000–2006. Syvistki et al classify Godavari delta as “Deltas in greater risk: reduction in aggradation where rates no longer exceed relative sea-level rise”. H Gupta et al (2012) suggest that decline in historic sediments of Godavari post damming has been as high as 74%.
Above: Graph indicating decadal sediment and water flow trends at Prakassam Barrage, across Krishna. Dam building also marked. From Rao et al, 2010
According to Dr. Rao, a comparison of data on annual sediment loads recorded along the Krishna and Godavari Rivers shows consistently lower sediment quantities at the locations downstream of dams than at their upstream counterparts, holding dams responsible for sediment retention. Reports based on bathymetric surveys reveal considerable reduction in the storage capacities of reservoirs behind such dams. Authors say: “Sediment retention at the dams is the main reason for the pronounced coastal erosion along the Krishna and Godavari deltas during the past four decades, which is coeval[23] to the hectic dam construction activity in these river basins.”
Impacts of this can be seen in destroyed villages like Uppada in Godavari delta, destruction of Mangrove forests and shoreline. Similarly Krishna delta is losing land at the rate of 82·5 ha per year, leading to destruction of mangrove forests and loss of land.
The study concludes: “If the situation continues, these deltaic regions, which presently sustain large populations might turn out to be even uninhabitable in future, considering conditions elsewhere, such as in southern Iraq, where the farmers downstream of dams across Tigris River in Iraq, Syria and Turkey are being forced to migrate to urban centres as the reduced river flows become overwhelmed by seawater.”
I talked with Dr. Rao and asked him, if his disturbing study had any impacts. He said, no one from the administration has contacted him ever about this issue.
Above: Sediments measured at Sir. Arthur Cotton Barrage across Godavari near the Delta from Rao et al, 2010
A similar study by IWMI[24] concludes: “Coastal erosion in the Krishna Delta progressed over the last 25 years (is) at the average rate of 77.6 ha/ yr, dominating the entire delta coastline and exceeding the deposition rate threefold. The retreat of the Krishna Delta may be explained primarily by the reduced river inflow to the delta (which is three times less at present than 50 years ago) and the associated reduction of sediment load. Both are invariably related to upstream reservoir storage development.”
Krishna Basin Water Disputes Tribunal Award, though mentions dam siltation (it mentions that in 5 decades, Tungabhadra Dam has silted up to 22% of its capacity), does not say anything about flow for flushing sediments or its importance to the delta in Andhra Pradesh, or if the “minimum instream flow” recommended by the Tribunal will address this issue. This is a major limitation of the tribunal, when advanced studies have been conducted on the Krishna River delta condition and its relation to upstream dams has been established beyond doubt. Only at one place does it mention that to reduce siltation of the Almatti Dam, sluice gates should be opened when water is flowing above the crest.
However, the Award states that issues like minimum in stream flows are not decided once for all and it is an evolving process. Let us hope that there is some space to address the issue of shrinking deltas through this.
Above:Decreasing Sediments of Krishna down the years from K Rao et al, 2010
In the upstream Maharashtra, more and more dams are under construction in the Krishna Godavari Basin. One of the proposed dams called Kikvi, at the headwaters of Godavari in Trimbakeshwar was cleared by the Forest Advisory Committee recently. Ironically, the proponent (Water Resources Department, Maharashtra and Nashik Municipal Corporation) justified this dam which will submerge more than 1000 hectares of land, by stating that one more large dam close to Kikvi: Gangapur Dam is heavily silted up. [25]Rather than desilting Gangapur Dam, the administration wants to build one more dam.
Above: Trends in Sediments in Godavari and dam building activity. From K Rao et al
Many dams in Krishna Godavari Basin in Maharashtra have been criticised for not contributing to increasing irrigation.[26]These dams are not only obstructing river flow, but are also acting as sediment traps. Unfortunately, the MoEF is not even considering impacts of sediments while appraising dams. In Karnataka, major projects are being undertaken by fraud, without environmental appraisal, violating Environment laws, [27]similarly in Andhra Pradesh, many projects are being pushed illegally without environmental appraisal and which involve huge corruption[28].
2. Cauvery Delta: Although detailed studies have not been carried out, there is a clear indication of salt water intrusion and delta erosion in this over developed basin, due to upstream dams. The saline-freshwater boundary map indicates a steady migration inland.
A study by Gupta et al, 2012, indicates that historical sediment flux of Cauvery was 1.59 million tonnes, which is now 0.32 million tonnes (average of 10 years) and hence, there is a whopping 80% reduction in sediment flux of the river.
Unfortunately, the Cauvery Water Disputes Award Tribunal between Karnataka and Tamilnadu does not even mention the word ‘sediment’ in its award. There has been no justification for 10 TMC feet (Thousand Million Cubic feet) water recommended by the Tribunal for Environmental purposes and its possible impact on sediment carrying (or even environment for that matter).
Pennar showed 77% reduction and Mahanadi showed 67% reduction in amount of silt reaching the delta in recent years. (Gupta et al, 2012)
3. Narmada Delta: The west flowing rivers like Narmada and Tapi do not form extensive deltas like the east flowing rivers. Nonetheless, sediments from a huge river like Narmada play an important part in the stability of Narmada delta and villages and ecosystems around it.
Above: From: H. Gupta et al, 2007 and 2012
Gupta et al (2012 and 2007) assessed daily water discharge and suspended sediment load data measured by CWC at two gauging stations, one upstream of the Sardar Sarovar dam (Rajghat), and another downstream of the dam (Garudeshwar).
Historical sediment discharge of Narmada was found to be 61 million tonnes and the current sediment discharge (average of last ten years of the study) was found to be 3.23 million tonnes, indicating a reduction of 95% sediment discharge.[29] The presence of dam reduces 70–90% of coarse and approximately 50% of medium-sized particles on their way downstream, allowing them to settle in the reservoir Comparative studies of average suspended sediment load at various locations on the Narmada River for more than two decades, show overall reduction in suspended sediment load in the river.
The study indicated 96% reduction in suspended silt flux in Sabarmati, 41% reduction in Tapi and 68% in Mahi.
4. Ganga- Brahmaputra Delta: Different studies put different values for individual and combined sediment load of the Ganga Brahmaputra system, which carries one of the highest sediment loads in the world. According to Islam (1999)[30] Ganges and Brahmaputra rivers in Bangladesh transport 316 and 721 million tonnes of sediment annually. Of the total suspended sediment load (i.e. 1037 million tonnes) transported by these rivers, only 525 million tonnes (c. 51% of the total load) is delivered to the coastal area of Bangladesh and the remaining 512 million tonnes are deposited within the lower basin, offsetting the subsidence. Of the deposited load, about 289 million tonnes (about 28% of the total load) is deposited on the floodplains of these rivers. The remaining 223 million tonnes (about 21% of the total load) is deposited within the river channels, resulting in aggradation of the channel bed at an average rate of about 3.9 cm/yr sediment.
Across the 20th Century, Syvitski et al suggest about 30% reduction of silt load in the river system. Gupta et al [31] suggest that the observed decrease in sediment load could be due to construction of several mega dams in the Ganga basin, closure of Farakka barrage (1974) and diversion of sediments laden water into the Hooghly distributary. They also caution that dams in Ganga and Brahmaputra can worsen the situation.
5. Indus Delta: Inam et al (2007) assessed annual sediment loads of the Indus river at Kotri Barrage (270 km upstream from river mouth) during the last 73 years. The study indicates that annual sediment load of the Indus river has reduced drastically from 193 Mt (between 1931 and 1954) to 13 Mt (between 1993 and 2003). According to them, construction of three large dams on the Indus river, namely Kotri Barrage, Mangla and Terbela led to this situation causing annual water discharge to reduce from 110 km3 to 37 km3, with disastrous impacts on the delta ecosystem and population.
Above: Variation of water and sediment discharge below Kotri Barrage in Indus basin: Inam et al
Dying mangroves in Indus Delta Photo: The Nation
Inam states : “Currently the Indus river hardly contributes any sediment to the delta or Arabian Sea.The active delta is reduced from 6200 km2 before construction of dams to 1200 km2. The sea water has travelled upstream upto 75 kms, combined loss of freshwater and sediment has resulted in loss of large areas of prime delta agricultural land and submergence of several villages in the coast. This has caused desertification and displacement of several hundred of thousands of local residents. Study of records and bathymetric maps from 1950 indicate widespread coastal retreat…The life on the delta is dependent on availability of freshwater and sediment. Severe reduction of both as a result of dams and barrages and associated structures in the upstream has resulted in pronounced erosion in parts of the delta and reduction in mangroves. Environmental studies to be extended to the entire Indus ecosystem from the mountains to the Arabian sea.”
Conclusions
It is clear that deltas and dependent populations and ecosystems have suffered due to near total ignorance about the impact of dams on sediment and deltas and if immediate action is not taken then, this will impact a huge population and a large eco-region in Indian subcontinent, as elsewhere.
The impacts of nutrient rich sediment retention and flow reduction is not limited to teh delta, but has also affected marine fish production[32]
The issue of impact of a dam on the sediment regime of the river is not being studied or considered at all while conducting Environmental Impact Assessments of projects, appraising the project for options assessment, environmental clearance, cost benefit analysis or through post clearance monitoring and compliance.
Sediment release and sediment transport through rivers is not being raised in trans-boundary river negotiations.
Looking at the severity of the issue and its far reaching impacts on millions of people in India and across the world, there is a need for adopting urgent and strong mitigation measures against sediment trapping in dams.
It has to be remembered that for older dams, older hydropower projects and most irrigation projects, there is no mechanism available to flush the accumulated silt.
Sediment retention also reduces the life of the dam, while starving the river and delta in the downstream of sediment. As per a study by SANDRP in 2006, India may be losing 1.95 Billion Cubic Meters of Storage capacity of its reservoirs annually.[33] This implies that the rivers are losing at least that quantity of sediment annually.
The frantic dam activity in Indian Himalayas at this moment will have a serious impact on Ganga Brahmaputra Delta in India and Bangladesh and Indus Delta in Pakistan. There is an urgent need to, firstly, acknowledge these links, assess the impacts, include them in cost benefit and options assessment, address the issues and implement mitigation measures, where relevant, abandon the projects where impacts are unacceptable projects unviable.
In case of the Ganga Brahmaputra delta, recent studies have indicated that the main source of sediment in the river is the Himalayas[34]. Of the entire sediment load of Ganga catchment (This study assumed it to be 794 million tonnes/year), 80+/-10 % comes from High Himalayas and 20+/-10 % comes from Lesser Himalayas.
Bumper to bumper dam/ hydropower project building is occurring in almost all of the Himalayan states in India, which is poised to make Indian Himalayas most densely dammed region in the world. All of these dams are located in the downstream of the Greater and straddling Lesser Himalayas and can together have a tremendous impact on Ganga’s sediment load. Uttarakhand is planning and building nearly 336 Hydroelectric projects,[35]while Sikkim and Himachal Pradesh too are building hundreds of hydro projects. Arunachal Pradesh intends to dam most of its rives to produce hydropower.
No studies on impact of these projects on sediment regime of the rivers are being carried out for; neither does the MoEF insist that projects will not be cleared unless such studies are carried out. Even Cumulative impact assessments are not assessing this aspect.
Some stark examples:
The Cumulative Impact Assessment Report of the Upper Ganga Basin in Uttarakhand [36](where more than one hundred dams are planned and under construction back to back) was doen by IIT Roorkee. This cumulative impact assessment did not study any cumulative impacts due to reduced silt load of the river following major dam push.
The Lohit Basin Study done by WAPCOS[37]which involves more than 12 dams across the Lohit River, one of the three main segments that form Brahmaputra, does not mention anything about impacts of dams on sediments. The only thing it states is very worrying : “Due to substantial storage capacity, the Demwe Upper reservoir will have high sediment retention capacity and a large proportion of sediments carried by the Lohit River will get settled in the reservoir.”
Siang Basin Study [38](by RS Envirolinks Pvt Limited), which involves three mega dams across the main stem Siang, completely obliterating free flowing stretches in the river,in addition to 42 hydropower dams, does not mention anything about sediment regime, although being specifically asked to address this issue by the Expert Appraisal Committee, Union Ministry of Environment & Forests (MoEF).
1500 MW Tipaimukh Mega Dam near Bangladesh Border, which has received Environmental Clearance from MoEF does not study the impacts of sediment retention on downstream Bangladesh, and this concern has been raised by the groups in that country. The Environment Management Plan of this project which can submerge 25000 hectares of forests does not even mention the word “sediment”.
The bumper to bumper dam building activity in Himachal Pradesh in Satluj, Beas, Chenab and Ravi [39]rivers will have a major impact on silt load reaching the Indus river Basin and the Indus Delta in Pakistan. However, none of the EIAs or EMPs mention any impact of the dams on the sediment regime of the river.
In conclusion, although the risks of delta subsidence, effective sea level rise and its impact on a huge population and ecosystems has been established, these risks are being entirely ignored in the current governance surrounding rivers and deltas.
National Centre for Sustainable Coastal Management It is unfortunate to see that MoEF’s National Centre for Sustainable Coastal Management, supported by MoEF and World Bank does not allude to this issue or raise it through any publications.[40] In conversation with SANDRP, Director R. Ramesh said that the center may look at these issues in the future. However, its publications on National Assessment of Shoreline Changes on Tamilnadu and Odisha[41] do not mention upstream dams, although robust evidence exist that Cauvery delta and Mahanadi, Brahmani and Baitarni deltas are eroding due to sediment retention. Let us hope this institute will try to highlight the impact of dams on deltas with the seriousness it deserves.
Recommendations
1. Urgently study impacts of sediment retention by dams on delta population and ecosystems: MoEF, Ministry of Rural Development and Urban Development should conduct an in-depth study to understand the scale of the problems and the extent of affected people and ecosystems due to sediment impoundment by upstream dams.
2.Urgently study the optimal level of sediments (and water regime) needed for stabilising deltas and reducing subsidence.
3. Urgently institute a study to assess the extent of sediment and flows needed to be released from upstream dams and feasibility of such releases on regular basis, mimicking the river’s hydrograph. Where dams have sluice gates, these should be opened in monsoons where feasible, to allow sediment flushing. Even in dry and stressed river basins like Colorado in the United States, such high releases for redistributing sediments have been conducted in the 1990s and again in 2013 with proper planning and impact assessment.[42]
4. In Krishna and such other basins, where delta subsidence, coastal erosion and related impacts like salinity intrusion and storm surges has reached serious proportions, specifically problematic dams should be considered for decommissioning.
Environmental Appraisal Process
Study of impact on sedimentation and siltation should be a part of the environmental impact assessment, environmental appraisal and clearance process.
There should be a separate section in EIA for e-flows and sedimentation studies. Similarly such studies should be mandatory part of cumulative impacts, carrying capacity and basin studies.
More dams in basins which support large deltaic populations and those having significant impacts of sediment retention by reservoirs should not be cleared.Let us hope that this chronically neglected issue receives the attention it deserves. Delta subsidence and ESLR due to upstream damming again highlights the complex and interconnected nature of the riverine ecosystem. The environmental governance in India ( as also South Asia) surrounding rivers has been treating rivers with an extremely piecemeal approach. It is clear that with the herculean challeneges we face now, such an approach is no longer affordable.
~~~~
…especially in the part called Delta, it seems to me that if the Nile no longer floods it, then, for all time to come, the Egyptians will suffer – Herodotus, History, c 442 BC (stated in Patrick McCully’s Silenced Rivers)
For PDF file of this blog, see: https://sandrp.in/Shrinking_and_sinking_delta_major_role_of_Dams_May_2014.pdf
Above: Sediment laden waters of River Elwha reaching the coastal waters after Elwha Dam Removal. From: gallery.usgs.gov
Bibliography
Patrick McCully, Silenced Rivers: The Ecology and Politics of Large Dams, Zed Books, 1996
Islam et al, The Ganges and Brahmaputra rivers in Bangladesh: basin denudation and sedimentation, Hydrological processes, 1999
R.J. Wasson, A sediment budget for the Ganga–Brahmaputra catchment, Current Science, 2003
B Hema Mali et al, Coastal erosion and habitat loss along the Godavari Delta Front: a fallout of dam construction (?), Current Science, 2004
Syvitski et al, Impact of Humans on the Flux of Terrestrial Sediment to the Global Coastal Ocean, 2004
Jason P. Ericsson, Charles J. Vörösmarty S. Lawrence Dingmanb,2Larry G. Ward Effective sea-level rise and deltas: Causes of change and human dimension implications, 2006
Michel Meybeckve et al Sea-level rise and deltas: Causes of change and human dimension implications
Inam et al The Geographic, Geological and Oceanographic Setting of the Indus River, Wiley and Sons, 2007
Walling et al, The Changing sediment loads of world’s rivers, Annals of Warsaw University of Life Sciences, 2008
Syvitski et al, Sinking deltas due to human activities, Nature Geoscience, 2009
Gamage et al. Do river deltas in east India retreat? A case of the Krishna Delta, Geomorphology, Volume 103, Issue 4, 15 February 2009
K Nageswar Rao et al Impacts of sediment retention by dams on delta shoreline recession: evidences from the Krishna and Godavari deltas, India, Earth surface processes and landforms, 2010
James Syvitski et al, Sediment flux and the Anthropocene published 31 , doi: 10.1098/rsta.2010.0329 369 2011 Phil. Trans. R. Soc. A, January 2011
H Gupta et al , The role of mega dams in reducing sediment fluxes: A case study of large Asian rivers, Journal of Hydrology, 2012
[6] The role of mega dams in reducing sediment fluxes: A case study of largeAsian riversHarish Guptaa,⇑, Shuh-Ji Kaoa,b, Minhan Daia
[7] Sediment flux and the Anthropocene James P. M. Syvitski and Albert Kettner January 2011, published 31 , doi: 10.1098/rsta.2010.0329 369 2011 Phil. Trans. R. Soc. A
[8] Effective sea-level rise and deltas: Causes of change and human dimension implications
Jason P. Ericsona, Charles J. Vörösmartya,b,1, S. Lawrence Dingmanb,2Larry G. Ward
b, Michel Meybeckve Sea-level rise and deltas: Causes of change and human dimension implications Jason P. Ericson a,⁎, Charles J. Vörösmartya,b,1, S. Lawrence Dingmanb,2Larry G. Ward b, Michel Meybeck
[9] Walling and Fang (2003), Vörösmarty et al., 2003; Syvitski et al.,(2005), Erisson et al, (2005), Walling (2008)
[10] Syvitski et all 2009
[11] Sinking deltas due to human activities, Syvitski et al, 2009, Nature Geoscience
[12] Sinking deltas due to human activities, Syvitski et al, 2009, Nature Geoscience
[13] Ericsson et all, 2006, Effective sea-level rise and deltas: Causes of change and human dimension implications
[14] Sinking deltas due to human activities, Syvitski et al, 2009, Nature Geoscience
[15]Syvitski et al 2009
[16]Syvitski et all 2009
[17] Harish Guptaa, et al The role of mega dams in reducing sediment fluxes: A case study of large Asian rivers
[20] K Nageshwar Rao et al, 2010, Impacts of sediment retention by dams on delta shoreline recession: evidences from the Krishna and Godavari deltas, India Earth surface processes and landforms
[22] K Nageshwar Rao et al, 2010, Impacts of sediment retention by dams on delta shoreline recession: evidences from the Krishna and Godavari deltas, India Earth surface processes and landforms
[23] Time period or age
[24] Do river deltas in east India retreat? A case of the Krishna Delta Nilantha Gamage Geomorphology, Volume 103, Issue 4, 15 February 2009, Pages 533–540
Inter-governmental Panel on Climate Change’s (IPCC) Fifth Assessment is falling into place. On the 31st March 2014, the report titled ‘Climate Change 2014: Impacts, Adaptation, and Vulnerability’, from Working Group II[1] was issued in Yokohoma, Japan. Working Group II assesses “the vulnerability of socio-economic and natural systems to climate change, negative and positive consequences of climate change, and options for adapting to it. It also takes into consideration the inter-relationship between vulnerability, adaptation and sustainable development.”[2]
This can be called as one of the more incisive Working Group Reports from IPCC. It states unequivocally that the effects of climate change are already occurring on all continents and across the oceans and world is ill-prepared for risks from a changing climate. According to Co-Chair of Working Group II, Chris Field, “The report concludes that people, societies, and ecosystems are vulnerable around the world, but with different vulnerability in different places. Climate change often interacts with other stresses to increase risk”.[3]
The report consists of two volumes. First volume contains a Summary for Policymakers, Technical Summary, and 20 chapters assessing risks by sector and opportunities for response. The sectors include freshwater resources, terrestrial and ocean ecosystems, coasts, food, urban and rural areas, energy and industry, human health and security, and livelihoods and poverty. A second volume of 10 chapters assesses risks and opportunities for response by region. These regions include Africa, Europe, Asia, Australasia, North America, Central and South America, Polar Regions, Small Islands, and the Ocean.
The summary for policymakers paints a sombre picture: “Climate change over the 21st century is projected to reduce renewable surface water and groundwater resources significantly in most dry subtropical regions, intensifying competition for water among sectors. In presently dry regions, drought frequency will likely increase by the end of the 21st century under RCP8.5. In contrast, water resources are projected to increase at high latitudes. Climate change is projected to reduce raw water quality and pose risks to drinking water quality even with conventional treatment, due to interacting factors: increased temperature; increased sediment, nutrient, and pollutant loadings from heavy rainfall; increased concentration of pollutants during droughts; and disruption of treatment facilities during floods. Adaptive water management techniques, including scenario planning, learning-based approaches, and flexible and low-regret solutions, can help create resilience to uncertain hydrological changes and impacts due to climate change.”
“Risks are unevenly distributed and are generally greater for disadvantaged people and communities in countries at all levels of development.”
Links with water
Being an integral and cross cutting issue, water features prominently in all of Chapters of the Working Group Report. Sections on Freshwater Resources, Costal systems and low lying areas, Food Security, Inland systems, etc. include important findings. It is significant to note that dams, hydropower projects, infrastructure measures like channelization, embankments, etc., are also mentioned in nearly all the chapters of the report. Couple of references indicate dams as a possible adaptation measure, but overwhelming references point to the contrary.
The collective picture that is arising through these reference is very important. A collation and analysis of all specific references to water infrastructure projects, read in tandem with the report indicates that:
1. Dams and infrastructure projects contribute significantly to “non-climate impacts” which, after interacting with changing climate, exacerbate the overall impact on human societies and ecosystems
o Sediment Trapping by reservoirs, exacerbates impact of sea level rise
o Hydropower affects local options
o Climate change and dams together affect a greater eco-region
o Increased flow fluctuations by dams exacerbate through climate change
2. In case of Flood Protection, dams and embankments may do more harm than good. Ecological measures would fare better.
3. Dams and Hydropower projects affect biodiversity, which is critical in facing climate change challenges.
4. In the tropics, global warming potential of hydropower may exceed that of Thermal Power
5. Dams increase vulnerability of weaker sections to climate change
6. Existing Dams have to be managed sustainably, with ecological considerations
7. Hydropower itself is vulnerable to Climate Change
~~~
The references used in WG II report are peer reviewed research from several authors.The specific references given below will play an important role in debunking the simplistic myth that dams and hydropower projects are climate friendly and can be considered as de facto adaptation measures to cope with Climate Change.
Some Relevant Extracts from Working Group II Report:
Dams and infrastructure projects contribute significantly to “non-climate impacts” which, after interacting with climate impacts, exacerbate the overall impact of climate change on human societies and ecosystems
Sediment Trapping by reservoirs, exacerbates impact of sea level rise
“Most large deltas in Asia are sinking (as a result of groundwater withdrawal, floodplain engineering, and trapping of sediments by dams) much faster than global sea-level is rising.” (Chapter 24: Asia)
“Human activities in drainage basins and coastal plains have impacted the coastal zone by changing the delivery of sediment to the coast. Sediment trapping behind dams, water diversion for irrigation, and sand and gravel mining in river channels all contribute to decrease sediment delivery, whereas soil erosion due to land-use changes help increase it. It is estimated that the global discharge of riverine sediment was 16-–19 Gt/ yr in the 1950s before widespread dam construction and it has decreased to 12–13 Gt/ yr. Out of 145 major rivers with mostly more than 25-year record, only 7 showed evidence of an increase in sediment flux while 68 showed significant downward trends. The number of dams has increased continuously and their distribution has expanded globally. As of early 2011, the world has an estimated 16.7 million reservoirs larger than 0.01 ha. Globally, 34 rivers with drainage basins of 19 million km2 in total show a 75% reduction in sediment discharge over the past 50 years. Reservoir trapping of sediments is estimated globally as 3.6 Gt/ yr to more than 5 Gt/ yr (Syvitski et al., 2005; Walling, 2012; Milliman and Farnsworth, 2011). Human pressure is the main driver of the observed declining trend in sediment delivery to the coastline.(Chapter 5 Coastal systems and Low Lying areas)
“Attributing shoreline changes to climate change is still difficult due to the multiple natural and anthropogenic drivers contributing to coastal erosion.” (Chapter 5 Coastal systems and low lying areas)
“The combined impact of sediment reduction, relative sea level rise, land-use changes in delta and river management on channels and banks has led to the widespread degradation of deltas. The changes of sediment delivery from rivers due to dams, irrigation and embankments/dykes creates an imbalance in sediment budget in the coastal zones. Degradation of beaches, mangroves, tidal flats, and subaqueous delta fronts along deltaic coasts has been reported in many deltas (e.g. Nile and Ebro, Sanchez-Arcilla et al., 1998; Po, Simeoni and Corbau, 2009; Krishna-Godavari, Nageswara Rao et al., 2010; Changjiang, Yang et al., 2011; Huanghe, Chu et al., 1996; very high confidence). Deltaic coasts naturally evolve by seaward migration of the shoreline, forming a delta plain. However, decreasing sediment discharge during the last 50 years has decreased the growth of deltaic land, even reversing it in some locations (e.g. Nile, Godavari, Huanghe). Artificial reinforcement of natural levees also has reduced the inter-distributory basin sedimentation in most deltas, resulting in wetland loss.” (Emphasis added.)
“The major impacts of sea level rise are changes in coastal wetlands, increased coastal flooding, increased coastal erosion, and saltwater intrusion into estuaries and deltas, which are exacerbated by increased human-induced drivers. Ground subsidence amplifies these hazards in farms and cities on deltaic plains through relative sea level rise. Relative sea level rise due to subsidence has induced wetland loss and shoreline retreat (e.g. the Mississippi delta, Morton et al., 2005; Chao Phraya delta, Saito et al., 2007; high confidence).” (Chapter 5 Coastal systems and low lying areas)
“There have been local variations in precipitation and runoff since 1950, but changes in sediment load are primarily attributed to over 50,000 dams and vegetation changes.” (Chapter 18: Detection and attribution of observed impacts)
Hydropower affects local options
“Hydropower dams along the Mekong River and its tributaries will also have severe impacts on fish productivity and biodiversity, by blocking critical fish migration routes, altering the habitat of non-migratory fish species, and reducing nutrient flows downstream. Climate impacts, though less severe than the impact of dams, will exacerbate these changes.”(Chapter 24: Asia)
Climate change and dams together affect a greater eco-region
“For one climate scenario, 15% of the global land area may be negatively affected, by the 2050s, by a decrease of fish species in the upstream basin of more than 10%, as compared to only 10% of the land area that has already suffered from such decreases due to water withdrawals and dams (Döll and Zhang, 2010). Climate change may exacerbate the negative impacts of dams for freshwater ecosystems.” (Chapter 3: Freshwater resources)
Flood Protection: Dams and embankments may do more harm than good. Ecological measures fare better.
“On rivers and coasts, the use of hard defences (e.g. sea-walls, channelization, bunds, dams) to protect agriculture and human settlements from flooding may have negative consequences for both natural ecosystems and carbon sequestration by preventing natural adjustments to changing conditions. Conversely, setting aside landward buffer zones along coasts and rivers would be positive for both. The very high carbon sequestration potential of the organic-rich soils in mangroves and peat swamp forests provides opportunities for combining adaptation with mitigation through restoration of degraded areas.” (Chapter 3 Freshwater Resources)
“Ecosystem based adaptation (EBA) can be combined with, or even a substitute for, the use of engineered infrastructure or other technological approaches. Engineered defenses such as dams, sea walls and levees adversely affect biodiversity, potentially resulting in maladaptation due to damage to ecosystem regulating services. There is some evidence that the restoration and use of ecosystem services may reduce or delay the need for these engineering solutions. EBA offers lower risk of maladaptation than engineering solutions in that their application is more flexible and responsive to unanticipated environmental changes. Well-integrated EBA can be more cost effective and sustainable than non-integrated physical engineering approaches (Jones et al., 2012), and may contribute to achieving sustainable development goals (e.g., poverty reduction, sustainable environmental management, and even mitigation objectives), especially when they are integrated with sound ecosystem management approaches.” (Chapter 3 and Also Chapter 15 Adaptation Planning and Implementation)
Dams and Hydropower projects affect biodiversity, which is critical in facing climate change challenges
“Freshwater ecosystems are considered to be among the most threatened on the planet. Fragmentation of rivers by dams and the alteration of natural flow regimes have led to major impacts on freshwater biota.” (Chapter 4: Terrestrial and Inland Water Systems)
“Damming of river systems for hydropower can cause fragmentation of the inland water habitat with implications for fish species.” (Chapter 4 Terrestrial and Inland Water Systems)
“Freshwater ecosystems are also affected by water quality changes induced by climate change, and by human adaptations to climate-change induced increases of streamflow variability and flood risk, such as the construction of dykes and dams”. (Chapter 3: Freshwater resources)
“Hydropower generation leads to alteration of river flow regimes that negatively affect freshwater ecosystems, in particular biodiversity and abundance of riverine organisms, and to fragmentation of river channels by dams, with negative impacts on migratory species. (Chapter 3: Freshwater Resources)
“Hydropower operations often lead to discharge changes on hourly timescales that are detrimental to the downstream river ecosystem.”
“Climate change and habitat modification (e.g., dams and obstructions) impact fish species such as salmon and eels that pass through estuaries.” (Chapter 5 Coastal Systems and low lying areas)
In Tropics, global warming potential of hydropower may exceed Thermal Power
“In tropical regions, the global warming potential of hydropower, due to methane emissions from man-made reservoirs, may exceed that of thermal power; based on observed emissions of a tropical reservoir, this might be the case where the ratio of hydropower generated to the surface area of the reservoir is less than 1 MW/km2”.
“Reservoirs can be a sink of CO2 but also a source of biogenic CO2 and CH4” (Chapter 4 Terrestrial and Inland Systems)
Dams increase vulnerability of weaker sections to climate change
“A number of studies recognize that not every possible response to climate change is consistent with sustainable development, since some strategies and actions may have negative impacts on the well-being of others and of future generations .For example, in central Vietnam some responses to climate change impact, such as building dams to prevent flooding and saltwater intrusion and to generate power, threaten the livelihood of poor communities. First, the relocation of communities and the inundation of forestland to build dams limit households’ access to land and forest products. Second, a government focus on irrigated rice agriculture can reduce poor households’ ability to diversify their income portfolio, decreasing their long-term adaptive capacity. Indeed, the consequences of responses to climate change, whether related to mitigation or adaptation, can negatively influence future vulnerability, unless there is awareness of and response to these interactions. Here, the role of values in responding to climate change becomes important from a variety of perspectives, including intergenerational, particularly when those currently in positions of power and authority assume that their prioritized values will be shared by future generations. (Chapter 20: Climate-resilient pathways: adaptation, mitigation, and sustainable development)
“Some documented impacts on dams, reservoirs and irrigation infrastructure are: reduction of sediment load due to reductions in flows (associated with lower precipitation), positively affecting infrastructure operation (Wang et al., 2007); impacts of climate variability and change on storage capacity that creates further vulnerability; and failures in the reliability of water allocation systems (based on water use rights) due to reductions of streamflows under future climate scenarios” (Chapter 9: Rural Areas)
“Infrastructure (e.g. roads, buildings, dams and irrigation systems) will be affected by extreme events associated with climate change. These climate impacts may contribute to migration away from rural areas, though rural migration already exists in many different forms for many non-climate-related reasons.” (Chapter 9 Rural Areas)
“Changes in water use, including increased water diversion and development to meet increasing water demand, and increased dam building will also have implications for inland fisheries and aquaculture, and therefore for the people dependent on them” .
“In the case of the Mekong River basin, a large proportion of the 60 million inhabitants are dependent in some way on fisheries and aquaculture which will be seriously impacted by human population growth, flood mitigation, increased offtake of water, changes in land use and overfishing, as well as by climate change. Ficke et al. (2007) reported that at that time there were 46 large dams planned or already under construction in the Yangtze River basin, the completion of which would have detrimental effects on those dependent on fish for subsistence and recreation.” (Chapter 7 Food security and food production systems)
Existing Dams have to be managed sustainably, with ecological considerations:
“Suggested strategies for maximizing the adaptive capacity of ecosystems include reducing non-climate impacts, maximizing landscape connectivity, and protecting ‘refugia’ where climate change is expected to be less than the regional mean. Additional options for inland waters include operating dams to maintain environmental flows for biodiversity, protecting catchments, and preserving river floodplains.” (Chapter 24:Asia )
Hydropower itself is vulnerable to Climate Change
“Climate change affects hydropower generation through changes in the mean annual stream-flow, shifts of seasonal flows and increases of stream-flow variability (including floods and droughts) as well as by increased evaporation from reservoirs and changes in sediment fluxes. Therefore, the impact of climate change on a specific hydropower plant will depend on the local change of these hydro-logical characteristics, as well as on the type of hydropower plant and on the (seasonal) energy demand, which will itself be affected by climate change”
“Projections of future hydropower generation are subject to the uncertainty of projected precipitation and stream-flow. In regions with high electricity demand for summertime cooling, this seasonal stream-flow shift is detrimental. In general, climate change requires adaptation of operating rules which may, however, be constrained by reservoir capacity. Storage capacity expansion would help increase hydropower generation but might not be cost-effective.”
“Observations and models suggest that global warming impacts on glacier and snow-fed streams and rivers will pass through two contrasting phases. In the first phase, when river discharge is increased due to intensified melting, the overall diversity and abundance of species may increase. However, changes in water temperature and stream-flow may have negative impacts on narrow range endemics. In the second phase, when snowfields melt early and glaciers have shrunken to the point that late-summer stream flow is reduced, broad negative impacts are foreseen, with species diversity rapidly declining once a critical threshold of roughly 50% glacial cover is crossed.” (Chapter 3 Freshwater Resources)
Let us hope that these collated finding will be helpful in addressing the myth that dams and hydropower projects are climate friendly and can even be looked at as adaptation measures. Let us also hope that the Working Group III Report, which will come out in less than a week’s time from now, will have lessons for hydropower development in line with the above statements in the WG II report.
Issues with WG III, Special Report on Renewable Energy
Findings of WG II contrast strikingly with Special Report on Renewable Energy Sources and Climate Change Mitigation (SRREN) [4]brought out by Working Group III in 2011.
One of the two lead coordinating authors of this report was Dr. Arun Kumar, from AHEC, IIT Roorkee. Notably, Dr. Kumar was also a part of the team which worked on Cumulative Impact Assessment of Hydropower projects in Upper Ganga basin of Uttarakhand[5]. The state suffered huge flood and precipitation damages in June 2013 (long after the report came out) and commissioned and under–construction hydropower projects had a large role to play in compounding the impacts of the disaster[6]. Ministry of Environment and Forests as well as the Supreme Court of India rejected this report. SANDRP had published a detailed critique of this CIA report at the outset.
Amazingly, the Hydropower Section of the above mentioned IPCC Special Report on Renewable Energy severely downplays and ignores the impacts of hydropower. For example, it does not allude to peoples protests to projects, impacts of projects by blasting and tunneling, downstream impacts, impacts of peaking, associated deforestation and related development, cumulative impacts of projects in a cascade, increasing climate vulnerability of the population, seismic impacts, increased disaster vulnerability of the region, etc.,. In fact, these impacts have been some of the most-discussed issues in hydropower discourse in many countries at the moment. The report makes strange statements like “trans-boundary hydropower establishes arena for international cooperation”, when we see across the world that hydropower projects on internationally shared rivers further conflicts and strife between nations. It also downplays methane emissions from hydropower.
In all, the section appears biased towards hydropower and does not do justice to IPCC’s rigorous and objective standards. The section should not have been accepted as it stands now.
Now, the Working Group III is yet to submit its Assessment Report to the IPCC. It will be discussed by the IPCC between 7-11 April 2014, in Berlin. We hope there is true depiction of hydropower in the Working Group III report, looking at the above mentioned impacts and also keeping in mind strong statements from Working Group II report made public on March 31, 2014.
Parineeta Dandekar, parineeta.dandekar@gmail.com
~~~
[1] The IPCC Working Group I (WG I) assesses the physical scientific aspects of the climate system and climate change. Working Group II (WG II) assesses the vulnerability of socio-economic and natural systems to climate change, negative and positive consequences of climate change, and options for adapting to it. It also takes into consideration the inter-relationship between vulnerability, adaptation and sustainable development. The assessed information is considered by sectors (water resources; ecosystems; food & forests; coastal systems; industry; human health) and regions (Africa; Asia; Australia & New Zealand; Europe; Latin America; North America; Polar Regions; Small Islands). The IPCC Working Group III (WG III) assesses options for mitigating climate change through limiting or preventing greenhouse gas emissions and enhancing activities that remove them from the atmosphere. (https://www.ipcc.ch/working_groups/working_groups.shtml)
The theme of this World Water Day, 2014 is Water and Energy. The occasion gives us an opportunity to take a look at the hydropower rush going on in the country at this moment.
Hydropower projects are being incessantly pushed from the highest quarters ( including the Prime Minister’s Office, through the formulation of Cabinet Committee on Investment, Ministries like Power, Private dam lobbies, etc.,) . Some environmentalists do not seem to bat an eyelid while labelling ALL hydropower as “Green”. (Director General of CSE was a part of the Kasturirangan Committee report which certified all hydro as green, did not object to two of the most destructive projects: Gundia and Athirappilly, did not stress that mini hydel projects should be appraised for their impacts)
Satluj, downstream Nathpa Jhakri Dam Photo: SANDRP partners
Despite its far reaching impacts, the general perception about hydropower, consciously pushed by developers, funders like World Bank [1]and ADB and also institutions is that they are ‘clean, green and sustainable’. ( The overall understanding of institutions like World Bank on the water-energy nexus is itself limited, as is highlighted by this critique by Shripad Dharmadhikary.[2])
With impacts of HEPs and protests from local communities increasing, we need to check these premises which blindly give a “Green and Clean” certificate to all hydropower, without qualification. On the occasion of the World Water Day, we attempt to look at some impacts of HEPs planned across India on ecosystems and local communities, the existing environmental governance and the justification behind pushing these projects.
Whither River? A typical HEP impounds water behind a dam, transfers it through a Head Race Tunnel (HRT) to the powerhouse where electricity is generated and transfers water back into the river through a Tail Race Tunnel (TRT). Prima facie, supporters of hydropower claim that water is returned to the river and hence hydropower is a renewable and green. However, the tunnels that carry water from dam to the powerhouse and back tend to be kilometers long, effectively drying the river between. Even for one project, this can be a long stretch. 588 MW Luhri HEP in Himachal Pradesh, on Sutlej will have Asia’s longest tunnel of 38.14 kms bypassing the river for 50 kms. Upstream Luhri, there are 3 dams bumper to bumper: 412 MW Rampur, 1500 MW Nathpa Jhakri and 1000 MW Karcham Wangtoo. Effectively, the entire river will flow through tunnels made by blasting fragile Himalayan Mountains or through stagnant waters behind dams. Same is the case of the Teesta basin in Sikkim and many other rivers.
Along with rivers, the aquatic biodiversity, specialist riparian forests, forests in submergence zones, groundwater recharge zones, habitats to numerous wild animals, watering holes of wildlife and communities too are being destroyed.[3] Seventy hydroelectric Projects in Uttarakhand will submerge more than 3,600 hectares of forests. Dibang Multipurpose HEP in Arunachal alone can submerge 5,056 hectares of forest while the Tipaimukh HEP in Manipur can submerge an unbelievable 25, 822 hectares of forest, providing 1 MW installed capacity for 16 hectares of forest submerged.
Diurnal fluctuations and impacts of peaking When the releases from power houses eventually meet the rivers, there is a huge fluctuation on a daily basis in the water level in the downstream. For example, in case of the 1,750 MW Demwe Lower HEP on the Lohit in Arunachal Pradesh, the water level fluctuations 100 kilometers downstream in the Lohit River at Dibru Saikhowa National Park will range from 70 cumecs to 1920 cumecs, each day in the lean season. This is a level fluctuation of 3-5 feet every day in the plains![4] In case of the Siang River, if all dams on the main stem and tribuataries are constructed, water level in the downstream DErring National Park will flucatute beween 23 feet everyday in the lean season![5]
Run ‘with’ the River Projects? Project Proponents, industry and even official committees are claiming that Run of the River (ROR) Projects are green as they do not involve major storage and do not alter the rivers flow over a 10 day period. ROR thus get an official tag of sustainability. In reality, most of the ROR Projects involve massive dams and massive storages behind these dams. They involve reservoirs which run upto ten or more kilometers.For example, the reservoir og Luhri will be 6.8 km long; Kotli Bhel IB will be 27.5 km, Kotli Bhel 2 will be 31.21 km and Lower Demwe will be 23 kms long.
At the same time, for the riverine ecosystem and downstream population, the daily fluctuations in the river levels is devastating. Over a hundred people have died in India due to sudden release of water from upstream hydro projects in non-monsoon months.
Impacts on the aquatic ecosystem: HEPs alter the master variable which governs major riverine processes: its flow.[6] Dams physically block upstream and downstream migration of fish species crucial for their spawning. Fragmentation of rivers, water fluctuation, dry river stretches and passage through turbines have a disastrous impact on fisheries and fish diversity which has been collapsing in all major rivers in country, mainly due to dams.[7]
Himachal Pradesh Fisheries Department has a ‘Negative list’ of rivers and streams rich in biodiversity where in situ protection of fisheries should take place[8]. Ironically, even in this region, hydropower plants are being sanctioned and set up, sometimes in cascades.
Dried Baspa River downstream Baspa Dam. Baspa River supported rich fisheries and fish diversity Photo: SANDRP Partners
There are no provisions for fish migration like fish passages and ladders, eflows. For example the 300 MW Baspa II HEP on Baspa River, in the negative list for fisheries does not have a fish ladder, and has been drying the river without e-flows. Fisheries Departments in Himalayan as well as Western Ghat States have become rubber stamps for providing No Objection Certificates to HEPs while taking monitory compensation. Himachal Fisheries department charges Rs 50,000 per kilometer and additionally, Rs 50,000 Per MW electricity generated as compensation. This means windfall profits to Fisheries departments and nothing to actual fish diversity that is being destroyed.
Hydel Power Dams coming up in the Western Ghats like the 163 MW Athirappilly and 200 MW Gundia will affect endemic and endangered fish diversity in the region, which is not mentioned in the cut paste EIAs of these projects. While WGEEP report categorically rejected both these projects, the HLWG headed by Dr Kasturirangan did not reject them. Instead it simply asked for a revaluation.
The 780 MW Nyamjangchu Project to come up in Tawang region of Arunachal Pradesh threatens one of the last remaining wintering sites of the Black Necked Crane and habitat of Red Panda, though the EIA of the project did not mention this fact. While the Cumulative Impact Assessment report on Upper Ganga HEPs submitted by Wildlife Institute of India recommended dropping 24 HEPs for their irreversible impacts on ecology, but the report of the IMG on Ganga Projects headed by B K Chaturvedi rejected this without giving any reasons.
Disaster potential[9] A critical issue left unaddressed in the environmental clearance, forest clearance and even report of committees like IMG on Ganga and HLWG on Western Ghats is the assessment of disaster potential of hydropower projects. Deforestation, building activities, boulder mining, tunneling and blasting, integral with hydropower projects in the Himalayas make the young mountain more prone to landslides and rivers more flood prone. Impoundment and water level fluctuations play a major role in landslides.
EIAs of mega projects like Luhri, which plans to have world’s longest tunnel does not even include impacts of this tunnel in EIA Report submitted by CISHME team. In the recent Uttarakhand disaster, projects like 400 MW VishnuPrayag, 330 MW Srinagar, 76 MW Phata Byung, 99 MW Singoli Bhatwari, 304 and 90 MW Maneri Bhali I and II & 280 MW Dhauli Ganga hugely increased the damages and loss of lives. If more projects on Alaknanda, Mandakini and Bhagirathi, cleared by MoEF and IMG, were present, losses would have been higher. However, there are studies after studies which do not mention the disaster potential of projects, like the recent Siang Basin Study.[10]
Muck disposal – an example of impacts of non-compliance Throughout the Himalayan states, rivers are littered and changing courses due to millions of tonnes of muck illegally dumped by the HEPs in the riverbed itself. This muck dumped by 330 MW Srinagar Project in Alaknanda bed hugely increased the disaster in Srinagar Town. Muck disposal plans of HEPs remain resolutely on paper, whereas on ground, muck is dumped at the most convenient sites: the riverbed. MoEF has refused to take action even when presented with evidence. The IMG report missed most of these ground realities.
Major struggles From Lahaul Spiti in the glacial north, Singoli Bhatwari & Phata Byung in Uttarakhand, to Subansiri Lower and Tawang in the North east, to the Athirappilly in Western Ghats of Kerala, most of the large (and also small) HEPs are being opposed strongly by local communities. India is witnessing one of its largest anti dam stir against the 2000 MW Lower Subansiri HEP in Assam where construction on the project has been stalled for 20 months. Why are the communities resisting at this scale? Why are litigations surrounding HEPs increasing? Do the communities have any role while decisions are taken in Delhi and private proponent’s offices about destroying their rivers? The answer is no.
Climate Friendly façade of Large Hydro: Large Hydro promoters, government, funders like World Bank and ADB as well as research institutions are supporting HEPs because of the claimed climate friendly nature of the projects.
This is hugely misleading. World over, HEPs are being increasingly recognized as being ‘False Solutions to Climate Change’. Reservoirs of HEPs (including RORs) emit Methane which is 21 times more potent as a greenhouse gas than Carbon dioxide. This emission is further boosted at each draw down of the dam.[11]
The trouble is, we have not conducted a single credible greenhouse gas emission study for any of India’s so-called ‘climate friendly’ hydros. The only project where this was a condition laid while granting a hasty environmental clearance was the 1000 MW Tipaimukh HEP. But here too, after 5 years of granting the EC the study has not been conducted. There is no logic behind labeling large hydro as climate friendly. On the other hand through deforestation, drying up of rivers, destruction of ecological services, instability, increased risks of landslides and flash floods, the adaptation and mitigation potential of local communities to Climate Change is hugely compromised.
With Climate change, Glaciers in Himalayas are receding faster than those at other mountains (ICIMOD). This is leaving moraine debris on the path of receding glacier, building up into moraine dams which can fail catastrophically, as was witnessed in Kedarnath disaster. In this scenario, hydropower dams, which depend largely on glacial melt are not only vulnerable to climate change, but have catastrophic impacts on the downstream population as was witnessed in Uttarakhand in case of 400 MW Vishnuprayag and 330 MW Srinagar Projects. Hence, claiming that HEPs in India are important from climate change perspective is unscientific.
Environmental governance: As per SANDRPs analysis, the Expert Appraisal Committee granting environmental clearance to River valley projects has not rejected a single project of the 262 project considered in last six years ending in Dec 2012[12]. Even when local groups and organisations like SANDRP have raised concerns about impacts of HEPs on rivers, ecosystems and communities, these have been routinely sidelined. While sanctioning cascades of HEPs, no credible CIAs or basin studies or carrying capacity studies are being performed. IMG report on Upper Ganga Projects has also come across as a huge disappointment in this aspect.[13]
Destroyed 400 MW Vishnuprayag HEP on Alaknanda. Photo: Matu Jan Sangathan
MoEF has openly stated that it does not have the capacity to ensure environmental compliance of clearance conditions and environment management plan. In the absence of any enforcement, violations have become a norm. Neither has the MoEF thought of stalling Environmental and Forest Clearancesof HEPs unless streamlined compliance is enforced, like it did for the case of Goa Mines.The pressure of lobbies seems to have blinded precautionary principle or democratic governance at all levels.
It may be noted that 50% of our existing HEPs are generating at less than 50% of their designed 90% dependable generation[14], while nearly 89% projects generate at below the promised levels! Per MW generation has fallen by about 25% in last two decades. On the other hand, micro-hydel projects are making remote places like Anjaw in Arunachal power secure without major impacts.
Sustainable development cannot be achieved by poor environmental governance, by discouraging community participation, by excluding affected communities from decision-making while externalizing impacts on local communities, ecology and future generations. Energy security and access to energy to poor and disadvantaged sections of the society is a very real challenge and there are ways to address this challenge, which are not ecologically and socially destructive. Let us hope that the Water-Energy Nexus also upholds the rights of the rivers and its people.
Most of the major rivers in the North East India are largely free-flowing till date, which is a rarity in India and the world. Their basins are home to unbelievable ecological and cultural diversity. Main rivers in Arunachal Pradesh which form the mighty Brahmaputra are the Siang (the Yarlung Tsang Po), Dibang and Lohit, which meet at the trijunction to form Brahmaputra.
Massive hydropower projects are planned on these rivers in cascade. They will have irreversible destructive impacts on the society, forests, rivers, biodiversity, ecosystems, cultural identity and downstream Assam.
Hydropower Flood in Arunachal Pradesh Map: Neeraj Vagholikar, Sanctuary Asia
Siang River alone has 44 dams planned along its entire length.
Yes, 44 dams. You have read it correctly. At least 44 dams in one sub basin of Brahmaputra River Basin. This is what was meant by MOU virus as Jairam Ramesh described it.
Siang River Basin The Siang river originates in the Chemayungdung mountain ranges which nearly sixty miles south-east of Mansarovar lake in the Mount Kailash range in Southern Tibet at an elevation of 5300 m. A spring called Tamchok Khambab spills from the glaciers which later gather breath and volume to become the Tsangpo, the highest river in world. Tsangpo river flows 1625 km in Tibet parallel to the main range of Himalayas before entering India through Arunachal Pradesh.
Before entering India, the river passes Pi (Pe) in Tibet and suddenly turns to the north and northeast and cuts a course through a succession of great narrow gorges between the mountain Gyala Peri and Namjabarwa (Namcha Barwa) in a series of rapids and cascades. The river then turns south and southwest and flows through a deep gorge across the eastern extremity of the Himalayas with canyon walls that extends upward for 16,500 feet (5,000 meters) and more on each side.
The river enters Arunachal Pradesh near Gelling from where it is known as Siang. The total length of Siang River is 294 km till its point of confluence with Dibang and Lohit River. After entering India the river traverses approximately 197.0 km to join the Siyom river. From there the length of the river till Assam border is 86.3 km. Flowing further 10.6 km in Assam the river joins the confluence of Lohit and Dibang. From this point forward it flows as Brahmaputra river in Assam and traverses a distance of about 195 km up to the confluence of Subansiri river on its right bank. Further downstream it is joined by Kameng at Jamugurihat near Tezpur, after another 123 km. From here it travels for another 134 km up to Guwahati.
River Siang Photo from: Global Descents
The elevation of Siang river catchment area ranges from 90 m to around 5800 m. The total catchment area of Siang river from its origin to its confluence with Lohit and Dibang rivers is 251,521 sq km. Out of this 236555.7 sq km area lies in Tibet. The total catchment area of Siang river in India upto its confluence with Lohit and Dibang rivers is 14965.30 sq km.
A question arises here, what will be the condition of the 294 km long Siang river if the proposed 44 dams are being built on the river. The Siang river basin study has the answer for this which is actually alarming “Only 85.5 km (29%) of free flowing water regime of Siang river will be left out of its total course in India i.e. 294 km of lotic ecosystem will be converted into 208.5 km of lentic ecosystem altering the entire Siang river aquatic system which will adversely impact the aquatic biodiversity and seriously affecting fish populations and their migration behaviour.”(page 11.23)
Three dams on the main Siang will convert the free flowing river into a three-stepped reservoir, without ANY flowing length of the river! These dams alone will affect more than 18,000 hectares of forests! If all the dams are built, water level fluctuations in the downstream D’Ering Sanctuary will be more than 23 feet every single day in the winter and other non monsoon seasons!
82.26% of the Siang basin is under forest cover (more than 15,000 sq kms), it is rich in orchids (more than 100 species!), holds 16 species of rhododendrons, 14 species of Bamboos and 14 species of canes and overall 27 RET species and 46 endemic plant species. 25 (18%) mammalian species found are Schedule I of WPA (Wildlife Protection Act), while 26 are under Schedule II! There are 447 species of birds, of which 31 are Schedule I species. The single basin consists of 5 Important Bird Areas !!(IBAs)
Formation of River Siyom, which will have multiple dams in a cascade Photo from: Team BHP
This information has been collated by the CIA (Cumulative Impact Assessment)/ CCS (Carrying Capacity Study) of the Siang Basin, which was an attempt to look at the scale and cumulative impacts of projects in Siang holistically.
Has the CIA commissioned by Central water Commission and done by RS Envirolink Technologies done an objective, scientific, independent assessment?
SANDRP sent comments about this 2-volume study with over 1500 pages to the Expert Appraisal Committee, Ministry of Environment and Forests which will be considering this basin study in its upcoming meeting on Feb 20-21, 2014. Submission below highlights that the study has very serious short comings and bias. The recommendation of dropping 15 (mostly small ones, all below 90 MW installed capacity) HEPs and re-configuring some others is welcome, but far from sufficient. The study itself is disappointing:
Projects planned in the Siang Basin Phot from CIA/ CCS of Siang Basin
Time Line of Siang Basin Study
Feb 2010
Ministry of Water Resources constituted an Inter-Ministerial Group on the directions of Prime Minister’s Office with a view to evolve a suitable framework to guide and accelerate the development of hydropower in the North East and also to assess the impact of the massive hydropower development in Arunachal Pradesh on downstream areas in Assam
Nov 2010
EAC discussed TOR for the Siang Basin CIA
Dec 23, 2010
MoEF issues TORs for the Siang Basin CIA
April 2011
EAC discusses sampling locations for the CIA on request of CWC
Dec 2011
Work of CIA for Siang awarded to RSET Pvt Ltd
May 2012
RSET says draft interim report discussed by TAC, but there is no meeting of TAC in May 2012, minutes of March and July TAC meetings (the ones before and after May 2012) on CWC website also do not mention any such discussion.
Nov 2012
EAC discusses Draft Interim report
Aug 2013
Draft Final report submitted to CWC
Sept 2013
RSET says Draft final report discussed by TAC, but the minutes of the Sept 2013 meeting of the TAC obtained under RTI donot contain any reference to the Siang basin study
DEC 2013
Draft Final Report submitted to MoEF
Feb 17, 2014
Critique of the Draft Final report submitted by SANDRP to EAC
Feb 20, 2014
MoEF’s EAC to discuss the Draft Final report
To,
Chairperson and Members,
Expert appraisal Committee
Ministry of Environment and Forests
Delhi
Subject: Serious inadequacies of Cumulative Impact Assessment (CIA) and Carrying Capacity Study (CCS) of Siang Sub-basin including Downstream Impacts
Respected Chairperson and Members,
We see from the agenda uploaded on the MoEF Website that Final Report of the Siang CIA/CCS Study commissioned by CWC and conducted by RS Envirolink Technologies Pvt Ltd will be discussed in the 72nd EAC Meeting to be held on 20-21 February 2014.
SANDRP has been analysing basin studies in the Western Himalayas and Brahmaputra Basin for some time now. Looking at the aggressive cascade hydropower development and its far reaching cumulative impacts, CIA/ CCS and Basin Studies should form the backbone of informed decision making by MoEF. Unfortunately, most studies being considered by the EAC are of a sub-standard quality and are shying away from addressing the cumulative impacts [1]. EAC itself is delinking appraisal of individual projects from basin studies, rendering the crucial process meaningless which is in violation of EIA notification of Sept 2006, wherein Form 1 Section 9 actually asks for cumulative impact assessment. Some of the recent orders of National Green Tribunal also make it CIA mandatory, thus making such delinking legally untenable.
Looking at the scale of ecological and social impacts of these projects and the significance of MoEF’s and EAC’s role, we urge the EAC to consider CIA/ CCS/ Basin Studies more seriously.
Main issues with Siang Basin Study include: (These are elaborated with reasons below)
1.No mention of social and cultural impacts!
2.Downstream impacts on Assam not studied in detail
3.Cumulative Disaster vulnerability, impact of projects on such vulnerabilities, Dam Safety Assessment, risk assessment not done
4.“Cumulative” Impacts not assessed on several aspects
5.Non-compliance with critical recommendations by the EAC:
a.Study is not compatible with similar studies done worldwide
b.No suggestions about ramping to reduce downstream impacts
c.No recommendation on free flowing length between two projects
d.No mention of cumulative impact on sediment regime
e.No mention of impact of road construction
f.BBM for eflows not used, despite agreeing to use it before EAC
g.Impact of Sand mining, boulder mining not conducted
h.Impact of specific projects not clearly studied
6.Eflows, one of the most significant issues, handled erroneously: NO ACTUAL ASSESSMENT OF E-FLOWS REQUIREMENTS AS REQUIRED BY TORs
7.No mention of Climate Change, reservoir emissions vis-à-vis cumulative impacts of such massive scale, how the projects would affect the adaptation capacity of the communities and region in the context of climate change
8.No stand taken on three mega projects on Siang Main Stem and other big hydro projects
9. No conclusion about how much length of the river is to be compromised
10. Number of sampling locations: TOR not followed
11. Source of information not given
12. Inconsistency, contradictions in listing of flora-fauna
13.Unsubstantiated advocacy: going beyond the TOR & mandate
14. Other inadequacies of CIA
15.Study should not be finalised without credible Public consultation across the basin.
Division of the Siang Basin into sub basins Phot from : CIA/ CCS Report of the Siang Basin
DETAILED CRITIQUE
1. No mention of social and cultural impacts! In the entire basin study, there is no mention of social and cultural impacts by these 44 projects which will together submerge more than 21,000 hectares of forests and affect the entire Siang Basin adversely. Needless to say, local communities depend heavily on the basin resources like fish, medicinal and food plants, timber varieties for their livelihoods. For example, more than 2000 hectares of multi-cropped, irrigated rice fields will be submerged by Lower Siang Project alone.
Adi Community that will be affected by the dams on Siang Photo with thanks from : Kaushik Shil
The CIA/CCS study needs to be re-conducted, in which social and cultural cumulative impacts are assessed with participation of local communities and downstream communities from Arunachal Pradesh and Assam. It may be remembered that Public Hearing of Lower Siang (in the latest instance, slated to be held on 31st January 2014) had to be cancelled due to a number of procedural issues, and also opposition from local residents [2]. It is incomprehensible how the CIA Study has no assessment of impacts on communities!
2. Downstream impacts on Assam not studied in detail The study assesses impacts specifically on Dibrugarh, Bokaghat (Kaziranga) and Guwahati. However, there are several villages, settlements, tea estates, agriculture, forests etc., on the Right Bank of Siang in Assam after Pasighat. This includes a major part of Dhemaji District of Assam. Impact on this region needs to be assessed. There has been opposition to Siang Dams from places like Jonai from Dhemaji, which have been ignored.[3]
Meeting protesting against Public Hearing of 2700 MW Lower Siang HEP Photo: Echo of Arunachal
According to the model used, the chainage for assessing impacts at D’Ering Sanctuary is between 20-33 kms from Lower Siang Dam. The next chainage is at 102 kms at Dibrugarh. Impacts on the stretch between D’Ering and Dibrugarh, for nearly 70 kilometres are simply not assessed! What can be reason behind this?
Level fluctuations at D’Ering Sanctuary, with Lower Siang, Middle Siyom and Upper Siang Projects is to the tune of 7.2 meters (23.66 feet!!) in lean season. This highlights the need to study impacts on the intermediate zone in Assam between Dering Sanctuary and Dibrugarh. The Study should not be accepted without these assessments.
3.Cumulative Disaster vulnerability, impact of projects on such vulnerabilities, Dam Safety Assessment, risk assessment not done
Upper Siang Stage I, Stage II and Lower Siang are huge projects with direct impact on downstream state. Even as issues of dam safety and risk assessment have gained high significance in Assam as can be seen in Lower Subansiri protests, the basin study/CIA does not include a word on dam safety, cumulative risk assessment, risk of landslips and landslides, seismic zones of projects, past earthquakes in the region, possible mitigation measures, disaster management, etc. There is no assessment of baseline situation about disaster vulnerability of the region and how the projects will change that. By its nature, a CIA/CCS/ basin study is best placed to assess these impacts.
Lanslides are a common feature of this region. Pic shows Yinkiong in Siang II Sub basin where several projects are planned. Photo: Team BHP
These points have been raised by KMSS, Assam and others. The Uttarakhand disaster of June 2013 underlines this and even the Supreme Court of India has asked for an assessment of how hydropower projects contributed to disaster in Uttarakhand. Looking at Uttarakhand Disaster as well as protests from downstream Assam where dam safety is a major issue, dam safety needs to be addressed in the CIA/ CCS. In the absence of all this, projects will not be allowed by communities, as can be seen with Lower Subansiri and Lower Siang.
4.Cumulative impacts not assessed on several aspects The study has a sketchy section (Chapter 11) on Cumulative impact assessment.
The minutes of 62nd EAC meeting noted, “The main objective of the study is to bring out the impact of dams being planned on the main Siang River and its seven tributaries on terrestrial and aquatic ecology, plant and animal biodiversity, including wild life, hydrology of the basin, etc.” (Emphasis is as in original.) However, the study has not placed emphasis on assessing these impacts.
Yar Gyap Chu: a River and basin which holds high religious significance for the Buddhists Photo: Kaushik Shil
Moreover, the study does not attempt to assess cumulative impacts of all the projects due to:
Blasting and Tunnelling: This is not mentioned even once in the entire study! When the disastrous impacts of blasting, tunnelling and related activities are fresh in our minds w.r.t Uttrakhand and Himachal Disasters, it is incomprehensible to see that this section is not mentioned at all in the basin study!
Community resources: No mention on loss of agricultural lands, homesteads, displacement, loss of forest rights, etc.
Infrastructure development: No mention of the impact of workers colonies, buildings on the society, landscape and cultural aspects, etc.
Greenhouse gas Emissions: Considering submergence of more than 20,000 hectares of dense to very dense forests and building of a large number of reservoirs in tropical climate, cumulative impacts on green house gas emissions should have been assessed.
Biodiversity, RET Species, Deforestation: While the report deals with these issues very sketchily, there is no statement as to what will be the cumulative impact of 44 projects on the above issues.
5.Non-compliance with critical recommendations by the EAC Interim basin study was discussed in the 62nd EAC meeting in November 2012. The EAC had given some important recommendations at that stage to be included in the study. However, most of the recommendations have not been complied with, these include:
Study is not compatible with similar studies done worldwide: EAC had specifically recommended compatibility with global studies. However, Siang CIA is not compatible with any global Basin and Cumulative impact Assessment Study. A Cumulative Impact Assessment is a multi-stake – holder process that assesses the cumulative and indirect impacts as well as impact interactions of the proposed dam or set of dams, as well as existing and planned projects from other sectors, on ecosystems, communities, and identified Valuable Ecosystem Components (VECs) within a specific spatial and temporal boundary. [4]
No suggestions about ramping to reduce downstream impact: EAC had specifically asked for ramping study with reference to downstream impacts. However, ramping studies are not done at all, although downstream impacts of the projects in isolation as well as together are huge.
No recommendation on free flowing length between two projects Although Upper Siang I, Upper Siang II and Lower Siang have no free flowing stretch between each other, the study refrains doing any assessments or from making any recommendations in this regard, contrary to EAC’s recommendation.
No mention of cumulative impact on sediment regime 44 projects with several mega reservoirs will have a profound impact on the sediment regime of the rivers as well as downstream impacts thereof. EAC had specifically asked to include sediment balance and impact, which is not discussed in the report.
The minutes of 62nd meeting of EAC says: “The Consultants were also asked to study and recommend on silt management considering “no dam” and “with dam” scenario as silt substantially impact the ecology and cause sedimentation particularly when its velocity is affected d/s due to construction of dam.” No such study has been conducted. In fact globally, sediment balance on cascade projects is a crucial element of study, which is completely left out in the present study.
No mention of impact of road construction Roads and related activities like deforestation, slope destabilisation, blasting, mining, muck dumping, all the cumulative impacts of peaking operation (needs to be done comprehensively, including the limitations that such operation of upstream projects will impose on downstream projects), etc have a critical impact on fragile geology. Role of roads for hydel projects was significant in Uttarakhand Tragedy in June 2013. EAC had specifically asked for “Impacts due to construction of approach roads”. This point is not touched upon in the report.
BBM for eflows not used, despite agreeing to use it in front of EAC Although the consultant agreed in the 62nd meeting that BBM will be used to assess eflows regime,[5] at the insistence of the EAC, in reality BBM has not been used in the study. The reasons given [6] that BBM is a “prescriptive approach”, “it takes too much time” and “only stakeholder in the basin is river and fish” is wrong, shocking and unacceptable.
The study forgets about the people, biodiversity and other stakeholders. Requirements of BBM were known at the time consultant agreed to use this methodology before the EAC. Is fluvial geomorphology, cultural practices, hydrological requirements and sediment balance not important blocks of BBM study?
Impact of Sand mining, boulder mining not conducted EAC had specifically asked for this study. This is critical as mining of sand and boulders from river bed has severe impact on riverine ecology, bed stability, erosion, flow velocity, etc. However, the study has not even mentioned this issue.
Yargyap Chu or the Medicinal RIver Photo: Team BHP
Cumulative Impacts of projects on biodiversity in sub-basins not clearly studied While the study has done impressive job in inventorysing ecological attributes of 11 sub basins, it has fallen woefully short in clearly communicating the individual and cumulative impacts of projects on Valued Ecosystem Components (VECs). This reduces practical application of the report. EAC had brought this up during the 62nd meeting.
Length of rivers to be assessed for downstream studies As per the minutes of the 43rd meeting of EAC held in Nov 2010 the report was to recommend: “What may be criteria for downstream impact study in terms of length of the river downstream to the tail water discharge point and what may be the parameters of such a study”.
The same EAC meeting recommended: “If the states do not change their policy of allotting elevation-wise river reaches for hydropower development, what criteria the EAC may adopt in restricting the river reach for hydropower development. Alternatively, what should be the clear river length of uninterrupted flow between the reservoir tip at FRL of a downstream project and the tail water discharge point of the immediate upstream project.”
“For peaking stations, what extent of diurnal flow variation may be considered safe for the aquatic life. There are examples where the release is drastically reduced during the long time for reservoir filling and huge discharge flows through the river during the few hours of peak power generation. This is detrimental to the aquatic environment of the downstream stretch of the river.”
“For muck disposal, what may be minimum distance that must be maintained between the outer boundary of the muck disposal sites and the river bank.”
6. Eflows, one of the most significant issues handlederroneously: NO ASSESSMENT OF E-FLOWS REQUIREMENTS The CIA has not done assessment of e-flows requirements at various locations keeping in mind the upstream projects. The very crude assumption it has made is by dividing the entire basin in Mahseer and Trout Zone and assuming certain water depths for these fish in lean, monsoon and non-lean, non-monsoon months. Several fisheries scientists do not support this classification or accept these two species alone as representing the ecosystem. The study assumes 50 cms water depth for Mahseer and 40 cms depth for Trout in lean season.[7] Then flows for maintaining that particular depth are calculated and recommended. Added criteria is that depth should not be less that 50% pre-project river depth.
Luxuriant Biodiversity of the Siang basin Photo: Team BHP
Here it is worth quoting the minutes of 62nd meeting of EAC:
“The EAC asked the Consultants to take comprehensive view of the environmental flow assessment and make final recommendations for each stretch. Committee asked to study international literature available on the subject and use the best suitable methodology for this exercise suiting to Indian conditions. The Consultants said that most appropriate method such as Building Block Methodology would be used by them. Detailed habitat simulation modelling for the entire year needs to be considered so that flow release requirement can be established not only for lean season but also for monsoon season and other months… The Consultants while submitted that public hearing as such is not a part of the study as per ToR, informed that BBM entails expert and stakeholder‟s consultations and would be followed.”
This has clearly not been done.
This approach is incorrect on various counts:
The habitat requirements of Mahseer and Snow Trout are higher than the assumed 0.5 m and 0.4 m. This has been confirmed by several fisheries scientists. The WII study on Upper Ganga Projects recommends a minimum of water depth of 1 meter for adult Mahseer (Tor species) (Table 7.6, Page 148) and at least more than 50 cms for Trouts (Schizothorax sps) (Table 7.8, Page 150). Incidentally these tables from WII Cumulative Impact Assessment have been used in the report without stating the source or credit. SANDRP has interacted with several fisheries experts who claim that 0.5 meters is a completely inadequate depth for adult Mahseer.
This faulty assumption has led to low eflows recommendations of 15% of average flows in non-lean non-monsoon months for Heo and Tato I Projects, this is lower even that EACs norms. This assessment and recommendations are clearly unacceptable.
The criteria of 50% water depth wrt pre-project depth is arbitrary and without any scientific justification. For Himalayan rivers with a stable hydrograph like Siang, 50% depth reduction is very high. As can be seen from Eflows chapter, after 50% depth reduction, most river stretches have less than 100 cms depth, which is just about the minimum depth required for an adult Mahseer or a spawning snow trout. However, Mahseer and trouts are abundant in these rivers. This just indicates the problems behind 50% water depth criteria. This should not be accepted.
The entire eflows discourse is not based on assessment of environment flows for various objectives and ignores most critical requirements.
Division of the Basin into Trout and Mahseer Zones Photo: From CIA/ CCS Report of Siang Basin
7. No mention of Climate change In the entire study, there is no mention of climate change, how changing climate would affect the rivers and projects and how project construction would add to climate change impacts and how they will reduce the adaptation capacity of the people and environment to cope with the changing climate. Deforestation to the scale of 21000 hectares of thick forests and complete loss of a biodiversity rich free flowing river has strong impacts in the context of climate change and these need to be assessed.
8. No stand taken on three mega projects on Siang Main Stem and other big hydro projects Three mega projects on Siang Main stem, namely the 6000 MW Upper Siang I, 3750 MW Upper Siang Stage II and 2700 MW Lower Siang will have a huge destructive impact on the entire ecology and society of the region. These three projects together will submerge 18,100 hectares of dense forest area and will convert entire river length between these projects: 208.5 kilometers, into unbroken sequence of reservoir-dam-reservoir-dam-reservoir-dam, with no flowing river between two consecutive projects. The study has not even attempted assessment of length of flowing river required between the projects and eflows allocation for this stretch.
L Section of the Siang River with 3 mega projects which do not leave any flowing river between them. Photo from: CIA/ CCS Report of the Siang Basin
Oppsition to Public Hearing of 2700 MW Lower Siang Project Photo: Echo of Arunachal
These projects in a cascade, destroying a complete flowing river are against the principle of sustainable development and even EAC’s minimalist norm of 1 km of flowing river between projects. A CIA/ CCS study should have raised this issue strongly as these projects are undoing most of the other recommendations. However, the study refuses to take an independent stand against these projects and fails its mandate of being an independent study.
Yamne Basin, claimed to host highest biodiversity in Siang is planned to have 4 projects back to back! Photo: Abor Country Travels
Similarly the study does not take stand on other big hydropower projects proposed in the basin. Most of the projects it has recommended to be dropped are relatively smaller projects, none are big ones. This shows bias of the consultants. The report is also not in consistent in its recommendations.
Positive suggestions: The study recommends dropping 15 projects and keeping some tributaries free from any hydel development. It also calls for including small hydel projects under the ambit of EIA. These suggestions are important and should be accepted. EAC should immediately ask MoEF to recommend changes in the EIA notifications to include all hydro projects above 1 MW.
The study has also asked for change in parameters of Tato II, Hirong, Naying and Siang Middle HEPs so that at least 1 km of river is left flowing between them. This is welcome and EAC should accordingly ask for changes in these projects. But the report has not done any study in this regard.
9. No conclusion about how much length of the river is to be compromised One of the TORs of the study include, as per the minutes of the 43rd meeting of EAC held in Nov 2010: “Considering the total length of the main river in the basin and the HEPs already existing and planned for future development, how many more HEPs may be allowed to come up. In other words, how much of the total length of the river that may be tunneled inclusive of the tunnelling requirement of all the projects that have been planned for development so that the integrity of the river is not grossly undermined.” (Emphasis added.) The report does not do an assessment on this. The B K Chaturvedi committee had recommended that not more than 50% of the river can be compromised. However, this report was to study this aspect, but has neither studied this, nor done analysis or reached any conclusion.
10. Number of sampling locations The minutes of 49th meeting of EAC held in April 2011 concluded that the number of sampling locations will be decided based on this criteria: 3 sites for project with over 1000 MW installed capacity, 2 sites for projects with 500-1000 MW installed capacity and one site for projects below 500 MW installed capacity. In addition 2-3 locations will be selected in the downstream areas.
If we go by this criteria, and considering 44 planned projects listed in the CIA, there should have been 15 locations for 5 projects with capacity 1000 MW or above, 4 for two projects with 500-1000 MW capacity and 37 for projects below 500 MW capacity, in addition to the locations in downstream areas. The CIA has not followed these directions from EAC, else sampling locations would have been about 60 and not 49 as included in the report.
11. Source of information not given Several annexures in Vol II (this too should have been put up on EAC website, but has not been, we got it from other sources), including Annex I says that it is prepared from “PREPARED FROM SECONDARY DATA & FIELD SURVEYS”, but which information has been obtained from field surveys and which information is obtained from which secondary source is not given. In absence of this it is difficult to verify the claims.
12. Inconsistency, contradictions in listing of flora-fauna
– In volume II, Annex I titled “LIST OF PLANT SPECIES REPORTED FROM SIANG BASIN”, which is supposed to include data from secondary sources and field surveys lists 1249 angiosperms and 11 gymnosperms. However, the pteridophytes listed in Annex II titled “LIST OF PLANT SPECIES RECORDED FROM DIFFERENT SUB BASINS OF SIANG DURING FIELD SAMPLING” do not find mention in Annex I or Annex III a/b/c.
– Out of 11 Gymnosperms listed in Annex I, only two figure in Annex II, rest do not get listed in any of the sub basins.
– The species Dicliptera bupleuroides and Phlogacanthus thyrsiflorus listed in Annex 1 Angiosperms do not get listed in any of the sub basins.
– Section 4.1.4 says Paphiopedilum fairrieanum is an endangered and Cymbidium eburneum is an endemic and vulnerable orchid species in Siang basin, however, these species do not get listed in any sub-basins in Annexure II or in any season in Annexure III. Same is the case with endemic orchid species of Siang basin, namely Calanthe densiflora, Dendrobium cathcartii, D hookerianum, Galeola falconeri, Liparis plantaginea and Paphiopedilum fairrieanum.
– Similarly among the Rhododendron species, threatened species like Rhododendron boothii, threatened species like Rhododendron falconeri, newly discovered and critically endangered species like Rhododendron mechukae (even though it was found in Yargyap Chhu sub basin), Rare species like Rhododendron arizelum, Rhododendron dalhousieaevar. rhabdotum,Rhododendron kenderickii, and R edgeworthii are not found in Annex II or III.
Rhododendron Species of Siang Basin Photo: Abor Country Travels
– Endemic cane species Calamus leptospadix also do not figure in Annex II or III.
– The CIA says, “The Siang basin as discussed above is also very rich in floristic resources and there are still number of areas in the basin which are either under-explored or yet to be explored”, however, a CIA is supposed to make recommendation how to ensure that such areas are explored before any more projects are taken up, but this report makes no recommendation in this regard.
– The CIA says that 17 Near Threatened (regional level) medicinal plants, 46 endemic species and additional 55 endemic species are reported in Siang basin, but CIA neither gives list of them, nor locations, how these will be affected by hydropower projects or recommendations to conserve them.
– The scope of study given in Annex 1, Vol. I says: “Preparation of comprehensive checklist of flora (Angiosperms, Gymnosperms, Lichens, Pteridophytes, Bryophytes, Fungi, Algae etc.) with Botanical and local name.” However, we do not find the local names listed.
The situation with respect to fauna species is no different, with similar inconsistencies, lack of specific sub-basin wise situations and recommendations to conserve them. This is true in case of mammals, birds, butterflies, amphibians, reptiles, inspects as also aquatic biodiversity. While the report makes some impressive general statements, but is found to be lacking in specifics mentioned above.
This sample list of inconsistencies and gaps shows that there are serious problems in these lists and the consultant should be asked to remove all these inadequacies. There is also need to get these lists peer reviewed by credible independent experts like those from WII.
13. Unsubstantiated advocacy: going beyond the TOR & mandate The CIA says in last para in section 12.3 titled “Downstream Impacts”, “Keeping the substantial storage requirement in Siang, storage projects in Siang needs to be re-configured, which may lead to merging of Siang Upper Stage I and II into single project to create storage.” There are several other such sentences in this section and elsewhere. This is uncritical acceptance of CWC assertions and is an advocacy for more storage projects in the name of flood moderation. This is clearly uncalled for in a CIA report and such uncritical acceptance of CWC assertions is also not what is expected from a CIA. In any case, this is also beyond the mandate of the CIA.
14. Other inadequacies of CIA
– The CIA does not contain the TOR, the scope of the study given Annex 1 of Vol I is not the TOR.
– 49th EAC meeting had asked for inclusion of Assam Experts in the study, but the study does not mention this.
– The 43rd EAC meeting held in Nov 2010 had asked for inclusion of assessment of the impacts of the projects on wetlands, floodplains, river morphology, sediment transport/ erosion/ deposits, impact on human activities and livelihoods and recommend necessary measures in these regard. The report mentions all these aspects, but fails to assess these impacts and make necessary recommendations.
– The Preface of the CIA claims that the TAC reviewed the draft interim report in May 2012 and draft final report in Sept 2013. We have checked the minutes of the TAC meetings and find that in May 2012 there was no TAC meeting. The 114th TAC meeting happened in March 2012 and 115th TAC meeting happened in July 2012, neither of the minutes include any mention of Siang basin study.
– The Sept 2013 meeting also did not include this report in its agenda. The report seems to be making false claims in this regard, they should be asked to provide minutes of the TAC meeting where this was discussed and what were the outcomes.
15. Study should not be finalised without credible Public consultation across the basin A comprehensive Siang Basin Study will give a cumulative picture of impacts on basin and on basin residents, including downstream population in Assam. The study is supposed to include important findings, which are separate from individual EIA reports. Even MoEF’s Strategic 12th Five Year Plan notes:
Paddy feilds in Siang Basin. Agriculture finds no place in the CIA Photo: Kaushik Shil
“Of late, the limitations of project-level EIA are being realized internationally. Project EIAs react to development proposals rather than anticipate them, so they cannot steer development towards environmentally “robust” areas or away from environmentally sensitive sites. Project EIAs do not adequately consider the cumulative impacts caused by several projects or even by one project’s subcomponents or ancillary developments. The new trend is to address environmental issues earlier in planning and policy making processes. This could be done through cumulative impact assessment.”
However, such a study cannot be complete without consultations held across the basin in a credible way with full information to the communities in the language and manner they can understand. The study should not be accepted without a credible process of Public hearing [8].
CONCLUSION We would like to urge the EAC NOT TO CONSIDER INDIVIDUAL PROJECTS UNLESS THE CIA/CCS Study is APPROVED through a participatory process. In Siang basin, the EAC has already granted EC to 2 projects, Scoping clearance to 16 projects (of which PH has been held for 8 projects) and nine projects will not need EC as they are below 25 MW. This renders the whole exercise of CIA/CCS meaningless!
We urge the EAC to consider all projects from Siang Basin only after CIA-CCS is finalised and keep the scoping and environmental clearances of projects in abeyance till then.
A good report on the Siang Basin CIA: Damn that river Author: Karthik TeegalapalliPosted on: 13 Oct, 2014: http://www.downtoearth.org.in/content/damn-river
By Malika Virdi and Emmanuel Theophilus, Himal Prakriti
While hydro-power is projected as clean energy, there is sufficient evidence to the contrary, on various counts. One of the major concerns about hydropower projects, is that the dams, whether they be impoundment dams or diversion dams (the latter going under the misleading euphemism nowadays of run-of-the-river structures), critically fragment a river. Regulation and release of water at extreme lows (often nil) and sudden releases apart, dams are an impassable barrier for migratory fish, progressively depleting populations past critical thresholds, eventually leaving rivers bereft of life. Dead rivers affect not only the freshwater aquatic realm, but also all terrestrial life dependent on rivers, including large human populations. The impacts are known to cascade down the entire river continuum down to the oceans. Not only does such river regulation have serious political implications in terms of equity and justice between proximate and faraway users, but far-reaching cultural repercussions as well.
Kurichhu HEP Photo: Druk Green
In the on-going discourse on the large-scale build-up of hydro-power projects in the Himalaya, which will soon be the most densely dammed region on earth, one encounters proposed part-solutions, often billed as mitigation measures. Ofcourse, every attempt at addressing the serious problems created by hydropower projects is desirable and welcome. However, which of these actually mitigate or provide solutions to the problems created by hydro-power projects, and which of them only serve to provide camouflage from public gaze, or a cover of legitimacy for mandatory approvals, does require to be looked at more closely.
We have been hearing for long about fish passes of various designs constructed on hydro-power dams in the US and in Europe, to allow the passage of many species of migratory fish, to travel to their breeding grounds in distant mountain rivers. None of the numerous hydro-power projects under construction in Uttarakhand have incorporated any provision for the passage of seasonal migratory fish, and this is puzzling. How are hydro-power projects cleared on environmental grounds and approved despite their disastrous impact on fish movement and subsequently on fish populations?
One instance of a proposed mitigation measure is what was proposed by WAPCOS for NTPC’s Rupsiabagar-Khasiabara HEP in the Gori river basin where we live. While the project has recently been denied Forest Clearance for diversion of forest land for the specific dam-site, it had earlier managed to secure overall Environmental Clearance on the basis of proposed mitigation measures, and is being cited here as a case in point. Addressing the problem of creating a barrier for movement of migratory fish, WAPCOS proposed an entire fish breeding-and-stocking programme. The proposal was for setting up facilities for producing seed of snow trout (Schizothorax richardsonii) at a cost of Rs. 16.05 million, for periodically stocking 3 cm long fingerlings with 100 fingerlings per km of river, for 10 km upstream and downstream of the dam structure, for 5 years. Serious money that could even sound like a serious effort. Only, anyone living close to the river knows that the proposed dam-site itself, let alone 10 km above it, is entirely uninhabited by any fish whatsoever. This was clearly a ‘mitigation measure’ proposed only to obtain environmental clearance. It is another matter that even WAPCOS’s species fish-list for the river was just a wish-list.
In the context of addressing the problem of fish-passage, we were informed of a fish-ladder constructed by the NHPC for the Kurichhu HEP in Mongar in Bhutan, so we undertook to visit and see the fish ladder design, and to speak to the hydro-power company to understand how effective it was. The Kurichhu is a medium sized Himalayan river in Eastern Bhutan, forming the upper main-stem of the Manas river which originates in Tibet. Access to it by road is long and circuitous, and after a year of trying to get away for long enough to visit, we finally reached there on the cloudy afternoon of 11th January 2014. Prior permission had been sought for the visit through contacts in India, and we were received and shown around with rare grace and courtesy by officials of DrukGreen, the company running the hydro-power project after handover to it by the NHPC of India. The sight of the ladder was thrilling, and we were even permitted take photos of the fish ladder.
Fish Ladder at Kurichhu HEP Photo : Authors
January is not the season for either upstream or downstream movement of fish in that zone, so we could not see fish movement in the ladder for ourselves. However, we gathered the following:
The dam is a 55 m high (from the foundation) concrete gravity dam located at an altitude of about 530 meters asl and is 285 meters across the beautiful, dark, blue-green Kurichhu river at Gyalpozhing. At full reservoir level 15.70 million m³ of water is impounded behind the dam. At the time of our visit, one of the four turbines was operational and there was a small release of water downstream of the dam. The fish ladder was in flow, releasing just 0.8 cumecs of water. The project authorities said that during such low-flows, this is the only flow from the dam, since there is no minimum flow required to be maintained by law in Bhutan. The ladder is a pool-and-weir type, with submerged orifices and centrally located notches. A pool and weir design is one of the oldest styles of fish ladders. It uses a series of small dams and pools of regular length to create a long, sloping channel for fish to travel around the obstruction, in this case the dam. The channel acts as a fixed lock to gradually step down the water level; and to head upstream, fish must either negotiate a slot, or jump over from box to box in the ladder.
The Kurichhu fish pass has a total of 98 baffles, each 1.5 m wide and 1.5 m deep, arranged at a distance of about 2.9 m. The total depth of each pool is 2 m. There are two exits (water entrances) to the fish pass, the lower exit placed 5 m lower than the other, to provide for flow at different draw-down levels. The vertical height between the water level of the ‘stilling basin’ (interesting name for a reservoir holding 15.7 million m³ of water) and the water entrance for fish from below the dam is 32 meters. To achieve this height, the fish-pass channel has to traverse a total distance of 320 m, leading to a slope of 1:10, and resulting in a drop in height per pool of 0.3-0.4 m. Quite impressive, except that the slot in the centre of each baffle does not exceed 25 cm in width. Clearly, no way for big fish, and Mahseer (Tor), the fish with the longest migration distance in this river, also happens to be the largest carp in the world.
We asked the project manager whether they know the fish ladder to be effective. He said that on a few occasions during the fish migration season, they had stopped the flow of water in the ladder and found some small fish in some of the drained pools. They did not know which species they were. We enquired whether there had been any systematic study of the efficacy of the fish ladder, in terms of comparing, with a baseline since commissioning the dam in 2002. Whether there was a change in species composition, or a significant change in upstream fish populations during this time? He replied that they had not.
Discussion: It is understandable that project authorities in Bhutan were not familiar with names of fish species or other particularities, because people in Bhutan in general do not catch or eat fish. This could stem from Buddhist tradition, but also from funereal custom, where one of the traditional options is that the body of deceased adults is dismembered and consigned to the river for fish to consume.
On enquiring about any documentation with regard to the fish ladder design, they kindly shared a document titled ‘Feasibility Studies for fisheries development in Kurichhu reservoir, Bhutan’ prepared for NHPC, Faridabad, by CIFRI, Calcutta. While CIFRI has been hired by NHPC ostensibly for extending their expertise on fish, they could have spared us their use of tired narratives of ‘development’. It is clearly beyond their area of expertise. Prefacing their feasibility study on fish passes with statements such as “advancement of human civilization and distortion of natural habitat go hand in hand,” and “requirement of electricity is synonymous with the development of civilization”, and more, just exposes their fait accompli. We photographed relevant pages onsite, and along with discussions, have gathered the following:
Since every fish passage requires to be designed to cater to the specific behavioural propensities and physical capabilities of a particular set of fish species inhabiting the river in question, certain stretches of the river were sampled by CIFRI. The fish they caught can be grouped into three broad groups:
Snow trout, mahseers and minor carps: Schizothorax richardsonii. S. Progastus, Barbodes hexagonolepis, Labeo dolycheilus.
Loaches: Garra lyssorhinchus, G. gotyla,
Catfish: Glyptothorax coheni, G. brevipinnis, Pseudocheneis sulcatus.
CIFRI did not catch Tor during sampling, but during dam building many fish were caught by workers and staff from India, one 15 kg and another 20 kg fish near Kurizhampa bridge. Fish of this size cannot be Barbodes or Chocolate Mahseer, and seem to be Mahseer of the Tor genus (species tor or putitora).
The three functional categories of fish migration in general are: Reproductive (spawning) migration, feeding (trophic) migration and refuge migration. For this, hill-stream fish are known to migrate between three major habitats: A wintering habitat, a feeding habitat and their spawning habitat.
Dams and other diversions for river regulation are seen to impact fish in five major ways:
Obstruction in the ascent of fish in their migration for spawning.
Reservoirs can inundate spawning habitat, silting up gravels,
Changes in river water quality due to inter-basin transfers and stratification of water.
Natural flows downstream are radically altered. This includes abruptness of changes in flow, in volume, velocity and seasonality.
Prevention of young migratory fish and refuge migrants from descending to lower reaches.
In addition, adverse repercussions result from indirect effects such as the disruption of the food-webs downstream, stranding of fish during rapid flow fluctuations, and siltation in the reservoir above the dam. The chemical, trophic and thermal properties of a river are greatly altered. Additionally, changes in slope, riverbed profile, structure of the bottom surface, submergence of gravel zones, and changes in the thermal and trophic regimes, affect the habitability of certain stretches of the river.
Designs of fish passages are many, and can be broadly categorized as follows:
Fish ladders. Pool and weir, baffle fishways, rock-ramp fishways, vertical slot.
Fish lift locks
Fish elevators
Fish trapping and hauling.
Pool and Weir Type Fish Ladder, Bonneville Dam, United States Photo: WikipediaSpecial Fish Ladder for Salmon in Sweden. Photo: Wikipedia
The basic information you need for designing a fish pass, is details about the species particularities such as normal cruising speed and burst speed of target species. Some important criteria are:
Provision of comfortable passage for all migratory species, including the poorer swimmers, over the entire length of the fish pass. To achieve this, provision for refuge against fast currents at regular intervals should be made.
Year-round functionality, under different flow regimes, temperatures and oxygen levels, notably to enable fish displaced by floods to return to their initial habitat.
Sufficient space or carrying capacity allowing massive upstream ascents during reproductive or trophic migration.
Positioning the entry of the fish pass so that it is readily identifiable and accessible to the migrants.
Attraction of fish to the fish pass entrance in the downstream (water exit) in case of upstream migration and deterring them from dead-ends and dangerous places.
Positioning of upstream outlet (fish exit) of fish passes far enough from spillways and turbines to minimize the risk of being swept downstream or being damaged.
Clearly, creating an artificial fish passage is complex and would not work if the multiple aspects are not considered and provided for. Ease of physical passage is just one important aspect. Migration is specifically timed to match various conditions, and even a delay in migration can nullify the purpose. For example, upwelling and excessive turbulence in the areas near the fish entrance are undesirable, as they can confuse migrating fish from finding the entrance. For this, the gates of the dam are required to be manipulated so that the heaviest spill is at the bank opposite the fish-way, with the result that the velocity barrier forms a diagonal lead, a traffic signal of sorts, across the river to the fish entrance. Apart from a sufficient ‘attraction flow’ at the entrance of a fish pass, projects elsewhere have experimented with directing fish traffic with the help of guiding screens, and the use of overblown ‘traffic signals’ such as acoustic arrays, strobe and mercury lights, and even electric fields.
At a fish passage such as the array at Kurichhu, it is critical that at the entrance of the fish-way, the gate is to be manipulated to ensure possible passage of fish. Depth and velocity to suit particular species need to be maintained. CIFRI recommended a ‘compromised’ depth of 25 cm to be sufficient to allow fish passage. In addition the gates should be regulated to ensure that all the baffles are submerged, allowing the fish to swim over them upstream comfortably. This was not the case, when we visited, the flow level did not allow for the baffles to be submerged, as visible in the photograph as well.
Even with a depth of 25 cm in the fish exit, the variable head-height as per the draw-down of the reservoir can create a higher velocity than desired. While CIFRI warns that this poses apprehensions regarding hindrance to fish migration, they dismiss these apprehensions summarily thereafter, stating that this high velocity is observed only for a short distance, which fish would be able to negotiate using burst speed (high speed, short duration). CIFRI mentions that it is only when the speed at the water entrance or any other point exceeds burst speed, (5-6 m per second) that fish would be unable to cross this speed barrier.
While variables such as water temperature and fish length are determinants of swimming speed of fish, CIFRI has assumed that Schizothorax and Barbodes can swim at 3-5 and 2-4 m per second respectively. They have taken the flow speed of water with head height, and fitted it to the equation for determining the velocity through the orifices in or over the baffles, and they are estimated to be ranging from 2.69 to 2.80 m per second, which they say, ‘permits the fish to cruise through the fish-way comfortably.’
There are some doubts here. Even a short distance of one baffle, or at just the entrance is critical, because if that is unpassable, the entire fish-way is unsuccessful. Further, CIFRI has arrived at burst-speed of fish for this river not by actual studies on specific species, but by inference from studies on fish in other countries. What strikes as doubtful about this basis, is their assumption that all other things being equal, a fish of any species is capable of equal burst speed, provided it is of the same length. This does not match anything one sees as evidence in the occupation of different fish species in different river stretches, nor in their striking speed while feeding competitively.
In order to test whether the fish ladder was ‘working’, CIFRI officials operated the fish pass in March (the beginning of the migration season) for 3 days and then closed the sluice gates to check. They found Schizothorax richardsonii, Garra gotyla and G. lissorhinchus in the top-most pool. They did it again in June and found 8 species in the uppermost pool. While it is clear from this that some fish are making it up the channel right upto the top pool, they have no way of knowing for sure whether they were getting through the 25 cm gap at different draw-down levels.
The critical question here is not just whether some fish are making it up the channel, but which species, how many, and are breeding populations making it up on time? A relevant study cited on the April 2013 issue of the Yale Environment 360,titled ‘Fish and hydropower on the U.S. Atlantic coast: failed fisheries policies from half-way technologies’ by J.Jed Brown and 6 other co-authors (Conservation Letters, Vol 6. Issue 4, p 280-286, July/Aug 2013) is instructive. The discussion by co-author John Waldman is titled ‘Blocked Migration: Fish Ladders on US dams are not effective’, citing this study goes on to say that fishways on rivers in the U.S. Northeast are failing, with less than 3 percent of one key species making it upriver to their spawning grounds.
Waldman says that “in most major rivers in the U.S., maintaining some semblance of the integrity of migratory fish runs past hydropower dams is dependent upon the fish using ladders and elevators”. They undertook a study of the success – or, rather, failure – of Atlantic salmon, American shad, river herring, and other species in migrating from the sea to their spawning grounds past a gauntlet of dams on three rivers in the northeastern U.S. – the Susquehanna, Connecticut, and Merrimack. Waldman says “what we found was grimmer than we expected. For one species, American shad, less than 3 percent of the fish made it past all the dams in these rivers to their historical spawning reaches. The sobering aspect of these contemporary studies is that they are based on the insubstantial number of fish today as compared to earlier massive migrations of these species, which numbered in the many millions. For the international community, the record of fish passage on rivers in the northeastern U.S. is a cautionary tale”.
He goes on to say that “hydropower has often been billed as a clean source of renewable energy, and generating electricity without polluting the air or producing greenhouse gases is commendable. But ‘clean’ is in the eye of the beholder, and any claims to being sustainable ignore its multifarious aquatic effects, including blocking fish passage, fragmenting habitat, and undermining a river’s fundamental ecological services.”
What Brown and co-authors found was bleak. One metric used was the percentage of fish passing the first dam that also passed just the second dam. For shad, the numbers were 16 percent on the Merrimack, 4 percent on the Connecticut, and 32 percent on the Susquehanna. But on these rivers, Waldman says, the second dam is only the beginning of the journey, and these rivers have multiple dams blocking access to historical spawning reaches. It’s important to put these results in perspective because they are merely relative to the present paltry numbers of fish that even attempt to migrate up these rivers.
The study says that there are three absolute numbers that matter. One is how many ran annually before the dam was created, the second is the numbers targeted for restoration in fish passage programs, and the third are the numbers that actually show up each year. On all the rivers examined by the study, restoration goals were in the hundreds of thousands of fish – at least one, if not two, orders of magnitude less than historic, pristine runs. Yet run sizes obtained across three decades ranged annually from a high of about 10 percent to, more commonly, 2 percent or less of the stated goals.
There are two significant aspects worth taking note of here. First, the three absolute numbers that matter, as mentioned in the paragraph above. The construction of a fish ladder must come with quantified stated goals, in terms of the number of fish that are required to pass as minimum, to achieve the desired stability of fish populations. This requires an estimate of populations prior to building the dam, and an estimate of the number that migrate unimpeded, as well as specific population dynamics. Fish migrations in large rivers can be in the millions, as already cited here from Brown and Waldman’s study. Here at the Kurichhu, or any other fish-pass in India, population and migration estimates, let alone quantified goals are a far cry.
Secondly, the study clearly illustrates that every subsequent dam upstream has a cumulative impact on the numbers of fish succeeding upstream, diminishing in orders of magnitude. This brings to the fore the critical importance of considering cumulative impact of multiple projects, despite ‘mitigation measures’, along an entire stream-length, before any clearance is given piece-meal.
While on the design for fish-passes on specific hydro-projects, there are many aspects other than physical passability provided by a fish-pass, that determine its success or failure. Changed flow, turbulence, and volumes can be disorienting for fish leading to serial delays, making it unlikely that the many fish make it to the spawning reaches at the optimal time in the river’s seasonal ecological cycle. The numbers of adults successfully returning downstream past the dams also sacrifice their future spawning potential. The flow out of an operating fish-ladder is often very small compared to the water going into the intake to the turbines, and fish will often choose the larger flow during descent, to their peril. At Kurichhu for example, the flow down the fish ladder is just 0.80 m³ a second, which is a fraction of the flows for the 4.75 m diameter intake of any one of the four 15 MW turbines.
There is also the larger question of flows in a river being regulated by series of dams, and sometimes being too low to provide the necessary cues for hormonal change and migration, puts paid to fish even reaching fish-ladders in the first place.
The study by Brown and colleagues in the US says that despite vast spending on modern technologies, contemporary shad migrations on these rivers are at least three to four orders of magnitude below the original unfettered run sizes, with similar results for salmon and river herring. While dams alone don’t explain these results; overfishing, habitat destruction, and alien species contribute – but there is widespread consensus among fish biologists that dams (such fish-passes notwithstanding) are a primary cause. Surely, a cautionary tale for India.
And here is another cautionary tale for India, where unlike Bhutan, fish are eaten, readily. Thirty-three years ago, standing on the Sutlej Barrage at Ropar in Punjab, I witnessed a strange sight. At the base of the barrage, there was some urgent movement in the cold blue waters of the Sutlej in early spring. Mahseer fish were attempting to migrate up and beyond the 10 meter high barrage. There, right along the buttress of the sloping spillway, one could see a living pyramid of thousands of fish upon fish, slithering up the side of the uni-dimensional triangle against the spillway, barely submerged in the leaking flow from one of the gates, and wriggling on top of and past each other, in a futile effort to make it over the barrage. While this may just have been a collective shoal strategy to get past smaller rapids, it was a death-trap for fish there, against a steep and high barrage. Some other men had already seen this, and I could see them wade up to the desperate and tenuous pyramid in knee deep water below the barrage, and carrying away fish in sack-loads.
Hydro-power projects in India may undertake to construct fish-ladders projected as mitigations measures to obtain environmental clearance, but that does not prevent the staff and others from making the best of the concentration of fish at the base of the fish-ladders and even at un-passable barrages and predating on them. The CIFRI study for the Kurichhu mentions that Indian workers hired by NHPC regularly fished at points of concentration during migration season, nullifying the purpose of the fish-pass. Clearly, the dam authorities will also need to be charged with the responsibility for protection of fish-passes, and other points of concentration even on dams without fish passes.
These are some of the aspects that require to be further investigated about fish-passes in our Indian context, and to be put on the table for discussion and closer scrutiny when mitigation measures are proposed by hydro-power projects.
Editor’s Note from SANDRP:
When the rivers in Himalayas are facing huge impacts of cascade hydropower projects, it is important to look at the role played by organisations like CIFRI ( Central Inland Fisheries Research Institute) which is supposed to be Asia’s “premier facility in the feild of inland fisheries research” CIFRI was hired as a consultant for recommending eflows for Teesta IV HEP in Sikkim and 780 MW Nyamjangchu HEP in Tawang, Arunachal Pradesh. In the case of Nyamjangchu, CIFRI recommended a flow of 3.5 cumces from the proposed barrage point, which is 14% lower than the lowest flows recorded (extrapolated) for that site. It is highly improbable that even CIFRI’s target species of snow trout will be able to sustain these drastic flow reductions. CIFRI has not raised a voice when multiple dams are being planned without fish ladders or realistic mitigation measures across the country when protecting riverine fish and fisheries is a part of its mandate.
In a strange contradiction, although India’s NHPC has built Kurichhu HEP and CIFRI has designed the fish ladder for a dam that is 55 mts high, the EAC of the MoEF in India unilaterally thinks that fish ladders do not work for dams, even as high as 42 meters, This EAC also includes representative from CIFRI.
Before concluding that fish ladders will or will not work in India, we need extensive studies on this subject for different rivers and projects. Unfortunately, none are being undertaken, in line with our overall apathy towards riverine fish diversity and fisheries. Good, scientific studies will help in designing ladders which can be useful for species specifically found in Indian rivers, or will conclude that ladders will not work in specific cases, in which case, the irreversible impact of the project will have to be looked at in a perspective beyond ‘mitigation measures’.
Kaldigarh HEP (9 MW in Uttarkashi district) The project heavily damaged in 2012 floods and it being in Eco Sensistive zone, the report says the project should not be allowed to restart without permission from central govt.
One of the two lead coordinating authors of this report was Dr. Arun Kumar, from AHEC, IIT Roorkee. Notably, Dr. Kumar was also a part of the team which worked on Cumulative Impact Assessment of Hydropower projects in Upper Ganga basin of Uttarakhand
SANDRP 