Rivers in different parts of the world have been dammed to fulfill human needs like water for irrigation, industries and domestic supplies, to control floods, and to produce electricity. These have often been celebrated as a human victory over nature, glorified as engineering marvels and claimed variously as highest, longest, etc as a matter of national pride. But rarely has there been a holistic assessment, or appreciation of what a dam does to the natural entity called a river and its adverse impacts on all the associated life forms, including humans.
By Manoj Misra
Yes, there is cost-benefit ratio assessed before a dam is approved for construction. But these assessments are based largely on economic considerations. Even the mandatory EIA studies fail to conduct a holistic impact assessment remaining unmindful of downstream and indirect impacts. Regrettably, post-facto assessments of dams are conspicuous by their absence. Resultantly actual benefits realised and true environmental and social impacts of dams remain poorly documented or understood.
[paperio_blockquote tz_blockquote_title=”” tz_blockquote_bg_color=”” tz_blockquote_color=”” tz_extra_class=”” tz_extra_id=””]It is in this context that we hold that “a dam is perhaps the worst form of man’s interference into nature’s functioning.”[/paperio_blockquote]
It is in this context that we hold that “a dam is perhaps the worst form of man’s interference into nature’s functioning”.
In any case raising any new dam in the 21st century is undesirable when their obvious adverse impact in a climate uncertain age is an invitation to frequent disasters and rising conflicts.
Turns dynamic system into static
A river is meant to flow. That is its life. What flows in it are not just water, but also sediments, nutrients, biota, and energy. This flow itself is variable. It varies from season-to-season, month-to-month, and even day-to-day at places. In snow-fed streams, it could vary from morning to evening. And it is this variability – its dynamism – that determines all the rest that defines it. Like it determines the sediment movement and deposition; wetting and drying of its floodplains and aquifer relationships; kinds of insects, fishes, crustaceans, reptiles, birds and mammals and the plant life that shall flourish in it; and the human livelihoods and cultural endowments (from birth to death) that relate and depend on it.
So when a dam is raised on a river, it strikes at the very vitals of it, since the river is no longer in control of its flow. It is now a dam manager that decides how much and when, if at all any ‘water’ shall be released down the concrete/mud structure into the river channel. And it is only ‘water’ that would be released, for all the rest including sediment, nutrient, biota, and energy is now captive in the reservoir behind the structure.
This difference is important to note, especially for the advocates of environmental flows and a belief that it is good enough for a river’s revival. Because the water that is released down the dam is not the same water that flowed down the river before getting impounded or diverted into tunnels. This water is much lighter and lifeless since there is little sediment or biota associated with it, the latter having been left behind in the reservoir.
[paperio_blockquote tz_blockquote_title=”” tz_blockquote_bg_color=”” tz_blockquote_color=”” tz_extra_class=”” tz_extra_id=””]This water is much lighter and lifeless since there is little sediment or biota associated with it, the latter having been left behind in the reservoir.[/paperio_blockquote]
Moreover, its chemistry in terms of dissolved oxygen, temperature and other critical parameters is different too, as is normal for water that has stood still (as in a pond or reservoir) against water that is moving down a gradient. Same applies to energy which would be different for different volumes flowing in the river.
It is often claimed by dam builders that it is only the monsoon period high flows – that otherwise goes waste (sic) into the sea – that they are collecting behind the dam. Nothing could be more preposterous and ecologically ignorant a statement to make than this since it is the monsoon period flow that is critical for the life of a river. It is the monsoon flow that enables a river to wet its floodplains, feed the associated aquifers and facilitate various life period requirements of plants and animals associated with it. How could the dam builders ignore the fact that water flowing in the river to the sea completes the vital hydrological cycle on earth and is a fundamental requirement for a stable climate on earth?
Converts a democratic system into an undemocratic one
A river, like any other natural entity, is an extremely democratic system. It embodies playfulness, freedom, happiness, and camaraderie and offers its bounties without any differentiation. Anyone, anywhere, and at any time can take a dip or take a handful of its waters or sit beside it to marvel, meditate or whatever. It feeds all its associated aquifers during high flows and does not hesitate to seek water from them in its lean season. It does not favour one insect, fish, amphibian, reptile, bird or mammal over another. It collects sediments from one bank to deposit it little later at another. Its meeting with the sea is a spectacle, being full of gravity and yet exhibiting total submission. It can be angry and gentle. Almost divine!
But once dammed and shackled it loses most of the above, in a pitiable state of captivity and destitution, as if begging for its life and reason to be. Reduced to being, an apology of its original self.
Robs Peter (many) to pay Paul (few)
To a river, all who live and prosper around and in her are her children. And those that live away from the river are likewise some other stream’s children.
Once a river is dammed, her children who live either upstream or downstream of the dam are deprived in different ways. Those in the upstream lands living in what is planned to drown to form the reservoir are uprooted from their homes and hearth and get displaced. This applies as much to humans as to the other life forms. Those in the downstream suffer the loss of livelihoods, cultural values and habitats (non-humans) from diminishing, irregular or ceased flow in the river. Their wells and johads fed by the flowing river begin to go dry and are soon abandoned.
All the above has been done to what end?
To draw water away from the river, feed into lined or unlined canals and supply some of it (for a large part gets evaporated away or stands beside the unlined canal as seepage) to somebody who many a time do not even know or bother to know wherefrom it has come. For him it is a largess from a sarkar (government) enabling him to grow more remunerative (not necessarily appropriate for the region or soil) crop, produce industrial goods or enjoy a water sufficient urban living. Often such ‘managed’ water supplies are appropriated by the elite, the well connected or the powerful at the cost of many who seldom or never receive the promised water. The number of these beneficiaries is often far less than the riparian (living beside the river) people who have lost out on their river.
In nutshell, it is a classic case of ‘robbing Peter (many) to pay Paul (few).
Converts self-reliant into dependent people
Traditionally people close or away from the streams had their own water access and utilisation strategies. Even today if you scan rural India on Google Earth, you can easily spot water bodies and even dug wells in and around villages. But if you happen to actually visit a village in all probability you would either find the water body dead or putrefying and the well certainly in glorious disuse.
This is the stark reality of a people turned water dependent from a previous state of water self-reliance.
A canal dug near a human habitation appears to promise an endless and easy supply of water through minors and distributaries. And often during the initial days of the canal in operation, water does seem enough and endless. The result is that the people, who till then accessed and managed their water from dug wells (later hand pumps) and local johads, soon begin to abandon their traditional water sources. Water in the dug well first goes bad for want of use and later dries out.
Johads become a place to dump liquid or solid refuse.
People soon lose all sense or necessity of managing their water locally, since somebody is managing it for them remotely.
But as the demands on the canal water increases due to increase in number and kind of stakeholders on it, trouble begins to emerge. Water supply being finite, soon the people who initially had enough supplies start to feel the pinch. The powerful and the better connected in the village begin to appropriate whatever supplies come the village way. Water conflicts become the order of the day. And worse the minor and the distributaries that till the other day had water – when it mattered – in them start to remain waterless for more and more period till many become eyesore relict of a broken system.
Impoverishes large tracts up and down the dam to presumably benefit some tracts away from the river
Dam planners and builders paint a rosy picture of things to come in its (dam) so-called ‘command area’. But never assess, what to talk about divulging, how the river’s riparian lands both upstream and downstream of the dam would get impoverished and degraded impacting adversely the life extant there.
One of the key functions of a free-flowing river is annual recharge during monsoon of its associated aquifers and wetting of its floodplains (riparian tracts), which in turn keeps riparian water sources (wells, bavdis, ponds, johads, etc) provided and functional as well as plants and animals in the floodplain enriched and thriving.
Once dammed, with flows both monsoonal and otherwise regulated, the river in its downstream loses its ability to feed the aquifers or to wet the floodplains (except during high to very high floods) in a regular manner. In the upstream, standing water occupies large area converting terrestrial landscape into aquatic, depositing silt in its bed, producing methane (responsible for global warming and climate change) from putrefying vegetation, losing water to high rate of evaporation and destabilizing farmlands and hilly soils adjoining the reservoir by permanently keeping saturated the associated aquifers.
In short, the riparian lands and life both upstream and downstream of a dam gets disturbed, impoverished and destabilized.
Many a time it is not just the riparian lands and people that suffer, but even lands and people far away from the river but close to the canals that carry the water diverted from the river. This happens when canals run through lands with a characteristic soil, biodiversity, crop choices and lifestyles. Additional water encourages people to change their traditional lifestyles and crop choices which in effect and in the long run might not be in the best interest of either the people or the lands.
Creates flash and devastating floods
Many dams have been raised to control floods in the rivers. The assumption is that floods by themselves are dangerous and undesirable.
The fact is that floods in rivers during monsoon period are as natural as heat and cold waves in summer and winter period respectively. And riparian people have over time devised suitable strategies to live with floods. As a matter of fact, small and medium-sized floods are looked forward to by the farmer as it replenishes his/her farmlands in terms of silt and nutrients. For high-level floods, which are periodic (10 year, 50 year, 100 year etc) riparian people have evolved coping strategies like indigenous forecasting methods as well as appropriate housing and other necessities of life to minimise losses if any.
[paperio_blockquote tz_blockquote_title=”” tz_blockquote_bg_color=”” tz_blockquote_color=”” tz_extra_class=”” tz_extra_id=””]As a matter of fact small and medium-sized floods are looked forward to by the farmer as it replenishes his/her farmlands in terms of silt and nutrients.[/paperio_blockquote]
Experience shows that while dams do hold small and medium-sized floods, which are otherwise useful to the riparian people they (dams) are unable to do so in case of high to very high floods. So when on account of high to very high rainfall the dam is unable to hold water anymore, it discharges a huge amount of water inundating farmlands and villages.
Consequently, a river which till the dam came up was an integral and benign part of people’s lives has been taken away from them and converted into a source of disaster through a process in which they had little voice or choice whatsoever?
Unsustainable extraction of groundwater
Water found below the ground level plays a number of roles and functions. This water is deposited in what are called aquifers.
It is one of the most reliable sources of water, keeping springs, wells, ponds, and rivers alive.
Aquifers get recharged whenever it rains over the ground. Rivers that carry the rain’s runoff recharge the aquifers in their high flow and benefit from them in their lean season to ensure base flows or well-stocked pools standing in the river bed. But the aquifers can get emptied if the rate of extraction from them is more than the rate of recharge.
Damming of rivers and the diversion of water away from the river dramatically changes the river’s natural hydrology and has led to the unsustainable extraction of groundwater in the country through a process that is neither readily appreciated nor understood.
As rivers go dry, people living alongside resort to groundwater as a source of water, often going deeper-and-deeper to fetch it as there is little aquifer recharge happening from the river. Alternatively, base flow in the river during the non-monsoon months which depended on backflow from the aquifers (filled during the monsoon high flows) becomes a thing of the past. The result is a dry river bed soonest the monsoon season is over.
Desiccation of river bed including floodplain soils becomes the order of the day with consequent adverse impacts on all related humans, plants, and animals alike. A thriving ecosystem consequently collapses. And the groundwater continues to get depleted.
On the other hand, in the dam’s command area, people initially flush with canal water resort to cropping change and multiple cropping which soon becomes the norm. In due course when the water in the canal (as explained before) becomes scarce, it is again the groundwater that comes to their aid. Here again exploitation of groundwater soon takes on unsustainable proportions as habits involving liberal use of water for agricultural, domestic or industrial use do not change easily.
[paperio_blockquote tz_blockquote_title=”” tz_blockquote_bg_color=”” tz_blockquote_color=”” tz_extra_class=”” tz_extra_id=””]Aviralta (unfettered flow) in our rivers is also the state’s avowed aim. So why are we still raising dams that destroy river’s aviralta?[/paperio_blockquote]
End result is that the groundwater from deeper aquifers, which should have been the last resort and more as a fall back source both in the river’s riparian zone as well as in the dam’s command area become first-use, preferred sources and the practice becomes highly exploitative and unmindful of where the water shall come from – once the aquifers have run dry?
Hydro-power is passé
The number of dams have been built, or are under construction in hilly terrain including the fragile Himalayas and the Western Ghats, to produce hydro-power, oft claimed as a cheap and reliable source of energy.
While the usefulness of hydro-power is undeniable and has served its purpose well over the last several decades, it is now passé since energy harnessed from solar, wind, biomass and tidal sources can more than match the reliability and economies of hydro-power. The environmental and social impact risks associated with the latter are far less than those associated with hydro-power.
Clearly, it is no longer required to raise any dam in the name of hydro-power.
It can be easily surmised that damming a river for any purpose is counterproductive and avoidable. It is anti-nature too. For the nation’s water security it is imperative that our rivers flow unfettered. Aviralta (unfettered flow) in our rivers is also the state’s avowed aim. So why are we still raising dams that destroy river’s aviralta?
As for water, let us remember that some water at hand is any day better than no water. The writing on the wall is stark and clear. Free rivers or face severe water scarcities and rising conflicts.
To borrow from Rahim:
[paperio_blockquote tz_blockquote_title=”” tz_blockquote_bg_color=”” tz_blockquote_color=”” tz_extra_class=”” tz_extra_id=””]Rahiman nadiya raakhiye, bin nadiya sab sun. (Keep your rivers lest all gets lost soon) [/paperio_blockquote]
(Manoj Kumar Misra is a forestry and wildlife expert, who served in the Indian Forest Service (Madhya Pradesh/ Chattisgarh cadre) for 22 years. He rose to become Chief Conservator of Forests (CCF) before seeking voluntary retirement. Today he is the Executive Director of the PEACE Institute Charitable Trust and Convenor of the Yamuna Jiye Abhiyaan. He holds Masters degrees in Mathematics, Forestry and Wildlife Management.)
(This article was originally published by SANDRP – an informal network working on issues related to rivers, communities and large-scale water infrastructure like dams: their environmental and social impacts, their performance and issues related to governance of rivers and dams. You can read the original article here – titled “DAM BUILDING MUST BE HALTED FOR A SAFE AND SECURE WORLD”)