Redesign dams, not rivers

Engineers require retraining, not the Ganga. This is where I left our conversation in my previous column. Why did I say this? The inter-ministerial committee in which I participated as a member was discussing how much the ecological flow - the water that should be left in the river for ecosystem and livelihood purposes - should be at all times. How much water is needed for the river to be a river, and not a drain?

The committee's deliberations had reached a flashpoint. My colleagues at the Centre for Science and Environment had analysed hydrological data to recommend an ecological flow regime that allowed 50 per cent of the total flow of the river for the six-month lean season. In addition, we proposed that during the high-discharge season hydropower development could use as much as 70 per cent of the total water. We showed that this 30:50 ecological flow regime would allow hydropower to make the most of the river flow and, therefore, would not have much of an impact on the total energy generated and tariff. Run-of-the-river projects, which used flowing water as the raw material for energy, generated as much as 80 per cent of their energy in six months.
 

But this proposal was unthinkable for hydropower engineers. They had "designed" their projects on either zero ecological flow or, at the most, 10 per cent. In this way, they would generate power with every drop of water in the low-discharge season. The Indian Institute of Technology (IIT), Roorkee, which is a key consultant to the government and to private hydropower developers, was asked to review the analysis. It provided a confidential note to the chairperson, disputing our analysis with calculations to show that tariff would increase by 30-60 per cent in the 30:50 scenario.

This view of the engineers was adopted as gospel. The draft final report circulated to all members provided for 20-25 per cent flow for nine months and only up to 30 per cent for the rest of the three months. But when we compared the IIT-Roorkee data with what had been provided earlier to the committee, we found one modification: the amount of flow in the river had drastically and inexplicably reduced. Since there was no water in the river, in all seasons, energy generation reduced - and, therefore, any provision for higher ecological flow would inevitably lead to huge increases in tariff. Delicious maths!

We then took up the matter with the chairperson. Our question was: what was the source of these raw data and how had these mysteriously changed? This questioning brought some changes. The subsequent report included a provision for 50 per cent ecological flow, but only in those situations where there was "drastic" reduction in water.

Therefore, the final report of the committee has accepted the need for 50 per cent flow but with conditions, which leave it vague and weak in application. We have differed and given an alternative view. Our analysis shows that winter (lean) flow is less than 10 per cent of the high monsoon flow in almost all 24 projects for which hydrological data are available. In other words, if less than 50 per cent of water is left in the river, it will be reduced to a trickle in these months.

The report is now lying with the government for a final view. Our position is clear that it is possible for hydropower development to be feasible, even if there is a mandatory provision for 50 per cent ecological flow for six months of lean season. It is not too much to give for a flowing, living river. But I believe this issue raises bigger concerns. First, the question of how the potential of hydropower generation is arrived at. In this case, the Central Electricity Authority estimated hydropower potential way back in the late 1980s. This estimation did not take into account ecological flow, competing needs of society for water or indeed anything else. But any reduction in this "potential" is seen as a financial and energy loss. Any reduction is resisted. But what is not questioned is the very basis of the potential itself.

Second, there is the question of the cost of generation. Energy planners push for hydropower because they say the tariffs are low and this source provides power during peak demand hours. But they discount water used as raw material and the necessity of a flowing river.

Third, there is the question of making hydro energy sustainable. Currently, the way projects are being executed is disastrous. But if any project is stopped, states ask for compensation - as Uttarakhand is doing - for not destroying the environment. This sets a bad precedent since it induces states to degrade the environment recklessly or be paid to be good. But this also happens because there is no framework to establish the boundaries for resource use. It is necessary to establish sound principles for hydropower development - ecological flow and ideal distance between projects.

The fact is that rivers cannot and should not be re-engineered. But dams can certainly be re-engineered to adapt to these limits.