The Sciences

Why It's Time to Reengineer Our Dams

A belief that the safety of reservoirs can’t be assured because of unknown factors emanates from a flawed presumption that not all lives are equal and that some sacrifice is essential for the progress of a country.

Governments are not the only entities responsible for undertaking irrigation projects, although they might be the most accountable. The modicum of trust placed on the promoters of big dams is often loaded with compromises on the design, management, honesty of conduct and awareness of risks to downstream areas likely to be affected during heavy flooding. Power generation, irrigation and piped water supply remain the limited  objectives of dams while flood management and ensuring ecological flow in river beds have been almost completely sidelined.

Environmental degradation is recognised as a small price to pay for economic growth and changes in the microclimate, impact to human lives, habitation, infrastructure and health are thought of as growing pains for larger gains. Governments continue to abuse knowledge-based institutions to compose favourable reports on environmental, social, rehabilitation safeguard norms and so clear various projects. The technical incompetence of regulatory agencies has become a matter of global ridicule.

The Dam Safety Bill of 2018 has been drafted to address technical issues linked to physical deformation and deterioration. However, it is completely insensitive to flood safety following the release of water from major reservoirs.

Hostility to climate change projections led by the US has strengthened many Indian states to come out strongly against the negative impacts, to effectively bulldoze their way through new project approvals. Telangana, Andhra Pradesh and Karnataka have gone overboard with their contempt for climate risks, the environment and safety, in a way that it appears the tragedies in Kerala and Uttarakhand have taught them nothing.

Given the existence of a strong dam-construction lobby, the political significance of the cement and steel structures that prop up these structures is obvious. Opposition to new dams and the decommissioning of older ones is fought tooth and nail by all political groups. In light of this, we should consider reengineering ageing dams as well as make the designs for new ones more inclusive.

Building a new paradigm

This entails that new reservoirs should be transparent in their operations, provide dedicated flow channels for routing floodwater, protect against catchment degradation, minimise siltation and offer assured irrigation and a drinking water supply.

Data linked to design and risks should be made accessible all stakeholders. Reservoir management should be automated using monitoring networks, flow models and robotic mechanisms linked to spillway operations. Advances in solar power generation could help engineers hybridise power generation using photovoltaics with hydel.

The major outcomes would be to create linked navigation programmes to service all stakeholders, enhance dam safety to incorporate risks linked to flooding, associate catchment protection with carbon sequestration as an economic activity, improve water-use efficiency in agriculture through conjunctive use and rainfed irrigation.

For puritanical thinkers, such an enlarged objective might appear too unwieldy, but the events of Kerala in 2018 and Uttarakhand in 2013 make it inevitable. Reengineering older dams will help create a new experience of the benefits of reservoirs based on what we’ve learnt from our failures.

Extreme weather events threaten dams and reservoirs and need to be actively dealt with. Carbon funding could be adopted to manage and restore degraded catchments, thus the serving dual purpose of catchment protection and carbon sequestration. The government will have to accord suitable land classification norms for protection against deforestation, and treat these areas as bio-reserves. The focal should be on reviving biomass without exposing the soil. No major construction, mining and any other soil-damaging activities should be allowed in these areas. All investments related to this exercise will need to be routed through a carbon-credit mechanism without stressing the exchequer.

When trees capture rainfall, they help prevent flash floods, moderate runoffs, limit soil erosion, enhance infiltration, increasing groundwater recharge and help regulate the local climate. The water is forced to flow through the soil instead of over it, making it more porous and contributing to the formation of a thick carpet of organic matter that can capture more carbon. Such a mix of forestry options in the catchment could significantly alter the inflow of water into the reservoir over an extended period.

Carbon capture and storage becomes ecologically relevant at the local level by protecting against siltation, landslides and flash floods. The captured carbon dioxide can be stored in the soil and other geological formations. Carbon capture can also be monetised as carbon credits.

Automating reservoirs

When reservoirs are operated based on personal judgements and are influenced by political opinions, and not fully supported by data, disasters result. As a bulwark against such decisions, reservoirs can be managed with the aid of a bouquet of technologies: automatic water-level recordings, satellite imagery, computer models and AI. Together, and by streamlining data obtained from areas upstream, downstream and around the reservoir, they can control spillway and canal operations, document all the processes and, crucially, inform better decisions.

It is important to acknowledge here that the technical landscape of hydrology, irrigation and ecology management is expanding at a pace much faster than what a small group of engineers can keep up with. At the same time, computers shouldn’t replace humans altogether; the relationship should be symbiotic. Automation allows engineers to operate several sections of a reservoir simultaneously without also inducing major manpower and skill constraints. Finally, lawmakers shouldn’t shy away incurring the additional expense because the impact on operational efficiency, water-saving, productivity, flood management and response to various environmental apprehensions will be worth it.

Any dam safety protocol should protect dams against all physical dangers, flooding and other accidents. The success of a protocol can be measured by its success in adopting practices that assure faith in the structure, its operations and how it responds in an emergency without disrupting life. Any other definition of safety can’t and shouldn’t be acceptable.

Sadly, however, the current thinking appears to be that the safety of dams and reservoirs can’t be assured because of unknown factors. This belief emanates from the presumption that not all lives are equal and that some sacrifice is essential for the progress of a country, even if it means loss of life.

Such an impression, carried by the Dam Safety Bill 2018, only gives more freedom to technocrats and planners to play with livelihood, property and life. This needs closer scrutiny and revision. There should be more accountability but there should also be a built-in insurance component. Disaster risk insurance schemes need to be identified and the costs integrated into infrastructure expenses. Further, these provisions will have to be reviewed every decade.

K.A.S. Mani is a groundwater engineer.

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