A legal framework to monitor dams

Just like a small leak can sink a ship, a small seepage or breaching can fail a huge dam if left unattended. Investigation reports of past dam failures in India point out that a majority of them had occurred due to breaching, overtopping, piping, slope failure or weak foundation as per the findings of the Central Water Committee (CWC).

The long-awaited Dam Safety Act-2021 has been enacted recently by the Government of India drawing out key safety actions for the owners of the dams. A legal and regulatory binding in the form of an Act was an urgent necessity since the country had already seen over 40 dam failures between 1917-2010 according to CWC.

Now the Dam Safety Act 2021 has set out a dedicated institutional system — Dam Safety Committee, Dam Safety Authority and organisation at the state and national levels. These are entrusted with the critical task of dam safety against disastrous situations arising from natural or man-induced causes.

It is now mandatory for these institutions to regularly prepare, mitigate and respond to any catastrophic situations in and around the dam structure to avoid losses to people and property along with downstream and upstream of reservoirs.

In the last three years, we have seen dams in Kerala, Karnataka and other states filling to the brim and overflowing with excess water due to heavy rains in a short span. It may be distressing to note that about 15 districts in Karnataka are going to experience high-intensity rainfall (above 100mm) in the coming days as per the report by KSNDMC which will lead to excess water stress on the dams in addition to heavy floods.

Failure of dams may simply occur sometimes due to overtopping of excess water. Consequent uncontrolled sudden releases from the dams have resulted in severe floods in downstream areas. Just in a span of 3 months between June-August in 2018, Harangi, KRS, Kabini and Hemavathy dams in the Cauvery basin reported an increase of 141% of the average annual flow. For instance, the KRS dam with a maximum inflow of 1.33 lakh cusecs on August 18, 2018, is the highest inflow in the history of the reservoir.

Similarly, Almatti and Narayanpur dams are confronted with even more challenging situations. We must know that 59% of the land area of India and 22% of Karnataka come under earthquake vulnerability. Authorities must now start comprehensive dam safety evaluation for each specified dam in their jurisdiction and re-examine if dams are resilient and need some more re-strengthening measures to resist earthquakes, floods or any hazards.

This Act signals a forewarning to the state and dam authorities to start preparing for better dam failure risk assessment, mitigation and emergency response systems. KRS dam was in the news for reporting some minor seepages and erosion recently. For centuries, dams have been serving the basic needs of irrigation, electricity and water supply needs of the rural and urban populations. They have the capacity to store and hold large quantities of water which helps in mitigating frequent floods and drought. Also, dams will turn out to be disastrous in case of failure.

The Dam Safety Act-2021 starts with a preamble stating constant surveillance, inspection, operation and maintenance of all specified dams for prevention of dam failure related to disasters to ensure their safe functioning.

From now onwards, the dam owners must make available the information relating to maximum anticipated inflows and outflows including flood warning and an adverse impact of the same to the population upstream or downstream of the dam, to the concerned district authorities and public.

Dam owners must also set out procedures to be followed for the protection of persons and property in the event of an impending dam failure. An Emergency Action Plan reinforced with technology, skilled responders, equipment and India Disaster Resource Network (IDRN) for each specified dam is the need of the hour.

The Dam Safety Act -2021 provides the much-needed legal regime to the Union and state governments — owners of dams — to make dam safety rules and regulations for implementation.

(The writer heads the Centre for Disaster Management, Administrative Training Institute, Mysuru)