Idukki Dam, in India's Kerala state. Photo: Sivaram V. / Reuters

By Euan Rocha, Rajendra Jadhav, and Promit Mukherjee; Editing by Alex Richardson
10 October 2018
KOCHI/MUMBAI (Reuters) – Joby Pathrose, a farmer living a kilometre away from the usually languid Periyar river in southern India, was woken in the night by the sound of rushing waters.
Hours later his plantations and everything he owned were completely submerged.
“There was absolutely no warning from the government side,” said Pathrose, describing the devastating flooding that hit his village of Okkal, in Kerala state, on 15 August 2018.
Pathrose says local authorities had advised his fields were safe, despite the incessant rains that battered Kerala at the peak of the monsoon.
More than 5mn people in Kerala were affected and over 200 were killed amid torrential rain and floods in August.
The flooding, dubbed the worst to hit the southern state in nearly a century, caused billions of dollars of damage to fields, homes and other infrastructure.
As the rain intensified in mid-August state authorities were forced to release water from 35 dams to manage rising waters in reservoirs, many of which are used to generate hydroelectricity.
Pathrose and others living near the Periyar say the sudden opening of dam gates without proper warnings to those living downstream was a big factor in the devastation.
More than half a dozen experts whom Reuters consulted were divided on the extent to which dam water spills contributed to the flooding, but almost all, including India’s Central Water Commission (CWC), said reservoirs levels were too high ahead of the disaster.

Water levels for three reservoirs in India's Kerala state in 2017 and 2018. Monsoon rains in 2018 filled the reservoirs to capacity, forcing spillways to be opened and causing massive flooding downstream. Graphic: ReutersHow Kerala’s dams failed to prevent catastrophe

“Because of this carelessness the disaster proportions were multiplied,” said Himanshu Thakkar, co-ordinator of the South Asia Network of Dams, Rivers and People (SANDRP), a non-governmental body that advocates for better water management practices.
The release of dam water, sharply criticised by some water management experts, has put a focus on reservoir operations and the need for better flood mapping and warning systems in India.
State government officials say the severity of the flooding was due to a once-in-a-century storm that could not reasonably have been prepared for, and that the spilling of dam water had little impact.
Reuters has learned the two largest reservoirs in Kerala — Idukki and Idamalayar — have been operating for years without any emergency action plans — a basic requirement for major dams worldwide. […]“One of the key advantages of a dam is it can help moderate floods,” said SANDRP’s Thakkar, an engineering graduate from the elite Indian Institute of Technology (IIT) Mumbai. “That didn’t happen as Kerala’s dams were already full by end-July. Dams aren’t supposed to be full before the end of the monsoons.”  [more]

Did Kerala’s dams exacerbate India’s once-in-century floods?