PUNE: Major reservoirs in India have filled up to 165% of the 10 year average, which requires deft management of water tanks. Any lapse could lead to large-scale flooding during the monsoon season, which is expected to have normal rain this year, experts said.

"We have 165% water level in the 123 dams monitored by the Central Water Commission(CWC), while the IMD has forecast a normal monsoon,” said Himanshu Thakkar, coordinator at South Asian Network of Dams, Rivers and People (SANDRP).

If the reservoir filling up process is not managed properly, it can lead to reservoir-induced floods. In fact, the cyclone Amphan can also pour lot of rainfall in West Bengal and Odisha."

Central Water Commission monitors live storage status of 123 reservoirs of the country on weekly basis, which account for about 66% of the total live storage capacity of the country.

Thus, the live storage available in 123 reservoirs is 168% of the live storage of corresponding period of last year and 165% of storage of average of last 10 years.

States having better storage than last year for corresponding period are Rajasthan, Jharkhand, Odisha, West Bengal, Gujarat, Maharashtra, Uttar Pradesh, Uttarakhand, Madhya Pradesh, Chhattisgarh, Andhra Pradesh, Telangana, Karnataka, Kerala and Tamil Nadu. Some big projects like Sardar Sarovar has 175% of normal storage while Iddukki has 168% of normal storage.

States having better storage than last year for corresponding period are Rajasthan, Jharkhand, Odisha, West Bengal, Gujarat, Maharashtra, Uttar Pradesh, Uttarakhand, Madhya Pradesh, Chhattisgarh, Andhra Pradesh, Telangana, Karnataka, Kerala and Tamil Nadu. Some big projects like Sardar Sarovar has 175% of normal storage while Iddukki has 168% of normal storage.

High water levels in dams just before the onset of the monsoon is likely to pose a big problem for dam management authorities. The high level of snowfall in the Himalayas is also expected to cause problem for rivers in north India.

"The Bhakra Beas Management Board (BBMB) has already warned about the high level of snowfall in the catchment areas, which when melts during summer and the monsoon season can create floods," said Thakkar.

There are reports that 12 generators on Idukki are not functional, which reduces release of water for power generation. High water levels in Idukki dam just before monsoon are not good as the dam does not have spillway," said Thakkar.

Floods induced by discharges from the Idukki had caused havoc in Kerala in 2018 and also in 2019. Similarly, high reservoir levels in Koyana dam in Maharashtra had led to massive floods in Maharashtra and Karnataka in 2019.