Kerala hydel reservoirs gain 13% storage in a week, but remain well below last year's levels

Pathanamthitta, Kerala: Water storage in Kerala's hydel reservoirs has increased by 13 percentage points over the past week following heavy rainfall, with reservoir levels rising by 4–5 percentage points a day during the wettest spell. However, as rainfall has weakened, inflows have slowed, and storage has increased by only about one percentage point per day over the past two days.

Despite the recent gains, the reservoirs are collectively only 48% full, around 35 percentage points lower than the corresponding period last year, raising concerns for the Kerala State Electricity Board (KSEB).

KSEB officials said the peak reservoir-filling season has nearly passed, and only steady, widespread rainfall over an extended period, not isolated heavy downpours, can significantly improve storage levels.

At the current storage level, the reservoirs can generate only 1,987.779 million units (MU) of electricity, compared with 3,154.478 MU that could have been generated on the same date last year.

This is typically the period when KSEB's hydel projects produce the highest amount of electricity. On Thursday, the state's hydel stations generated 22.834 MU, compared with 42.30 MU on the corresponding day in 2025.

Kerala's largest hydel project, Idukki, is currently at 46% storage, while the second-largest, Sabarigiri, stands at 53%. Rainfall recorded in the catchment areas until Thursday morning was 18.8 mm in Idukki and 43 mm in Sabarigiri. Storage levels in Sholayar and Idamalayar are 52% and 51%, respectively, while Kundala stands at 35%.

Although water levels have improved in smaller hydel projects, their contribution to electricity generation is limited. KSEB officials said long-term power generation depends mainly on adequate storage in the Idukki and Sabarigiri reservoirs.