Low rainfall keeps most Pazhassi reservoir shutters closed

Low rainfall has forced authorities to close most of the shutters opened at the Pazhassi Irrigation Project after inflow into the reservoir declined sharply, raising concerns over drinking water availability in Kannur district.

On Thursday (June 18), two shutters were opened temporarily following light rainfall in the catchment areas on Wednesday night (June 17), while all other shutters remained closed. Officials said rainfall in the catchment areas between June 1 and June 18 was nearly 50% lower than during the corresponding period in previous years.

The decision was taken as the reservoir’s water level fell significantly despite the onset of the southwest monsoon. Authorities have resumed water storage to safeguard drinking water supplies. Officials noted that this is the first time in the project’s history that inflow has remained so low even after mid-June.

Six of the project’s 16 shutters were opened on June 4 after warnings were issued to residents living along the Valapattanam river basin. The move was intended to release water stored during the summer into the river as part of monsoon safety measures. However, the catchment areas have received very little rainfall since the onset of the monsoon.

According to a senior official at the Pazhassi Irrigation Project, 24.7 cm of rainfall has been recorded between June 1 and June 18 this year, compared to 54.92 cm during the same period last year. Officials said the reservoir level stood at 21.02 metres when the shutters were initially opened. The Pazhassi reservoir supplies drinking water to nearly two-thirds of Kannur district and Mahe through 10 drinking water schemes operating from the reservoir.

Officials said water can be pumped only if the reservoir level remains above 18 metres. With rainfall remaining deficient and the water level approaching the critical mark, the shutters were closed and water conservation measures initiated. When the shutters were closed on Tuesday morning (June 16), the water level was around 18 metres. Even after a full day of storage, the level rose only to 18.75 metres by Wednesday morning.

However, rainfall received on Wednesday night increased the water level to 21 metres, prompting officials to open only two shutters of the dam. Under normal monsoon conditions, the reservoir is expected to reach its full storage level of 26.52 metres within a short period after the onset of rains.

The situation has revived memories of 2011, when a delay in opening the shutters at the start of the monsoon resulted in the reservoir overflowing within a day, inundating parts of Iritty town and nearby residential areas and causing losses worth several crores. Since then, the authorities have routinely opened one or two shutters whenever heavy rainfall warnings are issued to release excess water into the Valapattanam river.

The region has experienced intense heat over the past few days, with even isolated showers largely absent from the reservoir’s catchment areas. The reservoir depends mainly on inflows from the Barapole River, the Bavali River, and several smaller streams. Rainfall has also been below normal in the Brahmagiri forest region near Makkoottam, a key source area for the Barapole River.

Officials and residents are closely monitoring the situation, as a continued rainfall deficit could affect drinking water availability in the coming weeks.