Siruvani dam, the prime water source for the city of Coimbatore has reached it's dead storage levels as the monsoons have failed to show up this year. Both the Northeast and Southwest monsoons have failed to deliver at least the minimum rainfall in the District of Coimbatore. While all prime water sources in the district are in the verge of drying up, the situation at Siruvani dam is no different.
Located on the Western Ghats to the west of Coimbatore, the dam holds a storage level of 15mts with a water storage area of 22.46 sq/km. Sources point out that if the dam is filled up to its capacity, we can draw water for 283 days at the rate of 10 crore litres of water per day.
However, for the past seven years, the water storage level at the Siruvani dam has drastically gone below allowing the dam to reach it's dead storage levels. The present storage at the dam has gone to 45cms. This summer the northeast monsoons did deliver only 40mm of rain, while last year the rains were up to 300mm in the catchment area.
According to the current level of water in this dam, only 2 more meters of water is permissible to be withdrawn from the dam, which would fulfill the city's requirement for another 25 to 30 days maximum, say sources.
About 12 crores litres of water gets accumulated in the 85-year-old check dam at the pumping station of the Siruvani dam. At the check dam which is 12 feet deep, there is no setup to draw the accumulated water. The water has to be pumped using a submersible pump and brought to the pumping station and then to the treatment plant. But Kerala government's permission needs to be obtained to pump the water which is lower than 15mts.
Permission to draw water from the old check dam was given only once by the Kerala government in the past years. Hence, the Tamil Nadu water distribution officials have requested in written to the Kerala PWD officials seeking permission to draw water from this dam.
With permissions still pending, the water if drawn could help us extend the 30 days period to 45 days enabling the city to receive water till 1st week of February, 2017. After that the dam would remain closed and according to reports in the last 15 years the average rainfall in the catchment area of the dam is less than 100mm.
An official from the TWAD board said, “3.9 crore litres of water is drawn from the dam daily for drinking purposes. Going forward, due to the diminishing storage capacity, the same withdrawal levels have to be altered accordingly. Inspection is been conducted on the feasibility of fixing a submersible pump in the dam. Efforts are made to manage the drinking water supply for two months”.