The eight western districts have received an above average rainfall from south west monsoon. With the predictions showing a positive sign for the north east monsoon, the farmers and urban water managers can heave a sigh of relief.
In the past, there had been years when the region received below average rainfall during the south west monsoon that just exited. Though Pilloor reservoir, that caters to drinking water needs had surplussed more than once this year, this did not happen in Siruvani, that serves Coimbatore city, despite the rains as Kerala was maintaining the storage below the FRL.
For the second consecutive year, Coimbatore district received excess rainfall during the season from June to September. It has received 269 mm as against the season’s average of 195 mm. And, most of the 269 mm has come in September, says S.P. Ramanathan, head, Agro Climate Research Centre at the Tamil Nadu Agricultural University.
The district has received over 115mm this September as against the months’ average of 70.7mm. Last year, the district received 308.1mm. And, August 2019 alone brought in 221.3mm and that too in seven rainy days, he says. A day with over 2.5 mm precipitation is accounted for as a rainy day. Meanwhile, the north east monsoon prediction for Coimbatore is again good in that the Centre has said that there may be 318mm rainfall from October to December as against the average of 343.8mm.
According to the District Agro-Meteorology Unit under the Krishi Vigyan Kendra in Salem, Salem will receive an average rainfall of 359 mm during north east monsoon and average rainfall of 351 mm is expected during the monsoon here. During south west monsoon which started in June, an average rainfall of 386.5 mm was recorded till September 24. Namakkal district has received 49 mm excess of average rainfall expected during south west monsoon. According to officials, 340 mm rainfall is expected during the south west monsoon
On Friday, the water level at Mettur dam was 99.62 ft against a total scale of 120ft. The stored capacity of water in the dam was 64,340 mcft and the dam received an inflow of 35,000 cusecs of water. The discharge through Cauvery river was 20,000 cusecs of water and 850 cusecs of water was discharged through East-West canal.
However this year, the South West monsoons brought in 420.38mm of rainfall, in Krishnagiri as compared to the last year’s rainfall of 345.49mm rainfall, way above the annual average. The KRP dam with its storage capacity of 52 feeet has a current water level of 41 feet. Kelavarapalli dam in Hosur with its total storage capacity of 44.28 ft has a current water level of 39.36 ft.
For the second consecutive year, the south west monsoon in the Nilgiris brought intense showers. Scientists from the Indian Institute of Soil and Water Conservation (ICAR-IISWC) in Udhagamandalam, said that there had been “deficient” rainfall during the month of July in both 2019 and 2020 - that is 40 - 60% lesser than the average.
They added that these relatively drier months were followed up by higher quantities of rain over shorter spells of time over the last two years, increasing the chances of landslips and flooding events.The dams in the district are almost at full capacity due to the rains in the district during August and September of this year. According to the Tamil Nadu Generation and Distribution Corporation (TANGEDCO), most of the dams are above 90% of their total storage capacity.
Southwest Monsoon in Erode district during July and September was normal as most of the areas received rainfall this year. Officials at the Meteorological Department at the Collectorate said that the normal rainfall is 212 mm for the district and so far the district received 217 mm.
Due to rains in the catchment areas, the major reservoir in the district, Bhavani Sagar, received copious water in the past two weeks as water level is inching towards 102 feet. On Friday, water level at the reservoir stood at 101.92 feet against the full reservoir level of 105 feet.
(With inputs from Karthik Madhavan in Coimbatore, Rohan Premkumar in Udhagamandalam, S.P. Saravanan in Erode, Vignesh Vijayakumar in Salem and P.V. Srividya in Krishnagiri)