The year that just passed by, 2020, has been a year that gave Coimbatore less than the normal rainfall.
Data available with the Agro Climate Research Centre at the Tamil Nadu Agricultural University shows that as against the annual average of 674 mm, the district had received 638 mm rainfall.
But there is a positive point to be noted in the rainfall received in 2020, says the centre head Prof. S.P. Ramanathan and points out that the number of rainy days in 2020 was 52.
The average number of rainy days is 46. A day that sees over 2.5 mm precipitation is accounted for as a rainy day.
Of the four rainy seasons – winter, summer, south-west and north-east – the district had received excess rainfall in only two seasons – summer and south-west. During the summer season that covers March, April and May, the district received 170.5 mm in nine rainy days.
The average rainfall for the season is 136 mm and nine rainy days.
In the south-west monsoon season that extends from June to September, the district had received 296 mm in 26 rainy days. The average for the season is 210 mm and 16 rainy days.
The deficit was in winter and north-east monsoon seasons, says Mr. Ramanathan and points out that the shortfall in the latter is to be noted as the north-east monsoon season brings the maximum rainfall for the district.
As against the average rainfall of 305 mm for the season that covers October, November and December, the district had received 171 mm in 17 rainy days. And, in the winter season that covers January and February, the district had received 0.5 mm as against the average, 23 mm.
Compared to 2019, the district had received less rainfall. The year 2019 gave surplus rainfall in that the annual rainfall stood at 859 mm with the north-east monsoon alone accounting for 450 mm in 27 rainy days.
October 2019, in particular, was good because the district had received 246.9 mm, he adds.
The water level in the Siruvani Reservoir remains a cause for concern, say sources in the Corporation. As of January 2021, the water level is 38.8 feet. The full reservoir level is 49.5 feet.
The Kerala Government is maintaining water level at less than the promised level, they point out and recall that it had promised to maintain the water level at five feet less than the full reservoir level – around 44.5 feet.
A deficit of 5.7 feet from the promised level and 10.7 feet from the full reservoir level will leave the city with very little Siruvani water in the coming months, they add.
