‘Have identified water source to tide over deficit’

Over the last three years, the city had recorded its lowest rainfall of 5.05 cm between October and November 2016. The total amount of rainfall for the period was 33 cm of which, over 27 cm of rainfall was received in the month of December and ended thedry spell. While in 2017, the city had recorded over 61.79 cm of rainfall during October and November. In 2015, the city had received 104.93 cm during the same period.

The northeast monsoon (NEM) 2016 was the worst deficient at — 62 per cent in the last 140 years. NEM 2017 under neutral conditions witnessed normal rainfall.

A study by weather bloggers of Chennaiyil Oru Mazhaikalam notes that the average northeast monsoon rainfall reduced to 59 cm during the six years when it set in between November 1 and November 5, since 1901.

An official attached to the PWD said, “We can expect a few bouts of spells in the month of December. Otherwise, we have identified sufficientwater resources in and around the city to supply adequate water.”

According to the available data, the three city reservoirs namely Chembarambakkam, Poondi and Cholavaram currently have less than 15 percent storage against its Full Dam Level. As on Saturday, the water level in Chembarabakkam reservoir was merely 0.21 TMC against its Full Level Storage capacity of 3.65 TMC. It was merely 6 per cent of storage against its total capacity. Similarly, the Poondi reservoir had merely 0.38 TMC of water level against its total storage capacity of 3.23 TMC, which was only 12 per cent of its total storage.

The water level in the third reservoir was 0.04 TMC against its storage capacity of 1.08 TMC, tallying only four percent of its total capacity.

For the same corresponding period, the percentage of storage against Full Dam Level (FDL) of Chembarambakkam, Poondi and Cholavaram was 38 per cent, 31 per cent and 56 percent respectively in 2017.

The dams in the other districts including the Upper Aliyar, Aliyar, Parambikulam and Amaravathi maintained over 90 percent of its current water level against the Full Dam Level.