With people having to wash hands frequently in the light of the COVID-19 pandemic, two water experts have worked out estimates of the State’s water demand.
In the absence of any stipulation from authorities on the number of times one has to wash hands every day, the experts, P.M. Natarajan, former director, Centre for Climate Change, Periyar Maniammai University, Thanjavur, and V. Sivakumaran, former chief engineer, Chennai Metrowater, differ in this respect. Mr. Natarajan estimates the number of times as 15, whereas according to Mr. Sivakumaran, it is 10. Both accept that the duration of washing has to last 20 seconds.
In the former’s assessment, the water requirement will be 20 litres per capita per day (LPCD) whereas, in the estimate of the other, it will be 12 LPCD.
Both take the present population of the State as 8.2 crore, but differ again on how many people have to wash their hands. Mr. Natarajan’s calculation covers the entire estimated population, whereas Mr. Sivakumaran points out that only two-thirds of the State’s population may have to wash hands daily, leaving out elderly, children and the sick — this means around 5.5 crore people of the total of 8.2 crore. The former, by applying his yardstick, arrives at the figure of 1,640 million litres a day (MLD) as the State’s water demand, while the latter says it is 660 MLD.
N. Meenakshisundaram, water activist-engineer, said there was no shortage of water in the State, as there was enough availability of surface and groundwater.
As on date, the Mettur reservoir, the main source of water for irrigation and drinking water in a host of districts, has about 66 thousand million cubic feet (TMC) of water, against a capacity of 93.47 TMC.
At present, Chennai Metrowater’s treatment plants have the capacity of 1,494 MLD, and those of the Tamil Nadu Water Supply and Drainage Board, 2,146 MLD.
