Any report on Coimbatore's water condition has to include the reservoirs and rivers from which the city receives drinking water supply, the tanks in the city and then the ground water.
As far as the rivers – Bhavani and Aliyar – are concerned there is no pollution and the water is potable. At least this is what the Tamil Nadu Water and Drainage Board says. It extends the same credit to the quality of water in the Siruvani and Pilloor reservoirs.
To continue the good news, the ground water table has improved. It has gone up to such an extent that the level of increase has put Coimbatore second on the list of districts in the State that have seen an increase in water table.
Statistics from the Central Ground Water Board, a Government of India organisation, says that the water table in Coimbatore has gone up 13.92 m in the last 10 years. This puts Coimbatore next only to Namakkal, which tops the list with an increase in water level by 15.84 m.
Of the many measures the Board initiated to make this possible is authorising the non-government organisation, Siruthuli, establish rain water harvesting (RWH) structures across the city. Vanitha Mohan, Managing Trustee, Siruthuli, says the organisation, with financial assistance of Rs. 1 crore from the Board and cooperation from the district administration and Coimbatore Corporation, has created 215 such structures in the city. Eighty-five of those are roadside structures with concrete slabs and the rest are borewells.
The RWH structures have not only increased water table but also improved water quality, she says referring to a TWAD Board report.
This is true of all the RWH structures, adds R. Mylswami, Project Coordinator. In rural areas there is some cause for concern as far as the water table goes.
The sources there say that if the residents were to tap rainwater, thing will improve. A Siruthuli study in this regard says that 36,000 litres can be harvested in a year from terrace spread over 1,000 sq.ft., assuming that Coimbatore's average annual rainfall is 647 mm.
Moving over to the eight tanks, the situation is worrisome. Part of the Noyyal sub basin, the tanks' inlets convey only sewage, both domestic and industrial.
The result is that all the water parameters are way above the permissible limits, as documented in various studies, including Siruthuli's. Ms. Mohan says that all stake holders have to come together to stop inflow of sewage, remove water hyacinth from the tanks and give a fresh lease of life to the water bodies.
As if to answer her call, the Coimbatore Corporation has mooted a proposal to clean the tanks under the Phase II of the Jawaharlal Nehru National Urban Renewal Mission scheme. Sources in the civic body say that it will be a comprehensive scheme.