CHENNAI/ THANJAVUR: Tamil Nadu is facing a severe water crisis as 4,208 of its 14,141 water tanks have completely dried up. Failure of southwest monsoon and record summer heat have depleted water resources across the state. The situation is particularly alarming in delta districts, considered the rice bowl of the state, where 95% of the 764 tanks hold nearly nil water as the Mettur Dam was not opened on the scheduled date of June 12 due to delay in release of Cauvery water by Karnataka.
According to Water Resources Department (WRD) officials, as many as 5,814 tanks across the state have only 1% to 25% of their storage, while the overall storage condition of over 10,000 tanks is extremely poor. Madurai has recorded the highest number of dry tanks in the state, as 1,123 out of the 1,340 tanks in the district have no water.
The Cauvery delta districts — Thanjavur, Tiruvarur, Nagapattinam, Mayiladuthurai and Pudukkottai — have a total of 737 system tanks maintained by the WRD, of which, 694 get water from Grand Anicut canal, 41 from Vennaru river and two from Cauvery. Thanjavur district has the highest number of such tanks (537), followed by Pudukkottai (170) and Tiruvarur (28). Besides, there are 27 non-system tanks in the region.
Dry lakes in Thanjavur district have caused groundwater levels to plummet, disrupting Kuruvai crop irrigation. Farmers are facing severe additional financial strain because of the need to deepen the borewells to save their crops. Additionally, dried waterbodies force owners to herd their cattle to distant areas just to find drinking water for their livestock.
Nil storage level in 720 out of 764 tanks in delta dists
According to WRD officials, as on August 7, out of the 764 tanks, the water level in 720 tanks was categorised as dead or nil storage. In comparison, the water level was nil only in 24 tanks on the same date last year. At present, no tank has water storage of 50% or more. The storage is between 25% and 50% in one tank, and as many as 43 tanks have less than 25% storage.
Accordingly, the total water storage in the 764 tanks this year is 0.176 tmcft, which is 2.62% of the total capacity of 6.7 tmcft. In addition to the poor water flow in rivers, deficient rainfall in July also contributed to less water in lakes, said officials. It may be noted that while the average rainfall for July in Thanjavur is 56 mm, this year only 12 mm of rainfall was recorded in the district. In the first week of August, the average rainfall recorded in Thanjavur was 12.35 mm against the month’s normal average of 99 mm.
As most of these tanks are in the tail-end areas, the water stored is used for paddy cultivation, especially during samba season, and for recharging groundwater. However, farmers in the area stretching from Pattukkottai to Sethubavachathiram said they are seeing a considerable fall in the groundwater level. “Many farmers are now deepening their borewells as the groundwater level has gone down from 180 ft to 210 ft in many villages,” said KA Koothalingam, a farmer from Pallathur.
A senior WRD official told TNIE, “The poor storage has added to concerns over meeting drinking water requirements, besides supporting irrigation and industrial needs. The WRD has been exploring ways to convert select tanks into reservoirs and the department has already converted some through channels in Chennai and its suburbs. Officials are now considering the possibility of adopting a similar model in suitable locations in other districts.”