While many initiatives were carried out in Pune to mark the World Environment Day on June 5, the reducing water holding capacity of the city’s dams due to the deposition of silt needs to be paid attention to also.

Out of the four dams - Khadakwasla, Temghar, Panshet and Varasgaon - the first three are prone to silting. Silting is the process in which sand gets deposited at the base of the dam and it has already reduced the water holding capacity of Khadakwasla dam to half.

Reduction in capacity of damsSpeaking with iamin, Environmentalist Colonel (Retired) Suresh Patil said that he with his NGO Green Thumbs have been working on desilting of Khadakwasla since 2012 with the help of few corporates and other socially aware groups. Although over 1 lakh truck loads of silt has been removed from the dam, a lot still remains to be done.

"At the time of construction, the Khadakwasla dam had a capacity to hold 4 thousand million cubic feet (TMC) of water. Currently, due to deposition of sand at the base of the dam, nearly 2 TMC storage capacity has been exhausted," said Patil.

Khadakwasla which had 4 TMC storage capacity and supplied water to 80,000 Punekars when it was constructed, is now left with 2 TMC water storage capacity for a population that has grown by leaps and bounds.

Experts blame deforestation

Explaining the reason for the silting, Patil added, "Deforestration is the main reason why the sand loosens up and gets deposited at the base of the dam. This is a common phenomenon but its impact is now evident as desilting was not carried out on time." Over time the area around the dam has lost its green cover leading to a rise in the rate of silting. "This is one reason why only desilting is not the solution to the problem. We need to increase plantation around the dams and not only plant saplings but also see to it that they grow well," he said.

Increasing water shortage is also a reason for the civic authorities to concentrate on desilting all the four dams. An estimated 2 TMC water storage and supply capacity of the four dams could be increased if city and state water department, forest department and agriculture department work together to solve the problem. "The silt removed can be given to farmers as it is natural manure. Desilting increases water capacity as well as gives free natural manure to farmers and yet not much is done about it," said Patil.

While Patil works on Khadakwasla alone, he stressed that the other three dams should also be focused on to increase the water holding capacity.

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