COIMBATORE: NGO Kousika Neer Karanngal focusing on conserving water bodies in Coimbatore has successfully constructed a skin wall for surplus weir of Agraharasamakulam tank, which was found to be weak. The NGO also urged authorities to build similar skin walls while desilting water bodies to ensure safer water retention in the future.
The Agraharasamakulam tank receives water from the Outlet Management System (OMS) of Avinashi-Athikkadavu Groundwater Recharge scheme and other natural resources, which is one of the major water storage tanks along the Kousika river belt.
"The surplus weir of the tank, which holds 400 million litres of water, was found to be dangerously weak last year. Since it is a load-bearing structure, it may not be able to withstand hydrological pressure from water storage. Hence, we decided to construct a skin wall for the weir. With the support of Water Resources Department and experts from Public Works Department, we designed and constructed the skin wall with the help of private sponsors," said PK Selvaraj, Founder of Kousika Neer Karanngal.
"The wall was constructed alongside the existing weir by strengthening bunds on either side, ranging from three to 25 feet. The foundation of the skin wall was laid up to six feet beneath the existing structure, which effectively doubles the water holding capacity of the weir and allows it to manage excess load. The entire project was completed within a month," Selvaraj added.
Following completion of work at Agraharasamakulam tank, he mentioned that they are now focusing on two more tanks at Devampalayam and Vaiyampalayam, which benefit from resources associated with the Kousika River. He noted that weirs of these tanks are also weak and construction of skin walls could protect them from further damage.
Selvaraj said that building a skin wall is essential for weirs with seepage or have outlets located in load-bearing areas. "Skin walls can double the strength of weirs, preventing breaches and protecting water bodies. He called for these constructions to be part of the desilting process before the onset of monsoon," he said.
Additionally, he urged the district administration to examine all water bodies and assess durability of their weirs, recommending that they initiate the construction of skin walls when required.