Water Board dredges NS dam for city needs
For the first time, a massive dredging operation is being undertaken at the Nagarjunasagar Dam by the Hyderabad Metropoliton Water Board.
The purpose is to go deeper into the reservoir to lift dead storage water in order to meet the drinking water demand of Hyderabad city. With the successful completion of this dredging, water supply to the city will remain undisturbed for the next five months.
From the time since the three-phased Hyderabad drinking water supply scheme was launched in the year 1991, dredging into the reservoir has gone this deep, touching 500. 7 ft. The dredging operation that is costing the Water Board `5 crore, will be completed within the next 10 days. After the dredging operation, water can be drawn from 490 ft depth of the reservoir.
“Hyderabad requires 270 million gallons per day (540 cusecs) drinking water from Nagarjunasagar. This translates to 1.5 tmc ft per month. With dredging operations we may go till 490 ft where the estimated availability is 10 tmc ft of water. This way we are assured uninterrupted supply of water for the next five months”, said Water Board MD Dana Kishore.
Dredging operations involves an engineering expertise where a huge proclainer is installed on a structure and another JCB is used to balance the whole contraption and undertake the massive digging.
A nearly 1 km stretch is dug from the point where water is available in the reservoir to the already existing approach channel that connects the reservoir to Puttamgandi.
This is the point from where water will be transported to the Akkampally Balancing Reservoir.
A 12-metre wide and 7 metre deep approach channel will ensure smooth drawing of water from NS Dam. “If we get inflows from Srisailam soon, there will be a rise in the reservoir level which will be good. But even if there are no inflows, city’s drinking water supplies will remain unaffected. We had never imagined that NS dam level would reach 500 ftlevel which is 10 feet below the Minimum Draw Down Level” said Water Board director (revenues) K. Vijayakumar Reddy.