WRD plans to study state’s dams for nat’l hydro project

Panaji: As part of the World Bank funded National Hydrology Project (NHP), the water resources department (WRD) plans to undertake a hydrographic and topographic survey of the Selaulim Irrigation Project and Anjunem Irrigation Project, officials of the state government said.
The $175 million project aims to assess India’s water situation and to create real-time flood forecast systems across the country.In line with this, WRD also plans to install automatic weather stations (AWS) and automatic rain gauge real time data acquisition systems at various locations across Goa, said a WRD engineer.
“Sedimentation is considered as a matter of vital concern. It not only occurs in the dead storage but also decreases the live storage capacity, therefore the problem of sedimentation needs clear understanding,” the engineer said while explaining the need for the hydrographic survey.
Dead or inactive storage refers to water in a dam that cannot be drained by gravity, while live storage refers to the water that authorities can release either for flood control or for consumption.
“This study is part of the dam improvement project,” said WRD chief engineer Sandeep Nadkarni.
According to WRD officials, deforestation, overgrazing and improper cultivation around the water catchment areas increases the silt in water bodies. The silt or sediment deposits settle in the dam and reduce the capacity of the reservoirs over time.
“An in-depth study of this problem with possible remedial measures such as engineering structures, afforestation and soil conservation in the catchment areas for each reservoir is of immense value,” the officer said.
WRD has yet to identify an agency or consultant to undertake the survey but is confident that once the work order is issued, the hydrographic and topographic survey report will be available in six months. “The survey shall be completed within three months and a draft report should be submitted by the agency by end of the fourth month. The entire report with all analysis should be submitted in six months,” said an executive engineer.
According to officials, the survey will be conducted using integrated hydrographic survey systems such as echo sounders and computer software which will record the depth of the water catchment area in real time with fixed GPS locations.
The Centre’s reservoir sedimentation committee recommends that all states should undertake capacity surveys of water reservoirs at regular intervals. This monsoon, several low-lying areas were inundated and villages downstream of the Tillari Irrigation Project also went under after the Tillari river and its tributaries overflowed. The gates of the Anjunem dam were also opened to release excess water brought on by the heavy rainfall.