By Haresh Jhala
Gandhinagar, Aug 28 (SocialNews.XYZ) Sedimentation or silting is becoming an issue in the water reservoirs of Gujarat. In small dams it is a serious issue and in big dams too it has started having an effect; because of silting the water storage capacity is reducing at an average rate of 0.281 percent to 1 percent annually.
Environmentalists are now demanding that desilting be carried out in the reservoirs to restore their gross or live water storage capacity.
Citing the Central Water Commission's 2021 report, environmentalist Mahesh Pandya has shared data about the reducing capacity of a few reservoirs. Giving the example of Shetrunji Dam, he said, "The dam was completed in 1959, then it's gross storage capacity was 415.41 Million Cubic Meter (MCM), it's total loss upto the last survey was 81.22 MCM, on an average annually 0.38 percent water storage capacity is reducing."
Ukai Dam was commissioned in 1972, its live storage capacity was 7092.5 MCM. In the 2020 study the live storage capacity was recorded at 6256.055 MCM, meaning in 48 years, its live storage capacity loss is 836 MCM.
The Kadana Dam has lost 288.01 MCM live storage capacity in 43 years. When the dam was completed in 1977, its live storage capacity was 1203 MCM, in 2020 its capacity had dropped to 914.99 MCM.
Pandya has demanded that the state government should carry out dredging in the upper stream of dams. If silting reaches a level where desilting becomes unviable it will defeat the purpose of the dam. Not only that, there will be frequent floods downstream, water will not flow in the river for the entire year, and it will damage the ecology and fishing activities downstream of the dam.
Not only the Central Water Commission, even the state Water Resources Department is closely monitoring the situation and conducting surveys of the dams to check the gross and live storage capacity, said K A Patel, Secretary in the Water Resources Department.
Out of 204 small, medium and big dams, 38 dams' surveys have been completed and the results are available with the department. The survey of other dams is underway. The results of the survey do hint at increasing silting, but it is not yet at an alarming stage, feel officers.
According to Patel, dredging is not a solution because it is very costly and there is no guarantee of a hundred percent result.
Normally the average life of a dam is from 100 to 150 years.