There is a need to reverse this trend: member of task force
The Task Force for Quality Assurance in Public Constructions has expressed concern over the high rate of siltation in major reservoirs in the State and its impact on meeting the water requirements of farmers in the command area.
G.C. Tallur, member of the task force and a former Secretary of the Public Works Department, said on Saturday that there was a need to reverse the trend.
He was delivering a lecture on “Siltation of reservoirs of Karnataka', at a seminar on “Ensuring quality in public constructions and the need to adopt latest technologies to improve the quality of constructions”, here.
Mr. Tallur said that the Government had carried out hydrographic survey in seven major reservoirs to know the exact amount ofsilt accumulation and the results were shocking.
The survey was carried out in Tungabhadra, Malaprabha, Bhadra, K.R. Sagar, Narayanpur, Alamatti and Hippargi reservoirs, and the situation was bad in Tungabhadra, Narayanpur, Malaprabha and Alamatti.
In Tungabhadra, the loss of storage capacity owing to siltation was 28 tmcft. against the designed storage capacity of 132 tmcft.
In Narayanpur dam, against the 38 tmcft storage capacity, the loss of space in the reservoir due to siltation was 10 tmcft. Similarly, even in the relatively new project Alamatti, the storage capacity had come down by 5 tmcft from 123 tmcft to 118 tmcft. In Malaprabha, the storage capacity came down from 44 tmcft to 41 tmcft. Mr. Tallur said the total loss of storage capacity in these seven reservoirs owing to siltation was 49.1 tmcft. The situation was bad in the reservoirs including Chakra, Lingasugur, Supa, and Kodasalli used for generating power.
The loss of storage capacity in Supa was 28.98 per cent, in Lingasugur it was 3.87 per cent, and in Chakra and Kodasalli, it was 4.34 per cent and 1.17 per cent respectively. The total loss in the four reservoirs used for power generation was 1287.77 million cubic metres.
Apart from this, Mr. Tallur said, the details of silting in eight major and 32 medium irrigation projects, which were completed long ago and where the hydrographic survey was not conducted, was not known. The siltation status of the ongoing 19 major and 21 medium irrigation projects were also not known.
He said the Government should take immediate steps to arrest the flow of silt into the reservoirs by enacting the Catchment Areas and Development Act on the lines of the Command Area Development Act and Karnataka Rivers Streams and Tank Bed Authority Act to protect the river beds from ingression.