A Dam Safety Authority team led by KSEB chief engineer Karuppan Kutty on Sunday cleared the silt accumulated close to the Idukki arch dam after it was found that the water leakage through the sluice valve was more than the permissible level.
The team will also deploy divers to clear the silt in the Lower Periyar dam.
Mr. Karuppan Kutty said it was decided to immediately clear the silt as the water leakage through the sluice valve was noted to be at a higher level after a small break was noticed near it.
He said it would not have any impact on the structure of the arch dam and the silt clearing work was a routine one.
The unexpected silt clearing work disrupted the life of local people. The silt released into the Periyar near the Cheruthoni town polluted the water downstream. The decision to remove the silt at a time of drought drew criticism from the people as the water was being used for drinking and other purposes.
With sudden pollution of the river downstream, many hotels in the town closed by afternoon.
Babukuttan, a local resident, said there was no prior information about releasing the silt. With drought-like conditions, the Periyar was the only water source for those residing downstream of the dam.
Mr. Karuppan Kutty said it was a decision taken at short notice and the people could not be informed in advance. The silt was cleared to prepare for maximum water usage at the Moolamattom power house.
He said the water would clear up in a day or two once the silt settled in the river. The water level in the Idukki reservoir continued to be at the lowest level of the season since it was commissioned in 1975. The Idukki dam produces over 40 per cent of the electricity consumed in the State and is supported by a 780 MU substation at Moolamattom.
Mr. Karuppan Kutty said divers would clear the silt in the Lower Periyar dam and it was part of the routine work. As per an agreement with the Canadian company that constructed the dam, silt clearance work had to be undertaken annually in the reservoir. The dam with a large reservoir area is prone to high level of siltation as the land, including the Ten Chain area, is inhabited by people, where various activities lead to soil erosion.
Sunday’s work was limited to the arch dam area and the silt removed is of a minimum level. Mr. Karuppan Kutty said the divers employed at the Lower Periyar were supported by engineers of Kerala Electronics Limited.
KSEB engineers of the Dam Safety and Monitoring wing, Cheruthoni, and the Dam Safety Authority participated in the silt clearance work.