The Kerala Water Authority (KWA) has a huge challenge before it, technically and financially, as it endeavours to carry out desilting of the Aruvikkara dam.
A decision on whether the KWA should carry out the work by itself or should hand over the work to another agency having expertise in the process is expected soon. For the past few months, a technical committee has been studying the siltation levels in the dam and the process to be carried out to desilt.
Two years ago
Soon after the unprecedented drought experienced in the city in the summer two years ago, the State government had announced ₹4 crore for desilting of the Aruvikkara dam. But, as per the studies conducted by the committee, this amount was found to be grossly insufficient. “According to the estimates of the committee, we need at least ₹20 crore to carry out desiltation. We are not sure of how successful the process would be if we take it up. We have two choices – either to do the work by ourselves or award it to a company that has the expertise. A decision in this regard will be taken in two or three weeks,” said a KWA official.
Part of the KWA’s plan is to extract the sand from all the silt and sell it in the market to offset some of the cost involved in the desilting. Separating it from the clay, vegetation and other waste is going to be a tough task. An accurate estimate of the quantity of silt and sand also could not be prepared, as the deposits are all uneven.
Dam’s reduced capacity
Over the years, large-scale accumulation of silt beneath the dam floor had reduced its capacity almost by half. This has led to water shortage even when during seasons when the region received decent rainfall. The Peppara dam, which does not have any siltation according to the officials, is currently at full capacity.
“There is nothing to worry for us as of now, as the water levels in the dams here are at the maximum permissible levels,” an official says. However, the water level in the Karamana river went down as the Pozhi (estuary) remained open. The reduction in discharge from Aruvikkara dam in recent days also contributed to this.
The falling water levels in many rivers in the flood-hit districts had triggered speculation about a possible drought-like situation here.