DREDGING large dams to increase the region's water supply is not a feasible option, state government water experts say.
Deepening dams in times of drought, when they are already low, would actually be detrimental to local water supplies.
"Dredging dams to deepen storage would increase the volume of so-called dead storage, that is, water that is below the level of the outlet valve in the dam wall and therefore largely inaccessible," the water expert said.
"As a result when the dam storage is at very low levels dredging would also increase the amount of inflows required to refill the dam storage to a level where water could be released downstream once again."
There would be "considerable cost and logistics associated" with a task of such scale. For example, at full storage the surface area of Keepit Dam is 44 square kilometres, and deepening the entire dam by just a metre is a daunting task which would be costly and time consuming.
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The environmental impact would also need to be considered, including any impact on native fish remaining in the remnant water.
A spokesperson for WaterNSW wouldn't comment specifically on the issue of dredging dams, however the organisation is working on a number of other options to combat the drought.
"WaterNSW continues to work with local government and the NSW government to extend supply to communities in the state's north as intense drought condition persist, reducing dam inflows to near-zero," they said.
"WaterNSW's drought management strategy and the co-operation of downstream customers and other users has extended supply from northern storages well beyond what would have otherwise been possible."