ASDSO added that the estimate for repairs needed to non-federal dams with high hazard potential has jumped 60% to US$16B from US$10.1B over the same period. The breakdown of public to private dams is 54% to 46%, respectively.

In 2007, ASDSO estimates based on state data, approximately US$700M was invested to rehabilitate about 341 dams.

It added that the number of deficient dams has increased by more than a third over the last five years, citing the latest data from the National Inventory of Dams (NID), which is maintained by the US Army Corps of Engineers (ASCE)

The Association has called for a federal programme to help fund the rehabilitation of dams, which it said would help encourage parallel funding initiatives by states.

It added that it is aware of 272 project that could begin construction work within the next two to 24 months, at an estimated total cost of US$382M.

But to get rid of the historical backlog of work needed to be done on dams, it said that an extra 270 high hazard potential dams alone would need to be fixed annually at additional cost of approximately US$850M per year.