Shannon Creek Dam
The 30,000 megalitre Shannon Creek Dam is located west of Coutts Crossing and 18 kilometres south of Grafton on the NSW north coast.
It is an off-river storage reservoir that supplies water to the Clarence Valley and Coffs Harbour areas. The dam sources water from the Nymboida river near Nymboida. It’s designed to be used during dry periods to provide water supply security and reduce the impact of water extraction from the Orara and Nymboida Rivers during low flows.
Shannon Creek Dam is a Prescribed Dam under the Dams Safety Act 1978 and as such requires Surveillance Reports to be submitted to the Dam Safety Committee every five years. Abyss Solutions was asked to undertake a detailed inspection of the critical underwater elements of the dam including the Outlet Tower, the diversion conduit (320m long) including isolation valves, the ogee spillway wall, the bottom of the gangway piers and the aeration lines. Using a remote-operated vehicle (ROV) equipped with specialised underwater imaging and sonar equipment, high fidelity visual and sonar imagery was collected of all items, provided Clarence Valley Council with all the information they required.