Client: WA Water Corporation

Project Design:

WA Water Corporation

Contract Sum:  $2.3M


Balingup Dam Concrete Spillway

Balingup Dam is located around 3 km SSE of the town of Balingup which is approximately 200 km SE of Perth. The dam was constructed in 1963 and is a 9 m high zoned earthfill embankment with a crest length of 95 m.

A Dam Safety Review (DSR) was completed in April 2010 by SKM and identified that the main dam failure risk is overtopping due to inadequate spillway capacity (1 in 200).

The design incorporated construction of a new spillway with the capacity to pass a 1:10,000 AEP flood event without overtopping the dam. The works also included the decommissioning and removal of two saline settlement structures upstream of the dam and their associated asbestos pipework, the decommissioning and removal of the downstream pump station and the rerouting of the electrical supply from the pump station directly to the on-site chlorination building. As well as the upgrade of the outlet pipework (via sleeving and grouting) and new outlet valves and associated infrastructure.




  • Demolition of existing spillway
  • Excavation for new spillway
  • Construction of new concrete spillway
  • Construction of new filter layers
  • Re-lining of scour line and construction of new valve pits
  • Construction of inlet and outlet channels


  • Construction in live spillway
  • Working in operating dam environment
  • Acid Sulphate soils
  • Restricted access to work areas