Client: WA Water Corporation

Project Design:

WA Water Corporation

Contract Sum:  $2.1M


Kirup Dam Concrete Spillway

Kirup Dam lies on Kirup Brook, a tributary of the Capel River. It is situated approximately 196 km south of Perth (220 km by road) and 49 km south east of Bunbury. Kirup Dam impounds 60 ML at its Full Supply Level (FSL) of 235.47 m AHD, and has a water surface area of 2.6 Ha. The spillway capacity at Kirup Dam is less than modern design standards require. There is a small population at risk below the dam and loss of life is likely in the event of dam failure.

A risk assessment of the dam found that the dam has an unacceptable life safety risk compared to the ANCOLD Risk Assessment Guidelines criteria for societal risk. Remedial works are required to reduce the risk to ALARP. A concept design for the remedial works was completed in April 2019 recommending that a new side entry spillway be constructed.




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


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