2002 – Harvey Dam Project- Risk Management Strategies

Bob Wark, Colin Bradbury, Michael Somerford and Michelle Rhodes

The Harvey Dam project is a major component of the Water Corporation’s Stirling-Harvey Redevelopment Scheme, which was developed to provide potable water to Perth. The scheme will deliver 34 GL/annum or about 10% of Perth’s supply. The project timetable was tight. The decision to proceed with the scheme, made in June 1998, required Harvey Dam to be ready to impound water by June 2002.

Construction of the Harvey Dam was complicated by the following:

• The tight project timeline;
• The dam is located about 1.6km upstream of Harvey townsite and its population of 3000 people;
• Strict environmental constraints applied to construction noise, dust, blast vibrations and construction traffic;
• Variable ground conditions required flexibility within the contract in both the extent and type of ground treatment required;
• The need to maintain irrigation supplies throughout the construction period, from the existing aged Harvey Weir, which was located immediately upstream of the proposed dam; and
• The need to safely discharge floods at all stages of dam construction.

These and other issues required the development of risk management strategies for the project. The construction risks were allocated within the contract to provide for an equitable sharing of risk between the Contractor and the Principal. The paper describes the development and implementation of the risk management strategies and what lessons have been learnt from the process.