Wivenhoe Dam Spillway Clearing

Project Scope

The project involved flood repairs to the Wivenhoe Dam Spillway and primarily the clearing of the rock obstruction restricting outflow from the plunge pool, and the removal of debris from the spillway outlet channel.

The nature of the works included:

Breaking and removing approximately 27,000m³ of rock from the plunge pool obstruction.

Excavating approximately 5,000m³ of silt from spillway outlet channel.

Reinstating and shaping the spillway bench area (approximately 12,500m²) to prevent the stranding of fish.

Of particular significance were the stringent environmental measures implemented on the project.

Floating sediment barriers were installed downstream of construction activities and daily turbidity readings were taken to ensure water quality targets were achieved.

A full time “fish spotter” was dedicated to the contract who was responsible for the capture and relocation of stranded fish. The endangered lungfish was especially prevalent in the area and great care was involved in the rescuing of these fish.

Strict maintenance procedures were imposed on all site plant to avoid breakdowns and unwanted oil leaks. Working directly downstream of a major dam required unique safety procedures and methodologies in addition to constant liaison with Seqwater management.

Key Staff

Ben Dyson – Project Manager

Brian Moore – Site Supervisor

Challenges

Strict maintenance procedures imposed on all site plant to avoid unwanted oil leaks

Working directly downstream of the dam required unique safety procedures and methodologies

Stringent environmental requirements and measures implemented on the project

A doubling of the project scope was accommodated within the original contract duration

• Project:

  Wivenhoe Dam Spillway Clearing

• Location:

  Wivenhoe, Qld

• Client:

  Seqwater

• Practical Completion:

  November 2011

• Contract Period:

  14 Weeks

• Contract Value:

  $1.4 million