Manson Reserve Wetlands

Knox City Council had identified that a watercourse adjacent to the Dandenong Creek in Wantirna had run dry, and wished to rejuvenate it by diverting stormwater from a nearby drain.

Rather than installing the deep new drain by conventional excavation, Contek proposed to install the 285m length of 375mm diameter pipe by directional drilling. The efficiencies of this methodology were recognized by Council, and Contek was awarded the project.

Due to the size and depth of the entry and retrieval shafts, shields and steel plates were used to protect the excavations and the workers inside. Runs were bored out, prior to the pipes being pushed through in a style not dissimilar to pipe jacking. Deep pits were then constructed as designed, as were a penstock and sliding isolation board.

A formalized sediment basin was constructed at the outlet, alongside a maintenance access track.

Main Scope:

• Boring and installation of 285m of 375mm dia pipe
• Construction of sediment basin and access track
• Asphalt path reinstatements

Client: Knox City Council
Contract value: ~$490,000
Completion: May 2020