Backflow Prevention Devices

Project Scope

The Backflow Prevention Device Projects consisted of the installation of backflow prevention devices on existing stormwater lines in various locations throughout Brisbane.

The projects were part of the Lord Mayors commitment to deliver backflow prevention devices to twelve high priority sites across Brisbane. Due to the high profile nature of the projects they were subject to the scrutiny of several media outlets.

The scope varied at each location but generally involved the process of excavating down to existing storm water lines, installing sheet piles or shoring boxes, breaking and trimming an existing stormwater pipe, installing pre-cast concrete manholes, installing a backflow prevention device, and backfilling and re-instating the road.

The most challenging aspect of the project was the management of water inside the excavation. Excavations were exposed to stormwater, ground water and tidal river water. Specially designed plugs were developed for the project and installed in the existing stormwater lines to manage both stormwater and tidal river water.

De-watering operations were conducted constantly during the works and activities were planned around the tidal cycle which meant that work operations and specific activities had to be scheduled down to the hour.

Works were often conducted at night, in high traffic areas, which required specially engineered manhole lids to accommodate vehicular traffic during the day.

The projects were completed without traffic or environmental incident and prior to the dates for practical completion.

Key Staff

Brett Marais – Project Manager

Jesse Horton - Project Engineer

Ryan Rumble – Project Engineer

William Jones – Project Engineer

Paul McCann – Site Supervisor

Coby Roles – Site Supervisor

Challenges

Backflow prevention devices installed on live stormwater lines below the water table and subject to tidal influence.

Close management of de-watering operations.

Stormwater line required to be fully functional at all times.

Intense scrutiny from media outlets.

Works carried out on roads under traffic and required to be functional during working hours.

• Project:

  Backflow Prevention Devices - Multiple

• Location:

  Brisbane City, Chelmer, New Farm, West End, Milton, Bulimba, Chelmer, St Lucia, Auchenflower

• Client:

  Brisbane City Council

• Practical Completion:

  2013 - 2014

• Contract Period:

  34 Weeks (Combined)

• Contract Value:

  $6.6 million (Combined)