Shellharbour City Council – D&C GPT at Warilla

Optimal Stormwater was selected for the D&C of a GPT at Warilla. The site was very hydraulically challenging, with 3x 1800 pipes on a very flat grade entering a creek. The backwater and potential hydraulic impact of any solution made the design a complicated process. In the end a good compromise between efficiency, storage volume, safety and ongoing maintenance was found.

The best solution for this site was a P3018 CDS unit with double depth sump. It was located after the existing outlet so exclusion bars were also required.

The site was very tough, with poor ground conditions and lots of groundwater ingress into the excavation making for a very challenging construction. And with a 300ha catchment, the low flows never stopped coming from the pipes. Quality workmanship has seen a fantastic solution installed at Warilla.