Guilfoyle Avenue, Double Bay

Woollahra Council was experiencing problems with frequent occurrences of localised flooding of properties along Guilfoyle Avenue, Double Bay. This was a result of the existing stormwater drainage system capacity being significantly undersized, with a very low capability to convey stormwater flows.

MIEngineers was engaged to prepare concept and detailed road and drainage designs (including drawings) for the upgrade of the existing stormwater drainage system within Guilfoyle Avenue.

MIEngineers prepared the drainage design to allow the works to be completed in two stages, as required by the client, due to funding constraints.

• Stage 1 of the design included an upgrade of the drainage system within Guilfoyle Avenue and connecting to the existing drainage system within Ocean Avenue, providing a 7% reduction in the overflows during a 1 year ARI storm event.
• Stage 2 of the works required an upgrade of the Ocean Avenue drainage system, providing a 24% reduction in the overflows during a 1 year ARI storm event.

The upgrade of the existing drainage system required the existing services to be maintained at all times, with the extent of services relocations/adjustments kept to a minimum. To address this issue, we ensured the detailed site survey included accurate identification and location of all existing services. Using this information, the drainage design was able to be completed without requiring the need for existing services to be relocated/adjusted, providing a significant cost saving to the client.