Ramboll provided assistance to Clarence City Council to prepare a stormwater system management plan for the Bellerive-Howrah Beach stormwater catchment. This stormwater system management plan will be used as the basis for land use planning, emergency management, community consultation/education and capital expenditure planning.
To ensure these outcomes are achieved for the Bellerive-Howrah Beach Stormwater Catchment, the plan shall set out clearly the objectives for managing stormwater in urban catchments. It will define the existing and future flood behaviour from the local catchment runoff. By identifying the overland flow paths and associated flood affected (flood prone) land, we can also identify specific works, measures or actions to manage and mitigate flooding.
The plan will provide estimates of the capital and recurrent costs of works, measures or actions, with priorities and timeframes assigned to each of these measures. It will also define the obligation of the relevant stakeholders in funding, implementing and communicating the plans. Hydrologic and hydraulic models of the catchment were undertaken.
These models will be used to understand the level of risk in the public stormwater system within the urban area. The council can apply a risk management framework for flood mitigation and stormwater renewal works based on analysis of defined flood events. It will ensure stormwater systems are planned, designed and built with appropriate consideration of stormwater management principles by making better use of the statutory development and planning system.
It will also build resilience and consider climate change impacts. This way we integrate stormwater management into the urban water cycle to achieve the goals of social, environmental and economic sustainability. It also enhance community awareness of, and participation in stormwater management.