Dora Creek Floodplain Risk Management Study and Plan - Report

Introduction The Dora Creek Flood Risk Management Plan has been prepared for Lake Macquarie City Council (Council) in accordance with the NSW Floodplain Development Manual (April 2005 - Reference 1) and the August 2010 Flood Risk Management Guide – Incorporating sea level rise benchmarks in flood risk assessment (Reference 4) and:

Is based on a comprehensive and detailed evaluation of factors that affect and are affected by the use of flood prone land; Represents the considered opinion of the local community on how to best manage its flood risk and its flood prone land; and Provides a long-term path for the future development of the community.

The Dora Creek catchment is located on the western side of Lake Macquarie waterway, 30 km south-west of Newcastle and 120 km north of Sydney. Dora Creek has a catchment area of approximately 238 km2 and is the largest catchment flowing into the Lake Macquarie waterway which has a total catchment of 648 km2 (Figure 1). The study area focuses on the existing township of Dora Creek and includes the townships of Cooranbong and Avondale, where new and planned rural and urban developments are proposed within the floodplain. The upper limit of the study area extends above Freemans Drive to Cooranbong and downstream to the confluence of Dora Creek with the Lake Macquarie waterway. There are three main tributaries within the catchment with Dora Creek being joined by Jigadee Creek at Cooranbong and then Stockton Creek before draining into Lake Macquarie waterway at Bonnells Bay and Lake Eraring. Watercourses within the catchment area and above the tidal limit are narrow; Dora Creek is typically less than 15 m wide upstream of Freemans Drive. Below the tidal limit, the creeks become broader with Dora Creek varying from a width of 50m at the Sydney to Newcastle Freeway to 100m where it forms a delta into Lake Macquarie waterway. Upstream of the delta the Eraring Power station draws cooling water for steam condensation from Bonnells Bay, which passes under Dora Creek through a concrete tunnel and open canal.