Burrumbeet Creek Riverine & Stormwater Flood Investigation and Flood Mitigation

The objectives of the Flood Investigation include:

1) Revise the hydrology and hydraulic models developed by the 2013 investigation using the latest methodology and guidance around global warming level assumptions provided by Australian Rainfall and Runoff (ARR) v4.2, up to date LiDAR & detailed survey of drainage features to fill gaps in existing data.

2) Update the 2013 hydraulic model to include the stormwater network to model stormwater flooding, and interactions of stormwater flooding with riverine flooding.

3) Using the latest methodology and guidance around global warming level assumptions provided by ARR v4.2, produce design flood and planned-for flood event mapping that shows:

a) the extent, depth, level, hazard, velocity and time of inundation of the full suite of design floods listed at Section 4.5.1 below, that could plausibly occur now; and

b) the extent, depth, level, hazard, velocity and time of inundation of the full suite of design floods that could plausibly occur by the year 2100 (in 75 years’ time).

c) the extent, depth, level, hazard, velocity and time of inundation of the full suite of design floods that could plausibly occur 100 years from now.

4) Using the best available information (including community and stakeholder knowledge) document the history of flooding for Burrumbeet catchment area and provide a clear comparison of the relative magnitude of each historical flood event with the pre ARR v4.2 design flows and magnitudes (2013 Flood Investigation assessment) and design flows that could plausibly occur now as per ARR v4.2.

5) Provide a sound flood-risk mapping foundation for adoption or revision of flood risk-related land use and/or development controls (Urban Floodway Zone, Floodway Overlay, Land Subject to Inundation Overlay) for Ballarat Planning scheme in accordance with Victoria’s climate change adaptation policies including Clause 13.01 of the Victoria Planning Provisions.

6) Provide flood risk mapping products at property (or better) scale resolution, as required by the GHCMA for delivery of its planning permit referral and flood advice services.

7) Provide up to date modelling representing present day and future climate conditions, that can be used to determine average annual flood damages as well as flood mitigation solutions.

8) Determine the feasibility of establishing flood alerting/warning arrangements.

9) Complete a pre-feasibility analysis of potential structural mitigation options in the context of the risk mapping required to meet objective 3 above.

10) Provide the flood risk mapping & flood intelligence products (or updates to existing products) required to revise or develop:

a) Ballarat chapter of the Municipal Flood Emergency Plan (MFEP)

b) community flood risk information supporting increased community resilience (e.g. Local Flood Guides produced by the SES).

11) Provide reliable flood risk information for insurance purposes.