Floodplain Management
| The Bureau of Meteorology website (external link) provides daily River Height Bulletins (external link) across Victoria. Flood Data Mapping In late 2000, the former DNRE completed its Flood Data Transfer Project, which was developed to produce high quality, consistent and comprehensive Geographic Information System (GIS) maps showing a range of flood data for urban and rural flood plains in Victoria. The mapping and assessment has only been carried out for locations where information is available and of sufficient quality to justify delineation. Hence, the mapping is not a comprehensive range of all flood plains or all flooding problem areas, and broad flood areas indicated on the map may have some pockets of flood-free land (EGIS, 2000 June). Nonetheless, the Flood Data Transfer Project contains the most up-to-date flood information available. A key outputs of the Flood Data Transfer project is the formulation of Flood Data Maps that detail Floodway data and 1% Annual Exceedance Probability (AEP) Flood Extents. |  |
 Floodways & 1% Annual Exceedance Probability Flood Extent | Port Phillip and Westernport Floodways and 1% Annual Exceedance Probability Flood Extent Map. This map shows Floodways and areas of 1% Annual Exceedance Probability (AEP) Flood Extent. This data was sourced from the Flood Data Transfer Project, developed by EGIS Consulting. |
Floodways
Floodways generally comprise the most hazardous parts of the floodplain and are often associated with fast flowing floodwater and/or areas of relatively deep flooding (SKM, 1999).
1% Annual Exceedance Probability Flood Extent
The 1% Annual Exceedance Probability (AEP) flood event is one in which the applicable flood flow has a probability of 1% (or 1 in 100) of being equalled or exceeded. The flood data maps provide a record of all past mapping and known problem areas and should only be used for identifying the location of past flood problem areas (EGIS Consulting, 2000). This data is based on hydrological modelling and mapping, and will be used in the revision and development of Shire Planning Scheme overlays.
Planning
The Annual Exceedance Probability (AEP) Flood extent will form the basis for subsequent declaration of the Land Subject to Inundation Overlays (LSIO) and planning controls under the Victorian Planning Provision (VPP). LSIO identify flood prone land where the flood risk is not considered sufficient to denote a floodway or where there is insufficient information to define the floodway. Similarly, the floodway extents should be used for determining Urban Floodway Zones and Rural Floodway Overlays under the VPP. The criteria to delineate floodways and flood extents is in accordance with the Advisory Notes for Guidelines for Delineating Floodways (the former DNRE, July 1998), which incorporate flooding characteristics, socioeconomic and environmental factors.
Related Links
A wide range of flooplain data can be accessed via MapShare on the DSE website (extenal link) in the form of an interactive map, using information from DPI/DSE. The Catchment and Water Mapper section provides information on themes such as rivers, 1 in 100 year flood, floodways, and river basins.
References
EGIS Consulting (2000). Flood Data Transfer Project (formerly) DNRE. Victoria.
SKM (1999). Sinclair Knight Merz. West Gippsland Catchment Management Authority: Regional Floodplain Strategy. Melbourne, Victoria
© The State of Victoria, 1996 - 2009.
This document was last reviewed on 24/12/2008