Flood investigations involve a detailed technical analysis of historic information to determine future flooding possibilities and their impacts. Community participation and ground-truthing are essential parts of investigations.

A flood investigation will determine the impacts of various flood intensities and often looks at possible options to reduce expected damages.

Dependent upon funding, an investigation may also help to determine actions to be taken by emergency service agencies during times of flooding, and often recommends flood-warning systems to improve community awareness to risks posed. Once a flood investigation is completed Wimmera CMA works closely with local government to amend planning schemes so that learnings from the investigation are incorporated and planning development is managed to the appropriate flooding risks identified.

Flow Modelling Study

Wimmera CMA has also completed a flow modelling study of the Wimmera River and Yarriambiack Creek between Glenorchy, Horsham, and Warracknabeal. The study undertook hydrologic and hydraulic modelling of the waterways; it was completed in September 2009. The study assessed both current and 'pre-European' catchment-waterway-floodplain regimes.

Flood and Flow Investigation Reports

The following flood and flow investigations have been completed:

• Dimboola Flood Investigation 2003
• Dunmunkle Creek Flood Investigation 2018
• Glenorchy Flood Investigation 2006
• Halls Gap Flood Investigation 2017
• Horsham Flood Investigation 2003
• Horsham-Wartook Investigation 2019
• Jeparit Flood Investigation 2008
• Lower Wimmera Flood Investigation 2017
• LW Regional Flood Mapping Hydrology
• LW Regional Flood Mapping Hydraulics
• LW Flood Intelligence
• LW Site Visit and Data Collation

• Mt William Creek Flood Investigation 2014
  • Mt William Creek - Executive Summary
  • Mt William Creek - Appendicies
• Natimuk Flood Investigation 2013,
  • Natimuk Flood Investigation Appendicies>
• Upper Wimmera Flood Investigation 2014
  • Upper Wimmera - Executive Summary
  • Upper Wimmera - Appendicies
• Warracknabeal and Beulah Flood Investigation 2007
• Wimmera River & Yarriambiack Creek Flow Modelling Investigation 2009

• Warracknabeal and Brim Flood Investigation 2016
  • Flood Intelligence Report
  • Flood Mitigation Options
  • Flood Warning Assessment Report
  • Hydrology & Hydraulics
  • No Levee 100 year Flood Extent
  • Proposed Levee Height Map

Flood and Flow Extent Maps

AEP (Annual Exceedance Probability) Flood and Flow Event Extent Maps
Note: Wimmera CMA is not the lead agency to contact during a flood event.
You can find further information from: 

• Victoria Emergency website
• VicSES website
• BoM website - Wimmera Mallee Rainfall and River Conditions
• Wimmera Glenelg Storage Manager - water storage information

Please note that these maps are a lower resolution to enable quicker downloading. 
Find high resolution maps here.

Flood Map Locations	1-in-5 year event	1-in-10 year event	1-in-20 year event	1-in-50 year event	1-in-100 year event	1-in-200 year event
	AEP Flood and Flow Events
Beulah 2006		10%	5%	2%	1%	0.5%
Concongella 2015	20%	10%	5%	2%	1%	0.05%
Dimboola 2006	20%	10%	5%	2%	1%	0.5%
Dunmunkle 2017 - Boolite, Murtoa and Upper Dunmunkle Creek	20%	10%	5%	2%	1%	0.5%
Glenorchy 2006	20%	10%	5%	2%	1%	0.5%
Halls Gap 2017	20%	10%	5%	2%	1%	0.5%
Horsham 2002	20%		5%	2%	1%	0.5%
Horsham-Wartook 2019	20%	10%	5%	2%	1%	0.5%
Jeparit 2008	20%	10%	5%	2%	1%	0.5%
Jeparit 2008 - no levee	20%	10%	5%	2%	1%	0.5%
Lower Wimmera 2016 - downstream of Horsham	20%	10%	5%	2%	1%	0.5%
Mount William Creek 2014	20%	10%	5%	2%	1%	0.5%
Natimuk 2013	20%	10%	5%	2%	1%	0.5%
Upper Wimmera 2014	20%	10%	5%	2%	1%	0.5%
Warracknabeal 2007	20%	10%	5%	2%	1%	0.5%
Wimmera River & Yarriambiack Creek 2009 (inc. Horsham)	20%	10%	5%	2%	1%	0.5%
Yarriambiack Creek 2016 - Brim	20%	10%	5%	2%	1%	0.5%
Yarriambiack Creek 2016 - Warracknabeal	20%	10%	5%	2%	1%	0.5%
Yarriambiack Creek 2016 - Jung	20%	10%	5%	2%	1%	0.5%

PLEASE NOTE: Maps are provided for general community information purposes only.
Flood levels and floor levels are determined from information available at a particular time and actual levels may exceed those shown. For information about flood conditions and restrictions affecting a particular property, contact Wimmera CMA or the relevant council. Neither Wimmera CMA nor the State of Victoria claim or warrant that the information in this map is accurate, complete or up to date, and neither Wimmera CMA nor the State shall be responsible or liable in respect of any use of or reliance placed on it by any person.

Flood Warning Network

Wimmera CMA has worked with emergency response agencies and the community to develop the Wimmera Flood Warning Network. The network consists of radio-telemetry equipment at existing river and rain gauges throughout the Wimmera, linked to the Bureau of Meteorology (BoM) and Wimmera CMA offices.  The information is then fed into computer based models that are used to predict the likelihood of flooding that may occur, the extent of the flooding and the timing so as to provide information to emergency services and the community through early warning messages.

The system is under constant review, with all flood investigations considering opportunities for network improvement.

You can find real-time information from these gauges on the BoM website.