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Wimmera CMA

Street Address:
24 Darlot Street, Horsham, 3400
(enter via Gleed St)

Postal Address:
PO Box 479, Horsham, VIC, 3402
Phone: (03) 5382 1544
Fax: (03) 5382 6076
Email: wcma@wcma.vic.gov.au
 
Office Hours:
Monday to Friday, 8:30 - 5:00pm
(excluding Public Holidays and Christmas - New Year Closure.  Office may also be closed for short periods Monday mornings)

Flood Investigations and Flood Extent Maps

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.

 
 Flow Gauge Board on Wimmera RiverFlow Gauge Board on Wimmera River

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:


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: 

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%
Dimboola 2006 20% 10% 5% 2% 1% 0.5%
Dunmunkle 2016 - Boolite, Murtoa
and Upper Dunmunkle Creek
    5%       
Glenorchy 2006 20% 10% 5% 2% 1% 0.5%
Halls Gap 2008 10% 5% 2% 1% 0.5%
Horsham 2002 20% 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 
Expected regional extent
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%
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.




Flood Project Updates

Update: Dunmunkle Creek Flood Investigation

Sep 30, 2017
 
Dunmunkle Creek at Rupanyup Dunmunkle Creek at Rupanyup

Recommendations to reduce flood impacts from Dunmunkle Creek

Removing channel banks and redundant water storages are among recommendations from a flood investigation presented to more than 50 people at a series of meetings at Rupanyup, Boolite, Murtoa and Lubeck.

The Dunmunkle Creek Flood Investigation recommendations include removing remaining channel banks within the Brynterion Forest, removing channel banks north of Rupanyup where practical and removing redundant GWMWater storages at Rupanyup.

The investigation, with support from a community and agency led steering committee, also recommends additional modelling of stormwater impacts on the eastern side of Rupanyup to identify solutions for reducing flooding.

Meeting participants identified and discussed in detail the need for careful consideration to future road infrastructure such as culverts, bridges, fords and even the road surface itself, because all have an ability to control the flow of water in such a flat landscape.

People at Boolite requested further consideration to channel removal south of Rupanyup which was presented to the Murtoa and Lubeck meeting participants.  The final report will include issues and concerns put forward at the meetings.

The Dunmunkle investigation covers an area up to 20 kilometres wide and over 80 kilometres long from Glenorchy in the south to Watchem in the north.

Extensive computer modelling and mapping a range of flood scenarios from minor through to extreme helped verify where floods had previously been, then measured and predicted future flows directions, depths and extents. Channel decommissioning for the Wimmera Mallee Pipeline Project along with urban drainage and flood impacts on rural properties were all considered during the investigation.

Wimmera CMA Floodplain Management Team Leader Paul Fennell said the meetings provided an important opportunity for people to hear recommendations and ask questions.

“We were really pleased with the number of people who came along, as the community has provided significant input towards the study and helped us gain a more practical understanding of flooding throughout the entire catchment. This understanding has helped us shape the recommended options.”

Mr Fennell said one significant and tangible outcome for the community was having a significant bank of flood intelligence to utilise in future floods. This would enable timely warnings and help with emergency response for future flood events.

“The flood mapping provides valuable information for planning purposes because there is now better knowledge about where it is likely to flood in a range of scenarios including potential inundation of houses, roads and infrastructure that may be at risk from flooding. From here we will prepare the final report which will help the various authorities in future planning and funding applications to complete the recommended mitigation works.”

Wimmera CMA has managed the project in partnership with GWMWater and Yarriambiack, Northern Grampians and Buloke shire councils. Water Technology, who has extensive experience in flood investigations, is the project consultant.

Community members who weren't able to attend the meetings can view the presentation slides and maps from the meetings below. 

The final reports will be available online in the coming weeks.

Final Community Meetings Presentation - March 2017

Dunmunkle Creek Flood Investigation Maps - March 2017