Council identifies stormwater improvements

Published on 22 February 2024

Gannawarra Shire Council has identified more than 40 projects that would help improve its urban stormwater network during future urban flooding events.

A report on how flash flooding that occurred during late December 2023 and early January 2024 impacted the municipality’s 71-kilometre urban stormwater network was presented at Council’s February 2024 meeting.

The municipality received 70 per cent of its annual average rainfall in a two-week period, impacting Council’s drainage network, and was significant enough to be declared an emergency event by the Federal Government.

“Flooding resulting from rain on Christmas Day 2023, as well as on 2 January 2024 and 7 January 2024 impacted residents in many ways. This included many properties being inundated and numerous roads cut off, leaving residents unable to leave their homes,” Mayor Ross Stanton said.

“Although we have invested in upgrading stormwater pumps and regular maintenance over many years, we know that more can be done to reduce the impact of future events.”

Council staff have used data collected since the first flash flooding event to identify locations where high volumes of water pool when it cannot drain away, resulting in the identification of 42 projects at Cohuna, Kerang, Koondrook, Murrabit and Quambatook.

The proposed list of projects will be incorporated into Council’s long-term financial planning with a focus on sourcing external funding to complement Council investment to complete these works.

“Like many other Councils, Gannawarra’s older drainage infrastructure was installed prior to modern design standards being implemented and is influenced by a number of factors including pipe sizes, pipe grade and lack of suitable areas for large water detention basins,” Mayor Stanton said.

“These proposed improvements will enable an increased level of service to be provided to mitigate risks associated with these storm events.”

Residents whose home, infrastructure or business was damaged by the recent storm or flooding are encouraged to advise Council of this damage by phoning Council’s Flood Recovery Support Team on (03) 5450 9333 during business hours, visiting Council's Customer Service Centres at Cohuna and Kerang, or completing the form available under the "Have you been impacted by the floods/storms" heading at www.gsc.vic.gov.au/floods

List of proposed urban stormwater improvements

Cohuna

Location

Task

Golf Links Estate

Install drainage pump and clean drains

King George Street

Investigate drainage and pump at Grey’s Bridge to Gunbower Creek

Investigate underground drainage from Grey’s Bridge to Cohuna District Hospital

Weinburg Street

Investigate installing a pump

Western Road reserve

Raise pit lid and clear pipe

Liaise with Goulburn-Murray Water about cleaning Barr Creek

Liaise with Goulburn-Murray Water about cleaning drain from Tolls Road

Kerang

Location

Task

Airport Road/Borough Drive

Survey and reform drains

Consider larger drains along Airport Road from Borough Drive

Consider extra culvert at Airport Road/Borough Drive intersection

Consider diverting excess water onto Kerang Aerodrome site

Brolga Street

Investigate to connect Red Gum Drive to Boundary Street to avoid setting up a temporary pump

Croton Street

Install new drainage

Check levels of open drains alongside railway line

Dunlop Street

Investigate joining to Murphy Street and increasing pump capacity

Franke Street

Design drainage

Garvey Road

Investigate roadside drainage

Greenwood Street

Investigate possibility of detention basin on railway land

Hayman Lane

Consider second pump and power upgrade

Leng Street

Investigate overflow pipe to Goulburn-Murray Water drain

Investigate increasing the size of penstock valve or pump installation

Mill Street

Investigate improvements (pipe back to main line)

Mokana Street

Consider upgrade to overflow pipe into railway dam (check options for pumping out dam)

Ninth Street

Investigate pump at Murray Street intersection

Redgum Drive

Increase pump and pipe when upgrading Airport Road

Investigate gravity overflow pipe

Sherwood Drive

Investigate underground drainage

Tate Drive

Investigate upgrade pumps to increase capacity and discharge directly into Murray Valley Highway drain

Investigate detention basin in reserve

Wyndham Street

Investigate installation of permanent generator

Consider replacing diesel pump with electric submersible (after generator)

Consider upgrades to pump shed, new switch board and gantries

Investigate connections for portable generators

Purchase 150-200mm trailer mounted portable generators

Koondrook

Location

Task

Blair Street

Pump dam into main system or directly into Gunbower Creek

Caravan Park

Road and drainage upgrade (Stage 2)

Forest Street

Install drainage

Lily Street/Meharry Street/Murray Parade

Install drainage

Tramway Place

Investigate drainage in front of motel

Murrabit

Location

Task

Kerang Road

Drainage from golf course under road and to Edgar Road (possible underground past houses)

Quambatook

Location

Task

Mildred Street

Investigate drainage

Tennison Street

Investigate drainage

ABOVE: Council staff work to pump water out of Brolga Street, Kerang following flash flooding on 2 January 2024.