Levee Bank Flood Protection
Update at July 2019
Construction to raise the Murrumbidgee River levee system in Wagga Wagga started in October 2017, giving residents for the first time a 1 in 100 year level of protection against flooding.
Wagga Wagga City Council are undertaking the Main City Levee upgrade by way of a staged construction.
Stage 1 commenced in 2017 and was completed in January 2019. Section 1 was from Flowerdale, including the spillway, to Gobbagombalin Bridge. Section 2 was from Copland Street, including the spillway, to Kooringal Road Monumental Cemetery.
Stage 2 commenced in January 2019 and is expected to be completed in 2020. This stage is from Gobbagombalin Bridge to Cadell Place wall (parallel to Fitzmaurice Street) to Johnston Street and then from Riverina Playhouse to Copland Street.
The North Wagga levee is currently being evaluated by the Wagga Wagga City Council’s Floodplain Risk Management Advisory Committee. This flood mitigation option feasibility study is supported by a grant of $156,000 from the NSW Government.
The project is undertaking a feasibility study of the following options:-
Upgrade of the North Wagga levee to a 5% annual exceedance probability level of protection (1 in 20 year protection), with an equivalent upgrade to Hampden Avenue
Undertake a voluntary house raising/purchase scheme which encompasses residential properties in North Wagga and on the wider floodplain
This study will determine which option is more viable in terms of reducing flood risk exposure on the Wagga floodplain.
For updates follow the link to the Wagga Wagga City Council Projects page:
The following funding contributions have been made to cover the $23M cost of the Wagga Wagga levee upgrades:
City of Wagga Wagga - raising one-third share of $7.75M through a special rate variation, effective from 2016 and maintained for five years
State Government - stage 1 grant funding of $2M and stage 2 grant funding of $2.1M
Federal Government - $10M funding under the Community Development Grants Program
The levee bank flood protection system is the city’s single most important piece of infrastructure, safeguarding central Wagga Wagga and the central business area from the effects of flooding. The localised effects of a flood breaching the levee bank would be devastating and displace approximately 7,000 people however the broader reaching impacts on the regional economy would have negative flow on effects at a national level. Wagga Wagga’s immediate population is greater than 65,000 however the city is the goods and services hub for over 185,000 people, emphasising the strategic importance of the city to a regional population.
In the event of a flood breaching the levee up to 2,600 homes and 1,100 businesses will be inundated, the majority severely flooded. In addition, the Sturt Highway connecting Sydney with Adelaide will be closed and likely to be severely water damaged.
The flood protection system is predominantly an earthen levee and was initially constructed in 1956 following frequent flooding events. The levee has since been upgraded to a level that was considered capable of resisting a 1 in 100 year flood event, the equivalent of a river height to 11.49 metres. However, recent modelling of the system’s capacity and observations during flood events in 2010 and 2012 have revealed the system is not capable of resisting a 1 in 100 year flood and will only protect the city from a 1 in 60 year flood event.
Without adequate protection against inevitable flood events, the community is exposed to a high degree of risk and ultimately devastation if the levee fails. In addition, the community experiences unrelenting negative perceptions and realities relating to business confidence, insurance premiums and property values.
The insurance premiums of the city’s residents and business owners will continue to rise annually to reflect significant risk to flooding and the investment potential of property in the CBD reduced until the levee bank is upgraded and the risk mitigated.
As an example, following severe flooding to Roma in 2010, 2011, 2012 insurance companies refused to offer new policies and the town was considered uninsurable. Following the upgrade of the town’s levee bank system in 2013 insurance premiums have again been made available, reduced by an average of 45% and in some cases up to 90%.
Flooding to the city will inundate up to 2,600 homes and 1,100 businesses, displacing over 7,000 people.
Cost Estimate: Yes
Wagga Wagga City Council
Committee 4 Wagga
Consider the levee bank upgrades as the city’s highest priority and complete the project without unnecessary delays.