Overview

Wagga Wagga City Council and the Floodplain Risk Management Advisory Committee (FRMAC) have engaged the Centre for International Economics to undertake a feasibility study for the recommended flood mitigation options for North Wagga. The recommendations were developed and adopted from the 2018 Murrumbidgee River Revised Floodplain Risk Management Study and Plan.

Currently, there is a flood levee that provides protection for the village of North Wagga for an estimated 12% Annual Exceedance Probability (AEP) flood event. 12% AEP means that there is a 12% chance (or 1 in 8 chance) of a flood of such a level or higher occurring in any one year. However, many in the North Wagga community are calling for a greater level of protection.

At its Ordinary Meeting on Monday 11 March, Council accepted the Floodplain Risk Management Advisory Committee's recommendation and endorsed for the analysis reports to go on public exhibition and to invite submissions from residents and stakeholders.

Submissions were open for 42 days from 15 March 2024 until 26 April 2024.A further report following the public exhibition and submission period was presented to Council addressing any submissions and providing preferred recommendations for flood mitigation options for North Wagga.

Community Consultation

During February 2024, Woolcott Research and Engagement and Wagga Wagga City Council conducted community consultation to determine which of three options the community preferred to provide more protection for the North Wagga and floodplain community to mitigate flood risk.

This stage of the consultation consisted of an online survey and a telephone survey to gather feedback from residents across our Local Government Area.

The three options are:

Option one is Voluntary Purchase and Voluntary House Raising for eligible properties on the floodplain (i.e. including eligible houses in and around North Wagga, Oura, and Gumly Gumly).

Option two is a two-staged approach:

  • Stage 1 would involve raising the levee to a 5% AEP level (or 1 in 20 chance of a flood event in any year) to provide North Wagga with a greater level of protection. (The levee at North Wagga is currently a 12% AEP levee that provides protection against a 1 in 8 chance of a flood event in any year).
  • Stage 2 would involve the ‘surrounding works’ - raising a portion of Hampden Ave to provide a safe evacuation route for North Wagga residents and raising a section of Mill St to provide an evacuation route for residents within the East St Levee. This stage would also involve the building of bridges and excavation works to offset the levee and embankment and enable equivalent water flow.

Option three is a combined option, which would include three projects:

  • Project 1:
    • Upgrading the existing North Wagga Levees (stage 1 of previous option) and;
    • Offering Voluntary House Raising and Purchase to those outside the levee boundary (including eligible houses in and around North Wagga, Oura, Gumly Gumly). The purchase and raising would target houses where the risk reduction is greater than the cost of the voluntary house raising or purchase.
  • Project 2:
    • The ‘surrounding works’ as mentioned in Option 2, Stage 2 – raising access roads, installing bridges and performing excavation between Wagga and North Wagga along Hampden Ave.
  • Project 3:
    • Offering Voluntary House Raising and House Purchase to residents inside the North Wagga Levee system, where the risk reduction is greater than the cost of the voluntary house raising or purchase.

Outcome:

At its ordinary meeting on Monday 11 March, the Floodplain Risk Management Advisory Committee recommended to Council that they place the report and recommendation on public exhibition.

The committee’s recommendation is option 3 which entails the following:

  • Upgrading the existing North Wagga Levee system and offering Voluntary House Raising and Purchase, subject to risk reduction and cost effectiveness
  • Increasing the road heights and bridges along Hampden Ave to provide a safe evacuation route, subject to funding

A final recommendation from the Floodplain Risk Management Advisory Committee was to Council at its Ordinary Meeting on 27 May 2024. Council voted to accept the final report by the Centre for International Economics (CIE) and the recommendation to adopt Option 3: a combined approach.

This decision enables the Council to now begin planning for the implementation of the report’s two-stage approach which involves an upgrade of the existing North Wagga levee system to a five per cent Annual Exceedance Probability (AEP) level, or a 1 in 20 levee.

News and Updates