CBD and North Wagga Levee Upgrade
Since 2009, Council has been working towards the upgrade of the levees that protect Central Wagga Wagga and North Wagga Wagga.
Council has already undertaken an immense amount of work in relation to the upgrade of the levee systems. These projects have been partly funded by Commonwealth, State and Local Government.
As well as preparing for the upgrade of the levee Council has been active in rehabilitating the existing levees systems through capital projects as well as routine maintenance activities.
Council has completed the feasibility assessment for the upgrade of the levee systems as required by the State Government.The next phase of this project (from October 2012 to March 2013) is to have many and varied conversations with the community about the concept designs to:
- Gain community input into the levee design and construction
- Seek feedback on how the construction of a levee may impact adjoining properties
- Inform communities on how an upgraded levee will impact across the floodplain for future 1 in 100 floods
'1 in 100 Flood' Protection
The accepted engineering standard for levee protection is to an event equivalent to the 1% Annual Exceedance Probability (AEP), or a 1 in 100 year average recurrence interval.
In 2010, Council undertook flood modelling for a 1 in 100 flood event before and after the proposed levee upgrade. The maps show with an upgraded levee, the most significant difference is the protection the Central Business District of Wagga, a major regional economic and services hub, from inundation.
Click on the links below to view the 1 in 100 flood modelling maps pre and post levee upgrade:
History of Wagga Wagga Levees
After the 1956 floods Council decided to provide levee bank protection for the City area on the south flood plain. The year of 1956 was one of excessive rainfall in the catchment and frequent flooding in the minor range, with eight floods between 8.30m and 8.99m and one low level major flood of 9.58 m occurring.
The main commercial area of Wagga is protected by a levee which was constructed in the early 1960's. It was upgraded in the late 1970's and again in 1983 to accommodate problems that became apparent in the 1974 flood, to a 1 in 100 year standard. Temporary levees, in one form or another, had also been constructed around the village of North Wagga Wagga since 1936. These were formalised as a 1 in 20 year levee in 1990.
The northern floodway area is protected by low banks constructed in 1971 across the end of Kurrajong Lagoon and at the property "Eunonyhareenyha". An earlier bank existed on "Whyanawah". A levee which protects Gumly Gumly was temporarily constructed after the 1974 flood and formalised to a 1 in 10 year height in 1992. There is also a bank from North Wagga Wagga to Gobba Weir which holds water out of the northern flood plain to a height of 9.0m.