Riverine flooding, as the name suggests, relates to flooding of a river or a creek system.

What is 'riverine' flooding

Riverine flooding occurs when excessive rainfall over an extended period of time causes a river to exceed its capacity. It can also be caused by heavy snow melt and ice jams. The damage from a river flood can be widespread as the overflow affects smaller rivers downstream, often causing dams and dikes to break and swamp nearby areas.

The Wagga Wagga Local Government Area has a well documented history of riverine flooding related to the Murrumbidgee River.

Wagga Wagga City Council has been able to take advantage of this to produce a series of flood models for the Murrumbidgee River to assist in making improved decisions about activities and development on the floodplain.

1% AEP Design Flood Depth and Extent

A 1% Annual Exceedance Probability (AEP) flood event is equivalent to a 1 in 100 year flood, which is a major rain event that occurs on average once every 100 years (i.e. there is a 1% chance of a flood this size or larger occurring at a particular location in any given year).

However, as we are continually reminded, the environment does not conform to mathematical formulas and therefore a 1% AEP will occur whenever nature decides.

The below images and document outline the flood depths and extent of a 1% AEP Flood in Wagga Wagga.

Figure 8 - Wagga 1% AEP Design Flood Depths and Extent 2.1 MB Download

Probability of experiencing a given-sized flood in an 80 year period

The following table outlines the probability of experiencing the below flood sizes in an average 80 year lifetime. For reference, the 2012 flood that peaked at 10.56m had an AEP % of approximately 2.85%.

Annual Exceedance Probability (%)Approximate Average Recurrence interval (years)At least once (%)At least twice (%)

Riverine Flood Studies

Wagga Wagga Revised Murrumbidgee River Floodplain Risk Management Study and Plan - Volume 1 4.9 MB Download

Appendix A - Glossary 220.5 KB Download

Appendix B - Initial Community Consultation (Aug-Sept 2016) 212.3 KB Download

Appendix C - Flood Damages Assessment 334.5 KB Download

Appendix D - Hydraulic Categorisation - Floodway Definition 3.8 MB Download

Appendix E - Management Options Mapping 17.1 MB Download

Appendix F - Management Options Details and Costings 1.3 MB Download

Appendix G - Future Flood Risk Management 4.2 MB Download

Appendix H - Vegetation Management Plan 11.6 MB Download

Appendix I - SES Flood Intelligence Draft Updates 543.1 KB Download

Appendix J - Emergency Management Considerations for raising North Wagga Levee 806.6 KB Download

Appendix K - Dec 2010 and March 2012 Flood Warnings and Evacuation Warnings - Orders for Wagga Wagga 208.7 KB Download

Appendix L - Alternate North Wagga Evacuation Route 727.6 KB Download

Appendix M - Responses to Public Exhibition Submissions 655.0 KB Download

Figure 1 - Study Area 341.0 KB Download

Figure 2 - Key locations and floodplain communities 1.6 MB Download

Figure 3 - Wagga Wagga City Council LEP - 2010 8.1 MB Download

Figure 4 - Wagga Wagga 0.5EY Design Flood Depths and Extent 2.3 MB Download

Figure 5 - Wagga 10% AEP Design Flood Depths and Extent 2.2 MB Download

Figure 6 - Wagga 5% AEP Design Flood Depths and Extent 2.2 MB Download

Figure 7 - Wagga 2% AEP Design Flood Depths and Extent 2.1 MB Download

Figure 8 - Wagga 1% AEP Design Flood Depths and Extent 2.1 MB Download

Figure 9 - Wagga 0.5% AEP Design Flood Depths and Extent 2.0 MB Download

Figure 10 - Wagga 0.2% AEP Design Flood Depths and Extent 2.0 MB Download

Figure 11 - Wagga PMF Design Flood Depths and Extent 1.8 MB Download

Figure 12 - Hydraulic Categorisation - 1% AEP Event 1.8 MB Download

Figure 13 - Hydraulic Categorisation - 5% AEP Event 1.9 MB Download

Figure 14 - Hydraulic Hazard - 1% AEP Event 11.2 MB Download

Figure 15 - Hydraulic Hazard - 5% AEP Event 11.7 MB Download

Figure 16 - Emergency Response Planning Classification - 1% AEP Event 3.8 MB Download

Figure 17 - Emergency Response Planning Classification - PMF Event 3.6 MB Download

Figure 18 - Flood Planning Area - Post Levee Upgrade 1.7 MB Download

Wagga Wagga Revised Floodplain Risk Management Study and Plan - Stakeholder and Community Communication (2016-17) 318.7 KB Download