Study Objectives

Narrandera Shire Council commissioned the review of the Narrandera Floodplain Risk Management Study and the Narrandera Floodplain Risk Management Plan for the township of Narrandera. The overall objectives of the present study were to review the two aforementioned documents, define the nature of flooding which occurs in the urbanised parts of Narrandera during intense rainfall events, assess the impacts of flooding on the community, review existing Council policies as they relate to development of land in flood liable areas, consider options for the management of flood affected land and to develop a contemporaneous Floodplain Risk Management Plan for the town which:

• Proposes modifications to existing Council policies to ensure that the development of flood affected land is undertaken so as to be compatible with the flood hazard and risk.
• Proposes Flood Planning Levels for the various land uses in the floodplain.
• Sets out the recommended program of works and measures aimed at reducing over time, the social, environmental and economic impacts of flooding.
• Provides a program for implementation of the proposed works and measures. The present study deals with both Main Stream Flooding from the Murrumbidgee River and Major Overland Flow which occurs in the urbanised parts of the town, as well as the presently undeveloped areas immediately to its north.

Study Activities

The activities undertaken as part of present study, details of which are documented in this Floodplain Risk Management Study report included:

1. Undertaking a consultation program over the course of the study to ensure that residents and business owners in Narrandera were informed of the objectives, progress and outcomes over the course of the study.
2. Review of flooding patterns at Narrandera for flood events up to the Extreme Flood, as determined in the Narrandera Flood Study Review and Levee Options Assessment as well as developing a new set of flood models which were used to define the nature of Major Overland Flow at Narrandera.
3. Assess the impact a partial failure of the embankment which runs along the southern side of Murrumbidgee Irrigation’s Main Canal would have on flooding behaviour.
4. Assessment of the economic impacts of flooding, including the numbers of affected properties and estimation of damages.
5. Review of current flood related planning controls for Narrandera Shire and their compatibility with flooding conditions.
6. Review of existing flood warning and preparedness.
7. Strategic review of potential floodplain management works and measures aimed at reducing flood damages, including an economic assessment of the most promising measures and the preparation of a draft Flood Policy to guide future development in flood prone areas.
8. Ranking of works and measures using a multi-objective scoring system which took into account economic, financial, environmental and planning considerations.
9. Preparation of a Floodplain Risk Management Plan for Narrandera.