Study Objectives

Bourke Shire Council (Council__) commissioned the preparation of the Louth Flood Study_ (___Flood Study) and the Floodplain Risk Management Study and Plan for the village of Louth. The overall objectives of the Floodplain Risk Management Study (FRMS) were to assess the impacts of flooding, 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 Floodplain Risk Management Plan (FRMP) 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 first steps in the process of preparing the FRMP were the collection of flood data and the review and update of the flood modelling which was originally undertaken as part of the Rural Flood Study Darling River Floodplain (Bogan River Confluence to Louth) (URS et al., 2009). The updated flood modelling for Louth (denoted the Flood Study) formed the formal starting process of defining management measures for flood liable land and represented a detailed technical investigation of flood behaviour for the village.

The FRMS focuses on flooding that originates from the Darling River, as well as flooding that occurs as a result of heavy and/or prolonged rain that falls directly over Louth.

Study Activities

The activities undertaken in this FRMS included:

1. Undertaking a consultation program over the course of the study to ensure that the Louth community was informed of the objectives, progress and outcomes over the course of the study.

2. Analysis of historic stream flow data to generate the flood frequency relationships for the Darling River at Louth.

3. Development of hydraulic models and the definition of Darling River and local catchment flooding for flood events up to the Extreme Flood.

4. Assessment of the economic impacts of flooding, including the numbers of affected properties and estimation of flood damages.

5. Review of current flood related planning controls for Louth and their compatibility with flooding conditions.

6. Strategic review of potential floodplain risk management works and measures aimed at reducing flood damages, including a freeboard analysis and an economic assessment of potential flood modification measures.

7. Ranking of works and measures using a multi-objective scoring system which took into account economic, financial, environmental and planning considerations.

8. Preparation of a FRMP for Louth.