Study Objectives Key objectives of this study are to:,

The Green Square Floodplain Risk Management Plan has been prepared in accordance with the NSW Floodplain Development Manual (April 2005) and: Is based on a comprehensive and detailed evaluation of all factors that affect and are affected by the use of flood prone land; Represents the considered opinion of the local community on how to best manage its flood risk and its flood prone land; Provides a long-term path for the future development of the community. All possible management measures were evaluated in the Floodplain Risk Management Study (Reference 5) taking into account a range of parameters. This process eliminated a number of measures including:,

The overall objective of this study is to develop a Floodplain Risk Management Study where management issues are assessed, management options are investigated and recommendations are made. Thereafter a Floodplain Risk Management Plan detailing how flood prone land within the study area is to be managed can be completed. The objectives of the Flood Risk Management Study are to:,

AIMS OF THE CURRENT STUDY In broad terms, the current Floodplain Risk Management Study has investigated what can be done to minimise the effects of flooding in the Haslams Creek catchment and recommended a strategy in the form of a draft Floodplain Risk Management Plan. Specific objectives of the study include: a review of the results from the 1999 Flood Study; consideration of the potential for culvert blockages and associated flood impacts; the implementation of a community consultation strategy, to ensure community input is obtained at key times throughout the study; a description and quantification of the flood problems in the Haslams Creek catchment including the likely cost of flooding to the local community; the identification and assessment of potential floodplain risk management measures to reduce the risks and hazards of flooding; a detailed review of issues relating to planning and development controls within the floodplain. Don Fox Planning Pty Ltd has prepared a document entitled Report on Planning Issues as part of this study. It is reproduced in Appendix A. Included in this report, is a proposed draft Development Control Plan (DCP) entitled “Managing Our Flood Risks”; the development of a recommended draft Floodplain Risk Management Plan for the Haslams Creek catchment that outlines the best measures to reduce flood damage, based on environmental, social, economic, financial and engineering considerations.

Conclusions: The objective of the study was to undertake a detailed flood study of the Main Drain J catchment and establish models as necessary for design flood level prediction. This included the assessment of inputs to the catchment from Mirrool Creek. In completing the flood study, the following activities were undertaken:,

The Wollombi Flood Study Review and Model Upgrade completed in 2010 represents the initial stage in the floodplain management process and establishes the basis for the current floodplain risk management study. The objectives of the Wollombi Floodplain Risk Management Study are to:  Identify and assess measures for the mitigation of existing flood risk;  Identify and assess planning and development controls to reduce future flood risks; and  Present a recommended floodplain management plan that outlines the best possible measures to reduce flood damages in the Wollombi locality. This report documents the Floodplain Risk Management Study and presents a recommended Floodplain Risk Management Plan for the Wollombi Village.

Hilltops Council (Council) commissioned the Floodplain Risk Management Study and Plan for the township of Boorowa. 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: i) 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. ii) Proposes Flood Planning Levels for the various land uses in the floodplain. iii) Sets out the recommended program of works and measures aimed at reducing over time, the social, environmental and economic impacts of flooding. iv) Provides a program for implementation of the proposed works and measures. The FRMS focuses on Main Stream Flooding from the Boorowa River, Ryans Creek and Ryans Tributary, as well as two major un-named tributaries, Minor Tributary Flooding caused by high flows in the minor un-named tributaries which drain to the aforementioned watercourses, and Major Overland Flow areas which occur in the urbanised parts of Boorowa and its immediate surrounds.

The recommended Floodplain Risk Management Plan for the Griffith CBD catchments has been prepared in accordance with the NSW Floodplain Development Manual (Reference 6) and: * Is based on a comprehensive and detailed evaluation of all factors that affect and are affected by the use of flood prone land; and * Provides a long-term path for the future development of the community. Griffith is located approximately 450 km north of Melbourne and 560 km west of Sydney in the heart of the Murrumbidgee Irrigation Area (MIA). The CBD and residential areas of Griffith are located at the base of the McPherson Ranges (see Figure 1). Griffith and its surrounding villages of Yenda, Yoogali, Hanwood, Bilbul and Beelbangera lie within the Main Drain “J” catchment, which together with its network of drainage channels delivers runoff to Mirrool Creek. The Griffith CBD catchment has an area of approximately 9 km2. The upper part of the catchment is steep and covered in scattered timber and bushland. South of the bushland area the urban area begins and continues south to Wakaden St and the Temora-Roto Railway Line. This area is predominantly low density residential development. Griffith CBD lies to the south of the railway line, and is characterised by commercial and light industrial land uses. At the downstream extents of the CBD is the Main Canal which is raised above normal ground levels and is consequently a substantial obstruction to overland flow. The City of Griffith is not located on the banks of a major river system and therefore does not experience mainstream flooding as occurs at other centres within the Murrumbidgee River catchment for example Wagga Wagga. However, Griffith and its surrounding areas are affected by high volume rainfall events and also from flooding from the Main Drain J system. In the past, frequent flooding has occurred throughout the commercial areas of Griffith including Yambil Street, even in small rainfall events less than the 6 month ARI for example. Studies have indicated that this flooding has been due to a combination of catchment runoff, blockage and/or insufficient capacity of the sub-surface drainage systems and the associated siphon drainage systems, as well as the elevated railway and canal embankments that impede downstream overland flow paths. Within the study area flows are predominantly distributed and shallow at the upstream or northern sections of the CBD catchment and runoff generally ponds behind the various embankments that tend to be aligned normal to general flow direction such as the Main Canal and railway line, before being gradually discharged through the siphon outlets located under the Main Canal at the downstream boundary of the study area. The Flood Study (Reference 1) also found that the actual flow at the siphons was largely restricted by the upstream drainage system.

Hilltops Council (Council) commissioned the Floodplain Risk Management Study and Plan for the township of Boorowa. 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: i) 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. ii) Proposes Flood Planning Levels for the various land uses in the floodplain. iii) Sets out the recommended program of works and measures aimed at reducing over time, the social, environmental and economic impacts of flooding. iv) Provides a program for implementation of the proposed works and measures. The FRMS focuses on Main Stream Flooding from the Boorowa River, Ryans Creek and Ryans Tributary, as well as two major un-named tributaries, Minor Tributary Flooding caused by high flows in the minor un-named tributaries which drain to the aforementioned watercourses, and Major Overland Flow areas which occur in the urbanised parts of Boorowa and its immediate surrounds.

Hilltops Council (Council) commissioned the Floodplain Risk Management Study and Plan for the township of Boorowa. 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: i) 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. ii) Proposes Flood Planning Levels for the various land uses in the floodplain. iii) Sets out the recommended program of works and measures aimed at reducing over time, the social, environmental and economic impacts of flooding. iv) Provides a program for implementation of the proposed works and measures. The FRMS focuses on Main Stream Flooding from the Boorowa River, Ryans Creek and Ryans Tributary, as well as two major un-named tributaries, Minor Tributary Flooding caused by high flows in the minor un-named tributaries which drain to the aforementioned watercourses, and Major Overland Flow areas which occur in the urbanised parts of Boorowa and its immediate surrounds.