This Floodplain Risk Management Study investigates what can be done to reduce or manage the effects of flooding in the catchment. The Floodplain Risk Management Plan recommends a mix of strategies to manage the risks of flooding. Using the merits-based approach advocated in the NSW State Government’s Floodplain Development Manual (2005) and in consultation with the community, Council and state agency stakeholders, a number of potential options for the management of flooding were identified. These options included: • flood modification measures; • property modification measures; and • emergency response measures. An extensive list of options was assessed against a range of criteria (technical, economic, environmental and social). Hydraulic modelling of some of the flood modification options was undertaken to provide a comprehensive analysis of those options that would involve significant capital expenditure.

FLOODPLAIN RISK MANAGEMENT STUDY The specific aims of this study are to:,

A Floodplain Risk Management Study and Plan (FRMS&P) for the Beverley Park catchment has been prepared by Cardno Lawson Treloar for Kogarah Council. The FRMS&P identify and examine options for the management of flooding within the Beverley Park catchment floodplain and is prepared in accordance with the NSW Government Floodplain Development Manual (2005). A locality plan can be found in Figure 1.1. The outline of the study area can be found in Figure 1.2. Study Context This study consists of the two stages of the multiple stages of the Floodplain Management process which includes:,

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.

Flood Risk Management Study & Plan - Main report (Part 1 of 4) This Lake Macquarie Waterway Flood Risk Management Study and Plan constitutes a review of the second and third stage of the management process, namely the August 2000 Lake Macquarie Floodplain Management Study and the July 2001 Lake Macquarie Floodplain Management Plan. This review has been prepared by consultant WMAwater for Lake Macquarie City Council and was undertaken following a review of the 1998 Lake Macquarie Flood Study, to include the June 2007 long weekend storm/flood event and incorporation of the implications of climate change. The results of this Waterway Flood Risk Management Study and Plan Review will provide the basis for the future management of flood liable foreshores areas surrounding the Lake Macquarie waterway. The study concentrates on those areas of the foreshore within the boundaries of Lake Macquarie City Council, with no investigation of land within the Wyong local government area.

This report documents the Lake Wyangan Floodplain Risk Management Study and Plan which investigates and presents a flood risk management strategy for the catchment. The study identifies the existing flooding characteristics and canvasses various measures to mitigate the effects of flooding. The end product is the Floodplain Management Plan, which describes how flood liable lands within Lake Wyangan are to be managed in the future.

Introduction The Dora Creek Flood Risk Management Plan has been prepared for Lake Macquarie City Council (Council) in accordance with the NSW Floodplain Development Manual (April 2005 - Reference 1) and the August 2010 Flood Risk Management Guide – Incorporating sea level rise benchmarks in flood risk assessment (Reference 4) and: Is based on a comprehensive and detailed evaluation of 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; and Provides a long-term path for the future development of the community. The Dora Creek catchment is located on the western side of Lake Macquarie waterway, 30 km south-west of Newcastle and 120 km north of Sydney. Dora Creek has a catchment area of approximately 238 km2 and is the largest catchment flowing into the Lake Macquarie waterway which has a total catchment of 648 km2 (Figure 1). The study area focuses on the existing township of Dora Creek and includes the townships of Cooranbong and Avondale, where new and planned rural and urban developments are proposed within the floodplain. The upper limit of the study area extends above Freemans Drive to Cooranbong and downstream to the confluence of Dora Creek with the Lake Macquarie waterway. There are three main tributaries within the catchment with Dora Creek being joined by Jigadee Creek at Cooranbong and then Stockton Creek before draining into Lake Macquarie waterway at Bonnells Bay and Lake Eraring. Watercourses within the catchment area and above the tidal limit are narrow; Dora Creek is typically less than 15 m wide upstream of Freemans Drive. Below the tidal limit, the creeks become broader with Dora Creek varying from a width of 50m at the Sydney to Newcastle Freeway to 100m where it forms a delta into Lake Macquarie waterway. Upstream of the delta the Eraring Power station draws cooling water for steam condensation from Bonnells Bay, which passes under Dora Creek through a concrete tunnel and open canal.