Project summaries: 2013-14 Floodplain management grants
Ballina Shire Council
Investigation and design of Gallans Road cycleway floodway relief
Located south of Cumbalum Ridge, between the Emigrant Creek and North Creek floodplains, is the Gallans Road cycleway. The cycleway has been constructed on an embankment containing water and sewer mains which services the Ballina Heights estate, minimal cross drainage has been provided. The cycleway has been identified during Community Reference Group consultation as a restriction to movement of flood waters between Emigrant Creek and North Creek. This has been confirmed with flood modelling, which shows a floodway through the cycleway would restore natural passage of floodwater to North Creek and reduce flood levels in Emigrant Creek valley.
Bega Valley Shire Council
Merimbula Lake and Back Lake flood study at Merimbula and surrounds
A flood study will be undertaken for the Merimbula Lake and Back Lake at Merimbula including its corresponding tributaries of Merimbula Creek, Bald Hills Creek and Boggy Creek. The aim is to quantify the flood hazard to the community and existing critical infrastructure such as the Merimbula airport, the Merimbula Central Business District and the Princess Highway amongst others from both mainstream flooding in the nominated creeks but also from water level rise in the lakes adjoining the Merimbula township. It is proposed to investigate the effects of ocean boundary conditions on the lake water levels from elevated sea levels due to storm surge, entrance conditions and climate change effects due to sea level rise. Inundation maps will be produced using a combination of 1d and 2d modelling with hydrodynamic modelling of ocean boundary conditions in accordance with the 2005 NSW Government Floodplain Development Manual guidelines.
Canterbury City Council
Salt Pan Creek catchment overland flow and mapping study
Salt Pan Creek has a catchment area of 26 square kilometres. The catchment land use is primarily residential and commercial with some light industrial centres. A main stream Flood Study was completed in September 2011. This project is an Overland Flow and Mapping Study of the catchment and the scope of this project includes: (1) define and map the overland flow paths in the Salt Pan Creek catchment area in the Canterbury Local Government Area; (2) identify properties affected by overland flow paths to meet the requirements and objectives of the NSW Government's Flood Policy; (3) identify potential impacts of climate change in line with the NSW Government Flood Policy and available best practice technology; (4) utilise the information for Council's development controls; and (5) provide information for the investigation of stormwater amplification works.
The purpose of this project is to actively manage flood drainage systems on the Clarence floodplain. Drainage and flood mitigation works were undertaken on the floodplain, particularly from the 1950’s onwards, for agricultural development and protection of human life and infrastructure. These works had some unintended negative effects on the estuary and associated aquatic life including disruption to fish passage and exacerbation of problematic water quality events such as acid or low oxygen discharges. Published research shows that the active management of floodgates assists in the post flood recovery of the floodplain, improved water quality and acid sulphate soil management and provides better fish passage and improves wetland habitats.
The assets department encourages council to identify flood planning areas and to zone flood prone land appropriately under its comprehensive local environmental plan. Council’s current Flooding Map is based on separate ad-hoc flood studies undertaken to supplement individual development applications over an extended period of time (Council’s flood map existed prior to 1995). It has been demonstrated by Council’s engineers that the information contained in Council’s Flood Map does not reflect the current flooding impacts within the Local Government Area. As a result Council needs to undertake a comprehensive Local Government Area wide flood study in accordance with the NSW Government’s Floodplain Development Manual. Council has successfully completed the flood study for the Floodvale and Springvale catchments and for the Mascot area. Council in this project will cover the Botany.
A comprehensive Flood Study will be undertaken for the catchments of Goulburn. The study will involve community consultation, hydrological and hydraulic modelling, flood estimation and mapping, hazard identification and documentation of flood behaviour.
Greater Hume Shire Council
Jindera flood study, floodplain risk management study and plan
This project initially involves the completion of a comprehensive Flood Study for the Jindera Township aimed at identifying and mapping areas of flood risks due to both overland flow and main stream flooding. This will then be immediately followed by the completion of a Floodplain Risk Management Study and Plan that will identify and prioritise floodplain management options aimed at reducing the impact due to flooding on the local community. This study will also assist in developing emergency management plans to assist Council in managing future development in the town.
Hurstville City Council
Hurstville local government area - floodplain risk management study
Hurstville Floodplain Risk Management Study seeks to establish the extent of potential flooding in the local government area. This area has undergone substantial development since the early 1900's and is planned to become a significant regional centre and home to an increasingly diverse and populous community. A significant outcome will be to understand the extend of the flood issue, better inform our community of the risks, and establish a plan for the protection of property and our community into the future.
Kogarah City Council
Middle Bays floodplain risk management study and plan
Kogarah Council seeks funding for the completion of the Middle Bays Floodplain Risk Management Study and Plan. Council has now completed Floodplain Risk Management Plans in several major catchments including Beverley Park, Kogarah Bay Creek and Poulton Park. The Middle Bays Catchment, comprising Shipwrights Bay, Kyle Bay and Connell's Bay catchments is the next plan to be completed in this program. The project will draw on results of the recently completed Middle Bays Flood Study Revision. The development of the study and plan will provide strategic assessment of the impacts of management options for existing, future and continuing flood risk taking into consideration flood behaviour, flood hazard and the social, economic, ecological and cultural costs and benefits of identified options.
Kogarah City Council
Beverley Park channel diversion - Stage 2 construction of naturalised channel
Kogarah City Council adopted the Beverley Park Overland Flow Risk Management Plan in 2007. Identified as a priority in this plan, the Beverley Park Channel Diversion project diverts flow from the existing concrete lined stormwater channel via a newly constructed naturalised channel through the Beverley Park Golf Course, reducing downstream flooding and providing environmental benefits. Council received funding for Stage One works through the 2007/08 National Disaster Mitigation Program. This work involved the detailed design, consultation, environmental studies, and on-ground works including the construction of inlet and outlet structures from the existing channel and culvert connecting the channel with the golf course. Council now seeks funding for Stage Two works to construct the naturalised channel through the golf course and complete this flood mitigation project. The naturalised channel will reduce peak flood levels by up to 0.84 m, enhance biodiversity, provide an aesthetic feature for the Golf Course, and improve water quality discharged to Kogarah Bay.
Steep terrain and ridge-top development has lead to major flood risks within Ku-ring-gai arising from flash flooding along headwater streams and drainage depressions. The nature of the flash flooding hazard is significant and the speed with which it occurs means that there is usually no time for damage reduction measures to be put in place or for evacuation to be undertaken. The second sub-catchment to be prioritised is one of Ku-ring-gai’s most significantly flood affected areas. The complex nature of flash flooding events means that council has not previously had the resources to undertake detailed mapping at the local scale to provide information to inform flood risk management planning. Urban development occurred from the 1890s to 1950s. The catchment remains largely detached residential but is currently undergoing redevelopment requiring the need for updated flood mapping.
This project will provide a flood study that can be used as the basis of the flood risk management process and provide sufficient data to undertake a flood risk management study and plan to guide future flood risk management actions.
Leeton Shire Council is a small rural Council with a total population of around 12,000 people. Limited rating and development income generally deems projects of this scope outside council's operational capacity. Given the recent flooding events, this is not a delay that Council can justify so this project will help understand flood risks in Leeton.
Maitland City Council
Preparation of flood study of Paterson River
Maitland and Port Stephens have high population growth rates which add to development pressures, resulting in the need for a better understanding of the floodplains. This project involves flood study updates to the 1997 Paterson River Flood Study by upgrading from a one dimensional model to a two or three dimensional model. It will also have increased coverage and a digital terrain model. The study will incorporate flood mapping for floods up to a PMF (Probable Maximum Flood).
Marrickville Valley floodplain risk management study and plan
Marrickville Council in 2011 completed the first stage of the NSW Floodplain Development Manual for Marrickville Valley flood study. The floodplain risk management study and plan will identify and compare flood management options, including an assessment of social, economic and environmental impacts. The plan aims to reduce flood hazard and risk to people and property in the existing community and to ensure future development is controlled with consideration of flood hazard and risk. The plan will be used for sub-catchment management planning.
Nambucca Shire Council
Nambucca River flood risk management study and plan
It is proposed to review the 1999 Floodplain Study and carry out further investigations to reassess and identify impacts of flooding, especially the 1% ARI (average recurrence interval) and its associated inundation of the floodplain and built up areas of Scotts Head, Macksville and Bowraville. This project will utilise the new Hydrological Assessment information recently completed for the Nambucca River. Specific flood management actions will be identified following the study phase of the project.
Nambucca Shire Council
Deep Creek flood risk management study and plan
It is proposed to review the 1999 Floodplain Study and carry out further investigations to reassess and identify impacts of flooding. This project will utilise the new Hydrological Assessment recently completed for Deep Creek. Specific flood risk management actions will be identified following the study phase of the project.
North Sydney Council
North Sydney Council local government area wide flood study
North Sydney Council is updating its Local Government Area wide (10 square kilometres) early 1990s catchment studies to identify properties and council infrastructure that would be affected by flooding as a result of increased development, climate change and a sea level rise. The results will enable Council to provide accurate planning information for different storm events.
Parramatta City Council
Feasibility study for a flood detention basin at Woodville Golf Course, Granville
Little Duck Creek passes through several dense residential areas in Granville, NSW. A recently completed flood study for the area has indicated that many properties along the Creek could be flooded during a large flood event. The Duck River Floodplain Management Study and Plan has identified that it may be possible to reduce flooding in the area by building a flood detention basin at Woodville Golf Course. A feasibility study will be commissioned to investigate possible designs of the flood detention basin and estimate the costs and benefits of the basin. The results of the feasibility study will enable Parramatta Council to decide whether to proceed with basin construction.
The Parramatta River is the major river in the Parramatta Council area. It passes thousands of homes and businesses, including those of the Parramatta Central Business District (CBD), which is Australia's 6th largest CBD. Parramatta Council is starting the process of developing a Floodplain Risk Management Plan for the River, which will look at methods to manage flooding in the Parramatta area, and reduce the social, economic and environmental effects of future floods. Council will undertake the data collection and review which is the first stage of a Parramatta River flood study which highlights the available background information and associated data gaps that may need to be filled as part of the investigations.
Council is seeking to review and upgrade the existing Anna Bay Flood Study. The existing study was carried out using a one dimensional flood model and Council is seeking to upgrade the Anna Bay flood model to a relevant two dimensional model to improve the accuracy of the flood predictions. The Anna Bay and One Mile Beach areas are low lying and considered at risk from more frequent flooding as a result of sea level rise and climate change impacts. The upgraded flood study will review the impacts of sea level rise and climate change on flood levels in the catchment.
Tweed Shire Council
Murwillumbah central business district flood study
The project will provide a local flood study for the central business district and residential area located behind the Murwillumbah levee. The study will examine the local catchment flooding (Lavender Creek) as well as the effectiveness of trunk drainage systems and flood pump systems in order to determine design flood levels and identify potential mitigation and improvement measures. The study will incorporate a levee overtopping analysis to determine hazard areas. The findings of the study will inform development controls behind the levee.
Upper Hunter Shire Council
Preparation of Aberdeen flood risk management study and flood risk management plan
Aberdeen is located immediately downstream of the confluence of the Hunter River and Dartbrook. The town comprises approximately 2000 residents and a significant portion of the town including private residential land, community infrastructures and private recreation facilities are affected by flooding. The Great Northern Rail line and New England Highway both pass through Aberdeen and over the Hunter River and provide a significant barrier to the flow of floodwater through the catchment. The Aberdeen Flood Study was recently completed by Council with the assistance of the NSW Government and Council is committed to proceeding with the next stage of the project, being the preparation of a Flood Plain Risk Management Study and Plan.
Urana Shire Council
Flood study for townships of Urana, Morundah, Boree Creek, Oaklands and Rand
Flood study for the townships of Urana, Oaklands, Rand, Boree Creek and Morundah. The studies will address the issues/damages relating to the flood events that were witnessed shire wide during 2011/12. The flood studies will aim to provide an insight into the extent of damages that may occur in future flood events whilst providing council with actions and measure that will need to be addressed to provide further mitigation measures to the communities within the townships.
Wollondilly Shire Council
Picton (Stonequarry Creek) floodplain risk management study and plan
Provision and adoption of a Floodplain Risk Management Study and Plan in line with updated flood modelling that includes an assessment of climate change risks for Stonequarry Creek through the village of Picton.
Page last updated: 21 October 2013