The Mudflat Creek catchment is characterised by a distinct upper and lower section (refer Figure 1). The upper section of the catchment is located in the plateau area of Killcare Heights. This section of the catchment comprises of residential development around Wards Hill Road, The Scenic Road and Stewart Street together with a large proportion of natural bushland or rural type land. From the plateau the catchment slopes very steeply down undeveloped, densely forested slopes to the area bounded by Fraser Road and Hardys Bay. This lower section is relatively flat and low lying. Runoff from the plateau area drains to Fraser Road via two natural gullies. Pipe and overland flow systems convey flows from these natural gullies, through the residential areas to Mudflat Creek. Mudflat Creek then travels through the rear of properties 37-63 Fraser Road before reaching the bridge in Noble Road and its outlet to Hardys Bay. Measures and Comparisons in report are:,

The Mudflat Creek catchment is characterised by a distinct upper and lower section. The upper section of the catchment is located in the plateau area of Killcare Heights. This section of the catchment comprises of residential development around Wards Hill Road, The Scenic Road and Stewart Street together with a large proportion of natural bushland or rural type land. From the plateau the catchment slopes very steeply down undeveloped, densely forested slopes to the area bounded by Fraser Road and Hardys Bay. This lower section is relatively flat and low lying. Runoff from the plateau area drains to Fraser Road via two natural gullies. Pipe and overland flow systems convey flows from these natural gullies, through the residential areas to Mudflat Creek. Mudflat Creek then travels through the rear of properties 37-63 Fraser Road before reaching the bridge in Noble Road and its outlet to Hardys Bay. The recommended floodplain management measures for the Mudflat Creek catchment are summarised in Table ii in the summary report (The priority ranking is based upon a combination of reduction in flood risk, ease of implementation and cost/funding implications. There is no particular order of the measures within each priority categorisation).

This Floodplain Risk Management Study and Plan for the Mudgee Local Creeks has been prepared as part of a Government program to mitigate the impacts of major floods and reduce the hazards in the floodplain. Figure 1.1 shows the study area which comprises the urban part of town on the southern bank of the Cudgegong River. This area is drained by seven creeks in addition to Redbank Creek, which was included in the Mudgee Floodplain Management Study and Plan (Bewsher Consulting, 2002). That study dealt with mainstream flooding from the Cudgegong River which also influences flooding near the junctions with the creeks. The seven creeks investigated in the present study comprise Catchments A to F and Sawpit Gully. The Brief for the study issued by Council generally follows the scope of work required for a Floodplain Risk Management Study as identified in the Floodplain Development Manual (FDM, 2005). The NSW Government’s Flood Prone Land Policy and the FDM, 2005 form the basis of floodplain management in the State. Figure 1.2 shows the steps involved in the floodplain management planning process. This report is Volume 1 of the overall investigation and sets out the findings of the Floodplain Risk Management Study and contains the draft Plan. The results of the updated flood investigations of the various creeks are presented in Volume 2. Section 2 of the Study contains information on baseline flooding conditions on the floodplains, including a review of existing planning policies, assessment of the impacts of flooding on the community, flood warning and preparedness and environmental considerations. Section 3 is a review of possible Floodplain Management Measures which could be included in the Plan. Section 4 details the selection of Floodplain Management Measures. Floodplain Management strategies were assessed using a multi-objective approach based on technical, financial, environmental and social considerations and a preferred strategy outlined. Section 5 presents the elements of the draft Floodplain Risk Management Plan. Section 6 contains a list of definitions of flood related terms used in the study Section 7 contains a list of references.

Mudgee Flood Study 2021 Processed Hydraulic Model Results

South Creek is a 7.3 km2 catchment which drains to the southern shore of Narrabeen Lagoon through Cromer Golf Course (Figures 1, 2 and 3). The catchment area is predominantly occupied by urban development (59%) including both residential and commercial/light industrial development, with the remainder comprised of open space and forested areas (41%). The catchment has two main tributary branches. South Creek is the major watercourse and Wheeler Creek is the main tributary draining a significant proportion of the western catchment. In view of the increasing urban development and the need to accurately define the nature and extent of the flood problem, Warringah Council engaged Webb, McKeown & Associates to undertake a Flood Study. The primary objectives of this Flood Study are:,

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The 32km2 Erina Creek catchment is one of the major tributaries entering Brisbane Water at East Gosford (Figure 1). Figure 2 shows a digital terrain image of the study area and Figures 3 to 5 show further detail of the study area. Figure 6 indicates the current land use zones. The Erina Creek Flood Study Review 1990 was completed in 1991 (Reference 1), which utilised information available and current at the time hydrologic and hydraulic models to produce design flood profiles along the lower parts of Erina Creek. The aim of the present study is to update the Erina Creek Flood Study Review 1990 with currently available data, notably the use of airborne laser scanning (ALS) data and more sophisticated hydraulic modelling techniques as well as verification to the June 2007 event. All earlier flood studies of Erina Creek were superseded with completion of the Erina Creek Flood Study Review 1990. WMAwater was engaged by Gosford City Council to undertake the Erina Creek Flood Study Review utilising current technology and data. The information and results obtained from the study will provide a basis for development of targeted stormwater management strategies and a subsequent Floodplain Risk Management Study and Plan. The study was developed in order to meet the primary objective of defining the flood behaviour (50%, 20%, 10%, 5%, 2%, 1%, 0.5%, 0.2% AEP and the Probable Maximum Flood (PMF) design events) along the major tributaries in the Erina Creek catchment. The study area was significantly greater than for the previous 1991 Flood Study. This report details the results and findings of the Flood Study investigations. The key elements include:,

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