Brisbane Water is a youthful, wave-dominated barrier estuary. The water has its origin at the confluence of the Narara and Coorumbine Creeks, to the south–east of Gosford, and travels for approximately 18 kilometres in a southerly direction to its mouth at Broken Bay, about seven kilometres from the Tasman Sea, at Barrenjoey Head.
A number of towns surround the shores - Booker Bay, Davistown, Ettalong Beach, Gosford, Green Point, Kincumber, Phegans Bay, Saratoga, Wagstaffe, and Woy Woy. Contained within Brisbane Water are St Huberts Island, Rileys Island and Pelican Island. Adjoining is Brisbane Water National Park to the west and Bouddi National Park to the east. The total catchment area of the estuary is approximately 152 square kilometres.
A history of the estuary
The land adjacent to the Brisbane Water was occupied for many thousands of years by the Darkinjung and Kuringai Aboriginal peoples, who used it for cultural purposes.
Brisbane Water was named in 1825 in honour of Sir Thomas Brisbane, a Governor of New South Wales between 1820 and 1825. The estuary and foreshores have high scenic value and include areas of pristine vegetation. Access to key vantage points allow the public to experience the landscape character of the surrounds.
Development in the catchment is substantial, with urban, commercial and industrial land use placing pressure on the wetlands, creeks and streams which flow to Brisbane Water. Sediment, excess nutrients, litter, weeds and other pollutants all impact on the health and resilience of the catchments and in turn, of Brisbane Water.
Coastal Zone Management Plan for Brisbane Water Estuary 2012
A Coastal Zone Management Plan consists of a scheduled sequence of activities to achieve the following overarching aims:
- protect, rehabilitate and improve the natural estuarine environment
- manage the estuarine environment in the public interest to ensure its health and vitality
- improve the recreational amenity of estuarine waters and foreshores
- recognise and accommodate natural processes and climate change
- ensure ecologically sustainable development and use of resources.
The plan adopts a list of 183 actions. In recognition that resources are limited, and that some actions are dependent upon the implementation of others, in the first instance implementation focuses upon the top 72 highest priority management actions.
Updates on Ettalong Channel dredging program
The navigational channel from Little Box Head into the Ettalong Channel is prone to shoaling, and this has impacts for maritime passage. On 21 May 2018, the State Government announced further emergency dredging to reinstate navigational access particularly for the public ferry service on the basis that Central Coast Council had committed to apply for matching funding under the Rescuing our Waterways Program. This emergency program is now being implemented by the NSW Department of Industry—Lands & Water and NSW Roads & Maritime Services. Under a separate dredging program, Council will seek to use dredged sand to mitigate the impact of coastal hazards and improve beach amenity. The emergency dredging program ensures boating access for larger vessels is reinstated in the interim period.
Regular updates of the State’s dredging activities can be found on the Department of Industry's website
Brisbane Water Estuary Management Study (2010)
The Estuary Management Study uses the information from the Estuary Processes Study, together with feedback obtained from the community and additional studies, to define management objectives, options and impacts.
The Brisbane Water Estuary Management Study
- Identifies the significance of Brisbane Water in terms of broader coastal planning issues.
- Identifies essential features of the estuary, be they physical, chemical, biological, aesthetic, social or economic.
- Documents current uses and conflicts of use in Brisbane Water.
- Identifies possible land uses and assesses their impact on the essential features.
- Assesses the need for nature conservation and remedial measures.
- Identifies and assesses management objectives.
- Assesses planning controls, works and other strategies to achieve these objectives.
Brisbane Water Estuary Management Study Documents
Brisbane Water Estuary Management Study
BWEM Study - Figures
Appendix A - Photo Log
Appendix B - Community Consultation Materials
Appendix C - Assessment of the Ecological Consequences of GCC Management Plans
Appendix D - Sea Level Rise and the Estuarine Intertidal Zone
Appendix E - Management Issues
Appendix F - Management Options (Unranked)
Appendix G - Catchment Modelling Tool
Appendix H - CLAM Tool Report
Appendix I - Sediment Management Plan
Appendix J - Management Options (Ranked by Category)
Appendix K - Management Options (Ranked by Zone)
Brisbane Water Estuary Processes Study (2009)
Before management options for Brisbane Water could be meaningfully considered, it was necessary to define the ‘baseline’ conditions of the various estuarine processes and interactions between them by carrying out an Estuary Processes Study.
The Brisbane Water Estuary Processes Study was adopted by council in 2009.
Brisbane Water Estuary Processes Study Documents
Brisbane Water Processes Study App A - Stakeholder consultation material
Brisbane Water Processes Study App B
Brisbane Water Processes Study App B - Figures
Brisbane Water Processes Study App C - Figures
Brisbane Water Processes Study App C - Hydraulic Processes
Brisbane Water Processes Study App D - Figures
Brisbane Water Processes Study App D - Estuarine Morphology
Brisbane Water Processes Study App E - WQ Modelling
Brisbane Water Processes Study App F - Heavy Metal and Sediment Quality
Brisbane Water Processes Study App G - Acid Sulphate Soils
Brisbane Water Processes Study App H - Shoreline Assessment
Brisbane Water Processes Study App I - Mangroves
Brisbane Water Processes Study App I - Saltmarsh
Brisbane Water Processes Study App I - Seagrass
Brisbane Water Processes Study App J - Birds
Brisbane Water Processes Study App J - Macrobenthic Fauna in Mangroves
Brisbane Water Processes Study App J - Zostera and Fish Assemblages
Brisbane Water Processes Study App K - Crab Zoeae from Saltmarsh Mangroves
Brisbane Water Processes Study App K - Larval Settlement of Zooplankton and Phytoplankton
Brisbane Water Processes Study App L - Variation in Assemblages of Estuarine Organisms
Brisbane Water Processes Study App L - Habitat Related Biodiversity Patterns
Brisbane Water Processes Study App L - Macroinvertebrates
Brisbane Water Processes Study App N - Recreational Activities and Foreshore Land Uses