Text Box: Estuary Management Program

2007-2008 Annual Report
Water Catchments Team

























The 2007/2008 Estuary Management Annual Report was produced by Peter Coad and Kristy Guise under the direction of Ross McPherson Manager, Water Catchments, Hornsby Shire Council.  Comments, assistance with programs and report contributions were provided by staff from Council’s Water Catchments Team.



For further information contact:



Team Leader – Estuary Management

Water Catchments

Environment Division

Tel:       02 9847 6766

Fax:      02 9847 6598

Email:   pcoad@hornsby.nsw.gov.au

Web:    www.estuary.hornsby.nsw.gov.au



Hornsby Shire Council

Attachment to Report No. EN38/08 Page !Undefined Bookmark, V


Acknowledgements. i

List of Figures. iii


Executive Summary. 1

1      Lower Hawkesbury Estuary. 2

2      Estuary Management Plans. 4

2.1        NSW Estuary Management Program.. 4

2.2        Berowra Creek Estuary Management Plan. 4

2.3        Brooklyn Estuary Management Plan. 4

2.4        Draft Lower Hawkesbury Estuary Management Plan. 5

3      Estuary Management Projects. 6

3.1        Brooklyn and Dangar Island STP Water Quality Monitoring. 6

3.2        Calabash Bay Remote Chlorophyll Monitoring Probe. 6

3.3        Crosslands Masterplan. 7

3.4        Dangar Island Seagrass Protection and Education. 8

3.5        Impacts of Nutrients on Ecosystem Integrity. 9

3.6        Integrated Catchment Model 9

3.7        Kangaroo Point Vessel Pumpout Facility. 10

3.8        Predictive Modelling for Algal Blooms. 10

3.9        QX Disease and the oyster industry. 11

3.10      Recreational Fishing Infrastructure. 12

3.11      Removal of Derelict boats from Sandbrook Inlet 13

3.12      River Settlements and Foreshores Review. 13

4      Estuary Management Budget 14

5      Acronyms. 15

6      References. 15




List of Figures


Figure 1  The Lower Hawkesbury Estuary

Figure 2  Data collected by the probe for the period 29 January to 13 February 2008

Figure 3  Artwork from Brooklyn Public School

Figure 4  Community workshop 2 on Dangar Island

Figure 5  Deploying/collecting and processing control oysters

Figure 6  QX disease cells at 400x magnification

Figure 7  Old concrete fish cleaning table

Figure 8  New stainless steel fish cleaning table

Figure 9  Derelict boats to be removed from Sandbrook Inlet, Brooklyn



Hornsby Shire Council

Attachment to Report No. EN38/08 Page 5


Executive Summary


The management of estuarine areas in NSW is a joint partnership established as part of the NSW Government’s (1992) Estuary Management Policy.  In accordance with this policy, local government bodies facilitate Estuary Management Committees to oversee the development and implementation of Estuary Management Plans.  These plans identify and prioritise management recommendations for individual estuaries, to achieve the integrated, balanced, responsible and ecologically sustainable use of NSW estuaries.


The Estuary Management Annual Report for 2007/08, provides information on Hornsby Shire Council’s Estuary Management Program.  The majority of projects undertaken as part of this program are funded 50:50 by state and local government, with alternate grant funding sought as it becomes available.


During 2007/08 Hornsby Shire Council was responsible for implementing both the Berowra Creek (2000) and Brooklyn (2006) Estuary Management Plans.  Implementation of the Berowra Creek EMP (2000) was completed during this time and a review of the plan undertaken.  For a more integrated approach to estuary management recommendations from both of these plans will be incorporated into a Lower Hawkesbury Estuary Management Plan which will incorporate all the estuarine areas of the shire.  This plan is currently in draft form and was open for public exhibition at the time of writing of this report.


Council’s Estuary Management Program is coordinated by the Water Catchments Team, who are also responsible for water quality improvement and conservation, catchment remediation and total water cycle management.  Various other divisions within Council undertake work that has an influence on estuarine health and amenity and the estuary management program works in partnership with these sections including Bushland and Biodiversity, Environmental Sustainability and Health, Waste Management, Planning and Works.


Collaboration with other local and state government bodies, universities, local industry and the community are primary to the success of many estuary management projects.  Of particular note are the partnerships that have been established with universities to address research and information requirements, including; Australian National University, Macquarie University, University of New South Wales, University of Sydney, and the University of Technology Sydney.


Projects undertaken as part of Council’s Estuary Management Program during the 2007/08 financial year include:             

-    Continued maintenance and upgrades to the Calabash Bay remote chlorophyll monitoring probe

-    Continued maintenance and upgrades to the Kangaroo Point vessel pumpout facility

-    Dangar Island Seagrass Protection and Education program

-    Installation of a new fish cleaning table at Parsley Bay

-    Monitoring of QX disease in Sydney Rock oysters

-    Precommissioning monitoring of the Brooklyn and Dangar Island Sewerage Treatment Plant

-    Removal of derelict boats from Sandbrook Inlet





Hornsby Shire Council

Attachment to Report No. EN38/08 Page 6


1   Lower Hawkesbury Estuary


The Lower Hawkesbury River Estuary is a drowned river valley, which was incised into Hawkesbury sandstone bedrock during the historical ice ages, when ocean levels were much lower then present (WBM 2006).  The estuarine areas of the Hornsby Shire extend from the ocean entrance at Broken Bay upstream to Wisemans Ferry.  There are a number of major tributaries to the Lower Hawkesbury Estuary including Mangrove, Berowra, Mooney Mooney, Mullet, and Cowan Creeks.


Estuaries are influenced by both fresh and salt water inputs, making them unique natural areas.  They provide a variety of habitats that support plants and animals in a rich, diverse and highly interrelated web of aquatic and terrestrial ecosystems (NSW Government, 1992).  The ecology of the Lower Hawkesbury is diverse, containing mangroves, seagrasses, saltmarshes, soft sediments and rocky foreshores (WBM 2006).


The catchment is unique in that the foreshore areas contain significant forested areas with relatively little foreshore development.  The majority of the foreshore and adjacent land is national park (Kimmerikong, 2005).  The drowned river valley morphology, with steep sandstone slopes and incised gorges has meant foreshore areas are largely only accessible by boat.  Those foreshores that are relatively flat are mostly occupied by private development or natural mangrove barriers.  The large extents of national park and the rivers steep topography have limited access and development of foreshores, preserving the natural character and beauty of the estuary (BMT WBM 2008).


With its tall, highly weathered vertical sandstone cliffs and gorges, open waterways, secluded bays and expanse of natural vegetation the Lower Hawkesbury is on the of the most visually spectacular waterways in NSW.  The area is rich in both Aboriginal and European heritage and its accessibility to the population of Sydney and the Central Coast make it a very popular destination for a large number of recreational visitors (WBM 2006).  In addition, the Lower Hawkesbury provides a valuable conservation and educational resource with studies being conducted by students and professional researchers.


The most pressing issues facing the estuary as identified by the Berowra Creek and Brooklyn Estuary Management Plans are: catchment runoff; discharge from boats, sewage disposal; boating and tourism pursuits; aquaculture and fishing; marine and catchment ecology and diversity; heritage and cultural values; the effects of marina management; and wharf, jetty and shoreline development.


Hornsby Shire Council

Attachment to Report No. EN38/08 Page 7


   Figure 1: The Lower Hawkesbury Estuary

Hornsby Shire Council

Attachment to Report No. EN38/08 Page 8


2   Estuary Management Plans


2.1        NSW Estuary Management Program


In response to a growing concern for the state of Australia’s estuaries, the NSW Government developed a state wide Estuary Management Program.  Initiated in 1992, the aim of this program is the production and implementation of Estuary Management Plans (EMP) for all estuaries in NSW.  The program is focused on improving or maintaining the overall health and functionality of estuaries, holistically maintaining the integrity of each system; the chemical, physical and biological properties, as well as the economic, recreational and aesthetic values.  The process of managing an estuary in accordance with this program is initiated by the establishment of an Estuary Management Committee (EMC).


Estuary program decisions and activities are carried out by individual EMCs consisting of representatives from local and state government, residents, academic institutions, industry and other estuary user-groups.  Council currently facilitates the Lower Hawkesbury EMC formed in March 2008 through the amalgamation of the former Berowra Creek and Brooklyn EMCs.  This committee is responsible for overseeing the development and implementation of the Lower Hawkesbury EMP, currently in draft form.


2.2        Berowra Creek Estuary Management Plan


Implementation of the Berowra Creek EMP began in 2002 following its adoption by Council.  In 2007 the EMP was completed and a review undertaken by consultants BMT WBM.


Outcomes of the review show that of the 139 actions outlined in the Berowra Creek EMP, an impressive 112 were implemented fully. Only 13 actions were not implemented, of which a few were no longer relevant. In some cases the implementation of the action has resolved the problem, and no further work is required. More often, however, the actions require on-going commitment and maintenance.  Despite close to 100% implementation of proposed actions, some issues still pose a threat to the health and sustainability of Berowra Creek. Further, new aspects to some issues have become apparent. (BMT WBM 2008)


There are many issues identified within Berowra Creek that are relevant to the entire Lower Hawkesbury River. As such, actions in the Berowra Creek EMP that have been found to be successful in mitigating the issues should be adopted in the Lower Hawkesbury EMP. The Lower Hawkesbury EMP also provides an opportunity to expand on existing work and undertake new innovative actions to achieve a greater level of mitigation of existing threats to Berowra Creek, as well as the Lower Hawkesbury (BMT WBM 2008).


2.3        Brooklyn Estuary Management Plan


Implementation of the Brooklyn EMP began in 2006 following its adoption by Council.  The plan contains a list of recommended strategies that have been designed and prioritised according to the goals and objectives for the future of the Brooklyn Estuary, as agreed by the Brooklyn EMC. 


Goals and objectives for the future management of the Brooklyn estuary were developed through community and stakeholder consultation, input from the Brooklyn EMC and a sound appreciation of estuarine processes and human interactions.  Six overarching goals were defined for the management of the Brooklyn estuary:

1.   for the Brooklyn estuary to contain healthy, diverse and viable ecosystems

2.   for the Brooklyn estuary to provide opportunity for a range of ecologically and commercially sustainable estuary based industries

3.   for the Brooklyn estuary to be a place of great recreational value, with minimum impacts on the natural environment

4.   for the Brooklyn estuary to have good sediment and water quality which is compatible with aquaculture, ecosystem and human health requirements

5.   for the riverside village atmosphere, scenic beauty and character of the Brooklyn estuary to be enjoyed by residents and visitors now and in the future

6.   for the existing and future regulations and policies to be known, understood and adhered to by visitors and residents of the Brooklyn estuary.


For each goal, a series of specific objectives have been defined which describe requirements necessary to achieve the goals for specific aspects of the estuary.  Associated strategies and actions are implemented subject to available funding and resources.  All projects reported on in this report are outcomes of the Brooklyn EMP with relevant objective stated for each project report.


2.4        Draft Lower Hawkesbury Estuary Management Plan


A draft Lower Hawkesbury EMP was developed during 2007/08.  At the time of writing this report the plan was open for public exhibition with the expectation that the plan be adopted by Council in late 2008. 


To address the disparate nature of management on the Lower Hawkesbury the plan has been developed with an integrated whole of estuary approach, providing strategic direction for future management of the estuary and its associated assets.  Recommendations from both the Brooklyn EMP and the Berowra EMP have been incorporated into the plan.  The Lower Hawkesbury EMP recognises that the risks influencing the sustainability of estuarine assets are a direct consequence of the health of the catchments within which it lies and has adopted a risk management approach to developing and prioritising potential future management actions and strategies (BMT WBM 2008).


A series of workshops were undertaken to engage the community and relevant stakeholders in the development of the Lower Hawkesbury EMP.  During these workshops stakeholders were involved in:

-    identifying stakeholder values (assets) and issues related to the estuary

-    identifying overarching goals, visions, and objectives for the estuary

-    assessing estuarine health risks (related to defined issues) for their consequences on the assets and the associated likelihood of these impacts

-    evaluating and prioritising the identified risks

-    defining strategies and their associated actions to treat priority risks

-    determining target stakes of risk reduction the actions are to achieve.



Hornsby Shire Council

Attachment to Report No. EN38/08 Page 10


3   Estuary Management Projects


3.1        Brooklyn and Dangar Island STP Water Quality Monitoring


Objective 4.3 – Assess temporal trends and variability in water and sediment quality in the estuary (WBM 2006).


The Brooklyn & Dangar Island sewerage treatment plant (STP) commenced operation in early 2008.  A number of potential impacts from the outfall have been identified, including elevated nutrient levels and the effects of fresh water inputs on estuarine fauna species.  The Sydney Water Corporation has predicted that the installation of the STP will result in an overall reduction in nutrient loads entering the Hawkesbury River by eliminating the need for onsite sewage management systems in the surrounding area.


In order to detect potential impacts from the STP Council commenced a water quality monitoring program in June 2006 collecting baseline water quality data prior to the commencement of discharge from the STP outfall, located under Peats Ferry Road Bridge.  Six sites have been added to Councils routine water quality monitoring sites.  These additional sites were selected to monitor areas likely to be affected by the outfall (the outfall site, near upstream and near downstream) and control sites i.e. areas unlikely to be affected by the outfall (far upstream and far downstream).  The following parameters are measured at each site monthly: chlorophyll a, nutrients, faecal coliforms, suspended solids; enterococci, conductivity, temperature, salinity; pH; turbidity; and dissolved oxygen.  For results of this monitoring please refer to the 2007/08 Water Quality Monitoring Annual Report (HSC 2008).



3.2        Calabash Bay Remote Chlorophyll Monitoring Probe


Objective 1.3 – Develop a better understanding of ecological indicators through monitoring and research to help guide management decisions (WBM 2006).


Algal blooms have historically been a problem in Berowra Creek, often causing discolouration of the water and on occasion fish kills, especially around the deeper waters at Calabash Bay.  Blooms generally occur during periods of warm weather when there is an increase in nutrients in the water.  Depending on the algae species present, these blooms can pose a threat to local biota, the aquaculture and fishing industry, recreational pursuits and estuarine and public health.


During periods of algal blooms, Council works in collaboration with the Regional Algal Coordinating Committee (RACC), administered by the NSW Department of Environment and Climate Change (DECC), to monitor the bloom and inform the community of possible risks or estuary closures. 


In response to the issue of algal blooms in Berowra Creek, Council engaged the Department of Commerce Manly Hydraulics Laboratory (MHL) in 2002 to deploy a remote chlorophyll monitoring probe (YSI 6820 Sonde) at Calabash Bay.  Since this time, the probe has been collecting real time chlorophyll a, conductivity, salinity and temperature data from the estuary.  Data is transmitted every 15 minutes via a data logger and is displayed on the internet at www.estuary.hornsby.nsw.gov.au.


Chlorophyll levels in excess of 20µg/L are used as an indicator of a potential algal bloom.  If this level is exceeded a warning is sent via email to Council officers who then follow the procedures stipulated by the RACC. The last RACC notified, significantly elevated algae concentrations in the area occurred in January 2007, there were no harmful impacts from the minor bloom.


During 2007/08 the monitoring probe and buoy were upgraded to incorporate a Photosynthetically Active Radiation (PAR) sensor to measure the amount of sunlight entering the water and a thermistor chain to measure the water temperature at 1m intervals from the surface of the water to the bottom of the 14m deep basin.  An Acoustic Doppler Current Profiler (ADCP) was also deployed from the buoy for a number of months to collect current velocities in the area.


Data collected by the probe is supplemented by monthly sampling of phytoplankton species density and diversity and a range of other biological and physico-chemical data.  Maintenance of the probe is undertaken every three weeks during the warmer months and every four weeks during the cooler months by Council’s Water Catchments Team and MHL.


All Frames
Created with Tecplot 10.0-4-10    All Frames
Created with Tecplot 10.0-4-10 


Figure 2:  Temperature, PAR, chlorophyll, and salinity data collected by the probe for the period 29 January to 13 February 2008



3.3        Crosslands Masterplan


Objective 3.4 – Provide adequate infrastructure for passive recreational activities (WBM 2006).


In 2006 Council developed a Masterplan that provides direction to the future character, use, development and management of the landscaped recreation areas of Crosslands Reserve within the Berowra Valley Regional Park.  Accordingly, this Masterplan gives consideration to the directions and objectives set by the Berowra Creek EMP.  The development of this plan was overseen by a focus group which consists of representatives from State and Local Government, the community, park users and key stakeholders.  The Masterplan was adopted by Council in August 2006.


The Masterplan proposes a number of key improvements to the recreational and environmental amenity and the management of pedestrian and vehicular circulation on the site.  Principle improvements the Masterplan proposed include:

-    Entry area improvements

-    New riverside interpretation walk

-    Existing vehicular track removal

-    Reorganisation and refurbishment of the central carparking area

-    Reorganisation of boat launching ramp area

-    Riverbank improvement works

-    Improvement to visitor amenities, including toilets, picnic and BBQ shelters

-    Tree planting


Council completed detailed design, community consultation and construction of the new electric BBQs, shelters, riverside walk and improvements. Implementation of other stage 1 works has commenced and should be completed by mid 2009.  Funding has been derived from a number of sources including the Hawkesbury Nepean Catchment Management Authority (HNCMA), Sate Government Greenspace Grant and Council's Section 94 funds.



3.4        Dangar Island Seagrass Protection and Education


Objective 3.1 – Conserve, and where possible increase, the total areas of estuarine habitat (beyond natural variability) (WBM 2006).


This program, funded by the HNCMA, has provided an opportunity for Council to engage in community consultation and to work with government and community stakeholders to address attitudes and behaviours which lead to potential damage of the Dangar Island seagrass bed. 


The seagrass bed south of Dangar Island is under pressure from impacts of boating activities.  The area is subject to commuter boat traffic from the Dangar Island and Little Wobby settlements, recreational boating including water skiing, recreational fishing boats, houseboats and large boating events such as the annual Bridge to Bridge Water Ski Classic.  These boating activities cause damage to seagrasses in a number of ways: anchors and propellers uproot, damage and kill plants, causing fragmentation of seagrass beds; power boats disturb sediments, increase turbidity, reduce sunlight and can smother seagrasses.  These impacts all reduce the extent, condition and connectivity of the important aquatic habitat provided by seagrasses.


Activities undertaken during this program included successful negotiations between the NSW Maritime Authority and the NSW Water Ski Federation resulting in the 2008 Bridge to Bridge Ski Classic being undertaken with no detrimental impacts on the seagrass beds.  An education program and art competition were held for students at Brooklyn Public School and two community workshops were held on Dangar Island to inform the community of the importance of healthy seagrass communities and provide ideas on how boating activities can be carried out with minimal impact on seagrasses. 


Recommendations for future seagrass protection and education activities arising from the program include:

1.   Ensure future seagrass protection activities incorporate the Lower Hawkesbury River as defined by the Lower Hawkesbury EMP

2.   Establish a Seagrass Protection Partnership to facilitate future seagrass protection in the Lower Hawkesbury River

3.   Continue pro-active communication regarding the ecology of the Lower Hawkesbury River

4.   Establish an on-going community monitoring program for seagrass in the Lower Hawkesbury River


The success of this program was attributed to the exceptional community and agency support, in particular the HNCMA, the NSW Maritime Authority, the NSW Water Ski Federation, the Central Coast Community Environment Network and recreational fishing and boating clubs.




Figure 3:  Artwork from Brooklyn Public School Students                 Figure 4:  Community workshop 2 on Dangar Island



3.5        Impacts of Nutrients on Ecosystem Integrity


Objective 1.3 – Develop a better understanding of ecological indicators through monitoring and research to help guide management decisions (WBM 2006).


The conservation of seagrasses and sustainability of fisheries is of major social and economic concern in Australia and nutrient enrichment is a significant threat to these resources.  Research with the University of Technology Sydney (UTS), will provide an understanding of these issues by experimentally investigating a trophic cascade that links nutrient pollution, seagrass epiphytes and invertebrate grazers to commercially important juvenile crabs.  A trophic cascade occurs in a food chain when a predator suppresses the abundance of its prey, which in turn reduces the predation on the next trophic level of the food chain.


Investigation of trophic cascade effects that link nutrient pollution to the growth and survivorship of seagrass and commercially important species will provide knowledge crucial for improved future management of seagrass habitats.  The primary outcome of this study will be a model that can predict how changes in nutrient concentrations will influence population dynamics of commercially important fish species supported by seagrasses.  This information has therefore, direct relevance to managers of estuarine and coastal environments.


The outcomes of the project will enable the accurate predication of impacts of future nutrient loads on the growth and survivorship of seagrasses and associated fish species.  This information will be invaluable for developing policy for water quality guidelines, conserving seagrass and managing near-shore fisheries.



3.6        Integrated Catchment Model


Objective 1.3 – Develop a better understanding of ecological indicators through monitoring and research to help guide management decisions (WBM 2006).


Council has been monitoring water quality since October 1994 in order to measure long term water quality trends as well as the impact of catchment activities and remediation devices.  To progress the catchment modelling that was undertaken to support the implementation and assessment of the Total Water Cycle Management Plan, Council has engaged Cardno Willing and the Australian National University to develop an integrated catchment model.


It is envisaged that this modelling system will assist environmental managers in making proactive management decisions by being able to predict environmental, social and economic consequences and implications of the current management strategies and decisions.  This model aims to address the relationship between policy decisions, environmental flows, aquatic processes and ecological health.


The intent of this project is to embed the processes that ultimately impact on the estuary within policy/decision frameworks that lead to alteration of environmental flows and pollutant loads.  Accordingly, for the management of these flows and loads an appropriately constructed model is required to assist Council in identifying sources, pathways, interactions and impacts of pollutants through the catchment landscape and its waterways.


This project is intended to add further knowledge to our understanding of catchment and estuarine behaviour in response to human activities.  Specifically, this model will provide managers with an innovative tool whereby impacts to waterway health are considered and internalised when natural resource, social and economic decisions are being made.



3.7        Kangaroo Point Vessel Pumpout Facility


Objective 3.1 – Ensure there is sufficient sold and liquid waste management facilities for the volume of users of the Brooklyn estuary foreshore areas (WBM 2006).


The Kangaroo Point pumpout facility, funded by the (then) NSW Department of Land and Water Conservation, was officially opened in November 2002.  The facility was installed to enable boat users to dispose of effluent in an environmentally acceptable manner and as a practical solution to help restore water quality within the Lower Hawkesbury River. 


To date, the facility has collected over 1.1 million litres of effluent from both commercial and recreational vessels operating on the Hawkesbury River.  The summer months, December, January and February, are the busiest months each year.  Council and the NSW Maritime Authority are continuously working to raise awareness and compliance among boat owners and operators to protect the estuary form unnecessary sources of pollution.


During 2007/08 the facility underwent major upgrades to increase the reliability of the system and make it more user friendly.  Initially the facility required user codes to operate, this allowed council to collect data on the volumes of effluent being collected and identify commercial and recreational users.  Since the upgrades the system is operating on a start/stop operation and is free to all users.  The facility was connected to the new Brooklyn and Dangar Island STP early in 2008.



3.8        Predictive Modelling for Algal Blooms


Objective 1.3 – Develop a better understanding of ecological indicators through monitoring and research to help guide management decisions (WBM 2006).


The occurrence of algal blooms in the Berowra Creek estuary threatens both recreational and commercial pursuits, as such and early warning algal bloom program has been established.  The project will determine whether the issue of algal blooms can be addressed by predicting blooms in advance using an Artificial Neural Network (ANN).  The ANN will utilise data from an onsite real time chlorophyll a probe and data from the Bureau of Meteorology (BOM).  This project is the result of collaboration between Hornsby Shire Council, Manly Hydraulics Laboratory and the University of New South Wales.


This project will fill knowledge gaps for Council with regard to understanding algal bloom processes and mitigation.  In addition, it will provide managers with an opportunity to undertake proactive management strategies by being forewarned of an impending algal bloom, rather than reactive management, by responding to algal blooms only when they occur.  In being able to forecast algal bloom concentrations it is envisaged that Hornsby Council will apply the information to:

-    Improve monitoring efficiency, by monitoring only when problematic concentrations occur

-    Inform recreational users of potential public health risks

-    Inform oyster growers of potential bloom concentrations

-    Determine which environmental conditions are most dominant in causing problematic algal concentrations.



3.9        QX Disease and the oyster industry


Objective 2.2 – Provide support to the commercial fishing and oyster industry to help ensure their long term viability (WBM 2006).


QX disease, named after the state in which it was thought to originate, is a parasitic infection specific to Sydney Rock oysters cause by the protozoan parasite Marteilia sydneyi.  In 2004 QX disease decimated both cultivated and natural populations of Sydney rock oysters in the Hawkesbury River.


Since this time, Council and Broken Bay Oysters farmers have collaborated to undertake monitoring identifying the time of year that oysters become infected with QX disease in the Hawkesbury River.  This is known as the ‘Window of Infection’.  Methodology and training in the identification and analysis of QX disease were provided by leading expert Dr Rob Adlard of QLD Museum and the NSW Department of Primary Industries (DPI).



Figure 5: Deploying/collecting and processing control oysters              Figure 6: QX disease cell at 400x magnification



Every three weeks a basket of control (QX free) oysters from the Shoal Haven are deployed in the Hawkesbury River to remain for a period of six weeks.  After the six week deployment Council’s environmental scientists and oyster farmers dissect and analyse the oysters.  Data is recorded on the physical condition of the oyster, presence or absence of QX disease, and if present, the intensity and stage of the disease.


Data collected during the 2007/08 monitoring period indicates that oysters were infected with QX during a 15 week period, from 9th January to 3rd April 2008.  This is earlier in the year and approximately 3 weeks longer than the 2006/07 Window of Infection period (22nd February to 26th April 2007).













































































To be analysed





















Window of infection period for 2007/2008



3.10      Recreational Fishing Infrastructure


Objective 2.3 – Provide appropriate infrastructure for the boating and tourism industry (WBM 2006).


To improve visual amenity, hygiene and functionality Council obtained funding from the NSW DPI to upgrade the fish cleaning table located at Parsley Bay.  The original concrete table was replaced with a stainless steel table and moved closer to the waters edge.  This will allow easier cleaning, prevent the accumulation of waste from seabirds congregating near the table and provide more open space along the foreshore.


TAngler bins have also been installed at Parsley Bay, Berowra Waters and Wisemans Ferry to collect unwanted recreational fishing line as part of OceanWatch Australia’s TAngler Bin project.  This project aims to reduce the amount of fishing line irresponsibly disposed of in key fishing areas.  Fishing line placed in the TAngler bins is collected by Council and sent to OceanWatch Australia for recycling preventing injury to wildlife, unsightly litter and hazards to boats and other watercraft.




Figure 7: The old concrete fish cleaning table                          Figure 8:  The new stainless steel fish cleaning table


3.11      Removal of Derelict boats from Sandbrook Inlet


Objective 3.7 – Remove abandoned and derelict vessels from the Brooklyn estuary (WBM 2006).


Council is working in collaboration with the HNCMA on an estuary clean up program, removing a number of derelict boats from within Sandbrook Inlet. The NSW Maritime Authority, DPI and DECC are also partaking in the project, funded by the National Heritage Trust and the NSW Estuary Program.


Vessels abandoned on our foreshores potentially threaten local river health by restricting the connectivity of estuarine habitats including mangrove stands, saltmarsh communities and mudflats.  The vessels are also a source of pollution, releasing residual fuel, contaminated bilge water, rust, heavy metals and other toxicants to the waterway as the vessels perish.  Removal of these vessels will aid in restoring the scenic amenity of this area, particularly along the foreshore of Long Island Nature Reserve.


To acknowledge the historical significance of the vessels, in particular MV Surprise II, Council will salvage part of the vessel to display in the area.  MV Surprise was one of the last vessels to be used to transport fruit and vegetables along the Hawkesbury River.




Figure 9: Derelict boats to be removed form Sandbrook Inlet, Brooklyn



3.12      River Settlements and Foreshores Review


Objective 5.1 – Insure that future development is consistent with the nature, scale and scenic quality guidelines in SREP 20 (WBM 2006).


The purpose of the River Settlements and Foreshores Review was to examine the suitability of current planning controls for maintaining the qualities of the river settlements and foreshores of Hornsby Shire, with regard to emerging issues (Brooklyn and Dangar Island STP, limited infrastructure, community character) and current best practice.  The study area for the Review includes the river settlements along Berowra Creek of Berowra Waters, Dusthole Point, Neverfail Bay, Calabash Point, Coba Point, Marramarra Creek, Sunny Corner, and Milsons Passage, together with Dangar Island, Brooklyn and Wisemans Ferry.


The Review makes recommendations concerning amendments to the planning controls which apply to the river settlements.  The recommendations include rezoning residential properties on Dangar Island to the Environmental Protection E (River Settlement) zone, which means that inappropriate uses, such as agricultural structures, attached dwellings, and intensive animal establishments, would no longer be permissible.  The Review also suggests that the scale of development in the Environmental Protection E zone would be better managed by reducing the floorspace ratio which applies to the zone.


To assist in minimising impacts on the natural and built environment, the Review recommends that additional planning controls be drafted.  These include requirements for the design of roof forms, undercrofts, landscaping, boatsheds, seawalls, stairs and fencing, as well as identification of acceptable colours, materials and finishes.


The Review was on public exhibition from May to August 2007.  In June 2008, after consideration of submissions, Council resolved to prepare amendments to planning controls which would:

-    Permit, with development consent, short term accommodation and bed and breakfast accommodation across all river settlements;

-    Rezone residential properties on Dangar Island to the Environmental Protection E (River Settlement) zone;

-    Reduce the floor space ratio in the Environmental Protection E zone from 0.4:1 to 0.3:1; and

-    Specify a minimum Foreshore Building Line for Dangar Island.


Council has forwarded the proposed amendments to planning controls to the Department of Planning for certification for exhibition. Once certified, the proposed amendments will be placed on public exhibition.


Council also resolved to prepare a new River Settlements Development Control Plan (DCP), consolidating the existing DCPs applying to the river settlements and incorporating additional planning controls to assist in minimising impacts on the natural and built environment. The new DCP is currently being prepared and will be presented to Council for endorsement for exhibition.


The remaining recommendations of the River Settlements Review will be considered as part of a longer term review of Council’s planning controls, in the preparation of Council’s Comprehensive Local Environmental Plan, required to be finalised by 2011.



4   Estuary Management Budget


Council was successful in obtaining over $170 000 in grant monies during the 2007/08 financial year from various state and federal government agencies.  The primary sources of funding for the Estuary Management Program are the NSW DECC and the HNCMA who are responsible for distributing National Heritage Trust (NHT) funds.


Council will continue to seek grant funding to continue the implementation of the Brooklyn EMP and the proposed Lower Hawkesbury EMP as the opportunities arise.


Hornsby Shire Council

Attachment to Report No. EN38/08 Page 19


5   Acronyms


ADCP               Acoustic Doppler Current Profiler

ANN                 Artificial Neural Network

BOM                 Bureau of Meteorology

DCP                 Development Control Plan

DECC               NSW Department of Environment and Climate Change

DPI                   NSW Department of Primary Industries

EMC                 Estuary Management Committee

EMP                 Estuary Management Plan

HNCMA            Hawkesbury Nepean Catchment Management Authority

MHL                 NSW Department of Commerce Manly Hydraulics Laboratory

NHT                  National Heritage Trust

NHT                  National Heritage Trust

PAR                 Photosynthetically Active Radiation

RACC               Regional Algal Coordinating Committee

STP                  Sewerage Treatment Plant

UTS                  University of Technology Sydney


6   References


BMT WBM, 2008.  Draft Lower Hawkesbury Estuary Management Plan. BMT WBM Australia.

Hornsby Shire Council (HSC), 2008.  Water Quality Monitoring Program Annual Report. Hornsby Shire Council, Australia.

Kimmerikong, 2005. Scoping Study: Hawkesbury-Nepean River Estuary management Final Report.  Kimmerikong Pty Ltd.

NSW Government, 1992.  Estuary Management Manual.  Crown Copyright, Sydney.

WBM Oceanics Australia, 2006.  Brooklyn Estuary Management Plan.  WBM Oceanics Australia.