DRAFT
Tweed Coast Estuaries Management Plan 2004 - 2008
Cudgen, Cudgera and Mooball Creeks
May 2004
Prepared For
Tweed Shire Council
Prepared by
North Coast: 70 Butler St Byron Bay 2481 Tel: (02) 66855466 Fax: (02) 66809406 [email protected]
Draft Tweed Coast Estuaries Management Plan 2004 - 2008 Tweed Shire Council
Executive Summary
The Tweed Coast estuaries of Cudgen, Cudgera and Mooball Creeks, situated south of the Tweed River mouth between Kingscliff and Wooyung, are small barrier estuaries, highly regarded by the local communities, with substantial productivity and biodiversity values.
The 1997 Estuary Management Plan began a formal long-term management phase for the three systems. Implementation of the recommendations has been reliant on funding and support. The Plan has provided a good basis for the next phase of managing the three estuaries of Cudgen, Cudgera and Mooball Creeks, with a number of projects underway.
This Draft Estuary Management Plan integrates the conclusions of the Review of Implementation of the 1997 Plan, a summary of documents, policies and significant developments around the estuaries since 1997, and the contributions of community members who attended the community consultation meetings.
Healthy estuary ecosystems are those in which key processes are sustained, habitats remain intact, and human impacts do not cause further deterioration. This Draft Plan embraces the long-term vision of healthy, productive and attractive estuaries that can be resilient to all types of responsible land uses and possess healthy ecological and recreational values. This goal can be achieved through well-founded, cooperative and integrated management.
Water quality management is critical to sustainable overall management of the estuaries. The philosophical approach by the responsible authorities now is to focus on issues, not numbers. Water quality guidelines should be used to help achieve management goals and maintain values. This Draft Plan proposes the adoption of the Tweed River Water Quality Objectives for the three coastal estuaries.
General strategies are proposed for the protection, maintenance, rehabilitation, and enhancement of environmental values including water quality, entrance management, recreational aspects, and catchment management.
Environmental management authorities strongly support the total catchment management plan approach in addressing non-point source pollution such as agricultural runoff. The main objectives of these plans should be set with the downstream aquatic environment in mind. Such plans require targeted monitoring and assessment for effectiveness.
The concept includes the negotiation and statement of environmental quality goals, co-operative best management, and sharing of responsibility and costs. This approach has been carried through all the reports and recommendations of the NSW Healthy Rivers Commission, and is adopted by the Catchment Blueprint program.
The Blueprint or Northern Rivers Integrated Catchment Management Plan 2002-2012 is supported as the best chance of achieving the vision of healthy waterways and estuaries through a consultative, science and community based approach to solving the challenges of estuary management.
2 Australian Wetlands Draft Tweed Coast Estuaries Management Plan 2004 - 2008 Tweed Shire Council
Table of Contents
1 INTRODUCTION...... 7
1.1 ESTUARY HEALTH ...... 7 1.2 ESTUARY MANAGEMENT PLANNING ...... 7 1.3 CUDGEN CREEK ...... 8 1.4 CUDGEN LAKE...... 8 1.5 CUDGERA CREEK ...... 9 1.6 MOOBALL CREEK ...... 10 2 POLICY FRAMEWORK...... 11
2.1 THE NSW COASTAL POLICY ...... 11 2.2 COASTAL PROTECTION PACKAGE ...... 11 2.2.1 Comprehensive Coastal Assessment ...... 11 2.2.2 SEPP 71 - Coastal Protection...... 12 2.3 THE CATCHMENT BLUEPRINT...... 12 2.4 SEPP 14 AND 26 ...... 13 2.5 HEALTHY RIVERS COMMISSION (HRC) COASTAL LAKES STRATEGY ...... 14 2.6 HRC NORTH COAST RIVERS ...... 15 2.7 ECOLOGICALLY SUSTAINABLE DEVELOPMENT ...... 15 3 ESTUARINE PROCESSES ...... 16
3.1 FUNCTION ...... 16 3.2 NUTRIENTS ...... 16 3.3 ENVIRONMENTAL FLOWS...... 18 3.4 FUTURE ESTUARY PROCESSES STUDY ...... 19 4 WATER QUALITY...... 21
4.1 TWEED SHIRE COUNCIL MONITORING ...... 21 4.1.1 Cudgen Estuary ...... 21 4.1.2 Cudgera Estuary...... 21 4.1.3 Mooball Estuary...... 22 4.2 WATER QUALITY OBJECTIVES...... 22 4.3 RECOMMENDATIONS ...... 25 5 MONITORING ...... 26
5.1 MONITORING PROGRAM...... 26 5.2 RECOMMENDATIONS ...... 30 6 CATCHMENT MANAGEMENT...... 34
6.1 CUDGEN VEGETABLE GROWING AREA ...... 34 6.2 RECOMMENDATIONS ...... 35 7 STORMWATER...... 36
7.1 TWEED URBAN STORMWATER MANAGEMENT PLAN (1999)...... 36 7.2 DEVELOPMENT CONTROL PLANS...... 37 7.3 STORMWATER MANAGEMENT...... 37 7.4 WATER SENSITIVE URBAN DESIGN ...... 38 7.5 RECOMMENDATIONS ...... 39 8 ACID SULPHATE SOILS (ASS)...... 40
8.1 GENERAL STATUS OF ASS ...... 40 8.2 COUNCIL PROGRAMS...... 44 8.3 RESTORING THE BALANCE ...... 45 8.4 RECOMMENDATIONS ...... 45
3 Australian Wetlands Draft Tweed Coast Estuaries Management Plan 2004 - 2008 Tweed Shire Council 9 SEWAGE MANAGEMENT...... 46
9.1 HASTINGS POINT STP ...... 46 9.2 PROPOSED MOOBALL-BURRINGBAR STP...... 46 9.3 ONSITE SEWAGE SYSTEMS ...... 47 10 ENTRANCE MANAGEMENT...... 48
10.1 POLICY CONTEXT...... 49 10.2 HEALTHY RIVERS COMMISSION...... 49 10.3 RECOMMENDATIONS ...... 50 11 BANK EROSION...... 51
11.1 CUDGEN CREEK ...... 51 11.2 CUDGERA CREEK ...... 51 11.3 MOOBALL CREEK ...... 52 11.4 RECOMMENDATIONS ...... 52 12 FAUNA...... 57
12.1 AQUATIC FAUNA ...... 57 12.2 AVIFAUNA...... 57 12.2.1 Waders...... 60 12.2.2 Shore Birds ...... 60 12.2.3 Birds of Prey ...... 60 12.3 RECOMMENDATIONS ...... 61 13 FLORA ...... 62
13.1 MANGROVES...... 62 13.2 SEAGRASSES AND MACROPHYTES...... 62 13.3 CUDGEN CREEK ...... 63 13.4 CUDGERA CREEK ...... 63 13.5 MOOBALL CREEK ...... 64 13.6 RECOMMENDATIONS ...... 64 14 RECREATIONAL VALUES ...... 68
14.1 BOATING ...... 68 14.2 RECREATIONAL FISHING ...... 68 14.3 SWIMMING...... 69 14.4 RECOMMENDATIONS ...... 69 15 TWEED LOCAL ENVIRONMENT PLAN (LEP) 2000 ...... 70
16 GLOBAL WARMING AND SEA LEVEL RISE ...... 71
17 CHANGES IN THE ESTUARIES SINCE 1997...... 72
17.1 CUDGEN CREEK CATCHMENT ...... 72 17.2 CUDGERA CREEK CATCHMENT ...... 72 17.3 MOOBALL CREEK CATCHMENT...... 72 18 COMMUNITY CONSULTATION ...... 73
18.1 INDIGENOUS ISSUES ...... 73 18.2 GENERAL COMMUNITY...... 73 18.3 CUDGEN CREEK SPECIFIC ISSUES ...... 75 18.4 CUDGERA CREEK SPECIFIC ISSUES ...... 75 18.5 MOOBALL CREEK SPECIFIC ISSUES...... 76 18.6 OVERALL DESIRABLE OUTCOMES ...... 76 19 THE STRATEGY...... 77
19.1 HIERARCHY OF WORKS...... 77 19.2 WATER QUALITY ...... 77 19.3 NEW DEVELOPMENTS ...... 77 19.4 BUFFER ZONES...... 78 4 Australian Wetlands Draft Tweed Coast Estuaries Management Plan 2004 - 2008 Tweed Shire Council 19.5 HABITAT ...... 78 19.6 RECREATIONAL VALUES ...... 78 19.7 ENTRANCE MANAGEMENT ...... 78 20 IMPLEMENTATION SCHEDULE...... 79
21 STRATEGIES, ACTIONS AND COSTS 2004-2008...... 81
21.1 CUDGEN CREEK ...... 81 21.2 CUDGERA CREEK ...... 92 21.3 MOOBALL CREEK ...... 101 22 FUNDING SOURCES...... 111
23 REFERENCES ...... 113
APPENDIX 1 - WATER QUALITY ...... 116
A1 CLIMATE ...... 116 A2 CUDGEN ESTUARY ...... 118 A3 CUDGERA ESTUARY ...... 120 A4 MOOBALL ESTUARY...... 124 A5 COMPARISONS OF THE ESTUARIES...... 129 A6 INDICATIONS OF ACID SULPHATE RUNOFF ...... 130 A7 CONCLUSIONS ...... 132 A7.1 Cudgen Estuary ...... 132 A7.2 Cudgera Estuary ...... 133 A7.3 Mooball Estuary ...... 133
5 Australian Wetlands Draft Tweed Coast Estuaries Management Plan 2004 - 2008 Tweed Shire Council
List of Figures
FIGURE 1 INTERACTIONS BETWEEN FRESH AND SALT WATER WITHIN AN ESTUARY...... 19 FIGURE 2 BROAD OUTLINE OF THE FOUR MAIN STEPS IN WATER RESOURCE MANAGEMENT. ADAPTED FROM ANZECC (2000)...... 24 FIGURE 3 WATER SENSITIVE URBAN DESIGN GENERAL APPROACH ...... 39 FIGURE 4 AVERAGE RAINFALL BY MONTH AT KINGSCLIFF, 1969-2003. SOURCE: BUREAU OF METEOROLOGY...... 116 FIGURE 5 MONTHLY RAINFALL AT KINGSCLIFF IN 1974. SOURCE: BUREAU OF METEOROLOGY...... 117 FIGURE 6 FAECAL COLIFORMS AT CGN1OVER FOUR YEARS ...... 118 FIGURE 7 TOTAL NITROGEN AT CGN1 OVER FOUR YEARS...... 119 FIGURE 8 TOTAL PHOSPHORUS AT THE THREE SITES OVER FOUR YEARS ...... 119 FIGURE 9 CHLOROPHYLL A CONCENTRATIONS AT THE THREE SITES OVER FOUR YEARS...... 120 FIGURE 10 DO AT THE THREE SITES OVER FOUR YEARS ...... 120 FIGURE 11 FAECAL COLIFORM CONCENTRATIONS AT THE FOUR SITES OVER FOUR YEARS...... 121 FIGURE 12 FAECAL COLIFORM CONCENTRATIONS IN THE LOWER ESTUARY OVER FOUR YEARS...... 122 FIGURE 13 TOTAL NITROGEN AT THE FOUR SITES OVER FOUR YEARS ...... 122 FIGURE 14 TOTAL PHOSPHORUS AT FOUR SITES OVER FOUR YEARS ...... 123 FIGURE 15 CHLOROPHYLL A AT THE FOUR SITES OVER FOUR YEARS ...... 123 FIGURE 16 DO AT THE FOUR SITES OVER FOUR YEARS...... 124 FIGURE 17 DO AT CGR-3 OVER FOUR YEARS ...... 124 FIGURE 18 FAECAL COLIFORM CONCENTRATIONS AT THE FOUR SITES OVER FOUR YEARS...... 125 FIGURE 19 FAECAL COLIFORM COUNTS NEAR THE MAIN SWIMMING AREAS IN THE LOWER ESTUARY...... 126 FIGURE 20 TOTAL NITROGEN CONCENTRATIONS AT THE FOUR SITES IN THE YEAR 2000 ...... 126 FIGURE 21 TOTAL NITROGEN CONCENTRATIONS AT THE FOUR SITES IN 2001...... 127 FIGURE 22 CHLOROPHYLL-A AT THE FOUR SITES OVER FOUR YEARS...... 127 FIGURE 23 CHLOROPHYLL A AT THE UPPER ESTUARY SITE OVER FOUR YEARS...... 128 FIGURE 24 DISSOLVED OXYGEN (DO) CONCENTRATIONS AT THE FOUR SITES OVER FOUR YEARS ...... 128 FIGURE 25 DO AT THE UPPER ESTUARY SITE OVER FOUR YEARS ...... 129 FIGURE 26 TOTAL NITROGEN CONCENTRATIONS AT THE LOWER SITES IN THE THREE ESTUARIES ...... 129 FIGURE 27 FAECAL COLIFORM CONCENTRATIONS AT LOWER SITES IN THE THREE ESTUARIES ...... 130 FIGURE 28 TOTAL IRON CONCENTRATIONS IN THE MOOBALL ESTUARY OVER FOUR YEARS ...... 131 FIGURE 29 TOTAL IRON CONCENTRATIONS AT THE FOUR CUDGERA ESTUARY SITES, ON ONE DAY ...... 131 FIGURE 30 TOTAL IRON AT SITE CGN3 OVER FOUR YEARS ...... 132
List of Plates
PLATE 1 CUDGEN PLATEAU AGRICULTURAL AREA ...... ERROR! BOOKMARK NOT DEFINED. PLATE 2 RECENT STORMWATER WORKS SHOWING LARGE PIPE OUTLET WITH "DRY SWALE" - A PLANTED INFILTRATION CHANNEL ...... ERROR! BOOKMARK NOT DEFINED. PLATE 3 STORMWATER PIPE OUTLET TO CUDGEN LAKE ...... ERROR! BOOKMARK NOT DEFINED. PLATE 4 AGRICULTURAL DRAIN IN LOW-LYING AREA OF MOOBALL CATCHMENT ..... ERROR! BOOKMARK NOT DEFINED. PLATE 5 STORMWATER PIPE AND BANK EROSION IN MOOBALL CREEK...... ERROR! BOOKMARK NOT DEFINED. PLATE 6 OSPREY NESTS ON TOWERS AT THE KINGSCLIFF COAST GUARD STATION . ERROR! BOOKMARK NOT DEFINED. PLATE 7 MANGROVE DIE-BACK IN CUDGERA CREEK...... ERROR! BOOKMARK NOT DEFINED. PLATE 8 BITOU BUSH CONTROL ALONG MOOBALL CREEK ...... ERROR! BOOKMARK NOT DEFINED. PLATE 9 SMALL MOTOR BOAT MOORED NEAR CARAVAN PARK ON LOWER CUDGERA CREEKERROR! BOOKMARK NOT DEFINED. PLATE 10 PERSONAL WATER CRAFT IN CUDGEN CREEK ...... ERROR! BOOKMARK NOT DEFINED.
6 Australian Wetlands Draft Tweed Coast Estuaries Management Plan 2004 - 2008 Tweed Shire Council
1 Introduction
The Tweed Coast estuaries of Cudgen, Cudgera and Mooball Creeks, situated south of the Tweed River mouth between Kingscliff and Wooyung, are small barrier estuaries, highly regarded by the local communities, with substantial productivity and biodiversity values. These ecosystems are fairly typical of many small coastal estuarine creeks along the northern NSW Coast. They flow northwards behind the coastal sand barrier and have dynamic, generally constricted entrances that largely control their tidal and morphological characteristics (TSC, 1999).
Each estuary is subject to a range of natural and human impacts, including a balance of erosion and filling processes, agriculture, urbanisation and recreational pressures.
The accompanying report, Review of Implementation, has assessed the first Estuary Management Plan written in 1997 for the three estuaries. This section integrates the conclusions of the Review assessment, a summary of documents, policies and significant landscape changes since 1997, and the important contributions of community members who attended the community meetings.
1.1 Estuary Health
'Estuary health' refers to the maintenance of the components and processes of estuarine ecosystems, and reflects the general concept of 'ecological health'.
Managing the ecological health of waterways by maintaining species, populations and ecosystem integrity over time is a concept supported by the Australian and New Zealand Environment and Conservation Council (ANZECC) guidelines (ANZECC, 2000). The concept of 'ecological health' is a primary management goal. Healthy estuary ecosystems are those in which key processes are sustained, habitats remain intact, and human impacts do not cause further deterioration.
Measurable features in this Plan that indicate ecological health are described from scientific monitoring and the presence of natural features the community expects:
• abundance and diversity of key groups: fish, shorebirds, invertebrates (e.g. yabbies, prawns, soldier and bubble crabs) • preservation of critical habitats: no further loss of seagrass beds and subtidal/intertidal shoals • water that people can swim in and grow oysters in; safe levels of pathogens and low nutrients, trace metals and pesticides.
1.2 Estuary Management Planning
The Estuary Management Program was established in 1992 to restore and protect estuaries along the NSW coast. The Program targets a broad range of issues and engages local communities in the process.
7 Australian Wetlands Draft Tweed Coast Estuaries Management Plan 2004 - 2008 Tweed Shire Council The program focuses on improving or maintaining the overall health and functionality of an estuary, and maintaining the integrity of the whole system - its chemical, physical, and biological properties, as well as its economic, recreational, and aesthetic values (NSW Government, 1992).
The NSW Estuary Management Program encourages local communities to take responsibility for managing their own estuaries. The aim of this Plan therefore is to engage the community in each estuarine area in a partnership approach by providing a framework for maintaining and improving the ecological integrity of the three estuaries.
The framework of the Plan has been designed to encompass recreational and commercial uses of the estuaries and their catchments, in addition to the environmental focus. The Plan proposes a holistic approach to the management of the three estuaries.
The Plan therefore embraces the long-term goal of healthy, productive and attractive estuaries that can be resilient to all types of responsible land uses and possess healthy ecological and recreational values. This goal can be achieved through cooperative and integrated management.
1.3 Cudgen Creek
Kingscliff in the north is situated at the entrance of Cudgen Creek. This estuary is now permanently open through the installation of breakwalls in 1967, with the entrance frequently used by commercial and recreational fishers to gain access to the ocean. The estuary extends 9.4km to the south, meeting Cudgen Lake at Bogangar (TSC, 1999).
The highly modified Blacks Creek enters Cudgen Creek from the west about halfway along its course. Clothiers and Reserve Creeks enter Cudgen Lake, draining the western sections of the 66km2 catchment of Cudgen Creek.
Bogangar and Cabarita Beach lie at the southern edge of the catchment, southeast of the lake, while the new developments of Casuarina and Salt line the eastern sections between the estuary and the beach.
Cudgen Lake covers an area of 1.65 km2 and is generally less than 2m deep, effectively acting as a large detention pond, buffering upper catchment inputs to Cudgen Creek. The lake has been subject to several major fish kills due to impacts from Actual Acid Sulphate Soils (AASS) within the catchment (TSC, 1999).
1.4 Cudgen Lake
Cudgen Nature Reserve encompasses Cudgen Lake and is managed by a separate entity, the NSW National Parks and Wildlife Service. The Actions and Strategies outlined in this EMP are in accordance with the Cudgen Nature Reserve Plan of Management, and support the holistic approach to managing Cudgen Creek and its catchment.
8 Australian Wetlands Draft Tweed Coast Estuaries Management Plan 2004 - 2008 Tweed Shire Council Cudgen Lake and its upstream floodplains act as a natural flood retention basin from which water is drained slowly to the sea through Cudgen Creek. Floodwaters are generally released at approximately one-twentieth of the inflow rate (WBM Oceanics Australia, 1998).
The Healthy Rivers Commission's (HRC) Coastal Lakes Inquiry (2002) identified Cudgen Lake as one of the systems that should have a Sustainability Assessment and Management Plan prepared. The responsibility for this action was given to the then PlanningNSW and Department of Land and Water Conservation (who have now joined to become the Department of Infrastructure, Planning and Natural Resources (DIPNR)), in conjunction with Tweed Shire Council (HRC, 2002). At time of writing, this Assessment is planned for the near future (R. Hagley, DIPNR, pers. comm.).
In order to create a successful and integrated management plan for Cudgen Lake and its catchment, DIPNR and Council need to continue consultation with NPWS and the community. This is necessary to determine appropriate strategies, based on well- defined common goals, that will improve the lake in the long term with ecological and recreational processes and activities in mind. Regular meetings and workshops would reinforce this approach.
The boundaries of the estuary study can extend as far inland, seaward and along the coast as necessary to take in management issues that may significantly impact on the ecological and recreational values of the estuary, as well as development controls (NSW Government, 1992).
One strategy of the Cudgen Nature Reserve Plan of Management (NPWS, 1998) is that "the NPWS supports the principles of total catchment management and estuaries management and will liaise with local government and other authorities to maintain and improve the water quality in the Reserve and its catchment",
From this, the NPWS planned to "establish a coordinated cooperative approach to undertake studies and the management of Cudgen Lake, Cudgen Creek and its catchment through the Tweed Catchment Management Committee, involving the National Parks and Wildlife Service, the Cudgen Lake Restoration Committee and the Tweed Coast Estuaries Management Committee. Such management will aim for the ecological sustainability and environmental protection of Cudgen Lake, Cudgen Creek and relevant catchment areas".
1.5 Cudgera Creek
Cudgera Creek meets the sea at Hastings Point. The natural entrance is kept open most of the time due to the geomorphology of the headland and longshore movements.
It has a fairly straight channel and follows a 3.5km course south to Pottsville (TSC, 1999). The estuary has three major branches: i) Christies Creek opposite the entrance, ii) Cudgera Creek main channel, which branches off at North Pottsville, draining the Cudgera Creek locality in the west and surrounding agricultural lands, and iii) Palmvale Creek, which continues to the south, draining SEPP 14 Wetland south- west of the Pottsville shopping centre.
9 Australian Wetlands Draft Tweed Coast Estuaries Management Plan 2004 - 2008 Tweed Shire Council Cudgera Creek is physically relatively unmodified, as there has been no breakwall construction and relatively small-scale development within the 50km2 catchment (TSC, 1999). Recent developments include the Koala Beach and Seabreeze Estates in the upper catchment to the north and west of Pottsville.
1.6 Mooball Creek
Mooball Creek is the largest and most southern of the three creeks. The waterway runs parallel to the coastal dunes, extending approximately 9km south from its mouth at Potts Point. This estuary was once part of Cudgera Creek, however at some time it broke out to the sea at Potts Point (TSC, 1999). It is now permanently open to the sea through the construction of breakwalls.
Mooball Creek is joined by Crabbes Creek, which is the major drainage system in the area as well as a number of other tributaries west of Wooyung. Sheens Creek enters approximately halfway along Mooball Creek. This system drains a total catchment area of approximately 117km2. The catchment is largely dominated at its southern end by cane farming (TSC, 1999).
Pottsville has a relatively large urban area with further development occurring at Black Rocks Estate. The extended horseshoe-shaped canal system of Pottsville Waters, with two openings to Mooball Creek is located approximately 1.8km from the mouth (TSC, 1999).
10 Australian Wetlands Draft Tweed Coast Estuaries Management Plan 2004 - 2008 Tweed Shire Council
2 Policy Framework
2.1 The NSW Coastal Policy
The 1997 NSW Coastal Policy is the major Policy governing planning and management of the coastal zone. The Policy aims to provide for population growth and economic development without placing the natural, cultural, spiritual and heritage values of the coastal environment at risk. To achieve this, the Policy has a strong integrating philosophy based on the principles of ecologically sustainable development (ESD).
The Policy addresses a number of key coastal themes including: • Population growth in terms of physical locations and absolute limits; • Coastal water quality issues, especially in estuaries; • Disturbance of acid sulphate soils; • Establishing an adequate, comprehensive and representative system of reserves; • Better integration of the range of government agencies and community organisations involved in coastal planning and management; • Indigenous and European cultural heritage; and • Integration of the principles of ESD into coastal zone management and decision making.
The 1997 Coastal Policy includes coastal waters and lands one kilometre landward of the open coast high water mark, and land within one kilometre of coastal rivers, lakes, lagoons, estuaries and islands. The policy requires that: water quality will be maintained or improved, fisheries habitats protected and restored where possible; and coastal lands and aquatic environments with conservation values will be assessed and appropriate measures put in place to protect them (NSW Government, 1997).
All NSW Government Agencies are to take account of the policy in the preparation of their own policies and programs. Local councils are required to take account of the policy through a s.117 direction under the Environmental Protection and Assessment Act 1979 in the preparation of LEPs and when considering development applications (NSW Government, 1997).
2.2 Coastal Protection Package
The NSW Premier and Deputy Premier announced the Coastal Protection Package on 26 June 2001. The $11.7 million Package includes several components, outlined below:
2.2.1 Comprehensive Coastal Assessment
Comprehensive Coastal Assessment (CCA) is a key element of the Coastal Protection Package. It is a whole-of-government $8.6 million three-year program that aims to identify, analyse and assess data and information on the physical, biological, social, and economic values of the State’s coastline. 11 Australian Wetlands Draft Tweed Coast Estuaries Management Plan 2004 - 2008 Tweed Shire Council
Although the program is at an early stage, it is planned that the CCA will provide a wide range of information about the features and values of the land, estuaries, people and industries of the coast, and identify trends affecting them.
At the completion of the CCA, the State Government, local government, industry and communities will have better information available for improved State, regional and local planning and management decisions to better protect the coast. It will provide a regional context to inform local decision-making and strategic planning and will establish working partnerships between local and State Government.
During the preparation of this Plan, the authors met with representatives of NSW EPA and CSIRO at Cudgen Lake for the purpose of information exchange on the nature and status of the lake as part of the CCA process. It is anticipated that a document with associated ecosystem modelling as a basis for better management of the lake will be delivered in the second half of 2004.
2.2.2 SEPP 71 - Coastal Protection
The policy aims to protect and manage the natural, cultural, recreational and economic attributes of the NSW coastal zone. It also aims to ensure that development within the coastal zone occurs in a strategic manner, and that development is appropriate and suitably located in context to the adjacent and surrounding coastal attributes. Lastly the policy seeks to ensure that coastal development doesn’t place life and property in conflict or at risk.
Land that comes under SEPP 71 includes all land within one kilometre of coastal waters, estuaries and bays. The policy is an interim measure until: • Regional Strategies prepared under the PlanFIRST program are implemented with equivalent provisions for the coastal zone; • The Comprehensive Coastal Assessment (CCA) being coordinated by the Resource and Conservation Division of PlanningNSW is completed, thus enabling better data and tools to be available for improved decision-making on coastal planning and management.
2.3 The Catchment Blueprint
The Integrated Catchment Management Plan for the Northern Rivers 2002 – 2012 (The Blueprint) was prepared by the Northern Rivers Catchment Management Board (NRCMB) "to provide a clear directive for action and investment in catchment natural resources". The Blueprint is consistent with National and State Policy, involving consultation with key stakeholder groups.
The NRCMB in 2001 assessed the priority natural resource and environment management issues in the Northern Rivers catchment as Biodiversity, Water (both quality and quantity), Landuse Planning, Acid Sulphate Soils, and Aboriginal Cultural Heritage.
12 Australian Wetlands Draft Tweed Coast Estuaries Management Plan 2004 - 2008 Tweed Shire Council The NRCMB has adopted a "targets approach" to catchment repair under the Blueprint, and drafted the following objectives to achieve by 2011: • better management of biodiversity; • a land use planning system that protects prime agricultural land and reduces landuse-related conflict; • improvements in surface water and groundwater quality; • reduction in acid discharge from identified acid sulphate soil Hotspots; and • improved management and protection of sites with significant Aboriginal cultural heritage values.
The Blueprint further aims at: • ensuring Aboriginal and contemporary cultural heritage is protected, understood and incorporated sensitively into the economic activities of the community; and • encouraging community participation in the management of high conservation value ecosystems through the promotion of economic opportunities using market based incentives (carbon and biodiversity credits) and other mechanisms.
The Blueprint has a life of 10 years and the aim is that investment in the priority management actions will have a large impact in improving the environmental health and prosperity of the Northern Rivers catchments. Two of the systems targeted for early work are the wetlands of Cobaki Broadwater and Cudgen Nature Reserves.
Wetlands are seen as very suitable for restoration and better management in partnership with landholders because of the multiple benefits in biodiversity, waterway health, and economic and social benefits from healthier fisheries. Another of the Blueprint projects with application to the Tweed Coast estuaries is the mapping of estuary resources, including seagrass and mangrove areas, by NSW Fisheries. These maps will provide good baseline information for estuary managers and the community to assess changes over time.
2.4 SEPP 14 and 26
State Environment Planning Policies are legally binding across NSW. SEPP 14 (Coastal Wetlands) mandates that classified wetlands will be preserved and protected for environmental and economic reasons. Formal consent is required to clear, drain or fill designated wetlands. SEPP 26 (Littoral Rainforests) protects littoral rainforest from inappropriate development proposals. Tweed Shire Council has mapped the areas of SEPP 14 and SEPP 26. The maps are accessible on Council's website, and are summarised in Maps 10-12.
13 Australian Wetlands Draft Tweed Coast Estuaries Management Plan 2004 - 2008 Tweed Shire Council 2.5 Healthy Rivers Commission (HRC) Coastal Lakes Strategy
The Coastal Lakes Strategy (HRC, 2002) is an over-arching set of principles designed to improve the management of coastal lakes and their catchments.
The strategy incorporates: • principles for managing coastal lakes, • a framework for managing major classes of coastal lake, • a classification of coastal lakes, • requirements for preparing and implementing Sustainability Assessment and Management Plans for each coastal lake, • implementation arrangements, and • a range of supporting initiatives
Classifying coastal lakes is a first step towards the identification of a set of realistic goals for each lake, and a management plan able to achieve them cost effectively. Each coastal lake is classified according to its natural sensitivity, current condition of the water body and catchment, recognised ecosystem and resource conservation values, and other significant socio-economic factors.
Classification of coastal lakes has been defined as, in descending order: • Comprehensive Protection • Significant Protection • Healthy Modified Conditions • Targeted Repair
Principles of the Coastal Lakes Strategy are summarised as: • Each coastal lake and its catchment are to be managed as a whole system, treated as assets, are to address the unique characteristics and interrelationships of ecosystems, and must provide for adaptive management. • Management plans are to be sufficiently clear to create explicit obligations on the responsible public authorities. • The responsible public authorities are to be accountable for the condition of coastal lakes at the conclusion of each cycle of planning, action and assessment.
Sustainability Assessment and Management Plans are pivotal components of the Coastal Lakes Strategy. Each Plan will determine and record any other outcomes sought for a given coastal lake, its capability and limitations to sustain existing and likely human activities, the actions to be implemented, and the most appropriate selection and design of management tools. The Plans will also lead to the specification of explicit provisions in Councils' local environmental plans (HRC, 2002). Cudgen Lake is one of the pilot sites for the Sustainability Assessment and Management Plans.
14 Australian Wetlands Draft Tweed Coast Estuaries Management Plan 2004 - 2008 Tweed Shire Council 2.6 HRC North Coast Rivers
The HRC compiled recommendations within the North Coast Rivers report (HRC, 2003) that pertained to estuarine dredging, navigation and river health. It was recommended that future dredging of estuary entrances should only be carried out within the context of ecologically sustainable development, with explicit regard to managing estuary and river health. There are significant costs and environmental impacts associated with dredging, about which there is no current guiding government policy for tidal waters.
The HRC recommended the creation of a NSW entrance and estuary dredging policy that covers aspects such as the consideration of individual circumstances for each dredging application, appropriate regulatory and auditing regimes, and how specific decisions could be better informed of likely environmental responses of dredging (HRC, 2003). The formation of a taskforce was also recommended, to undertake a review of the goals and implications of dredging for navigation and boating safety.
2.7 Ecologically Sustainable Development
Ecologically Sustainable Development (ESD) requires the integration of environmental and economic considerations in the process of decision making, and incorporates a number of important principles including: • "The precautionary principle - if there are threats of serious or irreversible environmental damage, lack of full scientific certainty should not be used as a reason for postponing measures to prevent environmental degradation. • "Intergenerational equity - the present generation should ensure that the health, diversity and productivity of the environment is maintained, or enhanced, for the benefit of future generations. • "Conservation of biological diversity and ecological integrity, and • "Improved valuation and pricing of environmental resources.
15 Australian Wetlands Draft Tweed Coast Estuaries Management Plan 2004 - 2008 Tweed Shire Council
3 Estuarine Processes
3.1 Function
An estuary is defined as "a semi-enclosed body of water which has a free connection with the open sea water, which is measurably diluted with freshwater derived from land drainage" (Cameron and Pritchard, 1963, cited in Pierson et al., 2002)
Estuaries are dynamic coastal environments not only in terms of short-term responses to climate but at geological time scales due to natural processes that progressively convert estuarine water areas to terrestrial flood plains, levees and backswamps.
As remnants of central mud basins, cut-off embayments become increasingly important as the estuary evolves. They trap organic materials, act as nutrient processing systems and are biologically highly productive (NSW Government, 1997; Roy et. al., 2001).
The link between estuary form and function is based on interactions between: • Depositional environments with various morphologies and types of sediment that determine styles of nutrient cycling and create biological substrates, • Hydrological zones with characteristic water quality properties, and • Habitats that, to varying degrees, support estuarine biota.
Estuary hydrology is characterised by fluctuations in salinity due to inflows of freshwater and saltwater, ambient heating and cooling as seasonal weather conditions change, and mixing by currents. Mixing of water masses is influenced by tidal exchange (which relates to estuary type) and also by the size and shape of the estuary basin which determine the effectiveness of wave stirring and wind induced currents.
Salinity gradients become more pronounced as the estuaries approach maturity, mud basins infill, fluvial and estuarine deltas merge and riverine channel zones elongate. Salinity gradients are particularly enhanced in lower reaches of some semi-mature barrier estuaries where their tributaries experience more marine conditions than the main channel (Roy et. al., 2001).
3.2 Nutrients
In temperate Australia, because of the eucalypt-dominated vegetation, and the resultant fire regime and poor soils, estuaries in pre-European times were low nutrient systems and in particular nitrogen limited. Two hundred years of land clearing, agriculture and urban development have greatly increased nutrient loadings, and undoubtedly have enhanced primary productivity in most estuaries, expressed as algal growth, in some cases beyond sustainable levels (SoEAC, 1996).
16 Australian Wetlands Draft Tweed Coast Estuaries Management Plan 2004 - 2008 Tweed Shire Council Estuaries receive and store sediments and nutrients from the land. Estuaries cycle nutrients internally and regulate their discharge to the coastal ocean. Some nutrients are flushed to the sea in floods, and some are sequestered with the estuarine sediments as they accumulate (McComb, 1984).
Interest in nutrient cycling in estuaries is based on the assumption that rates of primary production and estuary productivity overall are regulated by the rate at which nutrients are introduced and cycled. Nutrient cycling is facilitated by the bacterial decomposition of organic matter and the consequent flow of the released energy to the ecosystem (Wetzel, 1999; Roy et al., 2001).
The essential nutrients produced and cycled in estuaries originate both from within- estuary sources (such as mangroves and seagrasses) and from the land, particularly the large floodplain wetlands that are closely coupled to estuaries. Seasonal exports of nutrients in rainfall events stimulate bacterial, phytoplankton and benthic microalgal production, which are important factors in coastal food webs.
The "detrital pathway" of energy flow begins with plant photosynthesis followed by the breakdown of the organic molecules with their rich energy stores and balanced nutrients, by fungi and bacteria. These microbial populations are then consumed by larger organisms in a food chain that features increasing orders of animal life (McComb and Lake, 1990).
The high plant productivity of wetlands and floodplain systems results from the efficient use of longer water-supply periods by inundation-adapted plants, and extensive recycling of essential resources such as nutrients and carbon through efficient conservation mechanisms (Wetzel, 1999).
Most dissolved organic carbon (DOC) generated in wetlands is derived from this high- rate photosynthesis and the subsequent breakdown of detritus. The energy-rich carbon moves to estuaries, and as it is partially utilised by the ecosystem the remainder becomes more resistant to breakdown. This process also results in a 'slow release' of the nutrients. This food material for fish stocks also increases in nutrient value as it is colonised by bacteria during passage through the estuary ecosystem (Rice and Tenore, 1981).
Case Example - Richmond River The Eyre and Twigg (1997) study of nitrogen and phosphorus behavior during post- flood recovery of the Richmond River Estuary was a landmark in the understanding of North Coast estuary nutrient processes. Although the Richmond is obviously a much larger estuary, the system functions are typical of many Australian estuaries.
During the flood phase, dissolved nutrients were found to be at higher concentrations in the upper estuary, and decreased gradually downstream, as dilution and mixing with marine waters increased. Dissolved oxygen and pH were lower at the head of the estuary, reflecting the influence of lower pH runoff. During recovery from the flood, dissolved and particulate materials established complex vertical and horizontal gradients. Ammonium concentrations were found to increase downstream from the head of the estuary. This was thought to result from decomposition of particulate nitrogen from the sediments which flocculated from flood waters as they met marine conditions during the flood phase.
17 Australian Wetlands Draft Tweed Coast Estuaries Management Plan 2004 - 2008 Tweed Shire Council Dissolved inorganic phosphorus was in highest concentrations at the head of the estuary, with rapidly decreasing concentrations moving downstream, as biological uptake and adsorption reactions removed dissolved phosphorus. Moving further downstream (as salinities rose) the pH increased, and an increase in dissolved phosphorus was observed. This was thought to be a result of desorption of phosphorus from mineral oxides, such as iron and aluminium, at higher pH values and during interactions with anaerobic sediments (Eyre and Twigg, 1997).
Excessive mineral nutrient loads from human land uses such as fertiliser use in catchments and sewage discharge, can have major deleterious effects on estuarine ecosystems through oversupply of bioavailable nutrients (Valiela et al., 1992).
The subsequent over-production of algae results in oxygen crashes when algae die and decompose, and at night when algae consume oxygen and produce carbon dioxide. The consumed oxygen is then no longer available for fish and other animals. Oxygen concentrations are thus a key indicator of estuarine health.
3.3 Environmental Flows
"Environmental flows", or "environmental water", describes fresh water flow (typically in-stream flow) that is maintained solely for environmental reasons, to maintain the health and biodiversity of a particular water related entity, such as a river, wetland, groundwater system or estuary. Environmental flows are essential to minimise damage to the health of aquatic ecosystems resulting from alterations to flow regime (Pierson et al 2002).
"Fresh water is an integral part of the definition of an estuary and so deserves primacy in all aspects of estuarine ecology… Changes to inflows have harmed many estuaries in the world" (Pierson et al., 2002). Fresh water flow is important for entrance morphology, with reduced flows allowing the entrance to completely or partially close. This closure can obstruct fish and crustacean migration, alter estuarine flushing and water quality, and alter the salinity gradient (Pierson et al., 2002).
Figure 1 below shows the interactions between the fresh water inflows and the tidally- driven salt water within a typical small estuary. The section view shows a well developed "salt wedge", in which fresh water overlies salt with a distinct measurable boundary between the two.
18 Australian Wetlands Draft Tweed Coast Estuaries Management Plan 2004 - 2008 Tweed Shire Council Simple Conceptual Model of Small Estuary Structure
Sea water Strong tides dominant Ocean
Freshwater dominant
Extensive Climate-pulsed shoaling land-derived Tidally-pulsed “Turbidity maximum” energy ocean-derived main oxidation and energy sedimentation zone
Plan View
Freshwater dominant Sea water Seasonally shifting dominant
Section
Figure 1 Interactions between fresh and salt water within an estuary
A study completed by Drinkwater and Frank (1994) reviewed the effects of reduced fresh water inflows to estuaries on fish and invertebrates, and concluded that a general decline in coastal fisheries occurred where there was a reduced flow of fresh water.
Loneragan and Bunn (1999) showed that freshwater flows to estuaries can have a strong positive effect on the production of commercial and recreational fisheries. The study also showed that the seasonal pattern of flow is equally, if not more important, than the magnitude of flow. Despite these potential links between flow and the secondary production of estuaries and coastal waters, there is still a common perception that 'the water going to sea is wasted' resulting in a continuing drive to regulate the flow of rivers in some regions.
Irrespective of the mechanisms that link river flow and fish production, the significant positive relationships between catches of fish and crustaceans and river flow, has important implications for river managers - they demonstrate that water flowing to the sea is not wasted (Loneragan and Bunn, 1999).
Natural flow patterns of estuaries should be mimicked as far as possible.
3.4 Future Estuary Processes Study
The processes identified from other systems would form one of the bases of a focused Processes Study of one or all of the three Tweed Coast Estuaries. Such a study should be considered, with the aim of identifying specific estuarine processes and pollutant sources in the three systems as a basis for more targeted management.
19 Australian Wetlands Draft Tweed Coast Estuaries Management Plan 2004 - 2008 Tweed Shire Council Processes studies can be large and costly, but such a processes study could be cost- effectively limited to answering specific questions such as: • what is the relative importance of different oxygen-demanding materials entering the estuary from major drainage networks? • what are the patterns of pollutant movements from urban areas during rainfall events? • what is the status of macroinvertebrates in the estuaries?
These investigations could be limited to one estuary for a detailed study, and extrapolated, with simple indicators examined in the other two estuaries to ascertain whether the patterns observed will operate over all three. Because of the similarity in size and land use in the three estuaries, it is thought that many patterns will be common, as can be seen in the Water Quality section (below).
20 Australian Wetlands Draft Tweed Coast Estuaries Management Plan 2004 - 2008 Tweed Shire Council
4 Water Quality
This section presents a summary and conclusions about water quality in the three estuaries, based on the physical and chemical data collected by Council over the last four years, and proposes an approach to setting water quality objectives for the three estuaries.
4.1 Tweed Shire Council Monitoring
The 1997 Estuaries Management Plan recommended that water quality sampling should be carried out every two months, with at least two specific events to be monitored each year (e.g. heavy rain). It was advised to monitor events through a full tidal cycle, while the regular sampling should be taken at high spring tides, and should involve samples taken from near the surface and near the bottom of the water column.
Since 1999, Tweed Shire Council has been undertaking water quality testing at set monitoring points along the three estuaries. The timing of sampling has ranged from fortnightly to six-weekly. The monitoring results have been assessed for trends and key features over the four years, and are detailed in Appendix 1. The main conclusions are outlined below.
4.1.1 Cudgen Estuary Based on the four year monthly monitoring program: • water quality in the estuary is within a range where focused improvements in catchment management are likely to produce a measurable effect in meeting water quality objectives; • faecal coliform counts indicate the lower estuary is almost always suitable for swimming, except after significant rainfall; • the monthly monitoring appears to be insufficient to distinguish particular pollutants in wet weather events, such as the widely reported erosion of topsoil from Cudgen vegetable growing areas; • agricultural and urban stormwater appear to be the dominant influence on pollutant inputs to the estuary.
4.1.2 Cudgera Estuary Based on the four year monthly monitoring program: • water quality in the estuary is within a range where focused improvements in catchment management are likely to produce a measurable effect in meeting water quality objectives; • faecal coliform counts indicate the lower estuary is suitable for swimming only in periods when rainfall is low; • the relatively small size of the estuary may be an important factor in the impact of wet season pollution events on the lower estuary, as there appear to be relatively high levels of some pollutants entering the lower estuary more frequently than in the Cudgen and Mooball estuaries; • agricultural and urban stormwater appear to be the dominant influence on pollutant inputs to the estuary
21 Australian Wetlands Draft Tweed Coast Estuaries Management Plan 2004 - 2008 Tweed Shire Council
4.1.3 Mooball Estuary Based on the four year monthly monitoring program: • water quality in the estuary is within a range where focused improvements in catchment management are likely to produce a measurable effect in meeting water quality objectives; • faecal coliform counts indicate the lower estuary is almost always suitable for swimming, except after significant rainfall; • agricultural and urban stormwater appear to be the dominant influence on pollutant inputs to the estuary
4.2 Water Quality Objectives
Traditional "command and control" approaches that have been used to deal with point sources of pollution "have produced an end of pipe and minimum compliance culture", and this approach is now not an appropriate method of addressing non-point or diffuse pollution (ANZECC, 2000).
The philosophical approach being applied now is to focus on issues, not numbers. Water quality guidelines should be used to help achieve management goals and maintain values. Management should not focus on individual guidelines, but be issue- based, addressing the overall problems (ANZECC, 2000).
Setting of water quality objectives for waterways involves a well-defined series of assessment steps: • an overall vision of what condition (or environmental values) is desired for the waterway, • the setting of guideline trigger values for local conditions, based on the ANZECC Guidelines, • definition of the specific water quality to be achieved, • formulation of a monitoring and assessment program, and finally, • stating a management response to the results (ANZECC, 2000).
Numerical criteria provide the basis for ascertaining how close current water quality is to meeting desired levels of water quality. The NSW EPA issued the Interim Environmental Objectives for Coastal Waters in 1999, with environmental values, their indicators and their numerical criteria. This approach was refined by the ANZECC Guidelines released in 2000.
The main changes from the 1992 Guidelines to the 2000 Guidelines relate to the emphasis on regarding water quality targets as guidelines, not standards. Australian waterways vary greatly, and are found in varying degrees of health. This fact means that flexibility is necessary in setting water quality objectives (ANZECC, 2000).
A third assessment relevant to setting objectives is the Tweed River and Catchment Interim Water Quality Management Plan (TRMPAC) (WBM Oceanics, 2000) developed mainly by Tony McAlister, and adopted by Council.
22 Australian Wetlands Draft Tweed Coast Estuaries Management Plan 2004 - 2008 Tweed Shire Council This last study reported the environmental values set by the Tweed River Management Plan Advisory Committee as: • aquatic ecosystem protection • production of edible raw shellfish • primary contact recreation (swimming and action sports) • secondary contact recreations (boating)
Table 1 compares ANZECC (2000) criteria with those developed by WBM Oceanics (2000) and the TRMPAC for the nearby Tweed River estuary. The latter were derived by integrating EPA objectives with water quality data obtained from a number of "largely undeveloped" waterways in southeast Queensland.
Table 1 Key water quality indicators and selected criteria Key indicator Criteria for estuaries Criteria adopted by TSC (ANZECC, 2000)1 for the Tweed River (WBM Oceanics Australia, 2000)2 Total Phosphorus 0.045mg/L3 <0.05mg/L Total Nitrogen 0.08mg/L4 <0.5mg/L Dissolved Oxygen 90% saturation (with >6mg/L professional judgement) Chlorophyll a5 2ug/L <10ug/L pH 7.5-8.5 (with 7-9 professional judgement) Faecal coliforms <150cfu/100mL (NSW <14cfu/100mL EPA) 1Criteria based on 80 percentile for those parameters where upper levels represent a risk, and 20 percentile for those (such as Dissolved Oxygen) where lower concentrations are a problem. 2WBM Oceanics note: "these objectives represent typical levels that are desirable over the longer period (weeks to months). Occasional violations…are not usually a major issue." 3Total Phosphorus: assessment of water quality data from reference sites gives a starting point for developing locally applicable criteria. Typical numbers are 0.02-0.05 mg/L (EPA, 1999). 4Total Nitrogen: analysis of water quality data for many healthy coastal lakes and estuaries indicates a range of 0.15-0.3 mg/L (EPA, 1999). The ANZECC Guidelines suggest 1.6mg/L (lowland river) and 0.08mg/L (estuary) - this indicates a mid-range figure would be appropriate for the freshwater-saltwater interface. 5Chlorophyll a is measured as ug/L (micrograms per liter)
Given the facts that the objectives, key indicators and criteria were developed locally through consensus, and based on consideration of data from reference ecosystems, it is recommended that the Tweed River Water Quality Objectives be used as a starting point for setting of objectives for the three Tweed Coast estuaries.
Two further criteria of interest are: (i) fringing vegetation: "In any water body, changes that vary the relative importance of detrital and grazing food chains should be minimised", and (ii) "Artificial watercourses should meet the objectives (including protection of aquatic ecosystems) applying to natural waterways at any point where water from the artificial watercourse flows into a natural waterway" (NSW EPA, 1999).
23 Australian Wetlands Draft Tweed Coast Estuaries Management Plan 2004 - 2008 Tweed Shire Council The EPA further state that "Local water quality varies naturally because of various factors, including the type of land the waters are draining (e.g. soils, slope), or rainfall and runoff patterns (e.g. ephemeral or permanent streams). Different land use and land management practices also affect water quality. Local Water Quality Objectives must take account of these variations, particularly for the environmental value of aquatic ecosystems."
"The approach to protecting the aquatic ecosystem should consider the whole range of interacting factors, such as variability of water quality over time, sediment interactions, river flow, local geology, land use, the needs of sensitive habitats, and people's uses for water. Assessing ecosystem health also requires using a range of indicators and considering local modifying factors-such as basalt soils that result in naturally higher nutrient levels, or estuary opening patterns that affect water quality. However, information on a full range of indicators may not be available from regular monitoring" (NSW EPA, 1999).
This work will usually be done by government agencies or government agency representatives on water management committees. The committees may recommend local refinements to Government for approval, through the Ministers for the Environment and for Land and Water Conservation (NSW EPA, 1999). The approach is set out schematically in Figure 2.
Guidelines Identify environmental Guidelines issue
Establish Monitor and goals and Report targets
Guidelines
Management Guidelines actions
Figure 2 Broad outline of the four main steps in water resource management. Adapted from ANZECC (2000).
24 Australian Wetlands Draft Tweed Coast Estuaries Management Plan 2004 - 2008 Tweed Shire Council
4.3 Recommendations
• Continue water quality monitoring within the three creeks, with new monitoring points included • Set objectives for water quality management • Consider costs and benefits of an Ecological Health Assessment
25 Australian Wetlands Draft Tweed Coast Estuaries Management Plan 2004 - 2008 Tweed Shire Council
5 Monitoring
Reliable data as a basis for management is fundamental in achieving the commitment to maintaining and improving the health of waterways. It was also recognised by the EPA that improvements in monitoring programs were needed to adequately address current natural resource management and reporting frameworks (NSW EPA, 1999).
A continued focus on quality assurance issues (specifically, data quality and consistency in the protocols used) and data sharing will assist in meeting the broad range of data needs. Coordination is necessary.
Water monitoring is defined as a scientific activity that: • makes measurements of indicators on a regular and event basis • adopts preferred protocols for data generation • makes assessments against standards or benchmarks
5.1 Monitoring Program
The approximately monthly monitoring by Council is valuable and should be continued. However, the sampling should be carried out at the same time of day wherever possible, and such environmental conditions as state of tide, weather, and visible water quality indicators such as colour, odour and appearance should be noted. The time of sampling is an important issue. Sampling in the early morning, for example, will measure lower oxygen concentrations than in the afternoon, particularly where nutrients and algae are elevated. However sampling at the same time of day will achieve the main objective of this type of monitoring, which is to detect trends over time.
The parameters monitored appear to be suitable, and should be continued. It is recommended however that nitrogen should be measured in the specific forms of ammonia (NH4-N) and organic N to enable better definition of processes, and Biochemical Oxygen Demand should be added to the suite of water quality parameters for the same reason.
Event monitoring as recommended in the 1997 Estuary Management Plan should be carried out, either through training of sampling staff in designing an event sampling program, or by engaging specialists. Three new “event” monitoring sites in Cudgen Creek and the agricultural drain from the Cudgen Plateau started in December 2003. Sampling at the new sites, known as Cudgen 4, 5 and 6, occur following 50mm rain in 24 hours. The locations of the new sites are:
• CGN4 - Cudgen Creek upstream of Jack Julius Park • CGN5 - First culvert on Tweed Coast Road, Cudgen end (major drain). • CGN6 - Cudgen Creek adjacent to Seaside City development site.
26 Australian Wetlands Draft Tweed Coast Estuaries Management Plan 2004 - 2008 Tweed Shire Council The siting of monitoring points in mid-estuary can provide valuable long term records, but monitoring of focus points in the drainage network will provide hard information on pollutant sources. It is recommended that consideration be given to an event monitoring program that would target, and quantify where possible, pollutant exports from each major agricultural drain in the estuaries.
One method widely used in other catchments is placement of a datalogger that can monitor around the clock for several weeks. Table 2 below highlights the advantages and disadvantages of the current water quality monitoring points, with recommendations for new or changed positions. Maps 1 to 3 highlight the recommended and existing water quality monitoring points for the three estuaries.
27 Australian Wetlands Draft Tweed Coast Estuaries Management Plan 2004 - 2008 Tweed Shire Council Table 2 Advantages and disadvantages of existing water quality monitoring points Site Location Advantages Disadvantages Recommendations Cudgen 1 Kingscliff Bridge Easy access, monitors WQ in Only observes stormwater Retain main swimming area pollution from Kingscliff on incoming tide, sediment input from Cudgen Plateau far upstream, limited opportunity to observe nutrient input Cudgen 2 Old Bogangar Road Easy access, monitors some Retain Bridge stormwater impacts from Casuarina Cudgen 3 500m downstream of Easy access, monitors Retain Cudgen Lake pollutant exports from lake Cudgen 4 - Event Upstream of Jack Julius Event monitoring - monitors Retain Monitoring Park runoff concentrations/loads of sediment and nutrients from high-risk agricultural area following 50mm rain in 24hrs Cudgen 5 - Event First culvert on Tweed Event monitoring - monitors Retain Monitoring Coast Road, Cudgen runoff concentrations/loads of end (major drain) sediment and nutrients from high-risk agricultural area following 50mm rain in 24hrs Cudgen 6 - Event Cudgen Creek adjacent Event monitoring - monitors Retain Monitoring to Seaside City runoff concentrations/loads of development site. sediment and nutrients from high-risk agricultural area following 50mm rain in 24hrs New site Main creek outlet from Event monitoring - monitors Need to design sampling Use this site for event Cudgen Plateau into runoff concentrations/loads of approach; difficulty of monitoring - Cudgen 7 Cudgen Creek sediment and nutrients from sampling in high flow high-risk agricultural area conditions
28 Australian Wetlands Draft Tweed Coast Estuaries Management Plan 2004 - 2008 Tweed Shire Council Table 2 cont/…
Site Location Advantages Disadvantages Recommendations Cudgera 1 Hastings Point Bridge Easy access, monitors WQ near Retain a swimming area Cudgera 2 Behind Caravan Park Easy access, monitors WQ at a Retain swimming area Cudgera 3 Koala Beach Bridge Easy access, monitors mix of Retain Pottsville urban runoff with Upper Cudgera agricultural impacts Cudgera 4 Western arm of Cudgera Easy access, swimming area, Retain Creek monitors ASS, agricultural, and possibly stormwater impact Cudgera 5 Downstream of Christies Monitors WQ impacts from STP No difference has been Repair floodgates/weir, Creek weir overflows observed in WQ results to reassess effectiveness date between upstream and of monitoring downstream of weir Cudgera 6 Upstream of Christies As above As above As above Creek weir Mooball 1 Pottsville Bridge Easy access, monitors WQ at Retain popular swimming site Mooball 2 Canal outlet Easy access, monitors Pottsville Retain stormwater influence on creek Mooball 3 Junction of canal arms Easy access, monitors general Retain canal health Mooball 4 Approximately 4km south Easy access, monitors general General mixing in this zone Consider elimination of Pottsville Bridge mid-estuary conditions removes clear patterns of pollutant impacts New sites Burringbar Drain Easy access, monitors potential Requires landholder Create site - Mooball 5 becomes Mooball Creek ASS and agricultural impacts permission at Wooyung from drains and upper catchment
29 Australian Wetlands Draft Tweed Coast Estuaries Management Plan 2004 - 2008 Tweed Shire Council 5.2 Recommendations
• Identify projects and works to be undertaken within these catchments in accordance with the priorities in The Blueprint • The Coastal Committee to consider undertaking an Ecosystem Health Assessment in one or more of the Coastal Estuaries • The Coastal Committee to consider development of a community monitoring program for collection of biological / observational data on birds, fish and other fauna
30 Australian Wetlands Draft Tweed Coast Estuaries Management Plan 2004 - 2008 Tweed Shire Council INSERT MAP 1 HERE - CUDGEN WATER MONITORING
31 Australian Wetlands Draft Tweed Coast Estuaries Management Plan 2004 - 2008 Tweed Shire Council INSERT MAP 2 HERE - CUDGERA WATER MONITORING
32 Australian Wetlands Draft Tweed Coast Estuaries Management Plan 2004 - 2008 Tweed Shire Council INSERT MAP 3 HERE - MOOBALL WATER MONITORING
33 Australian Wetlands Draft Tweed Coast Estuaries Management Plan 2004 - 2008 Tweed Shire Council
6 Catchment Management
The ANZECC (2000) Guidelines strongly support the total catchment management plan approach in addressing non-point source pollution, such as agricultural runoff. The main objectives of these plans would be set with the downstream aquatic environment in mind. Such plans require targeted monitoring and assessment for effectiveness (ANZECC, 2000).
The concept includes negotiation and statement of environmental quality goals, co- operative best management, and sharing of responsibility and costs. This approach has been carried through all the reports and recommendations of the NSW Healthy Rivers Commission.
The Northern Rivers Blueprint addresses biodiversity, vegetation management and restoration, and better land management. It can be supported by: (i) the community through membership of relevant committees and groups, and (ii) by Council through similar contributions by staff, and through providing "in-kind" services to Blueprint-related projects.
Reducing pollutant loads during rainfall and runoff periods should be a key focus for improving water quality. It is also important in managing longer-term impacts, such as polluted sediments. Protecting aquatic ecosystems requires mimicking natural river flow patterns as closely as possible.
Re-establishment of a functional riparian zone along the banks of the middle sections of the estuaries and major tributaries would assist with the reduction of in-stream nutrient levels. Similarly, restoration of large areas of floodplain wetlands would reinstate the values of nutrient and flood buffering, biodiversity, and productivity that have been lost because of historical land use.
These pollutant-reduction benefits would accrue due to the filtering effect that passage of stormwater through riparian vegetation has, and also due to the potential for significant riparian vegetation stands to intercept groundwater flows, and reduce potentially contaminating inflows of dissolved nutrients (WBM Oceanics, 2000).
6.1 Cudgen Vegetable Growing Area
The area of agricultural land between the village of Cudgen in the north and Depot Road to the south, known as Cudgen Plateau, experiences severe erosion of topsoil during intense rainfall periods. The red topsoil is carried into Cudgen Creek via one major drain, causing staining of the estuary, high turbidity, and a likely increase in nutrients within the waterway. Severe erosion episodes were reported by many community members at meetings.
Tweed Shire Council is working with the landowners of the Plateau to devise ways of minimising soil loss by changing land management practices with minimal impact on farm productivity.
34 Australian Wetlands Draft Tweed Coast Estuaries Management Plan 2004 - 2008 Tweed Shire Council Technical answers are available for most of these sediment management problems, including contouring of land, timing of particular farming activities, grassing of high risk zones, runoff diversion banks, filter strips, and installation of sediment control ponds and wetlands.
Riparian Zone Filter Strips Filter strips are a mechanism to protect riparian areas and waterways from the high sediment and nutrient loads associated with soil loss. Average soil losses can be as great as 40t/ha using traditional farming practices, or around 10t/ha using minimum tillage and modern methods of soil conservation (Prosser & Karssies, 2001).
Filter strips are grassed areas placed at the foot of the paddock, intercepting the soil loads, trapping and storing sediment before contamination of streams. The filter strips consist of vegetation that is dense at ground level, such as grasses. The increased roughness provided by the grass adds resistance and reduces the velocity of the flow. The reduced flow velocity means the sediments are not transported past this zone, providing the width of the strip is greater than the sediment load (Prosser & Karssies, 2001).
The sediment storage capacity refers to the process where during deposition the grasses can eventually become buried, no longer trapping any of the sediment. The sediment encroaches as a backwater initially, then forms a wedge in the direction of the slope. The sediment storage capacity has the ability to be renewed through regrowth of the vegetation over the sediment layer.
The width of the filter strip required depends on the size of the paddock, average annual soil loss, the gradient, and the length of riparian land into which the sediment is being deposited (Prosser & Karssies, 2001). The goal is to remain below the sediment storage capacity.
An intensive-farming situation experiencing high levels of annual soil loss, particularly when combined with a steep gradient, may require a filter strip width of such an area as to make it unrealistic. The effectiveness of filter strips requires low to moderate soil loss. The filter strip is not a remedy for poor farm practice, but an enhancement to sustainable farm management.
6.2 Recommendations
• Re-establish functional riparian strips along waterways • Continue to work with the Cudgen Landholders for improved land management techniques
35 Australian Wetlands Draft Tweed Coast Estuaries Management Plan 2004 - 2008 Tweed Shire Council
7 Stormwater
The impact of stormwater runoff on waterways has become a major environmental issue in all developed countries and is now widely viewed as an urgent problem requiring a coordinated management approach by government, technical specialists and the community. The task is twofold: to reduce the present impacts, and formulate long-term runoff management strategies that will satisfy the needs of economic development while ensuring environmental sustainability.
7.1 Tweed Urban Stormwater Management Plan (1999)
The Tweed Urban Stormwater Quality Management Plan (the Plan) has been developed in response to the Notice issued to all NSW Councils by the Environment Protection Authority under Section 12 of the Protection of the Environment Administration Act, 1991. The Plan was prepared by Tweed Shire Council for the urban areas of Murwillumbah, Tweed Heads and surrounding areas, and Tweed Coast Villages, including the catchments of Cudgen, Cudgera and Mooball Creek.
The purpose of the Plan is to ensure that Urban Stormwater management is addressed by Council and that issues are incorporated into the planning, budgetary and ongoing works activities of Tweed Shire Council.
The Plan lists a range of pollutant concentrations in stormwater (suspended solids, nitrogen, phosphorus and litter) typical of the Tweed coastal areas in different rainfall years. The Plan sets target reductions in the pollutant loads that must be met by developers and land managers, and development proposals must define what the pollutant loads will be and how they will be managed.
Table 3 presents a list of common stormwater pollutants and their likely origins in the environment, adapted from the Stormwater Management Plan.
Table 3 Stormwater Pollutants and their Possible Sources (adapted from TSC, 1999): Stormwater Pollutants Possible Sources Oil, Grease and Petroleum Products Run-off from roads, driveways Nutrients Agriculture, urban disposal of green wastes Biochemical Oxygen Demand (BOD) Related to nutrients and algal growth Pesticides and Herbicides Agriculture Metals Can be mobilised by acidic water, industry Bacteria and Viruses Livestock, pet waste, sewage overflows Sediment and Suspended Solids Erosion of banks and drains, dust Non-putrescible / Inorganic Litter Plastics, Cigarette butts Putrescible / Organic Litter Kitchen wastes, Garden wastes Chemicals that alter Water pH Industry, road run-off, lowland agriculture
36 Australian Wetlands Draft Tweed Coast Estuaries Management Plan 2004 - 2008 Tweed Shire Council 7.2 Development Control Plans
All of Tweed Shire Council's Development Control Plans (DCPs) are available on Council's website. Of these, DCP 16 is relevant to urban stormwater management.
DCP 16 (Subdivisions) has several subsections that relate to stormwater management on lands that are to be subdivided. Section D5 refers to the design of stormwater control structures, including hydraulics, hydrology, and stormwater detention.
The objectives of stormwater drainage design are as follows: • To ensure that inundation of private and public buildings located in flood-prone areas occurs only on rare occasions and that, in such events, surface flow routes convey floodwaters below the prescribed velocity/depth limits. • To provide convenience and safety for pedestrians and traffic in frequent stormwater flows by controlling those flows within prescribed limits. • Retain within each catchment as much incident rainfall and runoff as is possible and appropriate for the planned use and the characteristics of the catchment. • To ensure a development does not drain areas nearby zoned as Wetlands (Environmental Protection).
Section D7 details standards and prescribed water quality treatment measures with multiple aims of ensuring minimal erosion and sediment pollution, better water quality, better development design, and improved stormwater management.
7.3 Stormwater Management
Management actions in any field must be based on accurate understanding of a problem, and the processes of stormwater pollution need to be analysed in detail so that priorities can be set. Stormwater is made up of "critical pollutants" such as phosphorus, nitrogen and pathogens that are carried to waterways at rates and in volumes of runoff water determined by catchment topography, vegetation and rainfall (ARMCANZ and ANZECC, 1996; Lawrence and Breen, 1998).
The most influential factor is usually the degree of urbanisation of the catchment, because the development process clears vegetation, modifies drainage ways from the curves of natural streams to straight lines, and introduces large areas of hard surfaces such as roofs and roadways - leading to increased peak runoff rates. Most urban areas introduce elevated nutrients, hydrocarbons, pesticides and heavy metals to the water stream (NSW EPA, 1997, 1998).
Stormwater management within "greenfield" developments, that is new developments on previously uninhabited lands, are easier to implement, as techniques such as buffer strips, wetlands and bio-retention units can be incorporated at the design stage of the development.
37 Australian Wetlands Draft Tweed Coast Estuaries Management Plan 2004 - 2008 Tweed Shire Council However, improving stormwater management within existing developments is more difficult, with aspects such as available area and depth of pipes limiting options. This does not suggest that better stormwater management cannot be implemented in existing development areas.
Tweed Shire Council is about to undertake a trial of pit insert baskets in the main commercial area of Kingscliff. These baskets are designed for ease of maintenance and need to be cleaned regularly to be effective. A twelve-month monitoring program will assess the efficiency and effectiveness of this new and innovative design.
7.4 Water Sensitive Urban Design
The concept of water sensitive urban design (WSUD) is based on formulating development plans that incorporate multiple stormwater management objectives and involves a pro-active process which recognises the opportunities for urban design, landscape architecture and stormwater infrastructure to be intrinsically linked.
WSUD espouses the need to integrate stormwater management into the planning and design of urban areas. It presents a range of alternative planning and design practices aimed at changing the conventional layout and design of urban areas to achieve the multiple objectives of stormwater management outlined above (Wong, 2003).
The concept of WSUD is generic and applies across the entire spatial scale of urban catchment management, from a catchment-wide regional level to the precinct level to the local, on-site level.
At the regional level, the use of constructed stormwater wetlands in the urban landscape has become common practice in some areas as an effective means of stormwater quality improvement in addition to their other environmental and landscape/passive recreational values. The effectiveness of constructed wetlands in water quality improvement is well documented in the wastewater industry (Wong, 2003).
The extension of this technology to stormwater management brings with it unique challenges stemming from the variable nature of the hydraulic and pollutant loading on a stormwater wetland compared to wastewater treatment systems. The proper design of these systems is not a straightforward task owing to its multi-disciplinary nature, the general lack of practical experience in their management and operation in Australia and performance data on which design guidelines can be formulated.
Key planning and design objectives associated with WSUD are: • Communication with the community about reducing pollutants at source • Protect and enhance natural water systems in urban developments • Integrate stormwater treatment into the landscape by incorporating multiple use corridors that maximise the visual and recreational amenity of developments • Protect natural water quality from urban development • Reduce runoff and peak flows from urban developments by employing local detention measures and by minimising impervious areas • Add value while minimising drainage infrastructure development costs
38 Australian Wetlands Draft Tweed Coast Estuaries Management Plan 2004 - 2008 Tweed Shire Council Knowledge and understanding of WSUD is developing now in government, industry and research organisations. While at the present time there is still uncertainty and potential for delays in approvals and conflicts between authorities there is a general consensus that changes to existing methods must come about if estuary health near urban areas is to improve.
The difficulty of installing Water Sensitive Urban Design strategies into developed catchments ("retrofitting") is well known. Residents and water managers often have concerns about any potential increase in flood risk, space for facilities is usually scarce, and costs are likely to be higher because of constraints inherent in existing infrastructure such as roads, power and water supply lines.
One strategy that avoids many of these problems is the use of residential rainwater tanks. The re-use of stormwater and roofwater can provide substantial benefits to the community, including reduced "town" water use and peak stormwater discharges.
Other strategies for retrofitting include pit inserts, below-ground sand filters, rain gardens, stormwater harvest and re-use in golf courses, sports ovals, pervious paving, and on site detention in its various forms including rainwater tanks. Most of these are relatively low cost means of integrating treatment measures into a catchment. Council could lead by example within public areas such as shopping centres. The general approach is outlined in Figure 3.
Community Education
Rainwater Tanks Detention basins
GPTs, Buffer strips, Swales, Bio-retention systems
Sediment Basin
Wetland
Waterway
Figure 3 Water Sensitive Urban Design general approach
7.5 Recommendations
• Review Tweed Urban Stormwater Management Plan to identify stormwater treatment works required • Encourage soft options for stormwater treatment • Carry out a review of existing facilities and their effectiveness. Replace, upgrade or install infrastructure (pit inserts, sand filters, GPT's) as funds permit.
39 Australian Wetlands Draft Tweed Coast Estuaries Management Plan 2004 - 2008 Tweed Shire Council
8 Acid Sulphate Soils (ASS)
8.1 General Status of ASS
Most of the contaminants from acid sulphate soil areas that cause chronic and acute pollution of coastal rivers on the north coast of New South Wales flow from over- drained backswamps on alluvial floodplains. Poor water quality emanating from these areas is largely a result of acid sulphate soil oxidation products including acid leachate, high iron and aluminium, and low dissolved oxygen.
Despite the publication of a number of scientific works, mainly by Pat Walker of CSIRO in the 1960s, it was not until 1987 that the link between acid sulphate soils and a history of water quality problems and fish kills was generally recognised. In March of that year, following drought breaking rains, a 23 km stretch of the Tweed River turned clear revealing a large kill of aquatic organisms (Easton, 1989).
From the Manning to the Tweed, there are 5,039 km of drains more than 0.5m deep on acid sulphate soils. The majority of the acid sulphate problem in NSW is caused by historical drainage of former backswamp wetlands, and most backswamps are now artificially drained for agriculture (Tulau, 2002).
The management of backswamps is therefore a key issue in floodplain and acid sulphate soil management. The greatest challenges in remediating these areas are to remove the existing drains, floodgates and related structures in previously drained areas or to manage them in a more environmentally beneficial way. However, the vast majority of this land is now privately owned and managed for agricultural production including sugar cane, tea-tree, and dairy and beef cattle grazing (Tulau, 2002).
In relation to ASS, the Coastal Policy notes that "consideration will be given to the need for environmental studies which address ASS early in the planning and development process". ASS Risk Maps and EPA Guidelines are to be used in assessing proposals likely to disturb ASS. Environmental Impact Statements will be required in certain instances. Impacts of disturbed ASS are to be monitored and restoration and mitigation are to be undertaken. Management plans are to be prepared to effectively manage project level impacts and the remediation of ASS sites.
More generally, future local environment plans must give effect to, and be consistent with, the policy and a local environmental study must accompany rezoning applications.
The only area of "Hotspot" ASS on the Tweed Coast mapped by Tulau (1999) was in the catchment of Cudgen Lake. The severe fish kills in Cudgen Lake contributed to designation as a hotspot. In other areas, poor water quality may not be causing fish kills simply because fish are not trapped in anoxic and/or toxic runoff as they are in Cudgen Lake. Maps 4 to 6 show the ASS status of catchment lands in Mooball, Cudgera and Cudgen Creek areas.
40 Australian Wetlands Draft Tweed Coast Estuaries Management Plan 2004 - 2008 Tweed Shire Council INSERT MAP 4 HERE - CUDGEN ASS
41 Australian Wetlands Draft Tweed Coast Estuaries Management Plan 2004 - 2008 Tweed Shire Council INSERT MAP 5 HERE - CUDGERA ASS
42 Australian Wetlands Draft Tweed Coast Estuaries Management Plan 2004 - 2008 Tweed Shire Council INSERT MAP 6 HERE - MOOBALL ASS
43 Australian Wetlands Draft Tweed Coast Estuaries Management Plan 2004 - 2008 Tweed Shire Council
The Northern Rivers Blueprint addresses ASS issues under the "target" approach:
Acid Sulphate Soils Catchment Target: • 50% reduction in acid sulphate runoff from targeted Hotspots and specific problem sites by 2010 • 100% of land in all targeted Hotspots operating under an active management program by 2009. (The Hotspots include the Cudgen Catchment) • active management program - includes a consideration of stakeholder awareness/capacity, benchmarking of baseline soil, water and vegetation information
It is noted that during brief catchment inspections for this Study, indications of acid sulphate conditions (water colour and appearance, vegetation, iron oxides) were observed in drains in all three catchments. Council monitoring of water quality has also shown indications consistent with acid runoff during wet seasons.
8.2 Council Programs
Tweed Shire Council has managed a number of acid sulphate soil projects in the Cudgen Lake catchment. These projects have been funded by both State and Federal programs with significant contributions by Council and landholders. Soil and water surveys have identified sources of acidity with funding from the Natural Heritage Trust. Studies have indicated that 40-50 tonnes per hectare of existing acidity is contained within the ASS soils in the catchment.
The Cudgen Lake ASS Hotspot was one of only seven areas funded in the first round of funding. This program resulted in the preparation of the Cudgen Lake ASS Hotspot Remediation Management Plan. This program also led to remediation works including modified drainage and land use practices. Infilling of drains has aimed at minimising the export of acid and acid products from the catchment into the Cudgen Nature Reserve.
Recent investigation has indicated significant levels of metals have been exported from soil in the catchment over time and discharged into Cudgen Nature Reserve. Much of this load has deposited in the lake sediment.
Water quality monitoring of Clothiers Creek immediately upstream of the Cudgen Nature Reserve is continuing. Poor water quality associated with ASS has been recorded in the catchments of both Cudgera and Mooball estuaries. Further investigation work of these areas is required.
It is expected that areas within the Cudgera and Mooball Creek catchments will be categorised as Targeted ASS Sites in future (Mark Tunks, pers. comm.).
Management strategies developed for ASS in Tweed Shire are readily transportable to this and other coastal catchments. It is estimated that land and drainage management changes around McLeods Creek have led to an 80% reduction in acid and acid products discharge from that area into the Tweed estuary (Mark Tunks, pers. comm.).
44 Australian Wetlands Draft Tweed Coast Estuaries Management Plan 2004 - 2008 Tweed Shire Council 8.3 Restoring the Balance
A definitive study was carried out of floodplain ASS processes on the Clarence River in February 2001 during catastrophic fish kills in the north coast region. Johnston et al. (2003b) identified three major processes associated with the impacts of wetland drainage and ASS: 1. The accumulation and subsequent mobilisation of monosulphidic sediments in drain networks - the result of acid and metals (such as iron and aluminium) flowing from drained soils into drains, and reacting with organic matter. These monosulphides have a very high oxygen demand, and when disturbed by flows through the drains have a serious and rapid impact on water quality. 2. The interaction of ASS products such as sulphur and iron with flooded vegetation such as Water Couch, leading to anaerobic decomposition and a high oxygen demand. This results in "blackwater events", as the poor quality water flows into drains. 3. The slower drainage of acidic groundwater from the floodplain soils in the weeks following rainfall.
Johnston et al. (2003a) proposed a three-part strategy to address these pollution sources: (i) modify floodgates to enable controlled tidal exchange of drain water with fresh or estuarine water; (ii) use water retention structures to reduce the seepage potential of acidic groundwater; and (iii) redesign drains, such as filling of unnecessary drains, replace deep drains with shallow drains.
In other areas of the NSW coast, more fundamental solutions are being explored, particularly in examining opportunities for large-scale restoration of wetlands for water quality and biodiversity. In some cases where floodplain farming is failing economically, this approach is also to the advantage of landholders. The catchment Blueprint implementation is expected to develop this approach further.
8.4 Recommendations
• Further investigation of ASS potential is required in the Cudgera and Mooball catchments • Investigate large-scale restoration of floodplain wetlands • Investigate drain works, such as infilling, water control structures and shallowing of drains • Initiate extension work with landholders • Install monitoring points at high-risk drainage outlets to identify problem areas.
45 Australian Wetlands Draft Tweed Coast Estuaries Management Plan 2004 - 2008 Tweed Shire Council
9 Sewage Management
9.1 Hastings Point STP
Only one Sewage Treatment Plant (STP) presently operates in the three catchments, at Hastings Point. This Plant caters for some 8,000 equivalent persons (an equivalent person (EP) is a measure of volume - about 240 litres per day), with an average daily output of about 1.7 megalitres per day (ML/day). The effluent is of a tertiary treated standard using micro-screens and chlorine for disinfection.
The final effluent is pumped to a dune injection system behind the beach north of Hastings Point. The field groundwater is regularly monitored at two points for Conductivity, Nitrate, Lead and Faecal coliforms. The Plant is licensed by the EPA. There is moderate effluent storage capacity at the STP, however in extreme flood events the effluent can overflow to Christies Creek thence into Cudgera Creek. Council staff advise that effluent overflowed twice during 2001, but not since. An upgraded STP is planned, with the effluent load to double to 3.4ML/day. It is planned to increase storage at the Plant, and double the area of the dune injection field (if required).
9.2 Proposed Mooball-Burringbar STP
Recently, Council initiated a proposal for a new treatment plant at Mooball. Environmental assessment is presently underway, and the community will be invited to make submissions as part of the consultative process. The rationale for the new STP is that the villages of Mooball and Burringbar are unsewered, and that centralised sewage treatment will provide a better environmental outcome.
The STP is planned to cater for a load of about 600EP, equating to 144 kilolitres per day (about 0.144ML/day, compared with Hastings Point at 3.7ML/day). As part of the EIS process, issues such as effluent reuse, demand management, and placement of the STP itself will be examined in detail.
One innovative method emerging in other North coast areas is the use of well- designed constructed wetlands to "polish" and retain the effluent for appropriate periods to allow for evapotranspiration and wet weather detention.
A constructed wetland is an artificial shallow water-body full of dense waterplants, and the effluent is confined within "berms" or low walls for a period while natural processes operate on the effluent. A wetland as small as one hectare could greatly improve effluent management at the proposed STP, but in general, the larger the wetland the better.
46 Australian Wetlands Draft Tweed Coast Estuaries Management Plan 2004 - 2008 Tweed Shire Council
9.3 Onsite Sewage Systems
Tweed Council has adopted an On-site Sewage Management Strategy, based broadly on the principles and guidelines laid down in the NSW Government's Environment and Health Protection Guidelines, On-site Sewage Management for Single Households, and the Australian Standard AS1547.
Council staff are also in contact with officers at other regional Councils, including Lismore and Byron, where the Councils are co-operating in the development of an on- site design model. This spreadsheet model can be used by householders or consultants to design a system that is suitable for the owner's preferences and the site, and protection of the environment. All new dwellings in unsewered areas must follow the new approach, and existing systems will be assessed over time.
New types of treatment and effluent management systems are emerging, and it is expected that system costs and technical difficulties will decrease.
47 Australian Wetlands Draft Tweed Coast Estuaries Management Plan 2004 - 2008 Tweed Shire Council
10 Entrance Management
The entrances of Cudgen, Cudgera and Mooball Creeks are shaped by the prevailing coastal processes of tides, waves, floods and the longshore sand transport that flows along the coast in a predominantly northerly direction. The movement of sand at the entrance is a complex interaction of these processes whereby waves and flood tides move sand into the estuary where some of it is deposited but much of it is moved back out to sea again on the ebb tide. Entrance bars form at the confluence of these opposing flows. Under natural conditions, the entrance bar can form at the mouth or some distance inside the entrance.
Natural entrances on a sandy coastline tend to migrate along the beach in the direction of the longshore sand transport. The entrance training walls at Cudgen and Mooball creeks have stabilised or fixed the entrance and were constructed in the 1960s to alleviate flooding in the lower reaches of the estuary. The entrance of Cudgera Creek is generally constrained by the natural rocky headland of Hastings Point.
The training walls have the effect of moving the entrance bar to the end of the walls or slightly offshore. They also tend to create a deeper channel between the walls as flows are concentrated along them.
The stability of the entrance or its tendency to remain open to oceanic tidal flows is a function of the estuary’s tidal prism and the longshore sand transport rate. All three of the Tweed coastal estuaries have relatively small tidal prisms (~500,000 cubic metres) with entrances on a high longshore transport coastline (~ 500,000 m3/year). This means that the entrance bar is very shallow and consequently navigation is extremely difficult. Under certain conditions the entrance may become closed or partially blocked by a plug of sand. This was the case at Cudgera Creek in 1999 and again in April 2004.
Management of the entrances of these creeks should fully acknowledge the impact of the natural coastal processes. It is important that council and the community understand the implications of these processes and the consequences of human intervention on estuarine health.
Navigation in the lower reaches of the creeks and through the entrance to the ocean is hampered by natural coastal processes and at times navigation will be dangerous under certain conditions despite the presence of training walls.
Decisions to artificially open a naturally closed entrance should only be based on flood risk and public health concerns and undertaken with due regard to ecosystem health in accordance with an adopted estuary management plan.
An Issues Paper has been written for DIPNR (Hagley, 2003) addressing the difficult and complex questions surrounding the management of the Cudgen Creek entrance. The issue of entrance dredging generally has also been assessed by the Healthy Rivers Commission (HRC, 2003).
48 Australian Wetlands Draft Tweed Coast Estuaries Management Plan 2004 - 2008 Tweed Shire Council The DIPNR Paper contains information on past dredging, an overview of natural processes, the policy and planning context, environmental considerations, and cost estimates. The Paper details the 1967 construction of the breakwalls, the 1986 construction of the spur training wall - a 40m addition to the southern breakwall (1986 cost $23,000); dredging of a 320m channel 2.0m deep from the entrance to the boat ramp - 11,040 cubic meters (1986 cost $25,000).
Hagley (2003) also summarised a Public Works Department (PWD) report on close monitoring of the dredging and subsequent events. The PWD Assessment found that: 1) One-off dredging "proved to be futile" 2) Sediment filled the channel within three months 3) The Spur Wall was effective but only within 15m of the wall
10.1 Policy Context
Cudgen Creek is part of the coastal zone covered by the Coastal Policy, and the following relevant goals apply: • Goal 2: to recognise and accommodate natural processes and climate change • Goal 7: to provide for appropriate public access and use
The Coastal Policy provisions must be duly considered when assessing development applications and proposals in the coastal zone.
Hagley (2003) suggests that an Environmental Impact Study would be required for any dredging because the area is within 200m of the coastline, in an area of Acid Sulphate Soils (Class 1), the regular nature of the dredging required, and interaction with the longshore sand transport system.
10.2 Healthy Rivers Commission
The Commission reported that on the north coast, strongly diverging views about estuary dredging and entrance training walls emerged during the Inquiry (HRC, 2003).
Key HRC recommendations on the issue were that dredging of estuaries and entrances, for whatever reason, should be undertaken within the context of ecologically sustainable development, having explicit regard for river and estuary health.
A State Policy should be developed to guide decisions about estuarine dredging proposals. It is understood that this Policy will be issued in future.
The Issues Paper discussed potential environmental impacts of any dredging: • Hydraulic Impacts: increased tidal flows with impacts on water quality, ecology and bank stability. • Water Quality: elevated turbidity; increased saline intrusion to estuary - increased tidal flushing may improve water quality, but may also change estuarine species distribution and abundance of juvenile fish and invertebrates. • Ecological: Impacts to aquatic and riparian habitats, benthic communities, water birds and threatened species. • Bank Stability: destabilisation from wave action and increased tidal flows. 49 Australian Wetlands Draft Tweed Coast Estuaries Management Plan 2004 - 2008 Tweed Shire Council • Sediment Dynamics: increased mobility of sediments and impacts to longshore transport. • Sediment Quality: potential acid sulphate soils within the dredge spoils (high probability of ASS occurrence). • Noise: impact on residents. • Recreational Impacts: impacts on passive recreation such as swimming and canoeing, beneficial to boating activities with improvements to navigation and risk reduction.
At the Kingscliff community consultation meetings there was strong support for removing the southern Spur Wall. This action would require a lower level of environmental assessment, and would provide an opportunity to observe changed conditions and more understanding of processes by the community.
On the matter of possible dredging, this document has reported views put forward at community meetings, the State Government Agency position, technical factors and some of the ecological implications, particularly in the balance of fresh and salt water flows in the estuary. The competing arguments for and against dredging cannot be resolved without further information and understanding about short and long term impacts of any dredging. This would be gained from an Environmental Impact Study.
For this Plan, it is recommended that the Tweed Coastal Committee should assess community submissions and Government Agency views, then provide recommendations to Council within the context of the Healthy Rivers Commission (2003) guidelines and any State Estuary Dredging Policy that may be issued.
10.3 Recommendations
• Support the removal of the Spur Wall • Assess flood risks and health risks before determining entrance dredging regime (if any) • Erect warning signs in regards to the hazardous navigability • Develop and conduct community education that highlights the: • relationship of navigation access and the prevailing coastal processes; • the passive recreational value of the creek; • the proximity of the Tweed River where significant investment is made to improve navigation of the Tweed River entrance; • high cost of dredging and other possible solutions.
50 Australian Wetlands Draft Tweed Coast Estuaries Management Plan 2004 - 2008 Tweed Shire Council
11 Bank Erosion
The field inspections carried out for this study included assessments of prominent bank erosion sites highlighted in the 1997 Plan. However, as no measurements of the erosion focus points were made in 1997, it is difficult to know how much erosion has occurred since then. It is strongly recommended that a form of marker peg, or GPS positions, be installed to measure the rate of erosion. The following observations were made for each estuary.
11.1 Cudgen Creek
Bank erosion was still occurring along the southern bank cutting of the estuary, from the bridge seawards. This appears to be natural, and eroding relatively slowly due to the vegetation covering parts of the sand.
Another two areas of erosion were seen during the field audits that were not highlighted in the 1997 EMP. These were both located on the northern bank of the estuary, both west and east of the bridge in the recreational parks. The erosion occurring in the eastern park was relatively minor, however it is still of some concern to some community members.
Erosion in the western park, extending from the bridge to past the Cudgen Creek Rainforest Walk, was larger, possibly caused by a combination of undermining by the rising and falling tides, boat wash, and pedestrian access to the estuary with passive water craft.
Remediation works had been attempted through the dumping of rubble, although this appears to have failed in halting erosion in some sections, and only increased the hazards in the water.
11.2 Cudgera Creek
Remediation methods for managing bank erosion in the lower Cudgera Creek estuary include the placement of rubble on an affected site. This method has had varying levels of success, with erosion still occurring in most areas. Most areas in the lower estuary though have remained unprotected, with little ongoing erosion occurring.
A small section of erosion has been occurring upstream of Koala Beach Bridge. There is now a section of rock revetment (i.e. rocks packed in a containing cage) under a small stormwater pipe draining the Pottsville Public School site, evidently in order to disperse the energy from stormwater to reduce its impacts on the estuary bank.
Erosion is also occurring on the scour-bank at the Koala Beach Estate Park, along the western arm of Cudgera Creek. There is a large amount of undermining at this point, which appears to be ongoing.
51 Australian Wetlands Draft Tweed Coast Estuaries Management Plan 2004 - 2008 Tweed Shire Council 11.3 Mooball Creek
Bank erosion had been remediated in parts of the lower estuary through the use of treated-timber revetment walls. However, erosion was still occurring behind parts of the timber walls in some sections.
The placement of 'No Wash' signs upstream of Pottsville Bridge appears to have slowed the erosion process in unprotected areas, although there are parts where informal access to the estuary has heightened the erosion. The area highlighted in the 1997 EMP ("D") next to the eastern side of the bridge appears to have come under remediation, with signage occurring to discourage people entering the area.
Small-scale attempts at rock and rubble walls in the upper estuary have slowed the erosion process, although it is still occurring. The section of estuary that is extremely close to the Wooyung-Pottsville Road has heightened erosion due to people climbing the sheer drop to and from the estuary.
11.4 Recommendations
• Bank erosion management should be based on the principle of allowing natural bank erosion to proceed where it does not impact on infrastructure, private property or high conservation value vegetation.
• The Coastal Committee should develop management plans for the high priority bank management sites on public land.
• Private landholders should undertake works in accordance with the Tweed Estuary Bank Management Plan, 1998.
• Erskine (2003) completed a rehabilitation and management plan for Mooball Creek Reserve, between Mooball Creek and Overall Drive at Pottsville. The remediation techniques that have been detailed within the report can be utilised at other erosion sites across the three estuaries, with consideration to the individual site and rehabilitation requirements.
• These techniques can be used individually or in conjunction, and include: • realigning fallen trees; • establishing mangroves; • revegetating banks; • incorporating stone retaining walls in high-use areas; and • constructing formal creek access points
• Maps 7 to 9 highlight the areas of bank erosion along Cudgen, Cudgera and Mooball Creeks, and the remediation priorities associated with each area. Photo monitoring points should be established at the sites highlighted in Maps 7 to 9. Recommended remediation actions are detailed in Table 4 for each identified area.
52 Australian Wetlands Draft Tweed Coast Estuaries Management Plan 2004 - 2008 Tweed Shire Council
Table 4 Bank erosion sites, priorities and recommended remediation actions Area Priority Recommended Remediation Actions CN 1 High Revegetate banks and incorporate stone retaining walls, with formalised access points CN 2 Low Re-establish saltmarsh CN 3 High Establish mangroves along bank, with some formal access points constructed; Develop management plan for the site CN 4 High Revegetate bank, establish mangroves, align any fallen trees to reduce erosion; Develop management plan for the site CR 1 High Maintain brush mat slopes for erosion control and to access CR 2 High Condition new developments to construct formal access points, remove ineffective rubble and revegetate CR 3 High Condition new developments to construct formal access points to creek, revegetate banks in respect to residents' visual amenity CR 4 Low Revegetate banks, assess effectiveness CR 5 High Prepare designs to address erosion and construct formal access point to Creek MB 1 Medium Repair timber retaining walls, revegetate banks, install stone retaining walls in high-impacted areas, construct formal access points from grass to creek MB 2 High Revegetate bank, establish mangroves, install retaining walls where slope is too steep MB 3 Erskine Implement the Mooball Creek Reserve Rehabilitation and (2003) report Management Plan MB 4 Medium Revegetate bank, establish mangroves, formalise or block any access points MB 5 Medium Revegetate bank, establish mangroves, formalise some access points, block other access points MB 6 High Construct stone retaining wall or other bio-engineered option, extending north and south of erosion site to prevent cutting, establish bank vegetation and mangroves where possible
53 Australian Wetlands Draft Tweed Coast Estuaries Management Plan 2004 - 2008 Tweed Shire Council
INSERT MAP 7 HERE - CUDGEN BANK EROSION
54 Australian Wetlands Draft Tweed Coast Estuaries Management Plan 2004 - 2008 Tweed Shire Council INSERT MAP 8 HERE - CUDGERA BANK EROSION
55 Australian Wetlands Draft Tweed Coast Estuaries Management Plan 2004 - 2008 Tweed Shire Council INSERT MAP 9 HERE - MOOBALL BANK EROSION
56 Australian Wetlands Draft Tweed Coast Estuaries Management Plan 2004 - 2008 Tweed Shire Council
12 Fauna
Many estuaries along the NSW coastline support a range of bird life and other species that are of special concern because they are threatened, endangered or rare. In many cases, the reduction in population numbers has come about through the detrimental effects of human activities (NSW Government, 1992).
12.1 Aquatic Fauna
As yet, no specific study has been compiled on the presence of fish species within the estuaries of Mooball, Cudgera and Cudgen. However, during site investigations, many species were seen, including yellow-finned bream, flathead, sand whiting, stingrays, porcupine-fish, rock cod, blennies, wrasse, and many rock-pool associated fish near the entrances.
The estuary floors in many places were covered to varying degrees with worm and yabbie holes, depending on the locality within the estuary. Many stingray feeding depressions were also noted in the mid-sections of each system, indicating the presence of a food chain well into the estuaries.
The rubble under Hastings Point Bridge was assessed for value as fish habitat, following from the 1997 EMP recommendation to remove the rubble. The assessment concluded that the area has little value as habitat, as the rubble is covered in silt and sediment that has reduced the availability of suitable substrate for marine and estuarine creatures to take hold. The fish that are present under the bridge appear to be using the pillars as a food source and habitat due to the shading and protection it gives.
Anecdotal evidence suggested that approximately 20 years ago a rare oyster- spawning event occurred near the Hastings Point Bridge where the oysters were growing directly on the sand without structural support. Associated with the oysters was a black ooze that percolated through the sand and acted like 'quicksand'. These mud oysters have not been seen in the estuary in such large numbers since.
The breakwalls at Kingscliff are unnaturally devoid of marine life-forms, such as limpets, barnacles, sea anemone, and macro-algae. Normally, such man-made rocky shore environments would be covered in a diverse spread of marine life. Further upstream, near the boat ramp on Marine Parade, the presence of marine organisms returns. This phenomenon was attributed by several community members to a flood in 2002.
12.2 Avifauna
Cudgera Creek is the only natural entrance out of the three estuaries in question, and the presence of vulnerable species may indicate the ecological significance of this fact. Sooty Oystercatchers were seen feeding at the entrance, with other shorebirds (e.g. Crested Terns) present. An Osprey fledgling was also seen.
57 Australian Wetlands Draft Tweed Coast Estuaries Management Plan 2004 - 2008 Tweed Shire Council Only common seabirds were present at the lower estuary of both Mooball and Cudgen Creeks during the estuary inspections for this Plan, however Little Terns and Sandpipers have been sighted recently between Pottsville and Wooyung. With the presence of a fish-cleaning table at the Kingscliff boat ramp, the availability of food for scavengers such as seagulls and pelicans has increased in Cudgen Creek.
Mr. George Andrews of Tweed Bird Observers has provided a species list from observations of the recent period of 27 birds seen on Cudgen Creek, and 72 species in remnant rainforest and parks around Cudgen Creek. These are listed below (Table 5).
Table 5 Birds identified within the Cudgera Creek area Birds seen on Cudgen Creek Common Name Scientific Name Black Swan Cygnus atratus Little Black Cormorant Phalacrocorax sulcirostris Little Pied Cormorant Phalacrocorax melanoleucos Australian Pelican Pelicanus conspicillatus Great Egret Ardea alba Intermediate Egret Ardea intermedia Little Egret Aredea (Egretta) garzetta Eastern Reef Egret Ardea (Egretta) sacra White-faced Heron Ardea novaehollandiea Striated Heron Butorides striatus Royal Spoonbill Platelea regia Australian White Ibis Threskiornis molucca Osprey Pandion haliaetus Brahminy Kite Haliastur indus Whistling Kite Haliastur splenunis White-bellied Sea Eagle Haliaeetus leucogaster Whimbrel Numenius phaeopus Curlew Sandpiper Calidris ferruginea Black-winged Stilt Himantopus limantopus Pied Oystercatcher Haematopus longirostris Sooty Oystercatcher Haematopus fuliginosus Masked Lapwing Vallenus miles Silver Gull Larus novaehollandiae Crested Tern Sterna bengii Common Tern Strena hirundo Azure Kingfisher Aleedo azurea Collared Kingfisher Todiramphus cloris
Birds seen in remnant rainforest and parks around Cudgen Creek Common Name Scientific Name Australian Brush-turkey Alecturn lathami Pacific Baza Aviceda subcristata Crested Pigeon Ocyphaps lophotes Rose-crowned Fruit-dove Ptilinopus regina Brown Cuckoo-dove Macropygia amboinensis Peaceful Dove Geopelia placida (striata)
58 Australian Wetlands Draft Tweed Coast Estuaries Management Plan 2004 - 2008 Tweed Shire Council Bar-shouldered Dove Geopelia humeralis Spotted Turtle-dove Streptopelia chinensis Glossy Black Cockatoo Calyptorhynchus lathami Yellow-tailed Black Cockatoo Calyptorhynchus furnerus Little Corella Cacatua sanguinea Galah Cacatua roseicapilla Rainbow Lorikeet Trichoglossus haematodus Fan-tailed Cuckoo Cacomantis flabelliformis Shining Bronze-cuckoo Chrysococcyc lucidus Pheasant Coucal Centropus phasianinun White-throated Needletail Hirundapus caudacutus Sacred Kingfisher Todiramphus sanctus Laughing Kookaburra Dacelo novaeguineae Rainbow Bee-eater Merops ornatus Dollarbird Eurystomus orientalis Noisy Pitta Pitta versicolour Superb Fairy-wren Malarus cyaneus Striated Pardalote Pardalotus striatus Large-billed Scrubwren Sericornis magnirostris White-browed Scrubwren Sericornis frontalis Mangrove Gerygone Gerygone levigaster White-throated Gerygone Gerygone olivacea Brown Thornbill Acanthiza pusilla Little Wattle-bird Anthockaera chrysoptera Striped Honeyeater Plectorhyncha lanceolata Noisy Friarbird Philemon corniculatus Little Friarbird Philemon citreogularis Blue-faced Honeyeater Entomyzon cyanotis Noisy Miner Manorina melanocephala Lewin's Honeyeater Meliphaga lewinii Yellow-faced Honeyeater Lichenustomus chrysops Brown Honeyeater Lichmera indistincta White-cheeked Honeyeater Phylidonyris nigra Eastern Spinebill Acanthorhynchus tenuirostris Scarlet Honeyeater Myzomela sanguinolenta Mistletoebird Dicaeum hiundinaceam Rose Robin Petroica rosea Eastern Yellow Robin Eopsalitria australis Eastern Whipbirp Psophodes olivaceus Golden Whistler Pachycephala pectoralis Rufous Whistler Pachycephala rufurentris Little Shrike-thrush Colluricincla megarhyncha Grey Shrike-thrush Colluricincla harmonica Black-faced Monarch Monarcha melanopsis White-eared Monarch Monarcha leucotis Leaden Flycatcher Myiagra rubecula Rufous Fantail Rhipidura rufitrons Grey Fantail Rhipidura fruliginosa Willie Wagtail Rhipidura leucophrys Spangled Drongo Dicrunus brackeatus Magpie-lark Grallina cyanoleuca 59 Australian Wetlands Draft Tweed Coast Estuaries Management Plan 2004 - 2008 Tweed Shire Council Varied Triller Lalage leucomela Black-faced Cuckoo-shrike Coracina novaehollandiae Cicadabird Coracina tenvirostris Olive-backed Oriole Oriolus sagittatus Figbird Sphecotheres viridis White-breasted Woodswallow Artarmus leucorynchus Grey Butcherbird Craticus torquatus P ied Butcherbird Craticus nigrogularis Australian Magpie Gymnorhina tibicen Pied Currawong Strepera graculina Torresian Crow Corvus orru Regent Bowerbird Sericulus chrysocephalus Red-browed Finch Neochmia temporalis Welcome Swallow Hirundo neoxena Silvereye Zosterups lateralis Common Starling Sturnus vulgaris
12.2.1 Waders
Most estuarine waders are protected by the Japan-Australia Migratory Bird Agreement 1974 (JAMBA) and the China-Australia Migratory Bird Agreement 1988 (CAMBA). They are also listed as 'endangered fauna' under Schedule 12 of the NPW Act 1974. Waders utilise a number of habitats, both within and outside estuaries, on a daily basis (NSW Government, 1992).
A recent study of waders of the three estuary systems was carried out by local observers Marion Williams and Matthew Angus. Observations were carried out monthly over a one year period. Results of this study have not yet been produced, but it is hoped the results can be included in the final Plan.
12.2.2 Shore Birds
Terns and Gulls are a significant component of the bird life within the estuaries of NSW. The Kelp Gull, White-winged Tern, Common Tern and Little Tern are specifically mentioned in either Schedule 12 of the NPW Act 1974 or the JAMBA and CAMBA agreements.
12.2.3 Birds of Prey
There are a number of fish-hunting birds of prey that forage, roost and nest within the general vicinity of estuaries. These include the White-bellied Sea Eagle, the Whistling Kite, the Marsh Harrier, the Brahminy Kite, and the Osprey (NSW Government, 1992).
60 Australian Wetlands Draft Tweed Coast Estuaries Management Plan 2004 - 2008 Tweed Shire Council
12.3 Recommendations
• Committee to consider development of a community monitoring program for collection of biological / observational data on birds, fish and other fauna. • Develop and print a fauna guide to the Coastal Creeks as part of the Waters of the Tweed Series. • Develop cautionary and educational material and signage to identify the need to collect rubbish, lines, etc, to reduce injury to fauna.
61 Australian Wetlands Draft Tweed Coast Estuaries Management Plan 2004 - 2008 Tweed Shire Council
13 Flora
Estuaries and their associated wetlands 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 Tweed Shire Council's Vegetation Management Plan is available and outlines vegetation communities throughout the three study catchments. Maps 10 to 12 highlight the location of SEPP 14 Wetlands and SEPP 26 Littoral Rainforests within the three estuaries.
13.1 Mangroves
Mangroves occupy the fringe of intertidal shallows between the land and sea, and have the ability to withstand regular fresh water and salt water flooding (NSW Government, 1992). Mangroves grow along the shores of many NSW estuaries, and in some places form extensive forests. Avicennia marina (grey mangrove) and Argiceras corniculatum (river mangrove) are the two most common species (NSW Fisheries, 2004b).
Mangrove creeks are important habitats for fish, crabs, birds and other animals. Mangrove trees provide large amounts of organic matter, which is eaten by many small aquatic animals. In turn, these detritivores provide food for larger carnivorous fish and other animals (NSW Fisheries, 2004b). The soil or 'sediment' of the mangrove environment may be sand, but is more often rich mud, high in nutrients but essentially anoxic (NSW Government, 1992).
Mangroves also help maintain water quality by filtering silt from runoff and recycling nutrients, and act as a buffer for Melaleuca (paperbark) wetlands.
13.2 Seagrasses and Macrophytes
All seagrasses are marine angiosperms (flowering plants) that have completely adapted to life in a saline and dynamic environment. Seagrass beds serve a number of important and basic ecological roles: • source of significant amounts of detrital material; • an important mechanism for nutrient cycling; • substrate stabilisation; • variety of animal habitats; and • substrate for epibiota (small plants and animals living on the stems and leaves of seagrasses).
Seagrass beds are quite fragile and are susceptible to many of the modern pressures on estuaries. Once they are lost seagrass beds often do not re-colonise quickly (NSW Government, 1992).
62 Australian Wetlands Draft Tweed Coast Estuaries Management Plan 2004 - 2008 Tweed Shire Council NSW Fisheries is currently undertaking seagrass mapping of estuaries along the coast. Once this is completed, detailed knowledge of the extent of seagrass will be available to estuarine and catchment managers, as well as developers, for the future management direction of this flora.
13.3 Cudgen Creek
There are small patches of seagrass near the Old Bogangar Road Bridge, however they are covered in epiphytic growth, indicating high nutrients within the system. Lining the creek-side of the road adjacent to the Casuarina development, a wildlife fence prevents the entry of people to the creek banks. This will allow regrowth and rehabilitation of the riparian areas, although there may be weeds growing at an uncontrolled rate from previous visits by people.
The area on the southern bank of the Cudgen entrance, which was once a rutile mining area, has had good rehabilitation throughout, although there is the need for weeding to occur in areas. There is a dominance of Casuarina equisetifolia, the Horsetail She-oak, which is not local to the region.
It is recommended that this species should be removed over time, with replacement by local species. The site has a good coverage of sand by spinifex and Casuarina litter, although there are many garden escapees spread throughout the undergrowth.
Within the park on the northwest side of Kingscliff Bridge, small areas of saltmarsh occur near the entrance to the Cudgen Creek Rainforest Walk. This area should be protected.
13.4 Cudgera Creek
In most areas, the 50m buffer zone between development and waterways has been kept, however there are some areas where this is not so. Parklands in some parts of new developments have been cleared to the water's edge. Livestock grazing on saltmarsh within private property has occurred.
Mangrove recruitment appears to be high within the estuary, as evidenced in past aerial photographs. However, there has been recent dieback of large areas of mangroves within the lower estuary.
Seagrass beds are patchy throughout Cudgera Creek, however inspection of aerial photographs indicates the seagrass beds are slowly expanding over time. These beds support many small organisms, such as prawns, fish, and other organisms.
The old sand-mining drain connected to Christies Creek contains well- established seagrass beds, with worm and yabbie holes throughout the mud flats.
63 Australian Wetlands Draft Tweed Coast Estuaries Management Plan 2004 - 2008 Tweed Shire Council 13.5 Mooball Creek
Mangrove encroachment has occurred on sand shoals in the upper to middle estuary, as seen by past aerial photographs.
Bitou bush poisoning and removal is occurring along both sides of the Wooyung- Pottsville road, with rehabilitation of native species in its place. Revegetation is ongoing in the lower estuary region, with protective fencing around the sites of importance.
Within the estuary at both exits to the Pottsville Waters canals, extensive seagrass and macro-algae populations are present. The canals themselves are full of seagrass, all reasonably healthy in appearance, with little macro-algae present.
13.6 Recommendations
• Obtain seagrass mapping when available and include on Council GIS as vegetation layer • Adhere to a minimum 50m buffer zone of riparian vegetation on any new development site. • Ensure development applicants have access to terrestrial and aquatic vegetation mapping from all sources.
64 Australian Wetlands Draft Tweed Coast Estuaries Management Plan 2004 - 2008 Tweed Shire Council INSERT MAP 10 HERE - CUDGEN SEPPS
65 Australian Wetlands Draft Tweed Coast Estuaries Management Plan 2004 - 2008 Tweed Shire Council INSERT MAP 11 HERE - CUDGERA SEPPS
66 Australian Wetlands Draft Tweed Coast Estuaries Management Plan 2004 - 2008 Tweed Shire Council INSERT MAP 12 HERE - MOOBALL SEPPS
67 Australian Wetlands Draft Tweed Coast Estuaries Management Plan 2004 - 2008 Tweed Shire Council
14 Recreational Values
14.1 Boating
Boating in all kinds of craft is an extremely popular pastime on the three estuaries. The quiet and sheltered waters of the estuaries provide a safe and beautiful environment for activities such as bird watching, fishing, photography, and general enjoyment. Most motorboats are fairly small, with a low impact on the physical and ecological values of the waterways. However, concerns were expressed at some community meetings that a minority of boat users tended to break the accepted rules concerning boat speed and operation.
The use of canoes and kayaks is also widespread, and is likely to become more so following the full establishment of the Canoe Trail project. The main potential impact would be in access points to upstream sections of the creeks, where bank damage or littering may be a problem.
The general issues surrounding boat use are likely to intensify in coming years as population increases as a result of residential development, both underway and planned. These issues will be best managed by a Boating Plan of Management.
The NSW Waterways Authority has established the following criteria for prioritising the development of boating plans of management: • Waterbodies with a high degree of traffic management, user conflict issues, and/or environmental issues. • Waterbodies for which other agencies have formally advised the Authority that they are preparing plans, policies and similar documents which may impact on the Waterways Authority’s operations. • Waterbodies for which funding is readily available for the preparation of boating plans of management.
14.2 Recreational Fishing
Fishing is a popular pastime in NSW generally, with NSW Fisheries estimating around 1 million people fish per annum, taking approximately 13 million fish each year (NSW Fisheries, 2004a). A large-scale survey of recreational fishers by NSW Fisheries in 2001-02 showed that recreational fishing activity was greatest in estuarine (47%) and coastal waters (28%).
These findings are valid for the three Tweed Coast estuaries, where recreational fishing is widespread and highly valued by local residents and visitors. Many people at community meetings expressed their concerns and wishes for the estuaries in terms of recreational fishing values. There was a view that fish stocks have seriously declined over recent decades.
Recreational fishing is reliant on the health of the estuary. In this respect, it is logical that focused works to improve the environmental health of the estuaries will have a beneficial impact on the fish stocks that provide the resource base for the recreational pastime of fishing, as well as the fishing component of tourism in the coastal villages.
68 Australian Wetlands Draft Tweed Coast Estuaries Management Plan 2004 - 2008 Tweed Shire Council
In regard to management of recreational fishing, the Fishcare Volunteer Program, administered by NSW Fisheries from fishing licence funds, deserves support from the community and government. The aim of the program is to "develop a dynamic volunteer program to provide face-to-face sustainable fishing education to the community".
The program began in 1999 and now involves over 350 volunteers across NSW. Fishcare Volunteers are community members who donate their time and effort promoting awareness and advising anglers about the rules and values of sustainable recreational fishing. Volunteers have no enforcement powers, and only advise fishers in a friendly way.
Volunteers dedicate a minimum of eight hours per month to assist in a range of activities such as fishing clinics, catch surveys, fishing community events and volunteer training. The volunteers are identified by their blue uniforms.
14.3 Swimming
Similarly to fishing and boating, swimming is a widespread and popular activity in all three estuaries. Most swimming is done near the entrances, where often-clear ocean water provides an attractive and inviting vista. Large numbers of people swim in holiday periods, particularly at Christmas, but regular swimmers use the estuaries all year round. At community meetings, swimmers stated a strong interest in the maintenance and enhancement of the estuaries as safe and healthy recreational resources. The main perceived threats to these values were power boating and water quality issues.
Water quality is of more concern in the upper reaches of the estuaries, where people swim at a few favoured locations. Faecal coliform concentrations were observed to be generally higher in the upstream areas, although the origin of these bacteria cannot be distinguished by present monitoring methods (see Section 4 Water Quality).
14.4 Recommendations
• Develop a Boating Plan of Management to cover the three estuaries, with strong consideration for passive recreational uses • Encourage local fishers to support the FishCare Project • Further investigate the economic links between fisheries values in and around the estuaries and the coastal communities, as a basis for water quality improvement • Encourage passive recreation generally
69 Australian Wetlands Draft Tweed Coast Estuaries Management Plan 2004 - 2008 Tweed Shire Council
15 Tweed Local Environment Plan (LEP) 2000
The creation of the Tweed LEP 2000 brought together the Tweed LEP 1987 and LEP No 24. Changes in zoning from the 1997 EMP to today include: • expansion of National Park/Nature Reserve zoning north of the Cudgen Lake to cover a large area designated as Kings Forest/Osprey Nest potential development; • new National Park/Nature Reserve zoning near Wooyung; • changes in property zoning in Creek Street at Hastings Point from 2c (Development) to 7a (Environmental Protection - Wetlands); and • an increase in Urban Expansion zoning west of Koala Beach Estate.
Current zoning maps are readily available on the Tweed Shire Council website.
Casuarina is zoned as Residential Tourist, and Salt is classed as Tourism. Both of these areas are bordered by Environmental Protection (Wetland and Littoral Rainforest), (Habitat) and (Coastal Protection) classifications, effectively limiting any future expansion.
Nature Reserves cover a large area of the upper Cudgen Creek area, including Cudgen Lake and parts of its surrounds. The upper catchment and around Old Bogangar Road is primarily Rural, with Open Spaces set aside in Kingscliff and between the Old Bogangar Road Bridge and Cudgen Nature Reserve.
The areas of catchment upstream of the high tide marks of Cudgera Creek catchment are primarily Rural, Environmental Protection (Wetlands and Littoral Rainforest) and (Habitat) lands. There is very little area within the catchment that is zoned as Residential, although there is a large area from Koala Beach Estate west to Seabreeze Estate that is earmarked for Urban Expansion.
The coastal strip from south of Hastings Point headland to the northern edge of Potts Point is zoned Environmental Protection (Coastal Protection).
Mooball Creek catchment is primarily zoned as Rural, with large areas of Environmental Protection (Wetlands and Littoral Rainforest) throughout the floodplains and estuary edges. The creek banks from approximately Black Rocks Estate, on both sides of the waterway, to the entrance are classed as Open Space. The coastal strip from Mooball Nature Reserve at Wooyung north to the estuary entrance is zoned as Environmental Protection (Coastal Protection).
70 Australian Wetlands Draft Tweed Coast Estuaries Management Plan 2004 - 2008 Tweed Shire Council
16 Global Warming and Sea Level Rise
Increasing concentrations within the earth's atmosphere of various gases, largely derived from the burning of fossil fuels, are trapping solar radiation, and this is contributing to the "Greenhouse Effect" (WBM Oceanics, 2001; AGO, 2002).
Global warming has the potential to change weather systems, rainfall patterns, wind velocities and significantly cause mean sea level to rise (AGO, 2002). These factors can have an impact on the environment within the coastal zone.
Sea level measurements during the last century at Fort Denison in Sydney Harbour shows a rise of approximately 1.38 ± 0.18mm per year from 1897 to 1998 (AGO, 2002). However the Fort Denison records also indicate that sea level rise has occurred as a stepped rather than a constant function (WBM Oceanics, 2001).
The NSW coast spans the sub-tropics in the north to the mid-latitudes in the south and is therefore affected by weather systems of both origins. To the north are tropical cyclones during the summer months and depressions developing into easterly troughs (WBM Oceanics, 2001).
Further south, low pressure systems such as cut-off lows, migratory lows and east coast lows are a major source of severe weather, particularly in the colder months. These systems are all capable of generating storm surges and severe wave conditions along the coast (WBM Oceanics, 2001), with a likely increase in storm surge intensity due to climate change (AGO, 2002). Therefore many low-lying coastal areas are potentially at risk of inundation and/or impacts from heavy storms.
The best estimates of global mean sea level rise from the Intergovernmental Panel on Climate Change for the years 2050 and 2100, relative to 1990, were 0.2m and 0.5m respectively (WBM Oceanics, 2001). Thus the time frame is not strictly relative to this EMP. However, WBM Oceanics (2001) also reported that a sea level rise predicted for 2050 would result in a shoreline recession of 10m, and by 2100 the shoreline would recede by 25m.
However, the issue of sea level rise should not be ignored, but rather be planned for as soon as possible. Furthermore, the stepped nature of the process may mean that a rise in sea level that would be potentially threatening to the region is difficult to predict, and a time frame for the event may arise unexpectedly.
71 Australian Wetlands Draft Tweed Coast Estuaries Management Plan 2004 - 2008 Tweed Shire Council
17 Changes in the Estuaries since 1997
The following major aspects have changed in the estuaries since 1997:
17.1 Cudgen Creek catchment
• Casuarina development • Salt development • Road layout changes • Vegetation removal • New stormwater drains
17.2 Cudgera Creek catchment
• Koala Beach development • Seabreeze Estate development • Road layout changes • Vegetation removal • New stormwater drains
17.3 Mooball Creek catchment
• Black Rocks development • Black Rocks Bridge • Road layout changes • Vegetation removal • New stormwater drains
72 Australian Wetlands Draft Tweed Coast Estuaries Management Plan 2004 - 2008 Tweed Shire Council
18 Community Consultation
18.1 Indigenous Issues
Several submissions to the North Coast Healthy Rivers Commission hearings stated that those involved in natural resource management must establish mechanisms to involve all communities, including Aboriginal communities, in planning and management processes, and they must recognise that mainstream bureaucratic and committee processes are not conducive to Aboriginal involvement.
Aboriginal people themselves told the Commission that they would like to be heard, have their views respected and be involved in processes to advance river health, which take account of their cultural requirements.
In that regard, the Commission stated that agencies should have regard to the Boomanalla Statement when carrying out their processes or otherwise seeking Aboriginal input. That statement was prepared in response to Aboriginal representatives on various natural resource management committees seeking guidelines from their own people to assist them in speaking for Country.
The statement calls for protocols to guide agencies and other groups consulting with Aboriginal communities. One of the criticisms levelled at current natural resource planning initiatives is the lack of a whole systems approach, understood by the traditional owners but which they state is not being addressed sufficiently by the natural resource agencies.
The Commission found that Aboriginal people's aspirations for north coast rivers differ little from those of most other sections of the community, in the sense that Aboriginal people want clean water that is safe to drink and swim in, and from which they can collect raw shellfish for human consumption. They expect to find healthy fish and riverbanks covered by native vegetation affording visual amenity as well as ecological benefits. They also want access to rivers for traditional food and fishing for cultural, spiritual and medicinal purposes. The consultation processes leading up to the preparation of the NSW Indigenous Fisheries Strategy, confirmed those expectations, some of which the Commission has been advised will be addressed by that Strategy.
Regarding the Tweed Coast Estuaries Management Plan, consultations have been initiated with the Aboriginal people of the area, and indigenous participation was received at a one-day workshop with the Tweed Coastal Committee and Council staff.
18.2 General Community
As each estuary is unique, separate estuary-based community meetings were held to gain insight into the values the waterways held for the local residents, and to obtain local information about issues and management concerns for each estuary. Issues raised at these meetings are detailed below.
73 Australian Wetlands Draft Tweed Coast Estuaries Management Plan 2004 - 2008 Tweed Shire Council
General Issues Boats • The general concern is that personal water craft (PWC) users and some motor boat users ignore the speed limit for watercraft • This raises the issues of personal safety and bank erosion.
Biodiversity • There is a general concern that the abundance of fish is diminishing and questions were raised about the value of restocking the waterways. • Commercial fishers were losing jobs due to a loss of the resource base. • As a result of the increase in population and associated issues, there has been a corresponding increase in the number of seabirds that have sustained injuries, with increased mortality rates. • There is a lot of Bitou bush infiltrating the mangrove complexes. • Tree planting and revegetation should be a priority of any ameliorative action taken to improve the estuary, in the context of catchment management.
Water Quality • Residents are willing to learn what they, as individuals, can do to minimise the discharge of pollutants into the estuary. • Sugar cane farmers were aware of nitrogen-related impacts and are looking for better methods of source control of nutrients. • Concern about the impacts of the cane fields and drains on water quality. • Condong Sugar Mill records ASS levels in field drains as part of their operations. • The location and validity of the water quality sampling sites was also questioned. Monthly water quality and ecological monitoring is not sufficient. • Could conduct basic monitoring exercises that would be valid scientific data to be used in a report or as supporting documents etc.
Development • Estuary Management Policy set in 1992 has not been followed in the implementation and operation of coastal development, particularly new developments. Despite specifications in the Policy (or any other policy) short-cuts are usually taken by developers that are contrary to environmental conservation and protection. • What will the long-term effect of the projected population growth in the area have on the health of the estuaries. • Unregulated developments is of the highest concern in regards to impacts on the estuary, followed by agriculture and clearing of vegetation
Information • People are unsure of where to find the appropriate information regarding scientific issues and have asked if data can be published or made more accessible. • There does not appear to be many works happening to improve the estuary and general environment. • Location of Crown Land within the estuaries and the apparent restriction of recreational activities, privatisation of tidal inlets via the construction of fences, and possible discrepancies with survey data.
There was a very positive attitude expressed by several people towards these Estuary Plan consultations that have been undertaken by Council, and as a result of these meetings better dissemination of knowledge and community views will be harnessed in the cause of estuary health. 74 Australian Wetlands Draft Tweed Coast Estuaries Management Plan 2004 - 2008 Tweed Shire Council
18.3 Cudgen Creek Specific Issues
• Entrance is impassable at low tide, dangerous at mid tide. Coast Guard requires clear passage at all times for offshore rescues • Remove spur wall at entrance • Investigate effectiveness of dredging • Concerns that an EIS is required for each dredging operation • Danger marker between Coast Guard and boat ramp has no reflective tape, becoming a hazard at night • Concerns over the loss of cunjevoi, limpets, macroalgae, sea anemones and other rocky shore life during a flood event in 2002 • Fish kill event in February 2001 originated in or near Cudgen Lake, and was not caused by erosion from the Cudgen vegetable region • Soils eroded from the vegetable region can stain the water, increasing turbidity and nutrient content, for up to a week, depending on the rain • Waterfront structures such as cement "beaches" could be illegal and should be removed • Kingscliff Bridge constricts flow and should be widened when practical • Concerns over the way the Salt development has altered the environment with the construction of a rock wall within the creek, pylons and associated wharf, and large stormwater infrastructure that drains into the creek next to a large seagrass bed.
18.4 Cudgera Creek Specific Issues
• Concern over the die-back of apparently healthy mangroves within the lower estuary, which occurred around July 2003 • Increased shoaling within the estuary is thought to have reduced the tidal reach up the creek and possibly caused a pooling effect in some parts of the waterbody • Concerns over the cutting of a channel along the estuary to improve tidal flushing, and whether that would actually improve water quality • Koala Beach stormwater management impacts on Cudgera Creek through failing retention ponds • Siltation has increased below Koala Beach Bridge. • Koala Beach Bridge should be widened or replaced when practical to reduce flow constrictions • Impacts that the rubble under Hastings Point Bridge has on tidal flow • Concerns over trampling of seagrass beds • Concerns over the loss of saltmarsh, mangroves and natural vegetation on a waterfront property through livestock and clearing • The weir in Christies Creek should be removed or fixed up as it is causing erosion and reducing tidal flows • Concerns over the filling of low-lying flood-prone lands for future development • Fish and mud crab populations are decreasing within the estuary • A fish kill event occurred after a drought that correlated with an acid sulphate soil event
75 Australian Wetlands Draft Tweed Coast Estuaries Management Plan 2004 - 2008 Tweed Shire Council 18.5 Mooball Creek Specific Issues
• The proposed location of the Mooball-Burringbar STP is in the headwaters of Mooball Creek, on a floodplain - concerns over potential impacts on the creek • Concern about the impacts of Black Rocks Bridge on the creek • Stormwater management on new and existing estates • Would dredging the silted parts of the estuary impact negatively on the rest of the waterway • Operation and treatment of septic tanks in the catchment and the potential impacts on the creek • What types of macrophytes indicate good and bad water quality • Construction of roads could be impeding the natural morphology of the creek • Mixed opinions over fallen trees along the creek banks and whether they are beneficial to the stability of the banks • Questions over whether repairing the entrance could and should be done
18.6 Overall Desirable Outcomes
• Healthy estuaries • Good water quality • Stable stream banks • Natural riparian and instream vegetation • Fauna friendly environment (No clashing with recreation) • Accessible to a range of recreational usage • Education of the community about threatened species • Appropriate disposal of stormwater and wastewater • Source control (minimisation) • Provision of bins on rock walls etc for fishing line or other rubbish • Signage for sensitive areas etc. • Review of the speed limits in the river/estuary • Banning of PWC • Remedial measures taken on the Cudgera Bridge if possible
76 Australian Wetlands Draft Tweed Coast Estuaries Management Plan 2004 - 2008 Tweed Shire Council
19 The Strategy
This section of the Draft Plan describes the general strategies needed to maintain and enhance the protection and rehabilitation of environmental values (including water quality), entrance management, recreational aspects, and catchment management.
19.1 Hierarchy of Works
The 1997 Plan proposed a "Hierarchy of planning for works". That approach is endorsed, and adopted for this Draft Plan: • Is the proposed work recommended in the Estuary Management Plan? • Is the proposed work permissible under Council's LEP? • Is the proposed work permissible under other Plans of Management for the area? • Is community consensus to be sought through consultation? • Is permission of landholder required? • Is Development Approval required?
19.2 Water Quality
Water quality will be best protected and enhanced by following the guidelines and recommendations of ANZECC (2000), the NSW EPA, and the Healthy Rivers Commission reports. The Strategy proposes adoption of the key indicators and criteria developed for the Tweed River Water Quality Objectives as a starting point for setting of objectives for the three Tweed Coast estuaries, until other objectives are formed.
Water quality expresses the health of catchment management as well as estuary management. The second major component of the Strategy should therefore be focussed and effective catchment management, particularly under the Northern Rivers Blueprint.
19.3 New Developments
All new development should comply with all relevant Government and Council Policies, with adequate resources devoted to enforcement. Failure to ensure that development complies with regulation decreases community confidence in the government and feeds into lack of support for future strategic actions and plans.
All new development should be assessed in the context of the Water Sensitive Urban Design approach to water management of all kinds, including supply, treatment, and return to the water cycle. Opportunities to encourage green offsets and habitat rehabilitation by developers should be maximised, including making green offsets and rehabilitation a condition of the developments. Dedication of sensitive lands to Council should also be promoted.
77 Australian Wetlands Draft Tweed Coast Estuaries Management Plan 2004 - 2008 Tweed Shire Council 19.4 Buffer Zones
The objective of Buffer Zones is to protect and enhance scenic quality, water quality, aquatic ecosystems, bio-diversity and wildlife habitat and corridors. The Tweed Local Environmental Plan 2000 under the Local Government Act 1993 require Buffer Zones for development in or near areas that are environmentally sensitive, potentially hazardous or require special consideration. This clause applies to land that adjoins the mean high-water mark (or the bank where there is no mean high-water mark) of a waterbody (such as streams, lakes, estuaries, canals etc). Details for the situations where hazard and buffer zones apply can be accessed through the Tweed Local Environmental Plan 2000, section 31.
The minimum 50 metre buffer zone around the estuary banks recommended in the 1997 Estuary Management Plan appears to be appropriate, with community support and reasonable compliance over the last Plan period. This buffer zone allocation should be continued into the next Plan period, and where possible, increased. There should be conditions of consent for new developments adjacent to the estuaries to include rehabilitation of foreshores.
19.5 Habitat
Protection of key habitat areas relies heavily on protection of vegetation and water quality. Further mapping of key areas should be undertaken, and opportunities should be sought for restoration of representative habitat zones, particularly large areas with close connections to the estuaries.
19.6 Recreational Values
Protection and enhancement of recreational values for the people who live around and visit the three estuaries will be best achieved by continuing the present work in accordance with the 1997 Plan, in conjunction with ongoing consultation with the community. Passive recreation should be encouraged to reduce the conflict between recreational users of the estuary. Meetings and media releases (Tweed Link is an effective medium of communication) should be arranged for any recreation-related project around the estuaries, firstly to inform the community, and secondly to assimilate views and identify constraints.
19.7 Entrance Management
The issues surrounding entrance management, particularly at the Cudgen Creek entrance, are complex, with a long history and many implications. The removal of the Spur Wall has been strongly supported by the community, and appears to have few serious implications. Environmental assessment would be not as stringent for this remedial small-scale action as with a larger dredging project, and removal is supported in this Draft Plan. Warning signs of the hazards of navigation should be erected.
78 Australian Wetlands Draft Tweed Coast Estuaries Management Plan 2004 - 2008 Tweed Shire Council
20 Implementation Schedule
The following schedule of implementation has been formed, using the ranges of: High: Within 1 year Medium: 1-3 years Low: When funding becomes available
The costs involved in implementing the strategies and actions are listed as estimates only. They are either on an annual rate, signified by (a), and/or a once-off for the construction works, noted with (o). Cost estimates were derived by consulting with contractors where possible, Council staff, and Australian Wetlands' experience in similar projects.
79 Australian Wetlands
Draft Tweed Coast Estuaries Management Plan 2004 - 2008 Tweed Shire Council 21 Strategies, Actions and Costs 2004-2008
21.1 Cudgen Creek (Map 13)
Entrance Management Existing situation Desired outcome Actions required Priority Estimated Costs Performance Responsibility measures and Funding Cudgen Creek is used for Acknowledgment by the Support removal of the spur High $10,000 - $30,000 Localised effects of Council, boating access to the ocean community that navigation wall and monitor changes (o) spur wall removed. Waterways by recreation craft and the through Cudgen Creek to shoals. Authority, Coast Guard. entrance is risky and the risk DIPNR is not significantly reduced Erect warning signs that High $1,000 (o) Boating community Navigation in the lower by dredging that comes at a clearly state the risks to aware of navigation Creek and through the high cost and potentially navigation. risks entrance is strongly serious environmental governed by natural coastal impact. Develop and conduct Medium $2,000 (o) Increased community processes (longshore sand community education that awareness of transport, tides, waves, Boating consistent with the highlights the: navigation risks, fluvial flows). At times passive recreational value of • relationship of possible solutions and navigation is difficult and the creek. navigation access and benefits. dangerous. the prevailing coastal Reduced danger of collision processes; A small spur wall with marker in channel • the passive recreational constructed in 1986 value of the creek; confines the ebb tide flows • the proximity of the locally to a narrow channel Tweed River where along the northern bank. significant investment is made to improve Poor night visibility of navigation of the danger marker in channel Tweed River entrance; • high cost of dredging and other possible solutions.
Place reflective tape on High $200 (o) danger marker in channel
81 Australian Wetlands Draft Tweed Coast Estuaries Management Plan 2004 - 2008 Tweed Shire Council Cudgen Creek cont/…
Water Quality Existing situation Desired outcome Actions required Priority Estimated Costs Performance Responsibility measures and Funding Roughly monthly Water Compliance with WQ Setting of WQ Objectives. High Committee decision Improvement in key Council, DIPNR, Quality (WQ) monitoring. objectives WQ indicators NSW Continue WQ monitoring High $6,500 (a) Agriculture, Urban stormwater and EPA, NSW agricultural runoff input Catchment management High As per the Blueprint Fisheries, nutrients and other according to Catchment Northern Rivers pollutants to the estuary. Blueprint. Catchment Management Further implementation of High Part of Council's Authority Water Sensitive Urban ongoing operations (NRCMA), Design in stormwater and policy developer management development contributions, Environmental Consider costs and benefits Medium Committee decision grants e.g. of an Ecological Health Envirofund Assessment
Cudgen Plateau Agricultural Lands Existing situation Desired outcome Actions required Priority Estimated Costs Performance Responsibility measures and Funding Intense rain events cause Minimisation of soil loss Ongoing support of working High One Council Visual amenity of Department of mass erosion of topsoil on from Cudgen Plateau group to develop solutions. officer @ $50/hr, Cudgen Creek Agriculture, the Cudgen Plateau agricultural land. 3hrs/week - improved following DIPNR, Council, agricultural lands. $8,000 (a) heavy rain. Cudgen Plateau Changes in farm land Land Holders One major drain deposits management practices that Water Quality monitoring High $170 per sample Water quality the sediments into Cudgen minimise soil erosion with after rain events. per site monitoring results Creek and the Pacific resultant improvement on indicate a significant Ocean. farm productivity. reduction in solids
Boardwalk Existing situation Desired outcome Actions required Priority Estimated Costs Performance Responsibility measures and Funding Approximately one-third Completion of boardwalk Complete boardwalk Medium $140,000 - Boardwalk is completed Council completed between boat $180,000 (o) ramp and park at lower estuary
82 Australian Wetlands Draft Tweed Coast Estuaries Management Plan 2004 - 2008 Tweed Shire Council Cudgen Creek cont/…
Motor Craft and Speeds Existing situation Desired outcome Actions required Priority Estimated Costs Performance Responsibility measures and Funding Speed restriction signs are A safer estuary for passive Policing of PWC and boat High $150/hr officer and A reduction in motor Waterways in place (4 knots between recreational users, who do speeds and activities by boat, hours craft related speed Authority entrance and Kingscliff not have to avoid speeding Waterways. according to complaints on the Bridge, 8 knots upstream of craft and PWC. situation estuary. the same bridge). PWCs not to enter or Medium A reduction in bank erosion. traverse upstream of A reduction in bank Regular users include Kingscliff Bridge, restricted erosion from motor craft personal water craft (PWC). to only slowly traverse wash Public feeling that speed downstream to the open signs and jet ski regulations sea. are not complied with by a large group of motor craft Develop a Boating Plan of High $40,000 - $50,000 users. Management for the creek (o, for all three estuaries) Some bank erosion still occurring due to wash from speeding motor craft.
Cudgen Lake Existing situation Desired outcome Actions required Priority Estimated Costs Performance Responsibility measures and Funding Currently managed by Integrated management of Facilitate a working group of High $8,000 (a) Improvement in water NPWS, TSC, NPWS (DEC) under the Cudgen Lake and its the Tweed Coastal quality leaving the Lake Incentives for Cudgen Nature Reserve catchment with the Committee including NPWS and entering the landholders, Plan of Management. management of Cudgen and relevant Council estuary. DIPNR EMP Acts as a detention basin Creek estuary. stakeholders to address Implementation for rain and runoff from the management of water Continued partnerships upper catchment quality and overall health of between NPWS and Cudgen Lake. other stakeholders.
Water quality and Medium $15,000 - $25,000 catchment management (o) plan to be compiled with NPWS, taking into account the Sustainability Assessment for the lake when completed.
83 Australian Wetlands Draft Tweed Coast Estuaries Management Plan 2004 - 2008 Tweed Shire Council Cudgen Creek cont/…
Acid Sulphate Soils Existing situation Desired outcome Actions required Priority Estimated Costs Performance Responsibility measures and Funding ASS runoff impacts on Minimal impacts on the More detailed investigation High $30,000 - $60,000 No measured impacts Council, DIPNR, Cudgen Lake "Hotspot"; estuary. of ASS impacts on the (o, all three on the estuary. NSW NPWS management. estuaries. estuaries) Agriculture, Better understanding of Study reports as basis EPA, NSW Little knowledge of specific existing ASS impacts on the Install monitoring points at High - $15,000 - $30,000 for management plans. Fisheries, impacts on estuaries; estuary. high-risk drainage outlets to ongoing (o, a) NRCMA, mainly industry-based identify problem areas. Improved water quality Landholders, management of ASS Improved management of leaving drainage Industry, ASS-impacted areas. Comply with Plans of High network. Drainage Union Management (PoM's) for Improved water quality Drain Maintenance, ASS leaving drainage network. Management and Vegetation Management.
Further implement Best High $10,000 -$30,000 Management Practices and (a) conduct extension work with landholders.
Restoration of natural High $5,000 - $30,000 wetlands where possible per wetland
Waterfront Structures Existing situation Desired outcome Actions required Priority Estimated Costs Performance Responsibility measures and Funding A number of private Removal of private Progressively remove all High Highly variable Progressive removal of Department of licensed waterfront structures consistent with private licensed waterfront costs according to existing waterfront Lands. structures (pontoons, the passive recreational structures as licences size and type of structures. wharves, jetties) occupy value and the inherent expire, in line with NSW structure. Crown land in Cudgen navigation difficulties of the Government policy. No new waterfront Creek at Kingscliff Creek. structures Department of Refuse all new applications High Lands for private waterfront structures.
84 Australian Wetlands Draft Tweed Coast Estuaries Management Plan 2004 - 2008 Tweed Shire Council Cudgen Creek cont/…
Bank Erosion Existing situation Desired outcome Actions required Priority Estimated Costs Performance Responsibility measures and Funding There are some sections of The cessation of unnatural Address priority sites as per High $5,000 - $30,000 No increases in Council, remediation works (rubble) bank erosion. the bank erosion mapping unnatural erosion. NRCMA , at some erosion sites with DIPNR varying degrees of success Natural erosion to be Identify unnatural erosion High Included in above at reducing or stopping recognised and allowed to points. erosion. occur providing there are no threats to existing Construct good quality High Included in above Natural bank erosion, development, significant revetment walls or other accentuated by unnatural recreational facilities and bio-engineered solutions in forces (wash from motor areas of environmental these areas where craft), still occurs along the significance. necessary. foreshore as far as the former sand mining site. Install survey marker pegs Medium $200 - $1,000 (a) or photo positions at main New erosion has been erosion sites to measure the noted along the park on rate of erosion over time. both sides of the Coast Road on the northern bank Provide formal access to High - $10,000 - $50,000 of the estuary, apparently the water's edge. Med caused by both wash and trampling.
85 Australian Wetlands Draft Tweed Coast Estuaries Management Plan 2004 - 2008 Tweed Shire Council Cudgen Creek cont/…
Recreational Facilities Existing situation Desired outcome Actions required Priority Estimated Costs Performance Responsibility measures and Funding Several amenities (park An estuary that is utilised by Complete and promote High - $7,000 - $10,000 Positive community Council, DIPNR, benches, BBQ's, toilets, the community for relaxation proposed Canoe Discovery Medium (o,a) response and utilisation Developers parking) throughout the and education. Trail along the estuary. of facilities lower estuary. Adequate facilities available Install safe launching/exit Medium $5,000 - $10,000 No passive boat-launching along the estuary banks at ramp for canoes and other (o) facilities. designated recreational passive watercraft at Jack parks and grounds Julius Park. No pedestrian access over Cudgen Creek at Kingscliff Pedestrian and cycleway Install canoe launching site Medium $5,000 - $10,000 access for Kingscliff to and creek access point on (o) South Kingscliff the north-east side of Old Bogangar Road Bridge.
Review Regional Open High Part of normal Space Section 94 Plan for operations funding opportunities for a range of recreational activities.
Ongoing review of picnic Med - Part of normal facilities by Council. ongoing operations
Include pedestrian / High Part of bridge cycleway on new bridge and costs / or build a new pedestrian bridge at a suitable location
86 Australian Wetlands Draft Tweed Coast Estuaries Management Plan 2004 - 2008 Tweed Shire Council Cudgen Creek cont/…
Development Existing situation Desired outcome Actions required Priority Estimated Costs Performance Responsibility measures and Funding New developments of Development that is Continue WSUD approach High Reduced nutrients in Developers, Casuarina and Salt having ecologically sensitive and to stormwater management water quality analyses Council stormwater pipes to the has very limited impact on that can be identified as estuary. the estuary, its aesthetics Best management practices High $50/hr - Council stormwater-sourced. and its health. for sediment control during staff Sediment runoff from construction to be regularly Reduction in sediments development sites entering monitored. entering waterways. waterways. Adhere to a minimum 50m High No reduction in riparian Riparian vegetation in some buffer zone of riparian vegetation. areas not preserved, or is vegetation on any new only partly preserved. development site. Enhancement of existing and increase in Ensure development High extent of riparian applicants have access to vegetation. terrestrial and aquatic vegetation mapping from all sources.
Wherever possible, High encourage dedication and rehabilitation of riparian zones with development applications
87 Australian Wetlands Draft Tweed Coast Estuaries Management Plan 2004 - 2008 Tweed Shire Council Cudgen Creek cont/…
Stormwater Existing situation Desired outcome Actions required Priority Estimated Costs Performance Responsibility measures and Funding Only two stormwater No rubbish or other pollution Carry out a review of High $30,000 - $50,000 Reduced nutrients and Council, treatment devices (CDS entering the estuary through existing facilities and their (o, for all three other pollutants in water Developers, units) in Kingscliff. Rubbish stormwater pipes, with all effectiveness. estuaries) quality analyses that NSW EPA and other pollutants enter stormwater treated to can be identified as Cudgen Creek through reduce the pollutant load on Replace/upgrade/install High - As funds permit. stormwater-sourced. other stormwater pipes. the estuary. infrastructure (pit inserts, ongoing sand filters, GPT's) Reduction in sediments Tweed Shire Stormwater entering waterways. Management Plan in place, Encourage where possible but not site specific. the use of soft options for High stormwater management Council participates in (e.g., source controls such Stormwater Education and as street vacuum/sweeping Assessment Program (SEA) rather than wash-down, with other Shires. education, swales, wetlands).
Best management practices for sediment control during High construction to be closely monitored.
88 Australian Wetlands Draft Tweed Coast Estuaries Management Plan 2004 - 2008 Tweed Shire Council Cudgen Creek cont/…
Rehabilitation and Revegetation Existing situation Desired outcome Actions required Priority Estimated Costs Performance Responsibility measures and Funding Stage one of rehabilitating Coastal and estuarine Continued rehabilitation Medium $40,000 (a) Increase in native DuneCare, the sand mining site is foreshores that are works of sand mining site vegetation along LandCare, NHT complete. vegetated with local native and coastal strip. estuarine foreshore. Funding, species. Developers, Regeneration of the coastal Replacement of Horsetail Medium Included in Increased connectivity NRCMA, strip in ongoing. Aquatic habitat that is She-oak with local species. rehabilitation and width of native Council adequately managed and terrestrial and aquatic Horsetail She-oak is a where necessary Incorporate vegetation High vegetation. dominant species rehabilitated. mapping from all sources throughout the regeneration for both terrestrial and Improved stability of site, although it is not a local aquatic areas. banks through species. revegetation measures Identify areas of High High Large area of vegetation of Conservation Value and potentially good quality SEPPs from Council's forest with moderate weed vegetation mapping, and levels north of the Salt link with the Northern Rivers development Catchment Blueprint targets and outcomes.
Adopt aquatic vegetation High mapping results for management and rehabilitation plans, in line with Blueprint targets.
Revegetation and High rehabilitation along the creek edge associated with the Salt development.
89 Australian Wetlands Draft Tweed Coast Estuaries Management Plan 2004 - 2008 Tweed Shire Council Cudgen Creek cont/…
Education Existing situation Desired outcome Actions required Priority Estimated CostsPerformance measures Responsibility and Funding Seabirds and fish injured by Much reduced incidence of Develop cautionary and Ongoing $1,000 - $3,000 A reduction in rubbish NSW Fisheries, abandoned fishing rubbish injury to seabirds and other educational material and (o, a) entering waterways. Recreational such as line, hooks, and fauna. signage to identify the need Fishing Licence bait bags. to collect rubbish, lines, etc. Use of Canoe Trail. funds, Council Community is more General low level of knowledgeable about their Assistance to Australian High $2,000 (o, to Interest from the knowledge about estuarine environment. Seabird Rescue for cover all community about issues by residents and educational visit to one estuaries) Cudgen Creek's visitors coastal centre on Tweed environment coast
Continue dissemination of High - $1000 - $3000 water quality and riparian ongoing (a) vegetation management information through media, Council's Tweed Link and other programs.
Other educational/ Ongoing $500 - $2,000 (o, informative signs should be a) erected where needed, though rationalise multiple signs.
Complete and promote High $7,000 - $15,000 canoe trail.
90 Australian Wetlands Draft Tweed Coast Estuaries Management Plan 2004 - 2008 Tweed Shire Council
INSERT MAP 13 HERE - CUDGEN THREATS ISSUES
91
Australian Draft Tweed Coast Estuaries Management Plan 2004 - 2008 Tweed Shire Council 21.2 Cudgera Creek (Map 14)
Water Quality Existing situation Desired outcome Actions required Priority Estimated Costs Performance Responsibility measures and Funding Roughly monthly Water Compliance with WQ Setting of WQ Objectives. High Committee decision Improvement in key Council, DIPNR, Quality (WQ) monitoring. objectives WQ indicators NSW Continue WQ monitoring. High $12,500 (a) Agriculture, Urban stormwater and EPA, Fisheries, agricultural runoff input Catchment management High - As per the Blueprint NRCMA, nutrients and other according to Catchment ongoing Environmental pollutants to the estuary. Blueprint. grants, e.g. Envirofund, Further implementation of High Part of Council's developer Water Sensitive Urban ongoing operations contributions Design in stormwater and policy management. development
Consider costs and benefits Medium Committee decision of an Ecological Health Assessment
Christies Creek Existing situation Desired outcome Actions required Priority Estimated Costs Performance Responsibility measures and Funding A floodgate exists in this Protection of freshwater Redesign and reconstruct Medium $35,000 Maintenance of spatial Tweed Shire section of creek but is in wetlands (frog habitat) from the floodgate structure. extent of freshwater Council, DIPNR, need of replacement. The salt water inundation, community. NSW Fisheries, floodgate prevents prevention of increase in Cudgera damaging tidal inundation of mosquito breeding habitat, No increase in Drainage Union important freshwater enhanced passage through mosquito breeding wetlands. structure by fish. habitat.
Greater movement of fish through structure.
92 Australian Wetlands Draft Tweed Coast Estuaries Management Plan 2004 - 2008 Tweed Shire Council Cudgera Creek cont/…
Stormwater Existing situation Desired outcome Actions required Priority Estimated Costs Performance Responsibility measures and Funding Very few stormwater No rubbish or other Carry out a review of High $30,000 - $50,000 Reduced nutrients in Council and treatment devices. pollutants entering the existing facilities and their (o, for all three water quality analyses Developers estuary through stormwater effectiveness. estuaries) that can be identified as Tweed Shire Stormwater pipes, with all stormwater stormwater-sourced. Management Plan in place, managed to reduce the Replace/upgrade/install High As funds permit. but not site specific. pollutant load on the infrastructure (pit inserts, Reduction in sediments estuary. sand filters, GPT's). entering waterways. Council participates in Stormwater Education and Encourage where possible Assessment Program (SEA) the use of soft options for High with other Shires. stormwater management (e.g., source controls such as street vacuum/sweeping rather than wash-down, education, swales, wetlands).
Best management practices for sediment control during High construction to be regularly monitored.
Cudgera Creek Entrance Existing situation Desired outcome Actions required Priority Estimated Performance Responsibility Costs measures and Funding Entrance last closed in The natural regime of Install depth gauge that Medium - $1,000 (o) No impact on flooding Council, NSW 1999, and only twice in last entrance shoaling be kept, relates to health concerns ongoing or public health. Fisheries 15 years. Partially closed in though with respect to and flooding. Follow March 2004. flooding and public health Government protocols for concerns. entrance management.
Develop entrance High $10,000 (o) management strategy over time
93 Australian Wetlands Draft Tweed Coast Estuaries Management Plan 2004 - 2008 Tweed Shire Council Cudgera Creek cont/…
Hastings Point Bridge Existing situation Desired outcome Actions required Priority Estimated Costs Performance Responsibility measures and Funding Rubble placed under the Removal of the rubble Review options for removal Medium $5,000 - $30,000 No decrease in the Tweed Shire bridge during construction of rubble from under the (o, Council to seek health of the estuary. Council was not removed on bridge quotes from Improvement in tidal completion. Concerns about contractors, and the flows and flushing. the effect this has on the work to be carried out under Council's tidal flow up the estuary, as works program when it has narrowed the tidal funds are available) prism. There is little habitat value on the rubble.
Bank Erosion Existing situation Desired outcome Actions required Priority Estimated Costs Performance Responsibility measures and Funding There are small sections of The cessation of unnatural Address priority sites as per Med - $5,000 - $30,000 No increase in Council, bank erosion where the bank erosion. the bank erosion mapping High (o) unnatural erosion. NRCMA, DIPNR remediation techniques (rubble, caged rock walls) Natural erosion to be Identify unnatural erosion High Included in above Peninsular Street have had varying success recognised and allowed to points. erosion site does not at reducing or stopping occur providing there are no pose any threat to erosion. threats to existing Construct good quality Med - Included in above public safety. development, significant revetment walls or other High Erosion currently occurs at recreational facilities and bio-engineered solutions in Safe access for Koala Koala Beach Estate, behind areas of environmental these areas where Beach residents to the the primary school at North significance. necessary. creek with minimal Pottsville, and in the lower impact on bank stability sections of the estuary. Identify failing walls and High $5,000 - $20,000 replace or improve (a) Peninsular Street erosion protection. site poses public safety concerns. Install survey marker pegs Medium $200 - $500 (a) or photo positions at main erosion sites to measure the rate of erosion over time.
Investigate access to the Med - $1,000 - $2,000 creek from Koala Beach High (o) estate's parkland.
94 Australian Wetlands Draft Tweed Coast Estuaries Management Plan 2004 - 2008 Tweed Shire Council Cudgera Creek cont/…
Motor Craft and Speeds Existing situation Desired outcome Actions required Priority Estimated Costs Performance Responsibility measures and Funding Speed restriction signs are A safer estuary for Policing of PWC and boat High - $150/hr officer and A reduction in motor Waterways in place (4 knots between passive recreational speeds and activities by Med boat, hours craft related speed Authority entrance and Hastings Point users, who do not have Waterways. according to complaints on the Bridge, 8 knots upstream of to avoid speeding craft situation estuary. the same bridge). and PWC. PWCs not to enter or traverse Medium upstream of Hastings Point A reduction in bank Regular users include PWC. A reduction in bank Bridge, restricted to only slowly erosion from motor erosion. traverse downstream to the craft wash Public feeling that speed open sea. signs and jet ski regulations are not kept by a large Develop a Boating Plan of High $40,000 - $50,000 group of motor craft users. Management for the creek. (o, for all three estuaries) Some bank erosion still occurring due to wash from speeding motor craft.
Acid Sulphate Soils Existing situation Desired outcome Actions required Priority Estimated Costs Performance Responsibility measures and Funding Little knowledge of specific Better understanding of More detailed investigation of High $30,000 - $60,000 Study reports as basis Council, DIPNR, impacts on estuaries; processes and impacts. ASS impacts on the estuaries (o, all three for management plans. NSW mainly industry-based estuaries) Agriculture, management of ASS Improved management Improved water quality EPA, NSW of ASS-impacted areas. Install monitoring points at High $15,000 - $30,000 leaving drainage Fisheries, targeted drainage outlets to (o, a) network. NRCMA, Improved water quality identify problem areas. Landholders, leaving drainage Industry, network. Comply with PoM's for Drain High Drainage Union Maintenance, ASS Management and Vegetation Management.
Compile and implement Best High $10,000 -$30,000 Management Practices and (a) conduct extension work with landholders.
95 Australian Wetlands Draft Tweed Coast Estuaries Management Plan 2004 - 2008 Tweed Shire Council Cudgera Creek cont/…
Recreational Facilities Existing situation Desired outcome Actions required Priority Estimated Costs Performance Responsibility measures and Funding Park facilities at Hastings Point, An estuary that is Complete and promote High- $7,000 - $10,000 Positive community Council and with tracks to Cudgera Creek utilised by the proposed Canoe Discovery Med (o,a) response and utilisation DIPNR along the Hastings Point to community for Trail along the estuary, with of facilities. Pottsville section of the Coast relaxation and beginning and ending to be Road. education. promoted as Hastings Point Safe access for Koala Bridge. Beach residents to the Adequate facilities creek with minimal available along the Investigate access points to Med - $1,000 - $2,000 impact on bank stability estuary banks at Cudgera Creek from Koala High (o) designated recreational Beach estate's parkland. parks and grounds Review Regional Open High Part of normal Space Section 94 Plan for operations funding opportunities for a range of recreational activities.
Ongoing review of picnic Medium Part of normal facilities by Council. - Low operations
Creek Street, Hastings Point Existing situation Desired outcome Actions required Priority Estimated Costs Performance Responsibility measures and Funding Community dissatisfied with Affected sections of Monitor rehabilitation works. High $1,000 Specified areas Council, actions undertaken on property property rehabilitated rehabilitated. Developers, involving clearing of vegetation and managed Ensure Council manages High NSW Fisheries, close to the estuary. sustainably. and monitors the interface Any future development DIPNR between development and on the property does Eastern section of property has Reassurance for the environmentally sensitive not negatively impact been rezoned from 2c community that areas. on rehabilitated area, (Development) to 7a appropriate buffer zone existing vegetation, (Environmental Protection - management will be Further assessment of High $5,000 riparian buffer zone, Wetlands), requiring implemented. environmental status of aquatic habitats, and rehabilitation of this area. northern portion of property, associated fauna. in response to community Parts of the northern portion concerns and submissions. appear to be tidally influenced.
96 Australian Wetlands Draft Tweed Coast Estuaries Management Plan 2004 - 2008 Tweed Shire Council Cudgera Creek cont/…
Development Existing situation Desired outcome Actions required Priority Estimated Costs Performance Responsibility measures and Funding Riparian vegetation and Development that is Continue WSUD approach High Reduced nutrients in Council and other High Conservation ecologically sensitive and for stormwater management water quality analyses Developers Value vegetation in some has very limited impact on that can be identified as areas not preserved, or is the estuary, its aesthetics Best management practices High $50/hr - Council stormwater-sourced. only partly preserved. and its health. for sediment control during staff construction to be regularly Reduction in sediments Very little development monitored. entering waterways. investigation planned for the estuary in the near future. Adhere to minimum 50m High No reduction in riparian buffer zone of riparian vegetation. vegetation to remain intact on new development sites. Enhancement of existing and increase in Ensure development High extent of riparian applicants have access to vegetation. terrestrial and aquatic vegetation mapping from all sources.
Wherever possible, High encourage dedication and rehabilitation of riparian zones with development applications
97 Australian Wetlands Draft Tweed Coast Estuaries Management Plan 2004 - 2008 Tweed Shire Council Cudgera Creek cont/…
Rehabilitation and Revegetation Existing situation Desired outcome Actions required Priority Estimated Costs Performance Responsibility measures and Funding Regeneration of the coastal Coastal and estuarine Continued rehabilitation Medium $100,000 - Increase in native DuneCare, strip is ongoing. foreshores that are works of coastal strip. $200,000 vegetation along LandCare, NHT vegetated with local native estuarine foreshore. Funding, Horsetail She-oak is a species. Replacement of Horsetail Medium Included in Developers, dominant species She-oak with local species. rehabilitation Increased connectivity NRCMA, throughout the regeneration Aquatic habitat that is and width of native Council site, although it is not a local adequately managed and Formalise tracks to estuary Medium Included in terrestrial and aquatic species. where necessary and beach from the Coast rehabilitation vegetation. rehabilitated Road. Improved stability of Incorporate vegetation High banks through mapping from all sources revegetation measures for both terrestrial and aquatic areas.
Identify areas of High High Conservation Value and SEPPs from Council's vegetation mapping, and link with the Northern Rivers Catchment Blueprint targets and outcomes.
Adopt aquatic vegetation High mapping results for management and rehabilitation plans, in line with Blueprint targets.
98 Australian Wetlands Draft Tweed Coast Estuaries Management Plan 2004 - 2008 Tweed Shire Council Cudgera Creek cont/…
Education Existing situation Desired outcome Actions required Priority Estimated CostsPerformance measures Responsibility and Funding Seabirds and fish injured by Much reduced incidence of Develop cautionary and Ongoing $1,000 - $3,000 A reduction in rubbish NSW Fisheries, abandoned fishing rubbish injury to seabirds and other educational material and (o, a) entering waterways. Recreational such as line, hooks, and fauna. signage to identify the need Fishing Licence bait bags. to collect rubbish, lines, etc. Use of Canoe Trail. funds, Council Community is more General low level of knowledgeable about their Assistance to Australian High $2,000 (o, to Interest from the knowledge about estuarine environment Seabird Rescue for cover all community about issues by residents and educational visit to one estuaries) Cudgera Creek's visitors coastal centre on Tweed environment coast
Continue dissemination of High - $1000 - $3000 water quality and riparian ongoing (a) vegetation management information through media, Council's Tweed Link and other programs.
Other educational and Ongoing $500 - $2,000 (o, informative signs should be a) erected where needed, though rationalise multiple signs.
Complete and promote High $7,000 - $15,000 canoe trail.
99 Australian Wetlands Draft Tweed Coast Estuaries Management Plan 2004 - 2008 Tweed Shire Council
INSERT MAP 14 HERE - CUDGERA THREATS ISSUES
100
Australian Draft Tweed Coast Estuaries Management Plan 2004 - 2008 Tweed Shire Council
21.3 Mooball Creek (Map 15)
Water Quality Existing situation Desired outcome Actions required Priority Estimated Costs Performance Responsibilit measures y and Funding Most of the estuary Compliance with WQ Setting of WQ Objectives. High Committee decision Improvement in key Council, generally complies with objectives WQ indicators DIPNR, NSW guideline values over the Catchment management High - As per the Blueprint Agriculture, four years of monitoring. according to Catchment ongoing NSW EPA, Blueprint. NRCMA, NSW Roughly monthly water Fisheries, quality (WQ) monitoring. Continue WQ monitoring. High $10,500 (a) Environmental grants, e.g. Urban stormwater and Consider costs and benefits Medium Committee decision Envirofund, agricultural runoff input of an Ecological Health developer nutrients and other Assessment contributions pollutants to the estuary. Implement the Pottsville Med - $3,000 Canal Residents Education ongoing Program.
Further implementation of High Part of Council's Water Sensitive Urban ongoing operations Design in stormwater and policy management. development
101 Australian Wetlands Draft Tweed Coast Estuaries Management Plan 2004 - 2008 Tweed Shire Council Mooball Creek cont/…
Bank Erosion Existing situation Desired outcome Actions required Priority Estimated CostsPerformance measures Responsibility and Funding Small sections of bank The cessation of unnatural Address priority sites as per High $5,000 - $30,000 No increase in unnatural Council, DIPNR, erosion where the bank erosion. the bank erosion mapping. erosion NRCMA placement of remediation techniques (rubble, timber Natural erosion to be Identify unnatural erosion High Included in above walls) has had varying recognised and allowed to points. success at reducing or occur providing there are no stopping erosion. threats to existing Construct good quality Med - Included in above development, significant revetment walls or other High Erosion currently occurs recreational facilities and bio-engineered solutions in along the Coast Road (road areas of environmental these areas where in threatened by erosion) significance. necessary. and in the lower sections of the estuary. Identify failing walls and Medium $10,000 - replace or improve $50,000 (a) protection.
Install survey marker pegs Medium $200 - $500 (a) or photo positions at main erosion sites to measure the rate of erosion over time.
Implement the Mooball High - $200,000+ Creek Reserve ongoing Rehabilitation Plan.
Develop and implement Medium $10,000 - management plans for - High $20,000 per plan, other key erosion locations plus $200,000 implementation
102 Australian Wetlands Draft Tweed Coast Estuaries Management Plan 2004 - 2008 Tweed Shire Council Mooball Creek cont/…
Proposed Mooball Sewage Treatment Plant (STP) Existing situation Desired outcome Actions required Priority Estimated CostsPerformance measures Responsibility and Funding Proposal for a 600 Sewage effluent Integrate Mooball STP High $2,000 Effluent quality leaving Council, NSW Equivalent Person (EP) management that is planning with overall water the STP continuously EPA STP on creek bank at sustainable and has no quality objectives through a meets water quality Mooball village damaging impacts in the Council workshop. standards and catchment or the estuary. downstream monitoring Tweed Coast and Estuaries High $200 shows no deterioration. Committee is to be consulted during the assessment process and implementation of the STP.
Comprehensive High assessment of effluent management options.
Water quality monitoring High - $4,100 (a) points should be installed ongoing downstream of STP site for ongoing comparison before and after construction.
Motor Craft and Speeds Existing situation Desired outcome Actions required Priority Estimated CostsPerformance measures Responsibility and Funding Speed restriction signs are A safer estuary for passive Policing of PWC and boat High $150/hr officer A reduction in motor craft Waterways in place. recreational users, who do speeds and activities by and boat, hours related speed complaints Authority not have to avoid speeding Waterways. according to on the estuary. Regular users include PWC. craft and PWC. situation PWCs not to enter or Medium A reduction in bank Public feeling that speed Reduction in bank erosion. traverse upstream of boat erosion from motor craft signs and jet ski regulations ramp at Pottsville Bridge, wash are not kept by a large restricted to slow travel group of motor craft users. downstream to the sea.
Some bank erosion still Prepare a long-term Plan of Medium $30,000 - occurring due to wash from Management for Boating on $50,000 (for all motor craft. the estuary estuaries)
103 Australian Wetlands Draft Tweed Coast Estuaries Management Plan 2004 - 2008 Tweed Shire Council Mooball Creek cont/…
Acid Sulphate Soils Existing situation Desired outcome Actions required Priority Estimated CostsPerformance measures Responsibility and Funding Little knowledge of specific Better understanding of More detailed investigation High $30,000 - Study reports as basis Council, DIPNR, impacts on estuaries; processes and impacts. of ASS impacts on the $60,000 (o, all for management plans. NSW mainly industry-based estuaries three estuaries) Agriculture, management of ASS. Improved management of Improved water quality NSW EPA, ASS-impacted areas. Install monitoring points at High $15,000 - leaving drainage NSW Fisheries, Mooball Drainage Union targeted drainage outlets to $30,000 (o, a) network. NRCMA, has developed a Plan of Improved water quality identify problem areas. Landholders, Management for the leaving drainage network. Compliance with PoM's Industry, maintenance of drains. Comply with PoM's for High for Drainage, ASS and Drainage Union Drain Maintenance, ASS Vegetation Management Management and Vegetation Management.
Compile and implement High $10,000 -$30,000 Best Management (a) Practices and conduct extension work with landholders.
104 Australian Wetlands Draft Tweed Coast Estuaries Management Plan 2004 - 2008 Tweed Shire Council Mooball Creek cont/…
Development Existing situation Desired outcome Actions required Priority Estimated CostsPerformance measures Responsibility and Funding Black Rocks Estate Development that is Implement WSUD High Reduction in sediments Council and currently under ecologically sensitive and approach to stormwater entering waterways. Developers development. Pottsville has very limited impact on management Waters Estate is a canal the estuary, its aesthetics No reduction in riparian estate, with potential water and its health. Best management High $50/hr - Council vegetation. quality issues. practices for sediment staff control during construction Full compliance of to be regularly monitored. minimum 50m wide buffer zones Ensure development High applicants have access to Enhancement of existing terrestrial and aquatic and increase in extent of vegetation mapping from all riparian vegetation. sources.
Adhere to a minimum 50m High- buffer zone of riparian ongoing vegetation to remain intact on any new development site.
Wherever possible, High- encourage dedication and ongoing rehabilitation of riparian zones with development applications.
105 Australian Wetlands Draft Tweed Coast Estuaries Management Plan 2004 - 2008 Tweed Shire Council Mooball Creek cont/…
Recreational Facilities Existing situation Desired outcome Actions required Priority Estimated CostsPerformance measures Responsibility and Funding Very few recreational An estuary that is utilised by Complete and promote High - $7,000 - $15,000 Positive community Council and facilities in place except at the community for relaxation proposed Canoe Discovery Med (o, a) response and utilisation DIPNR the lower estuary. and education. Trail along the estuary. of facilities.
Small boat ramp upstream Adequate facilities available Map the existing formalised Medium $10,000 - Maintain safety and of bridge not accessible at along the estuary banks at creek access points and $25,000 visual amenity of low tide. designated recreational formalise or remove other facilities parks and grounds access points from Overall Drive. Limited use of boat ramp Recognition that Pottsville in accordance with the boat ramp is a minor facility Review Regional Open High Included in limitations and that shoaling will restrict Space Section 94 Plan for normal use funding opportunities and operations full range of recreational activities.
Encourage the Med - Coastal implementation of the Low Committee Tweed Council Cycle Plan.
Ongoing review of picnic Med - Included in facilities by Council. Low normal operations Maintain boat ramp at Low present standard
106 Australian Wetlands Draft Tweed Coast Estuaries Management Plan 2004 - 2008 Tweed Shire Council Mooball Creek cont/…
Stormwater Management Existing situation Desired outcome Actions required Priority Estimated CostsPerformance measures Responsibility and Funding Tweed Shire Stormwater No rubbish or other Carry out a review of High $30,000 - Reduced nutrients in Council and Management Plan in place, pollutants entering the existing facilities and their $50,000 (o, for all water quality analyses Developers but not site specific. estuary through stormwater effectiveness in meeting three estuaries) that can be identified as pipes, with all stormwater WQ objectives. stormwater-sourced. Only two gross pollutant treated to reduce the traps on the stormwater pollutant load on the Replace/upgrade/install High As funds permit Reduction in sediments drains along Mooball Creek estuary. infrastructure (pit inserts, entering waterways. (Pottsville Waters), and one sand filters, GPT's). stormwater pond with litter racks (Black Rocks) Encourage where possible High the use of soft options for stormwater management (e.g., source controls such as street vacuum/sweeping rather than wash-down, education, swales, wetlands).
Best management High practices for sediment control during construction to be closely monitored.
Implement the Canal Med - Residents Education High - Program. ongoing
107 Australian Wetlands Draft Tweed Coast Estuaries Management Plan 2004 - 2008 Tweed Shire Council Mooball Creek cont/…
Rehabilitation and Revegetation Existing situation Desired outcome Actions required Priority Estimated CostsPerformance measures Responsibility and Funding Regeneration of the coastal Coastal and estuarine Replacement of non-local Medium Increase in native DuneCare, strip in ongoing. foreshores that are with local species. vegetation along LandCare, NHT vegetated with local native estuarine foreshore. Funding, Horsetail She-oak and species. Formalise tracks to beach Medium $20,000 - Developers, Coastal tea-tree are and estuary from the Coast $100,000 Increased connectivity NSW Fisheries, dominant species Aquatic habitat that is Road. and width of native NRCMA, throughout the regeneration adequately managed and terrestrial and aquatic Council sites, although they are not where necessary Implement Mooball Creek High $200,000 vegetation. local species. rehabilitated Reserve Rehabilitation Plan. Improved stability of NSW Fisheries undertaking banks through aquatic habitat mapping in Incorporate vegetation High revegetation measures all NSW estuaries mapping from all sources for both terrestrial and aquatic areas.
Identify areas of High High Conservation Value and SEPPs from Council's vegetation mapping, and link with the Northern Rivers Catchment Blueprint targets and outcomes.
Adopt aquatic vegetation High mapping results for management and rehabilitation plans, in line with Blueprint targets.
Continue monitoring of High - $1,200 (a) transplanting of mangroves ongoing and rehabilitation of saltmarshes at Black Rocks Estate Bridge.
108 Australian Wetlands Draft Tweed Coast Estuaries Management Plan 2004 - 2008 Tweed Shire Council Mooball Creek cont/…
Education Existing situation Desired outcome Actions required Priority Estimated CostsPerformance measures Responsibility and Funding Seabirds and fish injured by Community is more Develop cautionary and Ongoing $1,000 - $3,000 A reduction in rubbish NSW Fisheries, abandoned fishing rubbish knowledgeable about their educational material and (o, a) entering waterways. Recreational such as line, hooks, and environment. signage to identify the need Fishing Licence bait bags. to collect rubbish, lines, etc. Use of Canoe Trail. funds, Council Much reduced incidence of General low level of injury to seabirds and other Assistance to Australian High $2,000 (o, to Interest from the knowledge about estuarine fauna. Seabird Rescue for cover all community about issues by residents and educational visit to one estuaries) Mooball Creek's visitors. coastal centre on Tweed environment coast.
Continue dissemination of High - $1000 - $3000 water quality and riparian ongoing (a) vegetation management information through media, Council's Tweed Link and programs such as the Canal Residents Education Program.
Other educational and Ongoing $500 - $2,000 (o, informative signs should be a) erected where needed, though rationalise multiple signs.
Complete and promote High $7,000 - $15,000 canoe trail.
109 Australian Wetlands Draft Tweed Coast Estuaries Management Plan 2004 - 2008 Tweed Shire Council INSERT MAP 15 HERE - MOOBALL THREATS ISSUES
110 Australian Wetlands
Draft Tweed Coast Estuaries Management Plan 2004 - 2008 Tweed Shire Council
22 Funding Sources
Funding for projects that will benefit estuary management can be sought from various sources, for example: • the NSW State Government will fund 50% of direct Management Plan works under the Estuary Management Program; • developments such as Casuarina, Salt, Koala Beach and Black Rocks through developer contributions, and any future developments; and • Envirofund programs.
The Catchment Blueprint implementation is likely to deliver significant funding over the next decade as investment in natural resource management.
A recreational fishing licence is required to fish in NSW, and revenue raised from licence sales is used in community programs to promote sustainable fishing and research under the Saltwater and Freshwater Recreational Fishing Trusts.
The Regional Open Space Plan for Council allows funding to be sourced for certain projects. Contributions Plan No. 26 Regional Open Spaces (CP 26) has been introduced to allow adequate funding and provision of regional open space and facilities to satisfy demand created by population growth in Tweed Shire.
The contributions collected by this plan fund the provision, augmentation and embellishment of regional structured and casual open space, pursuant to S.94 of the EP&A Act 1979. Casual open space includes non-organised, informal outdoor leisure activities, and land that is managed by the Council zoned Public Open Space 6(a) in the LEP. Structured Open Space refers to land developed for formal outdoor sporting purposes. CP 26 allows for a total regional open space works program of $4,510,000 for casual open space, and $23,419,500 for structured open space, giving a proposed total works program expenditure of $27,929,500 for regional open space over the period 2002-2022.
The provision of additional public open space and funding of capital works to upgrade or embellish open space is available from a number of sources: • Dedication of open space by developers in new residential subdivisions or other residential development creating additional demand for open space in accordance with • Council's Contributions Plans; • General Council expenditure allocations from rate revenue and other general income; • Grants from State or Federal Government for specific projects (eg Tweed Coast Bicentennial Park at Pottsville) and NSW Department of Sport and Recreation Capital Assistance Grants for sporting facilities and Regional Sports Facility Grants; • Monetary contributions by developers for provision or embellishment of open space in accordance with Council's Contributions Plans; • Land transferred to Council by land owners for other reasons such as rezoning agreements, provision of Works-in-Kind, etc; and • Land transferred to Council by State or Federal Government (eg Coastal Crown lands from Fingal to Wooyung recently transferred to Council management).
111 Australian Wetlands
Draft Tweed Coast Estuaries Management Plan 2004 - 2008 Tweed Shire Council
Environmental levies are being used in some areas to raise the funds needed to invest in green space, and in habitat restoration. One example of the benefits environmental levies can have for a Council area can be seen in the operations of Gold Coast City Council. As reported by The Courier Mail (June 26, 2003):
"The Gold Coast City Council plans to use its open space preservation levy to buy environmentally significant private landholdings, place development and management covenants on the land and re-sell it. People would be able to live on the land but would have to protect and manage it in accordance with the covenant."
During May 2003, $20m was spent on 2350ha of land at South Stradbroke Is., Pimpama, Tugun and Mudgeeraba. Gold Coast City Council plans to spend a further $12.3m this financial year (2003-04) on another 1000ha of land.
In NSW, the Great Lakes City Council has been actively buying floodplain wetlands presently under agriculture, and exploring innovative tradeoffs of allowing targeted development of elevated land in exchange for restoring large areas of natural lowland ecosystem. In this respect, the return from restoring wetlands on a large scale for stream and estuary health may be one of the most cost-effective ways for Councils to fulfill their obligations under all the relevant policies and plans.
Should an environmental levy be introduced to Tweed Shire Council, applications for further grant money can be made, as most State and Federal schemes will provide funds on a 1:1 basis - that is, for every $1 Council puts forward, the State or Federal body will contribute $1. Therefore, the more funds that can be initially put forward by Council, the more funds it can receive.
However, environmental levies can be controversial, and any such proposals need to be thoroughly researched and prepared before presentation to the community.
112 Australian Wetlands
Draft Tweed Coast Estuaries Management Plan 2004 - 2008 Tweed Shire Council
23 References
ANZECC (2000) Guidelines for Fresh and Marine Water Quality. Australian and New Zealand Environment and Conservation Council, Canberra.
ARMCANZ and ANZECC (1996) Draft Guidelines for Urban Stormwater Management. National Water Quality Management Strategy, Agriculture and Resource Management Council of Australia and New Zealand, and the Australian and New Zealand Environment Conservation Council, Canberra.
AGO (2002) Living with Climate Change. An Overview of Potential Climate Change Impacts on Australia. Australian Greenhouse Office, Canberra.
Drinkwater, K.F. and Frank, K.T. (1994) Effects of river regulation and diversion on marine fish and invertebrates. Aquatic Conservation:fresh water and marine ecosystems, 4, 135-151.
Easton, C. (1989) The Trouble with the Tweed. Fishing World, March 1989, pp 58 - 58.
Erskine, A. (2003) Mooball Creek Reserve: Rehabilitation and Management Plan - Draft. Environmental Training and Employment, Ballina.
Eyre, B., and Twigg, C. (1997) Nutrient behaviour during post-flood recovery of the Richmond River estuary northern NSW, Australia. Estuarine, Coastal and Shelf Science 44, 311-326.
Hagley, R. (2003) Cudgen Creek Dredging Proposal. Information Paper in response to Tweed Shire Council. NSW Department of Infrastructure, Planning and Natural Resources, Alstonville.
HRC (Healthy Rivers Commission) (2002) Independent Inquiry into Coastal Lakes Final Report. Healthy Rivers Commission. April 2002.
HRC (Healthy Rivers Commission) (2003) Independent Inquiry into The North Coast Rivers Final Report. Healthy Rivers Commission. March 2003.
Loneragan, N. R. and Bunn, S. E. (1999) River Flows and Estuarine Ecosystems: Implications for coastal fisheries from a review and a case study of the Logan River, southeast Queensland. Australian Journal of Ecology; 24, 431-440.
Johnston, S., Kroon, F., Slavich, P., Cibilic, A. and Bruce, A. (2003a) Restoring the balance: Guidelines for managing floodgates and drainage systems on coastal floodplains. (NSW Agriculture: Wollongbar, Australia)
Johnston, S.G., Slavich, P.G., Sullivan, L.A. and Hirst, P. (2003b) Artificial drainage of floodwaters from sulfidic backswamps: effects on deoxygenation in an Australian estuary. Marine and Freshwater Research, 2003, 54, 781-795.
113 Australian Wetlands
Draft Tweed Coast Estuaries Management Plan 2004 - 2008 Tweed Shire Council Lawrence, I. and Breen, P. (1998) Design Guidelines: Stormwater Pollution Control Ponds and Wetlands. The Cooperative Research Centre for Freshwater Ecology.
McAlister, T. and McLean, E. (1999) Bringing the Estuary Processes and Management Studies Closer Together. Conference Proceedings. 9th Annual NSW Coastal Conference, Forster. NSW Coastal Council.
McComb, A. J. (1984) Plant Biomass and Productivity in southwestern Australian Estuaries. In Estuarine Environments in the Southern Hemisphere (Hodgekin, E. P., ed.) Bulletin No. 161, Department of Conservation and Environment, Western Australia, pp. 97-111.
NPWS (1998) Cudgen Nature Reserve Plan of Management. National Parks and Wildlife Service.
NSW EPA (1997) Managing Urban Stormwater - Treatment Techniques. NSW Environment Protection Authority, Sydney.
NSW EPA (1998) Managing Urban Stormwater - Source Control (Draft). NSW Environment Protection Authority, Sydney.
NSW EPA (1999) Water Quality and River Flow. Interim Environmental Objectives, Tweed River. NSW Environment Protection Authority, Sydney.
NSW Fisheries (2004a) Recreational Fishing. [www.fisheries.nsw.gov.au]
NSW Fisheries (2004b) Estuarine Habitats. [www.fisheries.nsw.gov.au]
NSW Government (1992) Estuary Management Manual. NSW Government, Sydney.
NSW Government (1997) NSW Coastal Policy 1997. NSW Government, Sydney.
Pierson, W.L., Bishop, K., Van Senden, D., Horton, P.R. and Adamantidis, C.A. (2002) Environmental Water requirements to Maintain Estuarine Processes. Environmental Flows Initiative Technical Report, No. 3. Environment Australia, Canberra.
Prosser, I. & Karssies, L. (2001) Designing Filter strips to trap Sediment and Attached Nutrient. In Riparian Land Management Technical Guidelines Update, CSIRO Land & Water Australia, Canberra.
Reeve, I., Doyle, B., Brunckhorst, D., and Marshall, G. (2002) Independent Advice on the Link Between Sustainable Farming Practices, Farm Profitability and River Health. Occasional Paper for the Healthy Rivers Commission.
Roy, P. S., Williams, R. J., Jones, A. R., Yassini, I., Gibbs, P. J., Coates, B., West, R. J., Scanes, P. R., Hudson, J. P. and Nichol, S. (2001) Structure and Function of South-east Australian Estuaries. Estuarine, Coastal and Shelf Science; 53, 351-384.
SoEAC (1996) State of the Environment Australia. State of the Environment Advisory Council, DEST, CSIRO Publishing, Melbourne.
114 Australian Wetlands
Draft Tweed Coast Estuaries Management Plan 2004 - 2008 Tweed Shire Council Tulau, M. J. (1999) Acid Sulphate Soil Management Priority Areas. In The Lower Tweed Floodplains. Report. Department of Land and Water Conservation, Sydney.
Tulau, M. J. (2002) Agricultural Drainage in Acid Sulphate Soil Backswamps in New South Wales, Australia - Technical, Regulatory and Policy Responses. Department of Land and Water Conservation, Sydney.
TSC (1999) Tweed Urban Stormwater Quality Management Plan. Tweed Shire Council.
Valiela, I., Foreman, K. and LaMontagne, M. (1992) Couplings of Watersheds and Coastal Waters: sources and consequences of nutrient enrichment in Waquoit Bay, Massachusetts. Estuaries, 15, 443-57.
WBM Oceanics Australia (1998) Cudgen Nature Reserve: Cudgen Lake Management Study. Prepared for National Parks and Wildlife Service.
WBM Oceanics (2000) Tweed River and Catchment: Interim Water Quality Management Plan. Report to Tweed Shire Council.
WBM Oceanics (2001) Tweed Coastline Hazard Definition Study Final Report. Report to Tweed Shire Council.
Wetzel, R. G. (1999) Plants and water in and adjacent to lakes. In Ecohydrology, A. J. Baird and R. L. Wilby (Eds.). Routledge Publishers, London.
Wong, T. (2003) A Changing Paradigm in Australian Urban Stormwater Management. In Conference Proceedings, Integrated Urban Water Management and Water Sensitive Urban Design. 20th November 2003, Lismore NSW.
Personal Communications Jane Lofthouse, Tweed Shire Council Richard Hagley, Department of Infrastructure, Planning and Natural Resources Mark Tunks, Tweed Shire Council
115 Australian Wetlands
Draft Tweed Coast Estuaries Management Plan 2004 - 2008 Tweed Shire Council
Appendix 1 - Water Quality
The aim of this section is to organise and present Council monthly monitoring data in a clear, understandable way, to provide a broad picture of measured water quality in the three estuaries over the four years, and in particular to:
• present and comment on graphs and tables of water quality trends over time in each estuary • identify and interpret any anomalies or features of interest • use selected water quality parameters to compare the estuaries • examine the suitability of the monitoring approach and recommend any improvements
The section begins with a brief discussion of the Tweed climate and its interaction with water quality.
A1 Climate
The Far North Coast has a warm subtropical climate, with a pronounced wet season in late summer and autumn, sometimes extending into July. The dry season extends from late winter through spring into early summer, when severe thunderstorm activity can produce localised strong wind and intense rainfall. The catchments of the three estuaries receive some of the highest annual rainfall in NSW, with an annual average of 1798mm from 1969-2003 at the Kingscliff station (BoM).
Figure 4 shows mean monthly rainfall at the Kingscliff station, 1969-2003, and indicates that over this period, the wettest month is March, with an average of 234mm.
Mean Monthly rainfall at Kingscliff, 1969-2003
250
200
150 mm 100
50
0 Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec
Figure 4 Average rainfall by month at Kingscliff, 1969-2003. Source: Bureau of Meteorology.
116 Australian Wetlands
Draft Tweed Coast Estuaries Management Plan 2004 - 2008 Tweed Shire Council
However, individual years can feature much larger monthly or annual totals, for example 665mm in March 1974, or 326mm and 374mm in February and March of 2001 when large fish kills occurred in several North Coast waterways. These heavy rainfall events often arrive as intense downpours of large droplets, often associated with the low pressure systems of tropical origin.
These downpours mobilise both particulate and dissolved pollutants of all kinds from the catchments and transport them into the estuaries on high flows. Large rainfall events can result in massive pollution episodes, but in general, the very large events tend to carry the catchment loads out to sea. Small to medium events, and the residual loads left in the estuaries as the floods recede, can have a large impact on the estuaries because pollutants remain in the estuary. Figure 5 shows the variable rainfall pattern of the wet year of 1974. Rainfall totals of over 550mm in January, March and April, were followed by no rain at all in July.
Monthly Rainfall at Kingscliff, 1974 700
600
500
400
mm 300
200
100
0 Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov
Figure 5 Monthly rainfall at Kingscliff in 1974. Source: Bureau of Meteorology.
The following pages present a series of graphs and tables, visually presenting water quality data, with interpretation and comment. The graphs and tables are designed to be broadly consistent in size and format, so that readers can gain familiarity with the patterns and usage of terms. The graphs and tables are organised into sections dealing with each estuary, with a final section comparing the three estuaries for selected water quality parameters.
Each estuary section begins with a table of the 80 percentile (20 percentile for dissolved oxygen) figures for the most important parameters. The 80 percentile and 20 percentile figures are important because this statistical level for potential pollutants is defined by ANZECC (2000) as the cut-off point above or below which more detailed assessment is required. The "80 percentile (80%-ile) figure" means that in any set of numbers, 80% of the numbers are less than the 80%-ile figure.
The methodology involved combining and organising data from eighteen files supplied by Council, and processing the data in Excel spreadsheets.
117 Australian Wetlands
Draft Tweed Coast Estuaries Management Plan 2004 - 2008 Tweed Shire Council
A2 Cudgen Estuary
There are three monitoring sites situated in the Cudgen Estuary, ranging through CGN1 near the entrance, CGN2 in mid-estuary, and CGN3 downstream of Cudgen Lake. Table 6 lists 80 percentile (20 percentile for Dissolved Oxygen) concentrations over the four years.
Table 6 80 percentile concentrations of key indicators Site Faecal DO Salinity pH Chlor-a SS Total Total P coliforms (mg/l) (ppt) (ug/L) (mg/L) N (mg/L) (fcu/100mL) (20%-ile) (mg/L) CGN1 100 5.5 35 8.2 3.2 8.3 0.7 0.046 CGN2 188 4.46 25 7.6 3.3 7.6 0.8 0.042 CGN3 108 5.3 19 7.8 2.9 6.7 1.0 0.028
Comment: • Faecal coliform concentrations meet the guidelines at all sites except CGN2 • DO is generally less than the desired levels of 6mg/L • Salinity and pH indicate tidal flushing reaches throughout the estuary • Chlorophyll a levels are generally low, as is Suspended Solids • Total N is generally slightly higher than the guidelines, and elevated at CGN3 • Total P is within the Tweed River guidelines
Cudgen-1 Faecal coliforms, 1999-2003 500 450 400 350 300 250 200
cfu/100mL Primary contact (swimming) 150 id li 100 50 0
99 00 00 00 00 01 01 01 01 02 02 02 02 03 03 03 t- n- r- ul- t- n- r- ul- t- n- r- ul- t- n- r- ul- Oc Ja Ap J Oc Ja Ap J Oc Ja Ap J Oc Ja Ap J
Figure 6 Faecal coliforms at CGN1over four years
Comment: Faecal coliform concentrations near the lower estuary swimming areas are generally within the guidelines. As with most waterbodies, rainfall and runoff increases the risk.
118 Australian Wetlands
Draft Tweed Coast Estuaries Management Plan 2004 - 2008 Tweed Shire Council
Cudgen 1-3 Total Nitrogen, 1999-2003 4.0 3.5 CGN1 3.0 2.5 2.0 CGN2 mg/L 1.5 1.0 CGN3 0.5 0.0
99 00 00 00 00 01 01 01 01 02 02 02 02 03 03 03 t- n- r- ul- t- n- r- ul- t- n- r- ul- t- n- r- ul- Oc Ja Ap J Oc Ja Ap J Oc Ja Ap J Oc Ja Ap J
Figure 7 Total Nitrogen at CGN1 over four years
Comment: TN is elevated at all sites at times. The high concentration at CGN1 but not at the other sites during the winter of 2001 indicates urban stormwater inputs. This conclusion was reinforced by anecdotal evidence at the Kingscliff community meetings of poor quality stormwater runoff to the estuary in rainfall events.
Cudgen 1-3 Total Phosphorus, 1999-2003 0.25 0.20 CGN1 0.15 CGN2 0.10
0.05 CGN3 0.00
99 00 00 00 00 01 01 01 01 02 02 02 02 03 03 03 t- n- r- ul- t- n- r- ul- t- n- r- ul- t- n- r- ul- Oc Ja Ap J Oc Ja Ap J Oc Ja Ap J Oc Ja Ap J
Figure 8 Total Phosphorus at the three sites over four years
Comment: although TP concentrations are generally low, wet season inputs are evident, probably from agricultural and urban stormwater.
119 Australian Wetlands
Draft Tweed Coast Estuaries Management Plan 2004 - 2008 Tweed Shire Council
Cudgen 1-3 Chlorophyll a, 1999-2003 25.0
20.0 CGN1 15.0 CGN2 10.0 5.0 CGN3 0.0
9 0 00 00 0 01 01 01 1 2 02 02 2 3 03 03 t-9 n-0 r- ul- t-0 n- r- ul- t-0 n-0 r- ul- t-0 n-0 r- ul- Oc Ja Ap J Oc Ja Ap J Oc Ja Ap J Oc Ja Ap J
Figure 9 Chlorophyll a concentrations at the three sites over four years
Comment: Chlorophyll a is generally within the Tweed River guidelines.
Cudgen 1-3 Dissolved Oxygen, 1999-2003 10.0
8.0 CGN1 6.0 CGN2 mg/L 4.0
2.0 CGN3
0.0
99 00 00 00 00 01 01 01 01 02 02 02 02 03 03 03 t- n- r- ul- t- n- r- ul- t- n- r- ul- t- n- r- ul- Oc Ja Ap J Oc Ja Ap J Oc Ja Ap J Oc Ja Ap J
Figure 10 DO at the three sites over four years
Comment: DO processes appear to be fairly uniform throughout the estuary over the seasons. Note the familiar pattern of low DO in wet season, particularly in February- March 2001.
A3 Cudgera Estuary
There are four monitoring sites situated in the Cudgera Estuary, ranging through CGR1 near the entrance, CGR2 in mid-estuary, CGR3 downstream of the junction of two arms, and CGR4 in the upper estuary - where a western tributary carries stormwater runoff from both agriculture and possibly a residential area. Table 7 lists 80 percentile (20 percentile for Dissolved Oxygen) concentrations over the four years.
120 Australian Wetlands
Draft Tweed Coast Estuaries Management Plan 2004 - 2008 Tweed Shire Council
Table 7 80 percentile (20 percentile for DO) concentrations of elected parameters Site Faecal DO(mg/l) Salinity pH Chlor-a SS Total N Total P coliforms (ppt) (ug/L) (mg/L) (mg/L) (mg/L) (fcu/100mL) CGR1 144 5.62 34.9 8.2 2 11.8 0.62 0.042 CGR2 228 5.3 34 8.1 3 9.7 0.92 0.03 CGR3 426 4.62 32.9 7.9 3 11 1.1 0.05 CGR4 300 4.22 29 7.8 7 16.2 1.1 0.06
Comment: • Faecal coliform concentrations comply with the criteria only in the lower estuary • DO is low compared with the Tweed River guidelines • Salinity and pH are in the desired range • Chlorophyll a is within the guidelines • Suspended Solids are elevated at CGR4 • Total Nitrogen is above the desirable levels • Total Phosphorus is close to the guideline criteria
Cudgera 1-4 Faecal coliforms, 1999-2003 10000 9000 8000 CGR1 7000 6000 CGR2 5000 4000 CGR3 cfu/100mL 3000 2000 CGR4 1000 0
99 00 00 00 00 01 01 01 01 02 02 02 02 03 03 03 t- n- r- ul- t- n- r- ul- t- n- r- ul- t- n- r- ul- Oc Ja Ap J Oc Ja Ap J Oc Ja Ap J Oc Ja Ap J
Figure 11 Faecal coliform concentrations at the four sites over four years
Comment: fairly high numbers are seen during wet season. Both mid- and upper estuary sites register large concentrations.
121 Australian Wetlands
Draft Tweed Coast Estuaries Management Plan 2004 - 2008 Tweed Shire Council
Cudgera-1 Faecal coliforms, 1999-2003 500 450 400 350 300 250 200
cfu/100mL Primary contact (swimming) 150 id li 100 50 0
99 00 00 00 00 01 01 01 01 02 02 02 02 03 03 03 t- n- r- ul- t- n- r- ul- t- n- r- ul- t- n- r- ul- Oc Ja Ap J Oc Ja Ap J Oc Ja Ap J Oc Ja Ap J
Figure 12 Faecal coliform concentrations in the lower estuary over four years
Comment: elevated concentrations during the wet season even in the lower estuary suggest that pollutants mobilised by rainfall events impact on the whole of the relatively small estuary, and may represent coliform bacteria from agriculture and urban stormwater as well as bacteria from natural origins.
Cudgera 1-4 Total Nitrogen, 1999-2003
6.0 CGR1 5.0
4.0 CGR2
3.0 CGR3 2.0
1.0 CGR4 0.0
9 0 0 1 1 2 2 3 -9 00 -0 00 -0 01 -0 01 -0 02 -0 02 -0 03 -0 03 ct n- pr l- ct n- pr l- ct n- pr l- ct n- pr l- O Ja A Ju O Ja A Ju O Ja A Ju O Ja A Ju
Figure 13 Total Nitrogen at the four sites over four years
Comment: Total Nitrogen is often relatively high in the wet season, with the February 2003 sampling at the three mid-upper estuary sites indicating a significant nitrogen source upstream. It should be remembered that elevated concentrations in rainall events also mean very high loads, since the large volumes of runoff result in many more litres carrying the milligram concentrations.
122 Australian Wetlands
Draft Tweed Coast Estuaries Management Plan 2004 - 2008 Tweed Shire Council
Cudgera 1-4 Total Phosphorus, 1999-2003 0.18 CGR1 0.16 0.14 0.12 CGR2 0.10 0.08 mg/L 0.06 CGR3 0.04 0.02 CGR4 0.00
99 00 00 00 00 01 01 01 01 02 02 02 02 03 03 03 t- n- r- ul- t- n- r- ul- t- n- r- ul- t- n- r- ul- Oc Ja Ap J Oc Ja Ap J Oc Ja Ap J Oc Ja Ap J
Figure 14 Total Phosphorus at four sites over four years
Comment: the two upper estuary sites receive substantial phosphorus loads during wet periods, with one elevated concentration in October 2001. Similarly to nitrogen, this dry season spike may indicate processing of wet season inputs by algae.
Cudgera 1-4 Chlorophyll a, 1999-2003 35.0 30.0 25.0 CGR1 20.0 CGR2
mg/L 15.0 CGR3 10.0 CGR4 5.0 0.0
99 00 00 00 00 01 01 01 01 02 02 02 02 03 03 03 ct- n- r- l- ct- n- r- l- ct- n- r- l- ct- n- r- l- O Ja Ap Ju O Ja Ap Ju O Ja Ap Ju O Ja Ap Ju
Figure 15 Chlorophyll a at the four sites over four years
Comment: the upper estuary site CGR4 exhibits high concentrations at times, indicating algal access to nutrients.
123 Australian Wetlands
Draft Tweed Coast Estuaries Management Plan 2004 - 2008 Tweed Shire Council
Cudgera 1-4 Dissolved Oxygen, 1999-2003 10.0 CGR1 8.0
6.0 CGR2
mg/L 4.0 CGR3 2.0 CGR4 0.0
99 00 00 00 00 01 01 01 01 02 02 02 02 03 03 03 t- n- r- ul- t- n- r- ul- t- n- r- ul- t- n- r- ul- Oc Ja Ap J Oc Ja Ap J Oc Ja Ap J Oc Ja Ap J
Figure 16 DO at the four sites over four years
Comment: DO varies mainly with season, with low levels associated with rainfall, particularly at the upper estuary sites. The low concentrations in the flood year of 2001 suggest similar acid sulphate related processes as occurred in other North Coast waterways at that time.
Cudgera-3 Dissolved Oxygen, 1999-2003 9.0 8.0 7.0 6.0 5.0 4.0 mg/L 3.0 2.0 1.0 0.0
99 00 00 00 00 01 01 01 01 2 02 02 02 3 03 03 t- n- r- ul- t- n- r- ul- t- n-0 r- ul- t- n-0 r- ul- Oc Ja Ap J Oc Ja Ap J Oc Ja Ap J Oc Ja Ap J
Figure 17 DO at CGR-3 over four years
Comment: DO is highly variable, and reflects complex processes of organic matter breakdown, algal cycling of nutrients, acid sulphate and iron related oxygen demand, balanced by tidal flows and re-oxygenation at the water surface.
A4 Mooball Estuary
There are four monitoring sites situated in the Mooball Estuary, ranging through MBL1 near the entrance, MBL2 near several stormwater outlets carrying untreated runoff from a shopping centre and residential streets, MBL3 in the Pottsville Waters Canal, and MBL4 in the upper estuary. Table 8 presents concentrations of selected parameters at the 80 percentile (20 percentile for DO) level.
124 Australian Wetlands
Draft Tweed Coast Estuaries Management Plan 2004 - 2008 Tweed Shire Council Table 8 80 percentile (20 percentile for DO) concentrations of selected parameters at the four Mooball sites, 1999-2003. Chlor-a is Chlorophyll-a, a measure of algal concentrations. Site Faecal DO (mg/l) Salinity pH Chlor-a SS (mg/L) Total N Total P coliforms (20%-ile) (ppt) (ug/L) (mg/L) (mg/L) (fcu/100mL) MBL1 30 5.9 34.3 8.2 1.8 6.6 0.8 0.036 MBL2 32 5.4 34.5 8.1 3.2 5.5 0.646 0.024 MBL3 48 5.6 34.5 8.0 2.7 6.0 0.7 0.014 MBL4 110 5.2 30.2 7.8 3.7 11.0 1.3 0.036
Comment: • Faecal coliform concentrations are lower than the trigger level for recreational contact at all sites • Dissolved Oxygen concentrations are just less than the desired minimum level of 6mg/L; Dissolved Oxygen is more accurately measured as percent saturation, since oxygen levels in water vary with temperature, salinity and other factors, and for most accuracy should be measured over a 24 hour period • Salinity and pH figures indicate tidal flushing reaches into the upper estuary most of the time • Chlorophyll-a is generally substantially less than 10ug/L • SS (Suspended Solids) concentrations are well within the Tweed River range • Total Nitrogen concentrations are above the 0.5mg/L Tweed River guideline, and are particularly elevated in the upper estuary • Total Phosphorus concentrations are less than the Tweed River guideline
30mm rain Mooball 1-4 Faecal coliforms, 1999-2003 1200 MBL1 1000 126mm rain 800 MBL2
600 MBL3 cfu/100mL 400
200 MBL4
0
99 00 00 00 00 01 01 01 01 02 02 02 02 03 03 03 t- n- r- ul- t- n- r- ul- t- n- r- ul- t- n- r- ul- Oc Ja Ap J Oc Ja Ap J Oc Ja Ap J Oc Ja Ap J
Figure 18 Faecal coliform concentrations at the four sites over four years Figure 18 shows faecal coliform counts are generally below 200cfu/100mL, with occasional spikes to just over 1,000, associated with rainfall. These levels do not appear to have increased over the four years.
125 Australian Wetlands
Draft Tweed Coast Estuaries Management Plan 2004 - 2008 Tweed Shire Council
Mooball-1 Faecal coliforms, 1999-2003 500 450 400 350 300 250 200
cfu/100mL Primary contact (swimming) 150 id li 100 50 0
99 00 00 00 00 01 01 01 01 02 02 02 02 03 03 03 t- n- r- ul- t- n- r- ul- t- n- r- ul- t- n- r- ul- Oc Ja Ap J Oc Ja Ap J Oc Ja Ap J Oc Ja Ap J
Figure 19 Faecal coliform counts near the main swimming areas in the lower estuary
Comment: in general, indicator bacteria monitoring suggests that the lower estuary is suitable for swimming (primary contact) according to EPA Water Quality criteria.
Mooball 1-4 Total Nitrogen, 2000 2.0 MBL1 1.8 1.6 MBL2 1.4 1.2 MBL3 1.0 0.8 cfu/100mL MBL4 0.6 0.4 0.2 0.0
00 00 -00 -00 -00 00 00 00 00 -00 00 00 n- b- ar pr y n- ul- g- p- ct v- c- Ja Fe M A Ma Ju J Au Se O No De
Figure 20 Total Nitrogen concentrations at the four sites in the year 2000
Comment: nitrogen levels were highly variable in 2000. The elevated levels in winter- spring when rainfall was low probably indicates processing of nitrogen washed into the estuary in the wet season floods. There were no substantial rainfall events during this period. Estuarine nitrogen processes are complex, with cycling of this nutrient by algae and other organisms so that water column concentrations are often variable, with a loss of nitrogen over time. This cycle can be assessed using more detailed studies such as benthic (bottom) denitrification measurement.
126 Australian Wetlands
Draft Tweed Coast Estuaries Management Plan 2004 - 2008 Tweed Shire Council
Mooball 1-4 Total Nitrogen, 2001 2.0 MBL1 1.8 1.6 MBL2 1.4 1.2 MBL3 1.0 0.8 cfu/100mL MBL4 0.6 0.4 0.2 0.0
01 01 -01 -01 -01 01 01 01 01 -01 01 01 n- b- ar pr y n- ul- g- p- ct v- c- Ja Fe M A Ma Ju J Au Se O No De
Figure 21 Total Nitrogen concentrations at the four sites in 2001
Comment: the 2001 floods flushed nitrogen from the catchment to the estuary (again the upper estuary has the highest concentrations), and levels slowly fell during the drier period of the year, unlike the situation in 2000. Detailed study would be required to explain this pattern.
Mooball 1-4 Chlorophyll a, 1999-2003 25.0 20.0 MBL1
15.0 MBL2
mg/L 10.0 MBL3
5.0 MBL4 0.0
9 0 00 00 0 1 01 01 1 2 02 02 2 3 03 03 t-9 n-0 r- ul- t-0 n-0 r- ul- t-0 n-0 r- ul- t-0 n-0 r- ul- Oc Ja Ap J Oc Ja Ap J Oc Ja Ap J Oc Ja Ap J
Figure 22 Chlorophyll-a at the four sites over four years
Comment: this measure of algal activity suggests the upper estuary site (MBL4) generally features higher concentrations.
127 Australian Wetlands
Draft Tweed Coast Estuaries Management Plan 2004 - 2008 Tweed Shire Council
Mooball-4 Chlorophyll a, 1999-2003 25.0
20.0
15.0
mg/L 10.0
5.0
0.0
99 00 00 00 00 01 01 01 01 02 02 02 02 03 03 03 t- n- r- ul- t- n- r- ul- t- n- r- ul- t- n- r- ul- Oc Ja Ap J Oc Ja Ap J Oc Ja Ap J Oc Ja Ap J
Figure 23 Chlorophyll a at the upper estuary site over four years
Comment: although elevated concentrations are seen at times, associated both with wet season and dry season, the long term pattern indicates reasonable compliance with guidelines.
Mooball 1-4 Dissolved Oxygen, 1999-2003 12.0 10.0 MBL1
8.0 MBL2 6.0
mg/L MBL3 4.0 2.0 MBL4 0.0
99 00 00 00 00 01 01 01 01 02 02 02 02 03 03 03 t- n- r- ul- t- n- r- ul- t- n- r- ul- t- n- r- ul- Oc Ja Ap J Oc Ja Ap J Oc Ja Ap J Oc Ja Ap J
Figure 24 Dissolved Oxygen (DO) concentrations at the four sites over four years
Comment: the pattern indicates broad uniformity of oxygen trends throughout the estuary, with oxygen falls often associated with the wet seasons.
128 Australian Wetlands
Draft Tweed Coast Estuaries Management Plan 2004 - 2008 Tweed Shire Council
Mooball-4 Dissolved Oxygen, 1999-2003 10.0
8.0
6.0
mg/L 4.0
2.0
0.0
99 00 00 00 00 01 01 01 01 2 02 02 02 03 03 03 t- n- r- ul- t- n- r- ul- t- n-0 r- ul- t- n- r- ul- Oc Ja Ap J Oc Ja Ap J Oc Ja Ap J Oc Ja Ap J
Figure 25 DO at the upper estuary site over four years
Comment: Site MBL4 DO concentrations are often below the desired general minimum of 6mg/L, particularly in wet season. Note the severe falls during the 2001 flood period.
A5 Comparisons of the Estuaries
4.0 CGN1-CGR1-MBL1, Total Nitrogen,1999-2003 3.5 CGN1 3.0 2.5 2.0 CGR1 mg/L 1.5 1.0 MBL1 0.5 0.0
9 0 0 1 1 1 2 2 3 3 -9 -0 -0 -0 -0 -0 -0 l-0 -0 -0 ct eb g an y p ar u an y O F Au J Ma Se M J J Ma
Figure 26 Total Nitrogen concentrations at the lower sites in the three estuaries
Broadly, there is little difference between estuaries in TN near the entrances. MBL1 and CGR1 show elevated levels at times, with one high concentration at CGN1, attributed to urban stormwater and possibly fertilizer nitrogen from agriculture.
129 Australian Wetlands
Draft Tweed Coast Estuaries Management Plan 2004 - 2008 Tweed Shire Council
800 700 CGN1 600 500 CGR1 400
cfu/100mL 300 200 MBL1 100 0
9 00 00 00 0 01 01 01 1 02 02 02 2 03 03 03 99 0 0 0 00 0 0 0 00 0 0 0 00 0 0 0 /1 /2 /2 /2 /2 /2 /2 /2 /2 /2 /2 /2 /2 /2 /2 /2 26 26 26 26 26 26 26 26 26 26 26 26 26 26 26 26 / 1/ 4/ 7/ / 1/ 4/ 7/ / 1/ 4/ 7/ / 1/ 4/ 7/ 10 10 10 10
Figure 27 Faecal coliform concentrations at lower sites in the three estuaries
Comment: CGR1 stands out as having the highest number of samplings showing faecal coliform concentrations outside the swimming guidelines. As stated earlier, this may be the result of the relatively short length of estuary, and the resultant short term dominance of rainfall and runoff on estuarine processes, combined with elevated bacteria sources.
A6 Indications of Acid Sulphate Runoff
Measurement of acid runoff is difficult. Runoff occurs in floods or other rainfall events, the chemistry is complex and variable, and acid runoff is influenced by the catchment topography and size, the severity of the rainfall event, and the extent of any remediation works. In general, pH measurement can indicate acid production, whilst very low DO in drains or upper estuaries also often indicates acid runoff.
Total Iron concentrations measure one of the products of acid runoff, since the acidifying process in catchment soils mobilises iron and other metals, from where they flow or leach into the drain network and into estuaries. The ANZECC Guidelines (2000) do not recommend a guideline level for iron, however the 1992 guidelines recommended a general concentration of <1.0mg/L.
130 Australian Wetlands
Draft Tweed Coast Estuaries Management Plan 2004 - 2008 Tweed Shire Council
Total Iron, MBL1-MBL4, 1999-2003 mm 4.5 200
4 180 3.5 160 MBL1 3 140 120 2.5 MBL2 100
mg/L 2 80 1.5 60 MBL3
1 40 0.5 20 MBL4 0 0 9 0 0 1 1 2 2 3 t-9 r-0 t-0 r-0 t-0 r-0 t-0 r-0 Oc Ap Oc Ap Oc Ap Oc Ap
Figure 28 Total Iron concentrations in the Mooball Estuary over four years
Comment: the upper estuary site MBL4 records some of the conditions downsteam of the entry of major drains. Elevated Total Iron concentrations are associated with rainfall.
CGR1-CGR5, Total Iron, 13/3/2001 7 6 5 4
mg/L 3 2 1 0 CGR1 CGR2 CGR3 CGR4 CGR5
Figure 29 Total Iron concentrations at the four Cudgera Estuary sites, on one day
Comment: The pattern shows CGR3 and CGR4 featured the highest loads of iron in the March 2001 event. Experience suggests fish kills are a serious risk when iron is found in the water column in these concentrations. Excessive iron also has deleterious effects on ecosystems over the long term.
131 Australian Wetlands
Draft Tweed Coast Estuaries Management Plan 2004 - 2008 Tweed Shire Council
CGN3, Total Iron, 2000-03 2.5
2
1.5
mg/L 1
0.5
0
0 0 00 1 1 01 2 2 02 3 3 00 00 20 00 00 20 00 00 20 00 00 4/2 4/2 4/ 4/2 4/2 4/ 4/2 4/2 4/ 4/2 4/2 /1 /1 1 /1 /1 1 /1 /1 1 /1 /1 2 6 10/ 2 6 10/ 2 6 10/ 2 6
Figure 30 Total Iron at Site CGN3 over four years
Comment: Total Iron only exceeds 1mg/L on one occasion near the outlet from Cudgen Lake. Given the known ASS status of the catchment, this pattern suggests the lake is acting as a sedimentation and oxidation zone for the pollutants - to a large extent reducing impacts on the Cudgen Estuary.
A7 Conclusions
A7.1 Cudgen Estuary
Based on the four year monthly monitoring program: • water quality in the estuary is within a range where focused improvements in catchment management are likely to produce a measurable effect in meeting water quality objectives; • faecal coliform counts indicate the lower estuary is almost always suitable for swimming, except after significant rainfall; • the monthly monitoring appears to be insufficient to distinguish particular pollutants in wet weather events, such as the widely reported erosion of topsoil from Cudgen vegetable growing areas; • agricultural and urban stormwater appear to be the dominant influence on pollutant inputs to the estuary.
132 Australian Wetlands
Draft Tweed Coast Estuaries Management Plan 2004 - 2008 Tweed Shire Council A7.2 Cudgera Estuary
Based on the four year monthly monitoring program: • water quality in the estuary is within a range where focused improvements in catchment management are likely to produce a measurable effect in meeting water quality objectives; • faecal coliform counts indicate the lower estuary is suitable for swimming only in periods when rainfall is low; • the relatively small size of the estuary may be an important factor in the impact of wet season pollution events on the lower estuary, as there appear to be relatively high levels of some pollutants entering the lower estuary more frequently than in the Cudgen and Mooball estuaries; • agricultural and urban stormwater appear to be the dominant influence on pollutant inputs to the estuary, with a substantial impact from acid sulphate runoff.
A7.3 Mooball Estuary
Based on the four year monthly monitoring program: • water quality in the estuary is within a range where focused improvements in catchment management are likely to produce a measurable effect in meeting water quality objectives; • faecal coliform counts indicate the lower estuary is almost always suitable for swimming, the exception being after substantial rainfall; • agricultural and urban stormwater appear to be the dominant influence on pollutant inputs to the estuary, with a substantial impact from acid sulphate runoff.
133 Australian Wetlands