NSW Water Quality and River Flow Objectives About the Objectives Department of Environment, Climate Change and Water   Select from the scrolling list, statewide map or catchment list Select a catchment Barwon-Darling and Far Western Bega River Bellinger River Border Rivers Brunswick River Camden Haven and Hastings River Castlereagh River Clarence River Clyde River and Jervis Bay Cooks River Georges River Gosford and Northern Beaches Lagoons Gwydir River Hacking River Hawkesbury-Nepean River Hunter River Karuah River and Great Lakes Lachlan River Illawarra Lake Macquarie and Tuggerah Lakes Macleay River Macquarie-Bogan River Manning River Moruya River Murray River Murrumbidgee River and Lake George Nambucca River Namoi River Richmond River Shoalhaven River Sydney Harbour and Parramatta River Towamba and Genoa River Tuross River Tweed River Williams River

Cooks River
Water Quality and River Flow Objectives

| Contents | Background | Consultation | Objectives | WQOs | RFOs | Glossary | Bibliography| Map | At a Glance |

• Waterways affected by urban development
• Water Quality Objectives
• River Flow Objectives
• Estuaries
• Water Quality Objectives
• River Flow Objectives

This section gives the Water Quality Objectives (WQOs) and the River Flow Objectives (RFOs) for the Cooks River catchment, which should be used to develop plans and actions affecting water quality and river health. Only the priority RFOs are listed in this section, but the remaining objectives still need to be considered when developing management plans or dealing with particular local river conditions.

Waterways affected by urban development

Waterways within urban areas that are frequently substantially modified and generally carry poor quality stormwater. Local communities are often keen to see these waterways returned to conditions that are more natural.

Map: Urban development areas are shown in orange on the map.

Water Quality Objectives

Protection of:

	Aquatic ecosystems
	Visual amenity
	Secondary contact recreation

River Flow Objectives

	Maintain natural flow variability
	Maintain natural rates of change in water levels
	Minimise effects of weirs and other structures

Supporting information

• The majority of the catchment falls within this category. Existing programs to improve water quality will be complemented by stormwater initiatives and improvements in the environmental management of small premises.
• In some urban waterways aquatic ecosystems are considerably modified. A return to pristine aquatic ecosystems in these areas is unlikely and impractical. However, water quality conditions for existing ecosystems can be improved greatly for the benefit of local species and broader catchment health. Data from other local aquatic ecosystems of similar type, in areas that are not urbanised, may provide achievable criteria for these modified aquatic ecosystems.
• Catchment audits have been undertaken in the catchment to identify pollution sources.
• The recommended WQOs may not be achievable in the short term (within 5 years).
• Flow regimes have been significantly altered by the intensity of development in the catchment.
• Channelised stream sections with artificial banks need rehabilitation to provide water of a quality that will support aquatic ecosystems. Priority should be given to rehabilitating natural sections upstream of the channelised sections.

Estuaries

Being dominated by saline conditions, estuaries have hydraulic and water quality characteristics, and potential problems, that are often very different from those of freshwater systems.

Map: Estuaries are coloured purple on the map.

Water Quality Objectives

Protection of:

	Aquatic ecosystems
	Visual amenity
	Secondary contact recreation, as a short-term objective, within 5 years
	Primary contact recreation: assess opportunities to achieve as a longer term objective, 10 years or more
	Aquatic foods (cooked): assess opportunities to achieve as a longer term objective, 10 years or more

River Flow Objectives

	Protect important rises in water levels
	Maintain natural flow variability
	Maintain natural rates of change in water levels
	Minimise effects of weirs and other structures
	Maintain or rehabilitate estuarine processes and habitats

Supporting information

• Urbanised streams affect the estuarine system of the Cooks River. Programs should be tailored to meet the objectives, taking into account the catchment history of pollution.
• Parts of the lower estuarine reaches are underlain by potential acid sulfate soils, which should not be disturbed. Dredging and disturbance of bottom sediments (i.e. those below water level) can also have major impacts in these areas for the same reason.
• In the longer term (10 years or more), the environmental value of aquatic foods (cooked) may be achievable.
• In the long term (10 years or more), primary contact recreation may be achievable.
• Tidal patterns of the estuary will determine the extent of flushing and will, therefore, significantly influence water quality.
• Wetlands near Spring Street and Eve Street, Rockdale, require tidal inundation.

This page was published 1 May 2006