Georges River

Our water quality monitoring program has shown the Georges River estuary to have fair water quality. Find out more about the estuary and its unique features.

Georges River estuary is situated within the Sydney Metropolitan region of New South Wales. This estuary is classed as a drowned valley and is the main tributary of Botany Bay.

Two large water storages, the Woronora Dam and Prospect Reservoir, are situated in this catchment and are used for Sydney’s water supply. Liverpool Weir defines the upper tidal limit of the Georges River estuary.

Estuary health and features

Water quality report card

As part of our water quality monitoring program we assess the water quality and ecosystem health of an estuary using a range of relevant indicators. We sample a subset of the estuaries located between Taree and Wollongong every 3 years. The most recent sampling in the Georges River was completed over the 2019–20 summer when 2 sites were sampled on a monthly basis.

Georges River water quality report card for algae and water clarity showing colour-coded ratings (red, orange, yellow, light green and dark green, which represent very poor, poor, fair, good and excellent, respectively). Algae is rated 'fair' and water clarity is rated 'good' giving an overall rating of 'fair' or 'C'.

This report card represents 2 water quality indicators that we routinely measure: the amount of algae present and water clarity. Low levels of these 2 indicators equate with good water quality.

The report card shows the condition of the estuary was fair with:

  • algae abundance graded fair (C)
  • water clarity graded good (B)
  • overall estuary health graded fair (C).

Find out more about our estuary report cards and what each grade means. Read our sampling, data analysis and reporting protocols and find out how we calculate these grades.

We have monitored water quality in the Georges River since 2007. This table shows the water quality grades for this estuary over that time.

Georges River historic water quality grades from 2007-08 for algae and water clarity. Colour-coded ratings (red, orange, yellow, light green and dark green represent very poor (E), poor (D), fair (C), good (B) and excellent (A), respectively).

Grades for algae, water clarity and overall are represented as:

  • A – excellent
  • B – good
  • C – fair
  • D – poor
  • E – very poor.

As part of our Beachwatch program we assess swimming suitability at 4 swimming sites in Georges River using microbial indicators. We collect samples at each site weekly between October and April, and monthly from May to September, to calculate the suitability grade. Sampling is ongoing. Each grade reflects the most recent 100 water quality results to April 2022. Find out more about how we monitor beach water quality.

Local government area Swim site name Grade
Georges River Jewfish Bay Baths Poor
Oatley Bay Baths Poor
Carrs Point Baths Poor
Sutherland Como Baths Good

Estuarine, lake and lagoon water can sometimes be unsuitable for swimming, especially after rainfall when stormwater and wastewater can overflow into swimming areas. Learn more about what the grades mean and how we grade swimming sites on our beach classification webpage.

Physical characteristics

Estuary type: Drowned river valley

Entrance
location 		Latitude (ºS) –34
Longitude (ºE) 151.16
Catchment area (km2) 930.9
Estuary area (km2) 26.6
Estuary volume (ML) 271,393.5
Average depth (m) 10.5

Tidal exchange volume

Tidal exchange volume or tidal prism data is available for this estuary. This tidal prism was measured in 1991.

Tide state Flow
(106 m3)		 Local tidal
range (m)		 Sydney Harbour
tidal range (m)
Ebb flow 19.32 1.21 1.12
Flood flow 16.66 1.35 1.32
Notes: km2 = square kilometres; m = metres; m3 = cubic metres; ML = megalitres.

Water depth and survey data

Bathymetric and coastal topography data for this estuary are available in our data portal.

Land use

The catchment of the Georges River has been highly disturbed by a mix of land-use changes. About one third of the catchment is made up of urban and industrial areas, and a lot of the western catchment has been cleared for grazing, agriculture and horticulture. Undisturbed forest remains in about 40% of the catchment, mostly in the upper catchment.

Water use

Find out about water use in the Georges River, including information about major water users, real-time flow data, and environmental and water sharing plans.

National and marine parks

Community involvement

  • Georges Riverkeeper is a catchment management group that works with 8 member councils to improve the environment of the Georges River. They raise community awareness about protecting and restoring the natural environment and provide links for volunteers to get involved.
  • Greater Sydney Landcare Network is a community organisation and an umbrella group for a host of Landcare organisations in the region. They have a number of projects listed on their website and support volunteers to get involved in work to protect, restore and improve the natural environment of Greater Sydney.

Local government management

Local councils manage estuaries within their area unless the estuary is attached to a marine park. Wollondilly, Campbelltown, Liverpool, Fairfield, Canterbury–Bankstown, Bayside, Sutherland and Georges River councils manage parts of this catchment.