Shoalhaven River

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

The Shoalhaven River is a barrier river estuary with an open entrance. The estuary is large and flows from a freshwater river into the sea (the Shoalhaven Bight) between Bomaderry and Nowra. Thirty-four tributary streams flow into the river as it flows through the catchment, such as the Mongarlowe and Kangaroo Rivers. 

Estuary health and features

Water quality

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 between Wollongong and the Victorian border every 3 years. The most recent sampling in the Shoalhaven River was completed over the 2021–22 summer when 2 sites were sampled on a monthly basis.

Shoalhaven 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 'good' and water clarity is rated 'good' giving an overall rating of 'good' or 'B'.

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.

This report card shows the condition of the estuary was good with:

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

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 Shoalhaven River since 2007. This table shows the water quality grades for this estuary over that time.

Shoalhaven 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.

Physical characteristics

Estuary type: Barrier river

Latitude (ºS) –34.90
Longitude (ºE) 150.77
Catchment area (km2) 7085.8
Estuary area (km2) 31.9
Estuary volume (ML) 86508.6
Average depth (m) 2.9

Tidal exchange volume

Tidal exchange volume or tidal prism data is available for this estuary. This tidal prism was measured in 2005.

Tide state Flow
(106 m3)
Local tidal
range (m)
Sydney Harbour
tidal range (m)
Ebb flow 18.35 1.24 1.38
Flood flow  19.03  1.28  1.39
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 for Shoalhaven River estuary is one of the larger catchments on the south coast at more than 700,000 hectares in size. The catchment is moderately disturbed and include about 60% forest. It extends inland from the township of Nowra and south towards the township of Moruya and includes Morton National Park and Mount Budawang.

Grazing areas, including those around Braidwood, form about 30% of the catchment area. Urban areas occupy less than 5% of the catchment, including Nowra.

National and marine parks

  • The largest conservation area in the Shoalhaven River catchment is Morton National Park.
  • There is no marine park associated with the Shoalhaven River.
  • Comerong Island Nature Reserve sits at the mouth of the Shoalhaven River and is an internationally recognised habitat for a range of shorebirds and waders. 

Citizen science projects

Community involvement

Other features

  • The Nowra Bridge, which joins Nowra and Bomaderry, is of state heritage significance. It was built in 1881 and designed by famous American engineer C Shaler Smith.

Local government management

Local councils manage estuaries within their area unless the estuary is attached to a marine park. Shoalhaven City Council manage this estuary.