Tilligerry Creek

Our water quality monitoring program has shown Tilligerry Creek to have poor water quality. Find out more about the estuary and its unique features.

Tilligerry Creek is located on the Hunter coast of New South Wales and flows into Port Stephens from the south.

It is classed as a lake and is lined almost entirely by mangroves. Tilligerry Creek supports a large oyster industry.

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 located between Taree and Wollongong every 3 years. The most recent sampling in Tilligerry Creek was completed over the 2021–22 summer when 2 sites were sampled on a monthly basis.

Tilligerry Creek 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 'poor' and water clarity is rated 'poor' giving an overall rating of 'very poor' or 'D'.

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 poor with:

  • algae abundance graded poor (D)
  • water clarity graded poor (D)
  • overall estuary health graded poor (D).

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 Tilligerry Creek since 2010. This table shows the water quality grades for this estuary over that time.

Tilligerry Creek historic water quality grades from 2010-11 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: Lake

Latitude (ºS) –32.73
Longitude (ºE) 152.05
Catchment area (km2) 114.8
Estuary area (km2) 20.5
Estuary volume (ML) 51,714.4
Average depth (m) 2.5

Tidal prism

Tidal prism data is available for this estuary. This tidal prism was measured in 1993. 

Tide state Flow
(106 m3)
Local tidal
range (m)
Sydney Harbour
tidal range (m)
Ebb flow 5.45
Flood flow 4.85
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

Tilligerry Creek drains a highly disturbed catchment. Claiming estuarine saltmarsh for agriculture is the largest land use change. Other prominent features within the catchment include Newcastle airport, the Royal Australian Air Force base at Williamtown and several small residential communities. There is some remnant bushland.

National and marine parks

Community involvement