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Tilba Tilba Lake

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

Tilba Tilba Lake estuary is a small back-dune lagoon located on the south coast of New South Wales. It has an intermittently closed entrance.

The major tributary for Tilba Tilba Lake is Victoria Creek, which flows through private land. Historically there has been extensive land clearing in the area for various forms of farming.

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

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.

A

Algae

C

Water clarity

B

Overall grade

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

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

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

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

Go to estuary report cards to find out what each grade means, read our sampling, data analysis and reporting protocols, and find out how we calculate these grades.

Historical water quality grades

We have monitored water quality in Tilba Tilba Lake since 2008. This table shows the water quality grades for this estuary over that time.

YearAlgaeWater clarityOverall grade
2008–09EEE
2014–15CED
2018–19BCB
2019–20ECD
2020–21CDD
Physical data

Physical characteristics

Estuary typeBack-dune lagoon
Latitude (ºS)–36.33
Longitude (ºE)150.12
Catchment area (km2)17.1
Estuary area (km2)1.2
Estuary volume (ML)864.5
Average depth (m)0.9

Notes: km2 = square kilometres; m = 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 Tilba Tilba Lake is highly disturbed, with 65% of land cleared for grazing. About 20% of the catchment is forested, including a portion of Gulaga National Park.

Get involved

National and marine parks

Citizen science projects

  • iNaturalist’s Plants of Eurobodalla is a citizen science project that monitors plants found in the Eurobodalla region. 

Community involvement

Aerial view of Tilba Tilba Lake estuary showing a tranquil body of water with branching inlets surrounded by lush greenery. A narrow strip of sandy beach separates the lake from the open sea, with waves crashing onto the shore. The horizon reveals a clear sky above and hints at a vast ocean extending beyond.

Aerial view of Tilba Tilba Lake estuary.

Local government management

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

Eurobodalla Shire Council manages this estuary, which is located in Batemans Marine Park.

Improving water quality in Tilba Tilba Lake

Threatened species

Estuaries are important to our native animals as they provide food, shelter and breeding grounds.

Read more about the biodiversity in our estuaries.