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.
Algae
Water clarity
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.
We have monitored water quality in Tilba Tilba Lake since 2008. This table shows the water quality grades for this estuary over that time.
| Year | Algae | Water clarity | Overall grade |
|---|---|---|---|
| 2008–09 | E | E | E |
| 2014–15 | C | E | D |
| 2018–19 | B | C | B |
| 2019–20 | E | C | D |
| 2020–21 | C | D | D |
Physical characteristics
| Estuary type | Back-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.
National and marine parks
- Gulaga National Park and Eurobodalla National Park are the 2 largest conservation area in the Tilba Tilba catchment.
- This estuary flows into Batemans Marine Park.
Citizen science projects
- iNaturalist’s Plants of Eurobodalla is a citizen science project that monitors plants found in the Eurobodalla region.
Community involvement
- Eurobodalla Landcare is a volunteer network of 24 Landcare groups on the NSW south coast.
- The Coastwatchers Association is a community environmental and conservation group based on the south coast.
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.