Lake Mummuga borders the town of Dalmeny on the south coast of New South Wales. It is classed as a lagoon with an intermittently closed entrance.
Two small tributaries flow into Lake Mummuga. Most of the catchment area for the lake is in the Eurobodalla National Park and the estuarine waters are protected as part of the Batemans Marine Park.
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 Lake Mummaga was completed over the 2020–21 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 good (B)
- water clarity graded excellent (A)
- 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 Lake Mummuga since 2014. This table shows the water quality grades for this estuary over that time.
| Year | Algae | Water clarity | Overall grade |
|---|---|---|---|
| 2014–15 | B | A | B |
Physical characteristics
| Estuary type | Lagoon |
|---|---|
| Latitude | –36.16 (ºS) |
| Longitude | 150.13 (ºE) |
| Catchment area | 25.8 km2 |
| Estuary area | 1.7 km2 |
| Estuary volume | 1648.7 ML |
| Average depth | 1 m |
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 Lake Mummaga is relatively undisturbed with over 95% remaining forested, a small fraction being in Eurobodalla National Park. The urban area at Dalmeny accounts for 5% of land use.
National and marine parks
- Eurobodalla National Park is the largest conservation area in the Lake Mummuga 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 New South Wales south coast.
- The Coastwatchers Association is a community environmental and conservation group based on the south coast.
Aerial view of Lake Mummuga
Local government management
Local councils manage estuaries within their area unless the estuary is attached to a marine park.
Eurobodalla Shire Council manage this estuary, which is located in Batemans Marine Park.
Threatened species
Estuaries provide important breeding, nursery and feeding grounds for many animals, such as fish and birds.
Read more about the biodiversity in our estuaries.