Our water quality monitoring program has shown the Minnamurra River estuary to have fair water quality. Find out more about the estuary and its unique features.
Minnamurra River is classed as a barrier river estuary and is located in the Illawarra region just north of Kiama. This estuary supports a large stand of mangroves and swamp oak forests.
The catchment area and estuary are used for agriculture, mineral resourcing, tourism and recreation.
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 Minnamurra River 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.
The report card shows the condition of the estuary was good with:
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 the Minnamurra River since 2008. This table shows the water quality grades for this estuary over that time.
Grades for algae, water clarity and overall are represented as:
Estuary type: Barrier river
| Entrance location |
Latitude (ºS) | –34.63 |
|---|---|---|
| Longitude (ºE) | 150.86 | |
| Catchment area (km2) | 117.3 | |
| Estuary area (km2) | 1.9 | |
| Estuary volume (ML) | 1516.5 | |
| Average depth (m) | 1 | |
Tidal prism data is available for this estuary. This tidal prism was measured in 1992.
| Tide state | Flow (106 m3) |
Local tidal range (m) |
Sydney Harbour
tidal range (m) |
|---|---|---|---|
| Ebb flow | 1.28 | 1.42 | 1.41 |
| Flood flow | 1.2 | 1.35 | 1.38 |
Bathymetric and coastal topography data for this estuary are available in our data portal.
The Minnamurra River flows through a largely cleared catchment dominated by grazing and rural residential land use. Less than 10% of the catchment is urban and includes Jamberoo and Minnamurra. About 30% of the catchment is forested, which includes Budderoo National Park.
Local councils manage estuaries within their area unless the estuary is attached to a marine park. Kiama Municipal Council manages the Minnamurra River estuary.
Minnamurra River estuary and catchment is home to a number of threatened ecological communities, such as the Illawarra lowlands grassy woodland, Illawarra subtropical rainforest and swamp oak floodplain forest. Seagrass beds are also present in this estuary.
Read more about the biodiversity in our estuaries.