A NSW Government website

Nullica River

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

Nullica River is located on the south coast of New South Wales. It is classed as a lagoon with an entrance that is intermittently open and closed to the ocean.

This estuary flows into Nullica Bay, which forms part of Twofold Bay south of Eden. Most of the catchment is forestry land.

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 Nullica River was completed over the 2023–24 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 numerical scores for these 2 indicators are averaged to give the overall grade.

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 Nullica River since 2011. This table shows the water quality grades for this estuary over that time.

YearAlgaeWater clarityOverall grade
2023–24ACB
2011–12BBB
Physical data

Physical characteristics

Estuary typeLagoon
Latitude (ºS)–37.09
Longitude (ºE)149.87
Catchment area (km2)54.8
Estuary area (km2)0.3
Estuary volume (ML)176.1
Average depth (m)0.6

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 Nullica River is relatively undisturbed, with 95% currently forested, most of which is managed by Forestry Corporation. A small amount of the lower catchment around Nullica and Boydtown is cleared for grazing and rural residential properties.

Get involved

National and marine parks

Community involvement

Aerial view of the Nullica River winding through a dense forest with mountains in the background. A bridge crosses over a section of the river, and a sandy beach area is visible at the river’s bend.

Aerial view of Nullica River estuary.

Local government management

Local councils manage estuaries within their area. Where an estuary is attached to a marine park, marine park management teams are responsible for ensuring compliance with marine park zoning.

 Bega Valley Shire Council manages this estuary.

Threatened species

The forests around Nullica River estuary provide a stronghold for the critically endangered smoky mouse.

Find out more about the biodiversity in our estuaries.