Bournda Lagoon

Our water quality monitoring program has shown Bournda Lagoon to have excellent water quality. Find out more about the estuary and its unique features.

Bournda Lagoon is located on the south coast of New South Wales north of Merimbula. It is classed as a small creek with an intermittently closed entrance.

Estuary health and features

Water quality

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 Bournda Lagoon was completed over the 2020–21 summer when 2 sites were sampled on a monthly basis.

Bournda Lagoon water quality report card for algae and water clarity showing colour-coded ratings (red, orange, yellow, light green and dark green, which represent very poor, poor, fair, good and excellent, respectively). Algae is rated 'excellent' and water clarity is rated 'excellent' giving an overall rating of 'excellent' or 'A'.

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 excellent with:

  • algae abundance graded excellent (A)
  • water clarity graded excellent (A)
  • overall estuary health graded excellent (A).

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 Bournda Lagoon since 2017. This table shows the water quality grades for this estuary over that time.

Bournda Lagoon historic water quality grades from 2017 for algae and water clarity. Colour-coded ratings (red, orange, yellow, light green and dark green represent very poor (E), poor (D), fair (C), good (B) and excellent (A), respectively).

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

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

Physical characteristics

Estuary type: Creek

Entrance
location
Latitude (ºS) –36.82
Longitude (ºE) 149.94
Catchment area (km2) 34.5
Estuary area (km2) 0.1
Estuary volume (ML) 26.7
Average depth (m) 0.3
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

Over 90% of the of Bournda Lagoon catchment remains forested and protected within Bournda National Park and Bournda Nature Reserve. Grazing and urban areas account for less than 10% of the catchment.

National and marine parks

Citizen science projects

  • The Far South Coast Conservation Management Network supports the local community to better manage native biodiversity. The network organises citizen science projects, provides information for private landowners, manages a local plant database, and coordinates events.

Community involvement

Bournda Lagoon

Local government management

Local councils manage estuaries within their area unless the estuary is attached to a marine park. Bega Valley Shire Council manage this estuary.