Avoca Lake

We collaborate with local government to monitor the condition of Avoca Lake. Find out more about the Avoca Lake estuary and its unique features.

Avoca Lake is situated on the Central Coast of New South Wales between the townships of Avoca Beach and North Avoca. It is classed as a back-dune lagoon with an intermittently open entrance to the sea.

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 2 sites on a monthly basis over summer in Avoca Lake as part of a collaborative program with Central Coast Council.

The most recent sampling was completed over the 2020–21 summer. The results of the monitoring program, including a detailed water quality report card for Avoca Lake, are available on the Central Coast Council website.  

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.

As part of our Beachwatch program we assess swimming suitability at 1 swimming site in Avoca Lagoon using microbial indicators. Central Coast Council collect samples at each site weekly between October and April, and monthly from May to September, to calculate the suitability grade. Sampling is ongoing. The grade reflects the most recent 100 water quality results to April 2022. Find out more about how we monitor beach water quality.

Local government area Swim site name Grade
Central Coast Avoca Lagoon Poor

Estuarine, lake and lagoon water can sometimes be unsuitable for swimming, especially after rainfall when stormwater and wastewater can overflow into swimming areas. Learn more about what the grades mean and how we grade swimming sites on our beach classification webpage.

Water sampling and laboratory analysis was funded by Central Coast Council.

Physical characteristics

Estuary type: Back-dune lagoon

Latitude (ºS) –33.46
Longitude (ºE) 151.44
Catchment area (km2) 10.8
Estuary area (km2) 0.7
Estuary volume (ML) 293.2
Average depth (m) 0.4
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 Avoca Lake is moderately disturbed. Around half remains as forest, especially around the relatively steep slopes of the upper catchment. Land-use changes in the other half of the catchment have been driven by urban and rural-residential development, horticulture and grazing.

National and marine parks

  • No conservation areas are located within this catchment.
  • This estuary does not flow into a marine park.

Community involvement

  • The Central Coast Council Landcare Program helps coordinate a number of volunteer environmental groups, such as North Avoca Bushcare, Bulbararing Bushcare and Willdenow Bushcare, that work to conserve, protect and remediate the environment.
Avoca Lake

Local government management

Local councils manage estuaries within their area unless the estuary is attached to a marine park. Central Coast Council manage this estuary.

More information about this estuary can be found on the council’s Coastal lagoons webpage.