Council agrees to a staged policy for opening of Wonboyn Lake

It also agreed to meet regularly with relevant stakeholders to discuss implementation of entrance management policies, something residents had requested in deputations to council.

Councillors heard that Wonboyn Lake which is home to oyster leases, had never closed between 1930 and 2004 but then it closed in 2004, 2009 and 2019. The lake was mechancially opened twice in 2020 to address bushfire impacts.

The NSW government tends to take a minimalist approach with respect to intervention in ICOLLs (intermittently closing and opening lakes and lagoons) and this can be at variance with community expectations and the needs of the oyster industry.

Extended periods of closure are problematic for the oyster industry due to impacts on temperature and salinity within the lake. Inundation of foreshore and in-water infrastructure, including jetties, sheds and leases can also occur during extended periods of closure as the water level rises.

Council said that there is a range of private infrastructure around the edge of the lake, which sit as low as 0.34m AHD (Australian Height Datum), with a majority below 1m AHD.

Following the closure of the Wonboyn Lake entrance in late 2019 and negotiations around appropriate entrance opening triggers, the Wonboyn oyster industry, council and NSW Fisheries identified that a sustainable entrance management policy was required to support commercial, recreational and ecological activity in and around Wonboyn Lake.

Council's staged approach will mean that for the first five years, if the lake closes, mechanical opening will be triggered when the water level is at or above 1m AHD, or between 0.75m - 1m AHD for a period of at least two months and/or significant rainfall is predicted in the catchment (100mm+).

The policy states that there should be no more than two lower level openings (when the water is lower than 1m AHD) within a 12-month period.

After the first five years the trigger points rise to when the water level is at or above 1.4m AHD or between 1.1m- 1.4m AHD for a period of two months. The lake will also be opened if the water level is at or above 1.1m AHD if significant rainfall is predicted in the catchment (100mm+).

Council staff stated that in both phases, in exceptional circumstances such as concerns over water quality, council would consider an opening in consultation with the Wonboyn Oyster Industry, DPI Food Authority and DPI Aquaculture and with the approval of DPI Fisheries, DPIE Crown Lands and DPIE Biodiversity and Conservation Division.