Coombabah Creek sediment & tidal study

  • Project typeOcean, beaches & waterways
  • Project scheduleLate December 2020 to late December 2021
  • Completion Date31 December 2021
Coombabah catchment aerial view

The City is seeking to assess the condition of Coombabah Lake and surrounding estuary against projected changes in climate, rising sea levels, changing weather patterns and runoff from the upper catchment.

Current status

Coombabah Lake and surrounding estuary is part of the Moreton Bay Marine Park and is a declared Fish Habitat Area. The Coombabah wetland system is classified as a wetland of international significance under the Ramsar Convention. This wetland system is home to a variety of key fish species, migratory birds, ecosystems, and marine and freshwater plants.

Identifying current issues

Rising sea level may change the depth and extend of the lake and estuary, which in turn will affect the extent and composition of the intertidal ecosystems and wetland values.

Project details

The following investigations have commenced:

Tidal levels and bathymetry

In late 2020 the Department of Environment and Science deployed several tidal gauges in the lake and estuary and surveyed the topography of the lake. Data will be observed for 12 months and used to identify historical changes in hydrology dynamics.

Vegetation survey of the surrounding wetland area

The Department of Environment and Science is surveying the wetland to identify changes in vegetation patterns and its relationship to changes in tidal levels. This survey commenced in May 2021.

Sediment and benthic invertebrate study

In June 2021 the City will assess the sediment source, pollutants and biological health of Coombabah Lake and estuary. The results will be compared to previous studies undertaken approximately 20 years ago.

Project benefits

Assessing the area will bring many benefits:

  • data to support management decisions for climate adaptation of protected ecosystems in our city
  • understanding of the current ecological health conservation of mangrove, saltmarsh ecosystems and fresh water wetlands protect significant habitat for key fish species
  • support sustainable recreational fishing including bream, estuary cod, flathead, garfish, luderick, mangrove jack, sea mullet, tailor, whiting, banana prawns and king prawns
  • increased recreational opportunities including canoeing, walking, and bird watching
  • an increased relationship between the local community and the water environment.

This project supports advancing climate science action under the Queensland Climate Adaptation Strategy (Q-CAS) and is aligned with the Biodiversity and Ecosystems Climate Adaptation Plan for Queensland.