Leschenault Estuary

Physical

Ocean opening Permanently open (artificial 1951)
Estuary surface area 27 km²
Catchment area 1889 km²
Catchment: estuary ratio 70
Mean annual rainfall ~750 mm/yr
Mean annual discharge 358 GL/year (1998‒2007)
Catchment cleared 52%
Urban landuse 3%
Agricultural landuse 49%

Socio-economic

City/town Bunbury
Population 65 000
Population growth rate 1.5% pa
People per estuary area 2 407
Shipping trade 422 ship arrivals, 16.5 MTonnes of cargo (2016)
Commercial fishing None currently. Commercial fishing ceased late 1990s (targed species incl. yellow-eye mullet, King George whiting and yellow-finned whiting). Commercial crabbing for blue swimmer crab ceased 2001.
Recreation/tourism Dolphin centre, boating, crabbing, bird watching

The stunning Leschenault Estuary (Derbal Elaap) is highly valued by the community for its natural vistas, fishing, crabbing, and other recreational pursuits. The estuary is ecologically significant – home to dolphins and an important migratory route for many species of birds. These attributes are appreciated by both the local community and visitors to the area.

Unfortunately in recent times the estuary has shown signs of distress, with sedimentation, nuisance algae, harmful algal blooms and fish deaths. There is an urgent need to balance growing urbanization and intensification of agriculture with the long-term health of the estuary.

The region is very significant socio-economically. The Greater Bunbury area is one of the most populous areas in the state’s south west. It is forecast to grow from 61 000 to between 100 000 to 150 000 residents by 2031 (WAPC 2005). Development of the Bunbury port has led to many estuary modifications, including the creation of a permanent opening “The Cut” in 1951.

$7.5 million will be spent to understand and improve condition of the Leschenault Estuary and its catchments during the Regional Estuaries Initiative. This funding will be supported by co-investments from regional catchment groups, local governments and industry partners.

For the Leschenault Estuary, the Regional Estuaries Initiative will:

  • Work with the Leschenault Catchment Council for joint delivery of on-ground action and long term management strategies
  • Reduce the nutrient runoff from farms while supporting farm productivity in partnership with Western Dairy, Department of Agriculture and Food, farmers and local groups.
  • Work with local groups to restore stream function, move stock away from waterways and improve water quality by implementing river action plans
  • Fund stormwater upgrades and promote urban design to improve water quality
  • Support increased monitoring and modelling of the Leschenault Estuary and its catchments.
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