The Leschenault catchment, which drains to the Leschenault Inlet and then the ocean, is located about 160 km south of Perth, in the south west of Western Australia. Its area is approximately 2,020 km2 and includes the catchments of the Wellesley, Brunswick, Ferguson and Preston rivers, as well the Collie River catchment below Wellington Dam.
Artificial drains have been introduced in the flat Swan Coastal Plain areas to enable agricultural and urban land uses and to supply irrigation. This has led to a complex hydrological network of drains and natural rivers.
The catchment monitoring program’s objectives were twofold:
- to determine the nutrient status of the waterways and whether there had been significant changes in the nutrient status
- to provide nutrient data to support numerical modelling of catchment exports.
