Catchment

The waterway catchment is contained within the municipalities of Kingborough Council (which covers Bruny Island) and Huon Valley Council.  The catchment area is dominated by conservation management with vegetation types including buttongrass moorland, alpine complexes, stringbark eucalypt forests, pockets of rainforest, wet scrub, open dry forests, grasslands, and tall wet forests with shrubby understorey.

The catchment also includes significant areas of production forestry and grazing, with other agricultural practices (such as orchards), plantation forests and mining account for about 10% of the catchment.  The majority of agricultural land in the catchment occurs within several kilometres of the coast, or follows the major rivers and smaller rivulets.  Less than 10% of the catchment is classified as urban or industrial, and these areas are most concentrated around the waterway.  Traditional commercial activity in the catchment has stemmed from forestry and agriculture, with aquaculture and tourism rapidly expanding over the past twenty years.

The geology and soils are dominated by mudstone, sandstone and shales with intrusions of dolerite.  Alluvial and estuarine deposits of sand, silt, clay and gravel are found in coastal wetlands and the lower reaches and upper estuarine sections of rivers and rivulets.

Soil nutrient concentrations range from low to medium for total nitrogen, and from low to high for total phosphorus.  The colour of water in the Huon estuary comes from dissolved humic material in run off from peaty soils.  Erosion may also contribute to turbidity in streams.