• Catchment FactsTotal area: 1,195km2
  • Stream network length: 2,475km
  • Local Councils: Brisbane City Council, Logan City Council, Scenic Rim Council
  • Dominant land uses: urban, native bush, grazing, rural residential
  • Highly modified, urbanised catchment
  • Some grazing lands and natural bush/forested areas remain in the upper parts of the catchment
  • Riparian vegetation has been cleared from most waterways
  • Large volume of stormwater runoff into the waterways during/after storm events
  • Population growth is a major pressure on the catchment

Freshwater results

Lower Brisbane Catchment

  • Streams in poor condition.
  • Declines in the Nutrient Cycling, Aquatic Macroinvertebrates and Physical/Chemical indicators.
  • Improvement in the Fish indicator across both seasons, slight improvement in Ecosystem Processes.

Estuarine results

D+  Brisbane Estuary

  • Decreases in dissolved oxygen, turbidity and biological health rating with slightly higher sewage nitrogen signals detected.
  • Lower phytoplankton abundance.
  • Salinity throughout estuary lowest since 2001, indicative of high freshwater inputs.

Cabbage Tree Estuary

  • Increases in phytoplankton abundance and nitrogen concentrations at most sites.
  • Continued elevated phosphorus at all sites.
  • Continued low dissolved oxygen.