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Lower Brisbane River Catchment, Estuary and Tributaries
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Catchment Facts |
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- Total area: 1,195km2
- Stream network length: 2,475km
- Local Councils: Beaudesert (pop. 62,441), Brisbane (pop. 956,129), Logan (pop. 173,264)
- 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
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Freshwater results |
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Lower Brisbane Catchment |
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- Streams generally in very poor condition
- A similar pattern of scores across indicators and seasons to previous years
- Nutrient cycling, aquatic macroinvertebrate and fish indicators all continue to score poorly
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Estuarine results |
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Brisbane Estuary |
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- Much improved nitrogen and dissolved oxygen levels in middle reaches adjacent to the Oxley WWTP discharge
- Lower freshwater inputs resulting in higher salinity levels throughout
- Some riparian habitat remains intact in the inter-tidal zone of upper reaches, but is heavily impacted above the highest tide mark throughout much of the estuary
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Cabbage Tree Estuary |
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- Lower nitrogen loads adjacent to the Sandgate WWTP discharge but all indicators still not compliant with the new, more stringent guidelines.
- Intact natural riparian habitat on the southern banks of the estuary, but heavily impacted habitat on the northern side
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F |
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Oxley Estuary |
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- Elevated nutrients in lower reaches mainly as a result of exchange with the Brisbane River
- Elevated turbidity levels in upper reaches
- Intact natural riparian habitat in the inter-tidal zone thorughout, heavily impacted habitat above the highest tide mark
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