Caboolture Region Water Quality Study - Moreton Bay Regional ...

Caboolture Water Quality Study
6.0 CONCLUDING REMARKS
Variable patterns of water quality condition were resolved throughout the Caboolture region, including
variation in patterns of long-term trends over time. However, results suggest that more developed
(settled) areas, and some sites in agriculture areas, show evidence of deterioration in water quality.
Values for pH and dissolved oxygen were below reference values for the Northern Creeks. However,
these creeks are dystrophic systems, which are characterised by naturally low concentrations of these
indicators. Reference values for pH and dissolved oxygen for these water types need to be
determined to ensure that water quality can be assessed against guidelines that reflect “natural”
conditions more adequately.
The heavily industrialised areas had high concentrations of some toxicants in sediments and some
sites in close proximity to highways and major roads had elevated concentrations of total petroleum
hydrocarbons and lead in the sediments.
Faecal contamination was evident near some industrial sites and in canal developments, the latter
probably due to poor flushing, urban run-off and inputs from congregations of waterbirds. Despite
being suggestive of faecal contamination in Saltwater Creek and in some canals on Bribie Island,
these results were not derived from a sampling regime recommended by the National Guidelines
(ANZECC & ARMCANZ, 2000) and were therefore not directly comparable with the guidelines.
Overall, water quality, sediment and faecal coliform monitoring has resolved important trends in the
ecological condition of major waterways in the Caboolture region, and has highlighted “hotspots”
which present opportunities for management intervention to improve water quality.
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