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Figure 17: The sampling location for water quality data
from Draft Manning River Catchment and Estuary and Catchment Management Program 2021-2031 - Main document
4.3.2 Water quality results in the freshwater catchment
MidCoast Council’s Water Services team undertakes monthly water quality monitoring at six locations in the Manning freshwater catchment. Using this data to characterise water quality within the catchment is challenging due to its large and diverse geography, its dynamic nature and the relative paucity of water quality data compared to the scale of the system. Even at the sub-catchment spatial scale landscape influences such as riparian vegetation condition, landscape modification, and land-use cause great variation in water quality. Nevertheless, a review of past investigations along with existing water quality information provides some understanding of water quality characteristics in the Manning.
The results below collate 4-years of data from 2015-2018, recorded at the water monitoring station at the Bootawa offtake in the Manning River downstream from the confluence of Dingo Creek (Figure 17). The discussion presents key characteristics of ecosystem stressors including nutrients (nitrogen and phosphorus), turbidity, and an ecological indicator chlorophyll-a. River flow is presented against these key characteristics because the flow rate influences water quality.
As catchment specific thresholds for these analytes are yet to be determined for the Manning catchment, the default ANZECC aquatic ecosystem triggers for lowland east flowing coastal rivers have been used as a benchmark.
