The programme is coordinated by the State Government Department of Catchment Management and supported by local government organisations in our case The City of Stirling. Students have tested the water in Lake carine since 1990. Because it is an area of remanent bushland and receiving the runoff from surrounding urban areas, we are interested in the quality of the lake water in relation to the inlet sources, mainly subsurface flow and road drainage. Of major concern is the extension of the Reid Highway, planned to cut across the southern boundary of the wetlands.
Eutrophication is a major problem as nutrients cause algal blooms periodically in the lake.
This year is no exception as good rains in winter have mobilised nutrients following the lake drying out in the previous 1995 summer. The level of phosphorus varies from zero to 0.40 ppm. The algae appears to bloom as the phosphorus peaks in August to November. By then, the intense growth depletes the phosphorus in the water. Raised Phosphorus and Nitrate levels are an indication of mobilisation due to runnoff during early winter rainfall.