3.1 Water Quality
- The water quality in Dutch Lake
since 2000 has consistently been scored in the C-D grade range on the
District’s annual lake report cards.
The mean summer 2004 total phosphorus concentration was 88 ?g/L,
well in excess of the District’s 40 ?g/L goal and the highest average
concentration since 1997. Based on
this monitoring history Dutch
Lake’s water quality
is not supportive of swimming.
- The HHPLS identified a need to reduce
phosphorus loading by approximately 42 percent to achieve the desired goal
of 40 ?g/L, as well as to reduce nitrogen and total suspended solid
loadings. The HHPLS and modeling
performed for this plan also noted that internal phosphorus loading and
possibly phosphorus export from wetlands in the subwatershed were likely
significant sources of excess phosphorus in the lake.
- Development, redevelopment, and
reconstruction in the subwatershed will increase nutrient and TSS loads
from the watershed as well as increasing the volume of stormwater runoff,
potentially further degrading water quality in Dutch Lake
and streams and wetlands in the subwatershed.