And while other lakes in the watershed - including Pigeon, Sturgeon, Cameron received B grades in the report, other aspects of the watershed, such as wetlands and forest conditions, received a mixed bag of grades.
The new watershed report card released by Kawartha Conservation Authority 'highlights the need for actions to help improve the environmental health of Lake Scugog, and the surrounding lands that drain to the lake,' according to a release from the organization. The report card was among dozens released by conservation authorities across Ontario this month, as part of Canada Water Week (March 18 to 24).
Kawartha Conservation based the grades on 'key environmental indicators,' including surface water quality, groundwater quality, wetland conditions, and forest conditions - natural features monitored regularly to assess conditions, identify environmental changes, and target restoration and protection efforts.
According to Kawartha Conservation, the grade for Lake Scugog was based on the amount of phosphorus in the water - commonly found in fertilizers, sewage, detergents and soil from erosion - an element associated with weed and algae growth. The study also analyzed aquatic insect life as an indicator of general lake health.
The result was not a surprise for local environmental group the Scugog Lake Stewards.
"I don't think this grade from KRCA will be a surprise to anyone in the community, especially the Lake Stewards," said president Barb Karthein, who attributed the lake's current condition to a number of factors, including "relative drought conditions, heat and consequent lack of water flow-through.
"We have to realize that it will take time to remediate the historic levels of this nutrient, even with the actions taken by Kawartha Conservation, the Township of Scugog, the Region of Durham and the Stewards."
In regards to the lake's current state, Ms. Karthein outlined the role of invasive weeds.
"To the list of factors given for the excess phosphorus levels, we would add the recycling of nutrients from the composting of the lake's overwhelming water milfoil weed population," said Ms. Karthein. "Reducing this horribly invasive, non-native plant is very high on the Lake Stewards' list of "to do's."
According to the Kawartha Conservation report, the overall grade for the entire watershed was a C.
Kawartha Conservation also found that groundwater quality for Scugog aquifers that have monitoring wells all had low levels of nitrogen and chlorides, resulting in A grades.
However, while most wetlands in the watershed got As and Bs in the report, the Blackstock Creek basin received a C, while Cawkers Creek received an F. Those grades, according to the report, were based on factors such as a wetland's ability to 'improve water quality in lakes and rivers, reduce flooding and flood damage, stopping erosion and keeping carbon dioxide out of the atmosphere.'
Forest conditions in the watershed, based on the percentage and type of cover, received a C average.
The Blackstock Creek and Cawkers Creek basins, which drain into Lake Scugog, received Ds for surface water quality, while the Layton River, Nonquon River, and Southern Lake Scugog Tributaries basins got Cs.
"There is room for improvement," said Kawartha Conservation CAO Rob Messervey, "and the grades reinforce the need to continue our collective efforts with Durham Region, the Township of Scugog, and watershed partners. Further land and water stewardship activities, identified in the Lake Scugog Environmental Management Plan, need to be undertaken to improve the grades."
The 2013 Kawartha Watershed Report Card is available on-line at www.KawarthaConservation.com/reportcard.