Get to Know Mazinaw Lake
Mazinaw Lake is situated in portions of North Frontenac and Addington Highlands townships. It is the headwaters for the Mississippi River which flows to the Ottawa River. Part of the lake is within the boundary of Bon Echo Provincial Park. It has an elevation of 268 metres above sea level. The lake perimeter is approximately 49 kilometres and the deepest point is 144.8 metres.
The lake has two distinct basins—upper and lower, which are separated by a narrow channel at the base of Mazinaw Rock. Upper Mazinaw Lake receives inflow from Roluf and Crooked Lakes through Kilpecker Creek in Denbigh Township at the north end of the lake. Lower Mazinaw Lake receives inflow from Semicircle Creek and Bon Echo Creeks, and flows out through the Mazinaw Lake Dam at the south end of the lake.
There are three identified lake trout spawning shoals in Mazinaw Lake; the primary shoal is located on the south shore of Campbell Bay. This shoal is susceptible to the fall drawdown, and concerns have been raised regarding the survival of lake trout eggs over winter.
A habitat rehabilitation project to address drawdown concerns was completed in recent years. The other known lake trout spawning sites are located at the Narrows, and on the east shore of the south basin. Deep water spawning activity is suspected in Mazinaw Lake, although no sites have been confirmed.
Walleye spawn throughout the south basin, as well as at inflows in Campbell Bay, German Bay, and at the extreme north end of the lake. Water levels flowing out of Mazinaw Lake must be maintained throughout spawning season, April to May, to ensure protection of eggs and hatched fry in the river downstream of the dam. Spawning sites of other species have not been assessed. Figure 7.7 provides a list of fish species in Mazinaw Lake.
Species at Risk
Certain shoreline wetland habitats on the lake provide suitable habitat for a species at risk turtle, known as Blanding’s turtle (Emydoidea blandingii). The Blanding’s turtle is a Species at Risk (SAR) with a federal and provincial threatened SAR designation and is, therefore, afforded protection for itself and its critical habitat by the Fish and Wildlife Conservation Act, National and Provincial Parks Acts, the Natural Heritage component of the Provincial Policy Statement under Ontario’s Planning Act provides for the protection of significant portions of the habitat of threatened species, and SARA. These turtles are protected from collection or disturbance in all National Parks where it occurs. Because of delayed sexual maturity, Blanding’s turtle is affected by a variety of disturbances that affect both adult and juvenile turtles.
There are approximately 314 residential buildings and at least 4 marina/resorts located on Mazinaw Lake, and all of the residential buildings on the east shore are accessible only by boat. Water access only properties become inaccessible by boat once the fall drawdown has occurred The Bon Echo Provincial Park, Bon Echo Park proposed addition, and the Mazinaw Lake Enhanced Management Area are located along the western and eastern shore of the lake.
Under the current operating guidelines the priorities for this lake are flood control, healthy fisheries, continued recreation and tourism, maintained access to property and boat navigation, and low flow augmentation.
Currently, accurate shoreline development information is not available. However at last count in the early 1970’s, there were approximately 254 cottages on the lake.
Mississippi Valley Conservation Authority and its partner, the Mississippi Valley Lake Stewardship Network, are taking action through Watershed Watch, a program designed to protect and enhance the environmental health of lakes within the watershed. The monitoring results are posted as State of the Lake Reports. Each lake in the program is sampled every five years.