The northern portions of the Black River and Severn River Watersheds fall within the area of interest for the Muskoka Watershed Council, encompassing approximately 2,538 sq km.
The headwaters of the Black River are in the Township of Algonquin Highlands. From there, the river flows in a south-westerly direction through the southern portion of The District Municipality of Muskoka and northern portions of the Township of Minden Hills, City of Kawartha Lakes, and Ramara Township to Lake Couchiching. From Lake Couchiching, it enters the Severn River waterway and flows to Georgian Bay. Most of the land area in the Black River Watershed is Crown land, with the upper reaches being part of the old Leslie M. Frost Centre.
The portion of the Severn River Watershed that flows through the southern portion of Muskoka is the very bottom section of the Trent/Severn Waterway. The water flows from Lake Couchiching into the lower Severn River and out to Georgian Bay at lock 45 at Port Severn. Both the Kahshe and Morrison Lake subwatersheds flow into the Severn River.
- Source Water Protection – The Black-Severn Watershed
- Source Water Protection Assessment Report – Watershed Characterization for the Black-Severn Watershed