The Bonnechere River Watershed
The Bonnechere River watershed encompasses an area of approximately 2,400 square kilometers (935 sq. miles), a drainage half the size of Prince Edward Island.
Approximately 80 percent of the land in the watershed is privately owned.
Round Lake, Golden Lake and Lake Clear, are the primary storage lakes on the system.
The Bonnechere River is a controlled system. The dams along the system provide some ability to respond to weather events and control flooding.
Most of the river’s headwaters are in the geographic Township of Niven, Nipissing County (in Algonquin Provincial Park).
The river’s source is McKaskill Lake and North Branch in Algonquin Provincial Park. The river meanders through the forested and rocky Precambrian Highlands of the Canadian Shield, and then through open farmland with erodible clays, human settlements and scattered woodlands.
The river is navigable by canoe along much of its course, though portages are necessary at five well-known chutes (falls) and at several rapids.
The character of the Bonnechere River changes from cold and clear close to Algonquin Park, to warm and turbid as it approaches the Ottawa River near Castleford. The Bonnechere empties into the Ottawa River through a Provincially Significant Wetland.
The mean annual flow of the Bonnechere (at Castleford) is 19.2 cubic metres per second (cms), but flows have historically ranged between 33.6 and 7.59 cms. The minimum daily flow record has been 0.3 cms while the highest daily peak has been recorded at 286 cms.
Water flows and levels in the Bonnechere River are regulated from Jack Chute to Tramore Dam including Round Lake to the Ottawa River. There is one water survey station near Castleford, at the lower end of the watershed, which monitors regulated flow. Other gauges monitor only water levels controlled by specific dams.
Control and Electrical Dams on the Bonnechere River