Port Hope in Northumberland County, Ontario — Central Canada (North America)
History of the Ganaraska Watershed
Photographed by Tim Boyd, June 7, 2025
1. History of the Ganaraska Watershed Marker
The Ganaraska River watershed shaped thousands of years ago by glacial activity, flows through the Municipality of Clarington, the Municipality of Port Hope, and the Township of Hamilton. Its uppermost headwaters are found in the City of Kawartha Lakes and the Township of Cavan Monaghan. Historic events have shaped the watershed into its present-day condition. Most notable are the effects of dams and settlement patterns caused by the location of road and rail corridors. Today, the watershed supports, a productive agriculture community, and a mix of natural resources and recreational uses. In addition, residents depend on water from the watershed for domestic and industrial use.
The Ganaraska watershed is 280 square kilometres and supports a diverse biological community. The fisheries are supported by a sustainable habitat of cold to cool water within the upper two thirds of the watershed, with a diverse and migratory community in the lower main branch of the watershed. The Ganaraska River supports a fish community dominated by brook trout (salvelinus fontinalis), brown trout (salmo trutta), rainbow trout (oncorhynchus
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Prior to European settlement numerous aboriginal groups inhabited the region around and in the Ganaraska River watershed. During this time, the Ganaraska River watershed was a densely wooded area with massive stands of oak and pine trees. The Hurons resided in the region from Lake Ontario to Georgian Bay until the late 1600s, when the Iroquois forced the Hurons to move as far north as Lake Superior, After 1660 the Cayuga tribe of the Iroquois established outposts in the Rice Lake area and at Ganaraska (Port Hope), thus controlling the fur trade in the area.
In the early 1700s the Iroquois were forced out of the surrounding area by the Mississaugas, a stem of the Ojibwa-Algonkins from the Lake Superior region. The Mississaugas did not settle in any one place, and were nomadic in the area. The Ganaraska River was a major trade route and had several small huts along the river. In the watershed, there were three main walking paths that were similar to the present Walton
Photographed by Tim Boyd, June 7, 2025
2. History of the Ganaraska Watershed Marker
The French entered the area soon after Canada became a Royal Province of France in 1663. The French harvested oak and pine timber for building Royal Navy vessels. Interest in the White Pine resource grew after Canada became a British Colony in 1763. Permanent settlement in the Ganaraska River watershed occurred after 1793 near the mouth of the river. Settlement increased rapidly after the founding of Port Hope in 1798. By the 1840s, communities were created all the way north of the present 8th concession. Between 1860 and 1880 many of the communities in the watershed doubled in population.
Communities that had settled along the tributaries
Photographed by Tim Boyd, June 7, 2025
3. The Ganaraska River in Port Hope, 2025
On March 21, 1980, the flood of the century hit the Ganaraska River, It was caused by rainfall that was not particularly severe by yearly standards (5-year event), but which was relatively severe for the month of March (50-year event). Rainfall on frozen ground allowed little or no infiltration. It was concluded that the 1980 flood has a recurrence interval of 100 years. This event allowed the Ganaraska River to experience a flow of 421 cubic metres per second, causing 66 acres of downtown Port Hope to be flooded with water depths to 1.5 meters and velocities sufficient to knock down building walls. Even though the Ganaraska Forest was approximately 35 years old, the forest could not reduce the effects of the 1980 flood due to the frozen ground conditions and ice jams in the river. In order to mitigate further flood events like experienced in 1980, channelization of the river through downtown Port Hope was proposed and constructed. The river was widened and deepened over a distance of approximately 1,000 metres to allow for a greater capacity of flow through the Town. Since channelization has occurred, the Town has not experienced significant flood events, although localized seasonal flooding does occur throughout the watershed.
Erected by Municipality of Port hope.
Topics. This historical marker is listed in these topic lists: Indigenous Peoples and Communities • Natural Resources • Settlements & Settlers • Waterways & Vessels. A significant historical date for this entry is March 21, 1980.
Location. 43° 56.976′ N, 78° 17.515′ W. Marker is in Port Hope, Ontario, in Northumberland County. It is on Mill Street South 0.1 kilometers south of Walton Street, on the right when traveling south. Touch for map. Marker is at or near this postal address: 44 Mill St S, Port Hope ON L1A 2S5, Canada. Touch for directions.
Regionally, this marker is in the Kawarthas Northumberland Area and in Eastern Ontario. It is also in Central Canada. Globally, it is in North America, on the Great Lakes, in the Western Hemisphere, in the Western World, and in the Anglosphere. Historically, it finds itself in what was once a British colony, the Viceroyalty of New France, the Haudenosaunee (Iroquois) Confederacy, and Ruperts Land.
Other nearby markers. At least 8 other markers are within walking distance of this marker: Farley Mowat (a few steps from this marker); Rotary Foot Bridge (within shouting distance of this marker); Port Hope Cenotaph (about 90 meters away, measured in a direct line); Arthur T.H. Williams MP (about 90 meters away); Founding of Port Hope (about 120 meters away); 77mm German Field Gun (about 120 meters away); Cenotaph Plaque (about 120 meters away); Bluestone House 1834 (about 150 meters away). Touch for a list and map of all markers in Port Hope.
Credits. This page was last revised on June 11, 2025. It was originally submitted on June 11, 2025, by Tim Boyd of Hamilton, Ontario. This page has been viewed 187 times since then and 42 times this year. Photos: 1, 2, 3. submitted on June 11, 2025, by Tim Boyd of Hamilton, Ontario. • Andrew Ruppenstein was the editor who published this page.
