The County of Renfrew geographic information system contains “official names” for over 700 lakes, 200 creeks and rivers, and 50 wetlands. It also identifies 36 “quaternary watersheds” that occur wholly or in part in the County, as described in the table below. Knowledge of drainage patterns in these watersheds can provide insights into how activities in upstream areas may influence water quality and property values in downstream areas.

Renfrew County is entirely within the larger Ottawa River watershed. The Ottawa River has played a central role in Canada’s history: the homeland of the Algonquin peoples, a meeting place for Aboriginal peoples and early European explorers such as Champlain, and a means of trading and transporting fur and timber.

Aboriginal peoples arrived in the Ottawa Valley less than 10 thousand years ago, after the end of the most recent ice age. The valley itself originated about 600 million years ago in the Precambrian when only bacteria lived on the Earth. At that time the world’s continents were joined together in a single super-continent. When it broke apart, deep cracks – extending some 40 km to the base of the Earth’s crust - formed where the Ottawa and Bonnechere rivers are found today. These faults spread apart and the land between them dropped downwards, forming a wide valley with escarpments on either side, known as the Ottawa-Bonnechere Graben, extending from just north of the present Ottawa River channel in Pontiac County, Quebec south to the Mount St. Patrick Fault near Lakes Clear and Calabogie.

The advance and retreat of the Laurentide Ice Sheet shaped the present-day landforms and soils of Renfrew County. In some areas the glaciers scraped materials from the land surface and left mainly bare rock, elsewhere they deposited materials in landforms such as moraines, eskers, and kames.

The 2-km thick ice sheet had compressed the land surface by roughly 150 meters. As the glaciers retreated, the Atlantic Ocean rushed in and created the Champlain Sea, which flooded low-lying parts of the Valley as far west as Point Alexander. Massive amounts of melting water from the glaciers flowed east from the Rocky Mountains and western plains into the upper Great Lakes and broke through an outlet in North Bay into the Ottawa River and Champlain Sea. At the height of melting the Ottawa rivaled the Amazon in size. Meltwater carried rocks and sediment and helped carve parts of the present valleys of the Barron, Bonnechere, Chalk, Indian, Madawaska, Muskrat and Petawawa Rivers. Sediments transported into the Champlain Sea left extensive deposits of Leda Clay. Elsewhere, meltwater ponded and formed huge lakes, the precursors of today’s Lake Calabogie, Lake Clear, Golden Lake, Mink Lake, Round Lake, and Silver Lake. Vegetation later grew in these lake basins and decayed into peat, forming Renfrew County’s extensive wetlands and providing habitat for fish, waterfowl, and aquatic mammals.