Spotlight on Rivers of the South Okanagan Similkameen

Okanagan Similkameen Conservation Alliance Photograph courtesy of Bob Lincoln rivers
Photograph courtesy of Bob Lincoln
The South Okanagan Similkameen valleys are home to two major river systems, the Similkameen River and the Okanagan River. These rivers are part of the Columbia River system that flows to the Pacific Ocean at Astoria, Oregon.

Okanagan River

The Canadian portion of the Okanagan River is 37 kilometers long and has been significantly modified by irrigation and flood control dams, channelization, river flow containment dykes, riparian habitat loss, water extraction and urban development. According to the Outdoor Recreation Council of British Columbia, it is the 10th most endangered river in the province.

Similkameen River

The Similkameen River is also part of the Okanagan River basin. It drains approximately 9300 square kilometers of the east slope of the Cascade Mountains and the Interior Plateau. The majority of the watershed is in Canada. The Similkameen River flows into the section of the Okanagan River south of Osoyoos Lake. Historic and proposed dams and weirs are threats to the health of this river system.

How does a River flow?

Rivers provide a conduit for water to flow from the mountains to the sea. River water is provided by rain and snow that falls in the mountains. Snow is stored through the winter and released in the spring when temperatures rise. This causes high stream flows and sometimes local flooding but is also the time that the sand and gravel on the bed of the river channel moves. In natural river channels, it is this sand and gravel that forms the channel itself. So, the shape of the channel is actually formed during these high flows. Channels develop fast flowing areas called riffles and slow moving areas called pools. As the sand and gravel are transported and deposited, many river channels shift location and become longer, migrating back and forth creating a flat floodplain at the bottom of the valley. The floodplain is actually part of the river system because it is often flooded by the spring melt. The water here percolates through the floodplain to return to the river below the ground.

A Natural River

  • Provides critical habitat for salmon and trout in the river’s pools and riffles. Adult fish rest in pools and spawn on riffles.
  • Provides critical riparian habitat for dependent species. In the South Okanagan Similkameen this habitat consists of shrubs and trees such as the wild rose, dogwood, willow and cottonwood.
  • Reduces the risk of flooding of lands adjacent to the flood plain.
  • Deposits fine sediments on the floodplains which help improve water quality, help the forest and riparian areas grow and improve spawning habitat.

When protected, rivers serve as visible symbols of the care we take as temporary inhabitants and full-time stewards of a living, profoundly beautiful heritage of nature.

  • John Echeverria, Pope Barrow, Richard Roos Collins

  • Rivers at Risk: The Concerned Citizen’s Guide to Hydropower

  • How are we protecting our rivers in the South Okanagan Similkameen?

Three significant projects“These initiatives are all major projects that involve extensive collaborative work. It is very encouraging to not only see projects that benefit the river and salmon but also the commitment shown between First Nations, provincial, federal and municipal governments and local landowners.” Karilyn Long, MSc, Fisheries Biologist, Okanagan Nation Alliance.

Click here to learn about 'The Okanagan River Restoration Initiative'.

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