A Canadian Lake Was Drained In 1924. In 2021 It Tried To Come Back

If you have driven the Trans-Canada Highway east of Vancouver, you have driven across the bottom of a lake. Sumas Lake was pumped dry in 1924 and turned into some of the richest farmland in Canada. In November 2021, a river from Washington State refilled the old lakebed, volunteers sandbagged a pump station through the night, and the province counted more than 600,000 dead farm animals. What's beneath YOUR town? Personalized 15-page report — the rock, the name, the vanished places, your town's oldest map → https://hiddenprovinces.com For thousands of years the Semá:th lived around a shallow lake between Sumas Mountain and Vedder Mountain, a lake of salmon, sturgeon that could live a century and a half, and ducks that rose in clouds. Settlers saw floods and mosquitoes. In 1920 the province accepted Frederick Sinclair's plan: divert the Vedder River, dam the Sumas, and pump the lake into the Fraser. The pumps started on July 3, 1923, and by June 1924 the lake was gone. A 1967 roadside plaque praised the 33,000 acres reclaimed and never mentioned who used to live there. For a century the Barrowtown pumps have kept Sumas Prairie dry, through the 1990 overflow, the warnings of 1995 and 2015, and the night of November 16, 2021, when the Nooksack River crossed the border, broke the Sumas River dike and came within a few sandbags of refilling the lake from both ends. The river that brought the water had flowed this way before. It tried again in December 2025. Today the valley is split between a multi-billion-dollar plan to defend the prairie and a study that proposes letting part of the lake return, while the Semá:th, who were never compensated, ask for one thing: willing sellers only. Sources include the Sumas First Nation, the Chilliwack Museum and Archives, Heritage Abbotsford, The Reach Gallery Museum, the Stó:lō Research and Resource Management Centre, Chad Reimer's Before We Lost the Lake, the City of Abbotsford, BC Government news releases, Whatcom County, the Encyclopedia of Puget Sound, Finn et al. in Frontiers in Conservation Science (2024), the Raincoast Conservation Foundation, CBC News, Global News, CTV News, the Associated Press, KUOW, Cascadia Daily News, the Fraser Valley Current, Glacier Media, The Western Producer and Country Life in BC. Where sources disagree, on the size of the lake, the livestock losses and when the Nooksack last flowed north, the narration says so. Subscribe to The Hidden Provinces — beneath the map.