May 30, 1948: The Vanport City Flood

Portland, OR was a major shipbuilding during World War II. As many as 100,000 people were employed in the shipyards. Thousands of people flocked to Portland, many of them African-Americans who had moved to the Northwest from the South. The huge influx of people created a huge housing shortage.

Vanport City was a federal housng project built on 650 acres along the banks of the Columbia River north of Portland. As many of 40,000 workers lived in the city of Vanport during the war. After the war, layoffs thinned the population, but 19,000 workers still lived in Vanport City in 1948.

Despite the fact that Vanport City was on the largest river in the western United States, there was little concern. The winter of 1947-48 produced heavy snowfall amounts in the upper Columbia River basin. Warm temperatures in the spring caused rapid melting of the snowpack, and rivers and streams quickly jumped their banks. Despite the rising water, there still was little concern.

On Sunday, May 30th, a dike which supported a rail track on the west side of the housing development suddenly collapsed. The crevasse widened from 6 feet to 60 feet and then to 500 feet wide. It only took two hours to flood the entire city. The following day, the dike on the eastern side of town collapsed also, sealing the town’s fate.

There was almost no warning for the town’s 19,000 residents. Twenty five people drowned. The residents of the town lost all of their personal belongings, most escaping with just the clothes on their backs. Ten thousand homes were destroyed. Damage totaled $21 million. Vanport would never be rebuilt. The area is now a flood mitigation zone with parks and golf courses.

Category: Met 101/Weather History