The Columbia River overtopped its banks in Vancouver on Monday as the impact of melting shows and days of heavy rain works its way through the Columbia River watershed.
River levels passed 16 feet in Vancouver on Monday, causing minor flooding of islands and low-lying areas, as well as in several parks and trails along the river. The National Weather Service issued a flood warning for the Columbia River between Vancouver and Kelso through early Wednesday afternoon.
Forecasters say river levels were close to their crest as of Monday morning but cautioned that levels will rise and fall with the tides over the next several days. The elevated river levels will mean fewer vessels can pass safely under the “hump” of the Interstate 5 Bridge, meaning more bridge lifts for river traffic.
The flooding follows an unusually wet stretch of weather fueled by an atmospheric river of subtropical moisture that brought 1.44 inches of rain to Vancouver’s Pearson Field in a 48-hour period ending Saturday evening. Even heavier amounts fell at higher elevations, accelerating snowmelt feeding into the Columbia River and its tributaries.
The U.S. Army Corps of Engineers announced Sunday that it would begin holding back water at John Day Dam, causing flooding of parks upstream from the dam, to help moderate river levels in Vancouver.
“Of primary concern to us at this point is public safety,” said Steve Barton, chief of the Corps’ Columbia Basin Water Management Division. “This system of dams was built primarily to protect the public from catastrophic floods. While we cannot prevent all flooding, we can take steps to minimize the impacts of these powerful weather events.”
On the Lewis River, Swift Reservoir’s level was at 998 feet, two feet below its full pool level of 1,000 feet as of noon Monday. Yale Lake was at 479 feet, with a full pool of 490 feet, and Lake Merwin was at 238 feet, two feet below its full pool level of 240 feet, according to the National Weather Service.
The flooding in Vancouver is considered minor, though river levels will be the highest recorded since March 2017, when river levels reached 17.43 feet, according to National Weather Service Data. The highest recorded river level was 33.6 feet in June 1894, followed by 31 feet in June 1948 during flooding that destroyed the community of Vanport, Ore.
The National Weather Service warned those venturing into the river to be prepared for cold water and unusually powerful currents and be aware that objects typically exposed along the sides of the river channel are now be below the water’s surface and damage their boat.