Columbia River at flood stage, but only minor flooding expected
Corps of Engineers regulating dams to keep river near its banks
Owing to melting snow and exceptionally rainy weather this spring, the Columbia River water level has risen, causing minor flooding in several areas in Multnomah and Clark counties.
The National Weather Service reported Tuesday afternoon, May 31, that the river was at 17.2 feet at Vancouver, more than 1 foot above the 16-foot flood stage, which is when the water surface level begins to create a hazard to lives, property or commerce.
The weather service expects river levels to remain between 17.1 and 17.5 feet, just below 18 feet, when moderate flooding of lowland farmland and property would begin.
Scott Clemans, spokesman for the Portland District of the U.S. Army Corps of Engineers, said melting snow from the Cascades and the Rocky Mountains, along with a heavy amount of rain, has led to an increase in water flowing into the Columbia River Basin. As a result, the Army Corps of Engineers' Reservoir Control Center, which directs flood control operations in the basin, is working with river agencies to coordinate water flow through the river and dams, including Bonneville Dam in Cascade Locks, he said.
Clemans said Bonneville Dam is currently releasing 504,000 cubic feet of water a second. Bonneville's flow conditions for May have averaged around 297,000 cubic feet of water a second over the past 30 years, according to the Northwest River Forecast Center.
'We're trying to keep the river level as full as it can be without seeing significant flooding,' Clemans said, adding that the dams with storage reservoirs such as John Day and Grand Coulee have been releasing excess water in preparation for further snowmelt from the mountains.
The high water levels in the river could continue for a number of weeks, he said.
'We are not predicting a significant reduction in Columbia River waters for quite some time,' Clemans said.
Local areas affected
So far, some flooding has been reported on Sauvie Island and along the banks of the Columbia River that are used for camping and recreation, including Government Island and Cottonwood Beach near Washougal, Wash.
A Multnomah County sheriff's deputy and members of the Corbett fire department Saturday, May 28, rescued a 31-year-old Portland man after he had become stranded on high ground in Thousand Acre Park near Troutdale while searching for his missing dog.
Chinook Landing Marine Park in Fairview was closed Tuesday morning, May 31, because of high river levels and flooding in the parking lot and picnic areas, said Dan Kromer, parks and visitor services manager for Metro Regional Government. The M. James Gleason Memorial Boat Ramp in Northeast Portland is still open because it's high enough above the river, he said.
Some marina parks along the river in East County reported being affected by the rising water levels.
Jack Whitmore, owner of Big Eddy Marina in Gresham, said the marina's boat ramp was below water and its lower parking lot was flooded by up to 2 feet at the deepest spot.
'The biggest concern for us is if the access ramp (to the marina) goes underwater,' he said, noting that the water would have to rise about 1.5 feet more.
Portland Parks and Recreation on Tuesday closed the gangway and floating dock under the Burnside Bridge to bicyclists, pedestrians and boaters on the Vera Katz Eastbank Esplanade because of rising water, the first time in the dock's history that rising water has forced such a closure.
The closure is estimated to remain in effect for about a week, or possibly longer pending conditions and further evaluation.
During the last major flood in February 1996, the Columbia River reached more than 27 feet at Vancouver harbor, about 11 feet over flood stage. During the Vanport flood - which happened May 30, 1948 - the Columbia River rose to about 23 feet, 8 feet above flood stage.