The levee system along the Columbia River in Multnomah County could be in for an overhaul under a local bond measure in the upcoming primary.
Measure 26-243 asks voters to invest up to $150 million to upgrade the nearly century-old levee system to comply with federal flood standards. If passed, Congress would match those funds with another $100 million.
The measure would cost property owners 11 cents per $1,000 of assessed value a year. A home assessed at $246,712 — the average assessed value of homes in the county — would cost about $2.19 a month, according to the measure. The measure would apply to property owners within the county’s urban growth boundary.
If passed, the measure would repair and raise about nine miles of levee and floodwalls, upgrade seven pump stations, create power back-ups for outages, and commit $27 million to floodplain restoration. It would also build a levee and floodwall through a segment that was breached during the 1948 Vanport Flood.
An aerial view of the 1948 Vanport Flood, which breached part of the Columbia River levee system. That segment will get a new floodwall if a Multnomah County bond measure passes in the May 21 election.
Photo courtesy of the Oregon Historical Society Research Library, OrgLot131_010
If the measure doesn’t pass, the levee system would lose its federal accreditation and nearby property owners would need to buy flood insurance. Building regulations along the river would also become more stringent. For example, the first floor of a new building would need to be at least 10 feet high to be above flood elevation.
The region could also become increasingly vulnerable to catastrophic flooding, particularly during major rainstorms.
“We’re seeing really large rain events and those rain events require us to pump more water over the levees,” Multnomah County Drainage District Executive Director Jim Middaugh said. “When we’re seeing 15 inches of rain in 24 hours, our system is currently not designed to handle that level of rainfall.”
Multnomah County's Measure 26-243 asks voters to invest up to $150 million to upgrade the nearly century-old levee system to comply with federal flood standards. It would apply to property owners within the urban growth boundary.
Map courtesy of the Multnomah County Drainage District
The Columbia River basin is a large system spanning from British Columbia through Washington, Oregon and Idaho. Multnomah County is near its lowest point — sort of like being at the bottom of a large bowl — so major rain and snow runoff puts significant pressure on its levee system.
The system was originally built by farmers in 1917. Since then, it’s undergone a hodgepodge of various upgrades, Middaugh said, but nothing of this magnitude.
The district has been working toward getting funding for this overhaul for years. It hit some snags during that time, including dropping its initial ask of $195 million to $150 million to assuage local business concerns about tax increases, as reported by Willamette Week.
The voter registration deadline for the May 21 primary election, as well as the deadline for choosing a political party affiliation, is Tuesday, April 30.