The Columbia River exceeded flood stage at the Interstate Bridge Tuesday and that may mean more bridge lifts for Interstate 5 traffic.
The river reached 16.5 feet at the bridge, where the flood stage is 16 feet.
ODOT expects the level will reach 17 feet in the next few days—and perhaps higher depending on the rains.
Higher river levels have already meant more lifts of the lift span, which now average nearly two a day. Lifts usually last 15 to 20 minutes but can last longer.
More frequent lifts will mean more delays on I-5 in both Oregon and Washington.
The last time the Columbia River was this high at the Interstate Bridge was May 2011, when it reached 19 feet caused by rain and an early snowmelt.
The river reached 24 feet in 1996, part of major flooding in the Portland area.
The river is now running very fast at the Interstate Bridge, causing more ships to choose to pass under the bridge at the lift span at the north side of the river instead of the mid-river high span. By taking the lift span, vessels avoid speeding through the high span and making the quick swerve necessary to reach the swing span on the north side of the BNSF Railway Bridge, a half mile downstream.
Under maritime law, bridge lifts have priority over highway traffic. However, no lifts are allowed during the morning and evening commutes, from 6:30 a.m. to 9 a.m. and again from 2:30 p.m. to 6 p.m. most weekdays.
In 2015, average daily traffic on I-5 over the Interstate Bridge was 132,300.
The Interstate Bridge is jointly owned by Oregon and Washington and is operated and maintained by ODOT. The northbound span opened Feb. 14, 1917 and the southbound span opened July 1, 1958.