Drilling and Levee Investigations:
The first step in the investigation is to conduct an above ground survey of the levee system and identify all structures and vegetation on the levees. The next step is to explore the conditions of the levees beneath the surface. To do this, Levee Ready Columbia drills boreholes and removes soil samples from the levees and on nearby land.
In 2014, Levee Ready Columbia’s geotechnical engineering consultants took soil samples at 135 boring locations in the PEN 1 and PEN 2 districts. At nearly all of these locations, a drilling contractor drilled holes less than 8 inches in diameter, from 20 to 100 feet deep.
In 2017, Levee Ready Columbia assessed the levees in MCDD and SDIC, completing an additional 251 borings.
This project was funded through loans and grants from the Special Public Works Fund and Regional Solutions Infrastructure Fund, programs funded through the Oregon State Lottery and administered by Business Oregon’s Infrastructure Finance Authority.
Drilling Completed: As of May 1, 2017, Levee Ready Columbia successfully completed the drilling work required for about 9,000 feet total – which is equivalent to drilling a hole from the top of Mt. St. Helens to below sea level. On Marine Drive, average traffic delays due to lane closures were 2-3 minutes maximum, and the project was completed on schedule and under budget.
The soil samples taken during the drilling work will be used to create computer models to simulate how the levee will perform during a high-water event. We expect the results of that work to be completed in the fall.
Thank you to the Columbia Corridor Association, the Portland Freight Committee, the City of Portland, the City of Gresham, the City of Troutdale, the City of Fairview, and Multnomah County for being excellent partners and working with us to make this project a success.
Recent pictures from the field: