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2023-03-01 LAND briefingLocal Actions Non-Dam Alternative (LAND) briefing March 1, 2023 2:05 p.m. Present: Commissioner Swope, Commissioner Brummer, Commissioner Pollock, County Manager Erik Martin, Andrea McNamara Doyle of the Office of Chehalis Basin, Barbara Russell, Mindy Brooks, Eric Eisenberg, Lee Napier, Frank Corbin, J Vander Stoep, Ross McDowell, Erika Katt, Dave Rodgers of MIG, Mike Kroll, Kate Andrea McNamara Doyle of the Office of Chehalis Basin, Chatterton Guest(s): Owen Sexton (The Chronicle) Recorder: Rieva Lester Public comment: None. Andrea McNamara Doyle of the Office of Chehalis Basin (OCB) discussed the Chehalis Basin Strategy’s work with the Local Actions Non-Dam Alternative (LAND) briefing to provide options regarding flood mitigation, noting that the governor’s office directed OCB to review alternatives to a dam as flood mitigation. Andrea said the LAND group’s main focus is the upper Chehalis River basin and that areas downstream are being evaluated for potential impacts and mitigation. Dave Rodgers of MIG said the group is reviewing the following: Structural interventions: • Dams • Floodwalls and levees (greater than 6 feet) • River channel diversions Non-structural interventions: • Floodproofing, elevating, and/or relocating homes and businesses • Floodplain storage • Berms and floodwalls (less than 6 feet) • Local land use planning and building codes • Resiliency programs such as flood-warning systems, emergency preparedness plans, equipment pre-positioning, etc. Dave said the group is reviewing options, including potentially expanding the current levees. Dave and Andrea said LAND proposals being considered include the following: Waterflow diversion and improved conveyance • Construct a new 700-foot-wide, one-mile-long water diversion by excavating approximately 1.3 million cubic yards of soil west of the existing Mellen Street. • Remove the Existing Mellen Street Bridge and reconstruct it approximately 2,000 feet to the south to connect to Military Road, west of the Chehalis River and I-5. • Increase conveyance near the existing Mellen Street Bridge by removing approximately 1.3 million cubic yards of soil immediately upstream and for approximately 3,000 feet downstream of the existing Mellen Street Bridge. New and expanded levees / floodwalls • New levee on the north bank of the Chehalis River from north of Fort Borst Park downstream to Galvin Road (2.7 miles). • New levee on the east side of I-5 from China Creek south to Salzer Creek (3.3 miles). • New and expanded levees on the north and south sides of the Skookum chuck River (6.6 miles). • Expanded levee around the Chehalis-Centralia Airport (4.3 miles). • New levee on the north bank of the Newaukum River east of I-5 near (1.2 miles). • New levees on the north and south sides of China Creek from I-5 to the railroad tracks (2.3 miles). Commissioner Swope expressed frustration about the amount of money that would be spent on the proposals, which wouldn’t address flooding issues as well as a water retention facility would. He noted that the longer it takes to complete the flood protections, the more they will cost. Brummer said some aspects of the LAND proposals would be beneficial to incorporate in tandem with a flow-control structure, while others are not quantifiable or based in reality. Brummer said he wishes people would stop calling it a dam. He stressed that the county is proposing a flow-control project, not a dam. Commissioner Pollock said she’s concerned that the LAND proposals don’t address areas upstream of Chehalis. Andrea said recommendations will be presented to the Chehalis Basin Board in April. She said a public survey regarding the various proposals has been extended through mid-March. Andrea and Dave said preliminary cost estimate for the levees is just shy of $2 billion. Commissioner Pollock expressed concern that having multiple levees and stormwater back-flow preventers would put the area at risk should just one levee or back-flow preventer fail, whereas a water retention facility would offer one structure to maintain, lessening the odds of failure. Meeting adjourned at 3:05 p.m.