Group’s Flood Mitigation Proposals Cost Between $560M to $2.3B and Largely Focus on Centralia

Chehalis Basin Group Unveils Four Non-Dam Flood Prevention Proposals; Asks for Public Input


The Chehalis Basin Local Action Non-Dam (LAND) Alternatives Steering Group held a workshop earlier this month at the Great Wolf Lodge to give basin residents a first look at four proposals that now require public input.

The group was formed and funded through the Office of Chehalis Basin to look at large-scale flood mitigation in the Chehalis River Basin outside of a proposed water retention structure near Pe Ell. For reference, a 2020 preliminary estimate put the cost of the structure between $475 million and $675 million.

Office of the Chehalis Basin Director Andrea McNamara Doyle explained in an email that so far, $2.4 million has been invested in LAND to work with consulting groups, and the current contract ends June 30. McNamara Doyle estimated roughly 75% of the $2.4 million has been spent on the initial steps. Cost estimates of the various proposals by the LAND group range from $560 million to $2.3 billion.


Option One

The first option proposed by the group is the simplest. It features building safe structures along with floodplain management. It would aim to recreate how the river flowed before the floodplain was developed.

Safe structures, according to the LAND group, begin with having flood insurance and can include utility relocation, flood proofing, structure elevation and voluntary buy-out’s with compensation and relocation assistance. Floodplain management involves the restoration of floodplains surrounding the Chehalis and Skookumchuck Rivers. 

Some pros of the first option include flood protection from small flooding events, potential benefits for landowners who decide to restore floodplains on their properties using grant funding and potential environmental benefits. It would likely require adoption of flood-friendly land use and building codes by local municipalities to avoid further development. 

This option does not reduce the risk of flooding from catastrophic storm events. The LAND group estimates total costs to be around $560 million. 

Many parts of this option, including structure elevation and floodplain restoration, have already been practiced in the basin. While LAND is proposing expanding their use, these efforts are already ongoing. 


Option Two

The second option focuses on water flow conveyance and diversion. In other words, digging a new river fork to wrap around Providence Centralia Hospital. 

First, a new 700-foot-wide, one-mile long water diversion passage would be created by excavating approximately 1.3 million cubic yards of soil west of Mellen Street. 

Then, the Mellen Street Bridge would be removed and reconstructed approximately 2,000 feet south of its original location connecting to Military Road west of the Chehalis River and Interstate 5. 

Finally, in order to speed up water flow near Mellen Street, the project would require removing another approximately 1.3 million cubic yards of soil immediately to the north and approximately 3,000 feet to the south of the existing Mellen Street Bridge. 

These projects would be combined with the first option as well and would reduce flooding extent and lower water levels in the Chehalis and Skookumchuck rivers, China and Salzer Creeks and make improvements in the Newaukum River. 

Positives from this option, according to the LAND group, include reduced impact to structures, possible economic development benefits and reducing flood risk from catastrophic storm events. 

This option would require major infrastructural changes to a large portion of the Centralia community, including much of the neighborhood beyond the bridge. Other cons include complex permitting and land acquisition — including homes and other structures that would need to be obtained and demolished — balancing cut and fill requirements for 2.6 million cubic yards of material and providing less flood damage reduction than levees. 

It would also require extensive evaluation of documented cultural resources in the vicinity of the Mellen Street Bridge prior to any ground disturbance. It also doesn’t provide as much flood protection compared to levees. 

The price-tag on this option, LAND reported, could be anywhere between $1.2 billion and $1.7 billion. 


Option Three

Instead of focusing on the speed of water flow during flood events, the third proposed non-dam option focuses on constructing new levees as well as expanding existing ones. The LAND group mapped out a total of 20.4 miles of proposed levee construction and expansion. 

First, a new levee would be placed on the north bank of the Chehalis River starting north of Fort Borst Park and ending at Galvin Road, approximately 2.7 miles. Then, a new levee would be built east of I-5 from China Creek to Salzer Creek, approximately 3.3 miles. 

New and expanded levees would be added on both the north and south banks of the Skookumchuck River, approximately 6.6 miles. The levee around the Chehalis-Centralia Airport would be expanded as well, accounting for approximately 4.3 miles. 

Finally, new levees will be placed on the north bank of the Newaukum River east of I-5 and on the north and south banks of China Creek from I-5 to the railroad tracks, approximately 3.5 miles. 

This option also includes everything from the first option and, aside from the levees, would also expose many sections of China Creek that have been covered up. While this option would significantly reduce flooding in the Centralia area, it would raise water levels upstream of Mellen Street. 

This option would provide the most flood reduction to the most people out of the four proposals. Other positives listed from this proposal by the LAND group include economic development benefits.

Some of the cons include the highest construction-related impacts, increasing river levels in some locations, visual and community connectivity impacts and constraining rivers and creeks to limited areas. 

This option would require removing many downtown businesses, homes and possibly Centralia City Hall. It would involve challenging permitting and land acquisition issues. Estimated costs for this option range anywhere between $1.2 billion and $1.5 billion. 


Option Four

The final option proposed by the LAND steering group simply combines all three previous options. 

Benefits of combining all the options include potentially reducing the size and length of levees by combining them with water flow projects while providing the highest economic development possibilities and reducing flooding during catastrophic flood events. The LAND group also listed adoption of flood-friendly land use and building codes by local municipalities as a positive for options two, three and four.

Cons include the highest amount of displaced structures due to construction, permitting and land acquisition issues, additional access infrastructure cost and not providing as much flood damage reduction as levees in the third option. 

This option carries the biggest price tag of them all, with cost estimates ranging from $1.6 billion to $2.3 billion. 


Initial Public Reaction

McNamara Doyle said while no formal vote was taken at the Great Wolf Lodge workshop about the four proposals, attendees were still asked for their initial impressions.

“That said, there were folks in attendance who voiced support for each of the four options, and other folks who voiced concerns about all four of the options as well,” McNamara Doyle said. 

Consultants from MIG Inc. are still processing reports gathered from small groups at the workshop in order to summarize thoughts. 

McNamara Doyle explained the main goal of the workshop was to gather initial reaction to help decide if the projects are feasible, themes or consistent responses to concepts, pros and cons and to hear new ideas LAND might not have considered. 

At the City of Centralia’s regular City Council meeting last Tuesday, Chehalis Basin Flood Authority member Ron Averill expressed his thoughts on the proposals, and the high costs of the projects weren’t his only concern. 

“Unfortunately what I’ve seen in this, we in Centralia have really lucked out because we’re the center of attention in this particular project. But even in Lewis County, they don’t show what they plan to do to alleviate flooding in Chehalis or Adna or Boistfort Valley or Pe Ell and Doty. All of which took huge hits during the 2007 flood, much less what’s going to happen downstream with these projects,” said Averill. 


Looking For More Public Input

The LAND Steering Group plans to continue refining their proposals and have scheduled a Zoom webinar on Wednesday, Feb. 8, to provide an informational update on the currently considered options followed by a question and answer session for attendees. 

Registration is free, to sign up visit 

The webinar will start at 6 p.m. and is expected to last an hour. 

LAND was created after Gov. Jay Inslee and the Office of Chehalis Basin directed its formation to look for non-dam alternatives for flood damage reduction and flood prevention in 2021. 

Since November 2021 the group has held monthly meetings to gather input from businesses, tribal governments, city managers and technical experts to explore potential non-dam projects in the Chehalis Basin. 

The steering group itself is composed of a member from each of the following organizations: the Confederated Tribes of the Chehalis Reservation, the Economic Alliance of Lewis County, the City of Centralia Planning Commission, the Wild Salmon Center, the Quinault Indian Nation, Western Water Futures LLC, the Maughan Family Farm, American Rivers and Conservation Northwest. 

Third party partners of LAND include: MIG Inc., CollinsWoerman, ECONorthwest, Community Attributes Inc., Stowe Development & Strategies, GeoEngineers, Northwest Hydraulic Consultants, COWI North America and Stillwater Sciences. 

For more information on LAND visit For more information on the proposals discussed at the Great Wolf Lodge visit