The state Department of Ecology released a final “programmatic” environmental impact statement for the Chehalis Basin Strategy on June 2.

The Chehalis Basin Strategy is a program of “integrated actions” to reduce flooding damage and improve habitat throughout the Chehalis River Basin.

Through the programmatic EIS, which takes a broad look at the entire basin, Ecology reviewed four possible alternatives — a dam, levee improvements, local projects only and landscape changes.

No changes were made to the alternatives in the final EIS compared to the draft.

The strategy was built from the governor’s Chehalis Basin Work Group 2014 recommendation report prepared by the William D. Ruckelshaus Center. Jim Kramer, a consultant from the center, said Monday that the programmatic EIS helped those involved focus as they move forward.

“It narrowed down the options they think are viable for the future,” Kramer said.

Comments submitted during the comment period in 2016 addressed specific projects and not the programmatic EIS — that is, the comments focused on one alternative or another but did not address the overall situation. More than 500 comments were received.

Moving forward, the Chehalis Board (a group of seven members selected by stakeholders, including the Governor, tribes and the Flood Authority) will continue working with the public, tribes and stakeholders to develop recommendations for a long-term strategy. Final board recommendations are expected in spring 2019.

“We’ll do a feasibility analysis of the dam above Pe Ell and look at the restorative approach to develop specifics,” Kramer said. “It’s the next step. The next step will see the project apply for permits for the dam and an environmental review to define mitigation for any impacts. Restorative action could be in combination with the dam or in lieu or the dam.”

The Governor’s Work Group has recommended a $60 million biennium budget to the Governor, and that currently is being considered by the Legislature. Recommendations within that budget are: funding for construction of priority aquatic species habitat restoration projects; flood damage reduction projects by the Chehalis River Basin Flood Authority; and project-level environmental review for the dams being considered on the main stem Chehalis River to address questions raised during the public review of the EIS.

Other projects to mitigate flooding damage have been ongoing throughout the individual communities through the Flood Authority.

And while the process pushes forward through the Legislature and at the state level, other projects will continue to be ongoing.

“There will continue to be projects like the project to protect Montesano’s wastewater treatment plant that can be done now, as well as $20 million proposed for habitat projects,” Kramer said. “Progress is being made on the ground as we’re trying to figure out the key next steps for this comprehensive approach involving all the aspects we talked about. This next step will also be focused on creating a better relationship with landowners because their support and understanding is a vital part of it.”

The alternatives

Alternative 1 (the 2014 Governor’s Work Group Recommendation) included a dam and reservoir near Pe Ell, airport levee improvements in Chehalis and the Aberdeen/Hoquiam North Shore Levee.

Damage would be reduced in the upper and middle basin, as well as in Aberdeen and Hoquiam. Some areas would no longer be inundated and some would have a 10-foot reduction in inundation (though most areas would experience a .1-foot to .5-foot reduction in inundation).

The dam could reduce water quality by increasing water temperature, decreasing oxygen levels and increasing turbidity. Landslides could become more frequent along the perimeter of the proposed reservoir, and any failure in design of the reservoir in the event of a major earthquake could affect downstream communities.

There would be permanent losses of wetlands and forested vegetation, primarily because of the dam. Fish would be temporarily or permanently affected.

“The dam would have a significant adverse impact on the native species that use this area of the river,” according to the draft environmental impact statement.

Building a dam is generally contentious, the document notes.

According to the draft EIS, more than 1,000 structures would see reduced damage through Alternative 1. The North Shore levee would protect an additional 2,715 structures.

Alternative 2 does not include a dam, but it includes both the airport and North Shore levees. Also included in Alternative 2 are projects along I-5.

Alternative 2 results in a give and take of sorts, with floodwater depths reducing by .1 foot and 1 foot in parts of Chehalis and Centralia, but areas upstream of the levees and walls could see an increase in flood water by depths of .1 foot and .9 foot.

Permanent loss of wetlands are expected where the levees and I-5 projects would be constructed, but it would have fewer adverse impacts on wetlands than Alternative 1.

Nine hundred (900) structures would see reduced flood damage through Alternative 2. The North Shore levee would protect an additional 2,715 structures.

Alternative 3 relies on local projects to protect important buildings and infrastructure. While it would reduce damage to particular structures, it is not meant to be a basin-wide solution. Aberdeen and Hoquiam would continue to be at risk from coastal flooding without the levee, the EIS notes.

There are few adverse impacts, but the draft EIS noted continued flooding along I-5 and at the Chehalis-Centralia Airport.

“Alternative 3 has the potential to reduce threats to human health and safety when compared to the No Action Alternative because Alternative 3 would protect structures in the floodplain and allow people the option of safely waiting out many floods in their homes,” the draft EIS noted. “However, Alternative 3 would not improve the ability to access critical medical facilities as compared to the No Action Alternative …”

About 800 structures would see reduced flood damage through Alternative 3.

Alternative 4 focuses on restoring natural flood protection by reversing landscape changes that contribute to downstream flooding and erosion.

Engineered large wood and plantings would be added to create flow resistance to river channels and would reconnect river channels to floodplain storage. Some 21,000 acres of floodplain would face increased flooding through the reconnected channels. Alternative 4 looks at buy-outs, flood proofing and easements to address the increased flooding. Alternative 4 relies on landowner participation.

Some 16,000 acres of managed forestland would need to be converted, impacting current vegetation.

Alternative 4 also is incompatible with existing land uses, impacting some 12,000 acres of active farmland. And in relocating land uses, public utilities would need to be moved or decommissioned.

I-5, local roads and the Chehalis-Centralia Airport would continue to see flooding. And some roadways would see increased closures. During a 100-year flood, State Route 6 would be closed for four additional days, State Route 506 by one or two more days, and State Route 508 by two days.

More than 1,200 structures would see reduced flood damage through Alternative 4.

With no action, more than 1,300 structures are flooded during each 100-year flood.