Chehalis River Basin Flood Authority
The Chehalis River Basin Flood Authority is a state government program that oversees the watershed of the Chehalis River in Washington state. The commission focuses on flood control and river health, as well as habitat restoration, with particular attention to native plants, fish, and other aquatic species. It partners with various non-profits, local organizations, Native American communities and tribes, and other state and federal government agencies, often through its program, the Chehalis Basin Strategy.
The strategy, begun in 2016, has focused on habitat restorations, specifically on aquatic ecosystems and native vegetation. Over one hundred projects have been funded through the authority and strategy that include the removal of man-made obstacles that prevented fish migration, provided plantings of trees and shrubbery around creeks and tributaries that help increase biomass while lowering water temperatures, and purchasing of land near watersheds for permanent protection.
With a wide agreement on protecting local ecosystems, especially salmon habitat, migration routes, and spawning areas, competing proposals of various support and opposition have been introduced in the 21st century to solve the ongoing mission to mitigate flooding in the Chehalis River basin. A main component of the authority's flood control initiative is the creation of a dam in Pe Ell, Washington that focuses on protection and improvements of local habitats. Competing proposals, offered by tribal communities and citizen groups in the region, rely on natural corrections to the floodplain, including heavy biome restoration in the basin as well as the prevention of future construction in the watershed.
Chehalis River
The Chehalis River Basin encompasses over of creeks, rivers, and streams, and is a biome for indigenous amphibian and aquatic species, especially salmon, as well as mammals and birds, some of which are listed as endangered. The watershed is recognized as the second-largest river basin in the state, and is the largest river system within the borders.Flood history
Based on historical accounts from the Chehalis people and early non-Native settlers, seasonal flooding in the basin was considered to be normal and cyclical. Indigenous tribes did not build or maintain permanent structures in the floodplains and the first settlements in the 1800s were constructed on higher elevations. With the introduction of railroads in the 1870s, and a subsequent increase in timber harvesting due to the new rail systems, denuded forest land around the Chehalis River led flood waters to be mostly contained in deeper valleys and channels. Though some floods continued to occur, they were sparse enough that flood control measures were considered too costly and unnecessary. Development in the floodplain began in the early 1900s, and by the late 20th century, floods became more severe and more numerous.Aquatic habitats
The Chehalis River, with lower water flow and drier, warmer weather patterns, has experienced loss to fish runs and migration, including a loss of up to 87% in fish habitat, since the late 20th century. Native American communities have reported reduced catches during fishing. Salmon populations are recorded to be half of their historic numbers, with the census of Spring chinook approximately 23% of their average. Other endangered or crucial endemic species in the basin of particular interest under several programs and projects include the Oregon spotted frog and the coastal tailed frog.Flood control
By 2008, studies of flood control in the Chehalis Basin had cost $12 million and most reports or attempts were denied due to cost–benefit analysis that determined the funding of projects would not be offset by the savings that flood control measures would provide. After the January 2009 flood, additional reports were commissioned in 2011 and in the following year the governor, Christine Gregoire helped to form the Chehalis Basin Work Group to study and recommend flood control measures as well as the restoration of aquatic ecosystems.The river system within Lewis County by the turn of the 21st century had gauges operated by the United States Geological Survey. Specifically used to track the depth of the waters, it was run in conjunction with the county. In 2010, the flood authority implemented the installation of an online flood warning system available to residents in the Chehalis basin. Known as the Chehalis Basin Flood Warning System, it expanded a sensor network already in place, providing information on rainfall and temperature, as well as additional gauges. Alert warnings are sent via email and provide information on 13 rivers in the area. The system won the 2023 National Hydrologic Warning Council Operational Excellence Award.
Chehalis River Basin Flood Authority
The Chehalis River Basin Flood Authority was established in 2008 and manages flood control and concerns for the Chehalis River and its watershed. The program was initiated after the December 2007 floods which caused the loss of 1,300 homes in the region, the shutdown of Interstate 5, and total damages of over $900 million.The CRBFA is overseen and funded by the Washington State Department of Ecology Office of Chehalis Basin. The OCB, which began after legislative action in 2016, formally represents the Chehalis people and the Quinault tribes, as well as communities and counties that lie within the Chehalis watershed. Grays Harbor County is a member of the authority as are the communities of Aberdeen, Cosmopolis, Hoquiam, Montesano and Oakville. The cities of Centralia, Chehalis, and Napavine, as well as the town of Pe Ell, are joined with Lewis County as members. Thurston County and the town of Bucoda represent the northern reaches of the CRBFA.
The OCB, a direct descendant of the Chehalis Basin Work Group, was formally created in 2017., the board has seven members, two of whom are appointed by the Confederated Tribes of the Chehalis and the Quinault Indian Nation.
A comprehensive study, known as the Programmatic Environmental Impact Statement, was released by the Department of Ecology in September 2016 and detailed four options, titled "Alternatives", on flood control and the creation, protection, and restoration of aquatic habitats in the Chehalis River basin. Though the report agreed with long-standing ideas and proposals of local flood mitigation and ecosystem protections, the introduced options were also based on financial and timelines costs, as well as funding and community willingness. The alternatives included a dam and reservoir in Pe Ell, levee and dike builds, the purchase of land to create "non-structural flood protection", or allowing the upper basin and floodplain to return to a more natural state, allowing natural processes to prevent future flood issues. The most expensive options could cost as much as $1.8 billion, despite the report noting that a failure to reduce flooding in the basin over a 100-year span could potentially lead to $3.5 billion in losses.
In late 2024, the OCB requested an $80 million budget appropriation from the state legislature that is to fund the authority and basin strategy until 2027, helping to "aggressively pursue" various continuing projects, including the advancement to build a pass-through dam., the OCB, authority, basin strategy, and connected participants have completed 140 ecosystem restorations, which includes over of preservation, and provided flood protection for more than 200 residences and commercial buildings. The estimated costs during this period are listed at $152 million.
Chehalis Basin Strategy
The Chehalis Basin Strategy began in 2014 and is an organized partnership of county governments within the Chehalis River basin, various other regional governments, and the Washington Department of Fish and Wildlife. The partnership also includes associations with Native American tribes, environmental groups, scientists, and local citizens. The purpose of the CBS is to propose and research a combination of plans along the Chehalis River to mitigate flooding and to restore aquatic habitat, particularly for local Chinook salmon. The CBS is under the administration of the Office of Chehalis Basin.Aquatic Species Restoration Plan
Several undertakings are part of the Aquatic Species Restoration Plan, a main sub-program of the CBS and a focus under the WDFW that began in 2019. The project is more expansive in scope, focusing on restoring larger portions and sections of the basin, using natural remedies that increase and protect native habitats while providing long-term stability, such as against climate change, in the ecosystem. An official, ten-year plan was released in 2021., the ASRP has funded projects with partners in the amount of $28 million which has helped restore and of floodplain and waterway habitats, respectively. Efforts have also led to an additional of the Chehalis River watershed to be reopened to native fish species.Proposals
The initial proposal outlined several flood control reduction measures, with downstream levee improvements particularly at the Chehalis–Centralia Airport, and a flood retention dam in Pe Ell which is planned to limit catastrophic damage from 100-year floods within the Chehalis River Basin. Additional recommendations include a flood wall between Centralia and Chehalis to protect the interstate, purchasing property from current owners in the floodplains, and various forms of flood protections to existing buildings.Proposals regarding aquatic habitats encompass the construction of fish passages, replacing culverts and removing other fish migration barriers, biome protection via land acquisitions, replanting of native flora, and removing human-made obstacles to reconnect the basin system to its natural state. Projects began under a three-phase effort.
First phase
The first phases of the strategy began in 2012 and declared achieved in the early 2020s with a combined 140 flood and habitat projects completed at a cost of $152 million. One of the first projects included the construction of evacuation routes and farm pads on farmlands that were susceptible to floods. Due to flooding from the Great Coastal Gale of 2007, design plans began in 2011 to help mitigate future farm losses, especially for livestock. A combined 23 pads were built in Lewis and Gray counties by 2017 at a cost of $866,000 and no loss of farm animals or farm equipment were recorded after a large January 2022 flood event.As part of early funding in the mid-2010s of $50 million, Grant, Lewis, and Thurston counties received disbursements of $6.0 million to begin work on fish passages, including eight culvert removals that opened over of waterways in Lewis County. In 2016, Grays Harbor County and several communities in its borders received approximately $3.9 million from the state to fund the removal of barriers in the Johns River basin, design and permit efforts for future projects, and several fish barrier improvements on various streams and creeks.
Projects in the early phases that focused on specific cities, towns, and communities include a new pump house in Hoquiam that replaced an ineffective, aging pump that was to be used to as a starting point for future levee builds. Log jacks were installed in Montesano that helped increase the riverbank of the migrating Wynoochee River, which was threatening the local wastewater plant that, during flooding, would have inundated the community with sewage runoff. The fortification also increased the habitat of aquatic species and extended the operating life of the plant by several decades. A new dam was constructed on Mill Creek in Cosmopolis and provides additional flood protection for over 200 homes in the area; the structure included fish ladders, which helped immediately restore the migration of local fish species. An aging and failing pump installed during World War II at the Chehalis–Centralia Airport was replaced in 2018 with a redundant dual-pump electric system, protecting the airfield and the local shopping district.
Improving or repairing aquatic ecosystems has been widespread in the basin and has included projects focused on interconnecting creeks, streams, and rivers. Efforts include the Stillman Creek Restoration Project near Boistfort, focusing on erosion control, habitat restoration, and to restore the floodplain and course of the waters.
Efforts under the Aquatic Species Restoration Plan include fish passage restoration of the Middle Fork Wildcat Creek, a Cloquallum Creek tributary in McCleary, and a silvopasture effort on the Skookumchuck River. Additional ASRP restoration projects include fish passages in Elma and Oakville, and habitat improvements to creeks and their watersheds within Lewis County and the city of Chehalis.