China Creek, which runs through Centralia, Washington, floods on a regular basis, especially under sustained rainy conditions like those that occurred this January. It is also a tributary to the Chehalis River, which has experienced eight catastrophic flood events since 1970. In an effort to ameliorate the situation, Windward engineers and ecologists are helping to restore the original stream and floodplain upstream of downtown Centralia. The naturally functioning floodplain stores flood waters during flooding, then releases the water over a period of time, reducing peak flows downstream. Instead of inundating downtown Centralia roads and sidewalks, excess water is safely detained, reducing flood damages and making life safer for residents and business alike. Although the project is still incomplete, positive results are already being observed. In an interview, City of Centralia Public Works Director Kim Ashmore explained that water is already being held back from downtown, and that recent flooding might have been noticeably worse without the flood control area, flood basins, and engineered ponds already installed.
Upon completion, the project will do more than just prevent flooding. The restored floodplain and creek will provide much-needed habitat for both plants and animals, including a depressed population of coho salmon, the state-listed sensitive species of Olympic mudminnow, and other native species. Restoring the floodplain will also restore the groundwater; cool water inflow that is essential to maintaining temperatures that support native species. In addition, the entire area is being revegetated with native species of vegetation. Windward is performing ongoing vegetation monitoring to ensure that native plant species develop into habitat and that invasive species are minimized. This is creating aquatic, wetland, and terrestrial habitats, in which animals that are native to the Centralia-area can thrive.
Read more in Centralia’s Chronicle.