Congratulations to the Chehalis River Basin Flood Authority (CRBFA) team for receiving the National Hydrologic Warning Council (NHWC) Operational Excellence Award for the flood warning system’s outstanding sustained performance. This award is given to organizations that have developed and maintained an exceptional hydrologic warning system.

Floods are frequent in the Chehalis River Basin, with five of the largest historical floods occurring within the last 20 years. With a population of 175,000 residents, the basin consists of the 125-mile-long Chehalis River; the Black, Elk, Hoquiam, Humptulips, Johns, Newaukum, Satsop, Skookumchuck, Wishkah, and Wynoochee rivers; and their tributary streams. The epic 2007 and 2009 floods in this area prompted Washington Governor Christine Gregoire to create the Chehalis River Basin Flood Authority in 2010.

The CRBFA authorized the development of a flood warning system specific to the Chehalis Basin in 2010. This system was developed and designed to be a web portal for flood information serving flood preparedness decisions by community leaders and provide improved data to support and leverage river forecasts in the Basin. The system started with 22 new hydrometeorological sensors for rainfall, temperature, and stream gaging. Currently, the system database includes nearly 300 sensors that report in real time, rather than the previous 15-minute increments. Most of these sensors are professionally maintained, owned, and operated by other agencies, and all these data are available to help inform flood mitigation activities at a fraction of the cost to the Flood Authority.

WEST has assisted in all stages of the creation, operation, and maintenance of this flood warning system.

A key focus through the years has been making the system more visible to the community. Efforts have included the use of webcams, highwater alert emails, improved inundation maps, and developing better visual presentations of important data. WEST has assisted in these efforts and has presented webinars to provide awareness and advice on flood preparedness to the public.

After more than a decade without a major flood, record flooding returned to the Chehalis River Basin in January 2022.The CRBFA’s long-term support and investment paid off and the system worked when it was needed most, as providing this information in an accessible way helped to prepare the public and provide meaningful updates on inundation forecasts. The Chehalis River online flood inundation maps received more than 30,000 page views during the January 6-7, 2022, flooding.

Learn More:

To read more about the Chehalis River Basin Flood Warning System, visit: https://chehalis.onerain.com/ or learn more about the Chehalis River Basin’s history and future at the Office of the Chehalis Basin and the Chehalis Basin Strategy websites.

Chehalis residents can improve their personal flood preparedness by downloading a personal flood emergency response plan.

To learn more about the National Hydrologic Warning Council and its awards, visit the organization’s website here.

WEST Consultants, Inc. is an internationally recognized specialized water resources engineering firm and Small Business with offices in Arizona, California, Oregon, Texas, and Washington. WEST has a staff of over 70 highly trained engineering and scientific professionals and support staff. Click here to learn more about our hydrologic data collection services, including our work on the Chehalis River Basin Flood Warning System.