Maximizing returns on investing in barrier culvert removal in Washington state


PRINCIPAL INVESTIGATOR: Sunny Jardine (University of Washington)

CO-INVESTIGATORS: Daniel Holland (NOAA Northwest Fishery Science Center), Mark Scheuerell (University of Washington), Robert Fonner (NOAA Northwest Fisheries Science Center), Braeden Van Deynze (University of Washington)


Hundreds of culverts at Washington state stream crossings contribute to declines in fish populations by blocking migration passage and limiting access to critical habitat. A federal injunction requires that Washington restore 90 percent of blocked habitat with state-owned culverts by 2030. Given state-owned culverts comprise only a fraction of the system and budgets are limited, it is critical to prioritize barriers where fish will benefit the most from restoration.

It is important to view barrier culvert removal in terms of water system connectivity; if one barrier is restored, barriers downstream must also be restored in order for the action to be effective. With funding from Washington Sea Grant and workshop feedback from tribes, agencies and jurisdictions, researchers created a decision support tool allowing managers to prioritize barrier culverts for removal based on stream connectivity, type of salmon habitat restored, budget restrictions, and more. The tool combines multiple geospatial datasets to identify restoration plans that account for watershed connectivity to maximize user-defined objectives at a given funding level. Managers can use this built-in optimization framework or, through other features, ​​explore researchers’ data by creating customized figures and maps or get estimates of habitat gains and costs of plans they themselves define. This tool will enable planners and jurisdictions to identify and prioritize state-wide barrier culvert restoration for quality habitat restoration within given budget constraints.