The agency created the fish passage program in 1991 to inventory, prioritize, and correct fish passage barriers along Washington State Department of Transportation (WSDOT) highways. This program has dedicated funding to target correction of high priority fish passage barriers through stand-alone fish passage projects.

Fish passage barriers are also corrected through larger transportation projects. Since 1991, more than half of the fish passage barrier corrections have been completed through such projects. While these usually are not the highest priority barrier corrections, it is an important avenue for efficiently correcting barriers while equipment is mobilized and construction activities are happening on the road in the vicinity of the barrier.

Fish passage barrier inventories and assessments

WSDOT contracts with the Washington Department of Fish and Wildlife (WDFW) to inventory, assess, and determine the amount of fish habitat blocked by fish passage barriers on state highways.

• Find the methods used to conduct this work in the Fish Passage Inventory, Assessment, and Prioritization Manual. WDFW stores the inventory and assessment data in the Fish Passage Diversion Screening Inventory Database (FPDSI).
• WSDOT maintains its own Fish Passage Site Management application, accessible to all WSDOT staff, which updates weekly from FPDSI.
• The WSDOT Fish Passage Inventory interactive web map has information on WSDOT fish passage sites and is available to the public and all WSDOT staff.

Designing barrier corrections

WSDOT designs fish passage barrier correction projects following the Water Crossing Design Guidelines, primarily using the Stream Simulation or Bridge design methods. Other design options may be used depending upon location and site characteristics. Refer to the WSDOT Hydraulics Manual for additional design guidelines.