Work Underway to Restore Fish Passages in WA
June, 2020
Otak, working as a sub-consultant to HNTB Corporation, is providing design and engineering services on an ambitious project for the Washington State Department of Transportation (WSDOT) to renovate or replace up to 450 culverts and restore safe fish passages throughout the state’s Northwest Region. The project is in response to a mandate by the federal government. The current goal is to complete 450 culverts in two phases, the first phase is to complete Preliminary Hydraulic Designs (PHDs) for all the culverts within the next three years, and to complete the final designs and construction within the next ten years.
In 2018, native tribes in Washington won a lawsuit against the state for allowing construction of more than 2000 culverts across State roads that, according to the lawsuit, diminished the number of spawning fish below the amount that was assured to be protected in the Treaty between the State and the Tribes. The culverts were constructed decades ago when the science on fish migration was preliminary so while the state, offices of WSDOT, Fish and Wildlife and Parks, complied with state and federal guidelines for the construction at the time, the U.S. Supreme Court sided with the tribes that the culverts were now acting as barriers. The court concluded that 2,000 culverts must be listed as a high priority and corrected by 2030.
Otak was one of the firms chosen to work on the HNTB team because it is one of few engineering firms with the breadth of skills to be able to perform this work and has the capacity to get the job done quickly. The Otak team is being led by Russ Gaston, Principal and Project Manager. Otak’s Stream Design Engineers are playing a crucial role in the hydrologic design that must meet the project’s criteria and be in compliance with state and federal regulations. In addition, Otak is applying its experience with MicroStation, the CAD software WSDOT uses and is a unique skill among engineering firms.
Otak has initiated scoping on to complete PHDs for ten of the fish passage culverts, to have them completed within three months after WSDOT provides surveys of each location. The team will determine if a more efficiently designed culvert, a bridge, or natural streaming will be the best solution at each location. The culverts, generally placed under roadways, need to allow a flow of water that isn’t too fast or too shallow or results in a waterfall at either end.
“The job is not simply to replace culverts but to look at alternatives such as avoiding passage near a road, using bridges, or adding water passages that mimic natural streams,” Gaston states. Otak’s Stream Design Engineers are conducting a preliminary hydrologic design report to examine the movement of water and overall watershed sustainability to determine the best way forward for each culvert. Each Fish Barrier Culvert replacement is estimated to have a design cost of around $400,000.