Aquatic Organism Passage (AOP) in Culvert Design
Author: Casey Kramer (WSDOT)
There are more than 1,987 identified barriers to fish passage in the Washington State highway system and over 1,500 have been identified by the Washington State Department of Fish and Wildlife (WDFW) having significant habitat (more than 200 meters upstream). Since 1991, the Washington State Department of Transportation (WSDOT) has completed a total of 285 fish passage projects statewide. Collectively, these projects have improved access to more than 971 miles of potential habitat upstream.
In March 2013, a U.S. District Court injunction (part of the U.S. v. Washington State culverts case) required Washington State (WSDOT, WDFW, Department of Natural Resources, and State Parks) to correct hundreds of culverts in Western Washington by 2030. WSDOT currently has over 1,000 culverts that apply to this injunction, with over 840 of them having significant habitat. To meet the requirements, WSDOT estimates it will need to correct an average of 30-40 culverts each year until 2030. The injunction allows WSDOT to defer corrections up to 10 percent of the total blocked upstream habitat, however only until the end of the culverts useful life.
The injunction directs WSDOT to use bridges or “stream simulation” culvert designs to correct culvert barriers. Stream simulation design has a variety of definitions; however the common theme is to simulate natural stream processes by providing a structure that is wider than the measured bankfull width and has a streambed with a similar gradient as the existing stream reach. The estimated cost for this work is $310 million per biennium. The total estimated unfunded cost for the program was originally estimated in 2013 at over $2.4 billion.
To accelerate the scoping, design and construction of the fish barrier removal projects WSDOT developed four specialized fish passage teams in the various WSDOT regions within the culvert case area. Currently the teams are designing 33 fish passage projects to be ready for advertisement in the 2015-2017 biennium, in addition to scoping approximately 75 projects for future design. The teams have and will continue to create efficiencies by working exclusively on fish passage and other stream related projects.
This presentation will provide background of the U.S. District Court injunction, design standards being utilized and before and after examples of several fish passage barrier removal projects.
Keywords:
How to Cite: Kramer, C. (2014) “Washington State Fish Passage Barrier Removal Projects”, National Hydraulic Engineering Conference 2014. 1(2014).