Thesis
Hydraulic stream-simulation design option for culvert construction in eastern Washington to meet fish passage criteria: how big is big enough?
Master of Science (MS), Washington State University
2008
Handle:
https://hdl.handle.net/2376/100125
Abstract
In the Pacific Northwest, the survival and restoration of anadromous salmon and other Endangered Species Act listed species have been a concern with access to habitat being identified as one of the critical issues. Inadequately designed culverts can prohibit fish from accessing vital habitat. State agencies in Washington found 1,676 impassable culverts just at state road crossings. The preferred method these organizations are using to size replacement culverts for fish passage is the stream-simulation design method. In this method, the width of the culvert bed must be equal to 1.2 times the bankfull width of the channel plus two feet. As a result, culverts are much wider than the stream channel and very expensive to implement. The objective of this research was to evaluate the trade-offs between culvert replacement cost and the percent of time passable for fish. Using the program FishXing, average barrel velocities and water depths as a function of discharge were calculated for fifteen circular culverts in Eastern Washington deemed impassable in the fish passage barrier removal program. Based on estimated daily average stream flows for an entire year, the amount of time each culvert was passable for fish was compared to the construction costs for a series of culvert diameters so that culvert costs versus the number of days that fish were not able to pass through the culvert over the course of a typical annual hydrograph could be examined. Additionally, the days that fish were not able to pass through the culvert were compared to migratory periods for different fish species. As culvert diameter increased so did construction costs for all fifteen culverts. For eight of the culverts the weakest swimming fish increased passability as the culvert diameter increased while the strongest swimming fish were able to pass during all flows. For the other seven culverts the strongest swimming fish's passablity decreased as culvert diameter increased while the weakest swimming fish's passablity increased. This research will allow decision makers to examine the trade-offs between the cost and the percent of time passable for fish to more effectively prioritize how restoration dollars are being spent.
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Details
- Title
- Hydraulic stream-simulation design option for culvert construction in eastern Washington to meet fish passage criteria
- Creators
- Kathryn Michelle Mozes
- Contributors
- Michael E. Barber (Degree Supervisor)
- Awarding Institution
- Washington State University
- Academic Unit
- Civil and Environmental Engineering, Department of
- Theses and Dissertations
- Master of Science (MS), Washington State University
- Identifiers
- 99900525199501842
- Language
- English
- Resource Type
- Thesis