The Dalles Dam Fish Passage Improvements
Successful fish passage is critical to operations at The Dalles Dam. HDR has ongoing work with the Portland District to evaluate and prepare studies, alternative reports and designs for how to provide a backup supply of water to the auxiliary water system (AWS) to facilitate fish passage and survival. The AWS supplies water to the east, west and south fish ladder entrances in order to attract upstream migrating adult fish. Up to 5,000 cfs of water is currently supplied to the AWS by two fish turbines located on the west end of the powerhouse. If one or both fish turbines failed, water supplied to the AWS would be severely limited or eliminated.
HDR is working with the Portland District to reevaluate several new alternatives that were previously eliminated by the U.S. Corps of Engineers. These include constructing a large pumping plant, constructing a penstock with stilling basin, using available pipe capacity in the abandoned fish locks, and replacing the existing fish turbine units. Each of these alternatives has been reviewed from a proof-of-concept perspective to ensure they are still viable options. Furthermore, a total capital cost has been developed for each alterative so that a common cost comparison can be made between each option.
After analysis, HDR recommended a preferred alternative that best achieves the design goals at a minimum cost followed by final design, plans and specifications.
- Professional Services: Engineering, Engineering & Design, MEP Engineering, Marine & Ocean Sciences, Structural Engineering
- Project Type: Civil Works, Dams and Hydraulic Structures, Engineering, Environmental, Fish Facilities, Levees, Natural Resource Management
- Related Projects: Federal, Federal Engineering, Water, Water Resource Management