Alden fishway projects have included:
- Lifts/elevators
- Denil ladders
- Alaska steeppass ladders
A number of these facilities were also hydraulically modeled at Alden prior to construction at the dams. Successful installation of upstream passage facilities is dependent on expertise and knowledge of a wide range of biological and engineering parameters. Factors affecting selection, siting, design, construction, and operation of an upstream fishway include:
- Behavior and swimming ability of species
- Site-specific hydraulic conditions
- Water quality (temperature, turbidity)
- Economic impacts on project operation
- Maintenance requirements
- Federal and state agency guidelines
Alden employs:
- Civil and mechanical engineers and fisheries biologists with extensive experience in evaluating all types of fish passage facilities in the lab and field
- Technicians and associates who have conducted hydraulic model studies of fishway entrance conditions and complex configurations
- Three‑dimensional CFD capabilities to solve complex flow problems and simplify physical modeling of alternatives
By understanding the importance of involving the resource agencies in the design of fish passage structures, we are able to obtain rapid and meaningful agency interaction and response to permitting issues. Based on a history of successful interaction and mutual respect, a long-standing working relationship has been established with the Federal Energy Regulatory Commission (FERC), the U.S. Fish & Wildlife Service (FWS), the National Marine Fisheries Service (NMFS), and many regional, state and local agencies.
