It’s all in the science for fish passage solutions

5 December 2022



Fish passage solutions can be complex. Here Kleinschmidt gives an overview of some of the projects it has been involved with across North America which range from trap and haul facilities to dam decommissioning


“It is an exciting time to be in the fish passage sciences. Technological advances and innovations in fish passage technologies, and in the tools we use to measure and model the physical and biological world in support of fish passage design and effectiveness testing, continues to advance the science,” says Bryan Apell, Senior Fisheries and Aquatic Ecologist at Kleinschmidt. 

For more than 55 years, Kleinschmidt has provided engineering, regulatory, and environmental consulting services to energy companies and government agencies across North America. It has also provided biological and engineering fish passage and hatchery consulting services for more than 250 projects located across the region. 

All fish passage projects arise from an initiative or objective to protect or restore a population of one or more fish species within a watershed. A multidisciplinary team of biologists, engineers, and regulatory specialists is required to have knowledge and experience to evaluate and develop fisheries protection and restoration plans in the context of fish passage requirements. Consultants must be able to work with stakeholders and clients to streamline and develop science-based plans designed to optimise the benefit to the species, while also balancing the clients’ needs and implementing cost-saving ideas along the way.

A suite of hydroacoustic technologies can be used to measure the physical characteristics at a site that will ultimately inform the design of fish passage and protection facilities. These include the use of:

  • Single and multibeam sonar for bathymetric survey.
  • Acoustic Doppler current profiler technologies to measure flow vectors for use in 3D modelling.
  • Sound imaging cameras (DIDSON or dual frequency identification sonar, and ARIS) to generate high resolution images to investigate fish behaviour at fish passage structures and monitor entrainment rate.
  • Telemetry (acoustic, passive integrated transponder and radio) to monitor fish as they approach and pass dams or other migration barriers. 

Many of these technologies have been around for a while but improvements in range, precision and resolution continue to improve, resulting in better data which ultimately helps to enable more informed designs.  

Kleinschmidt has worked on various fish passage facilities including nature-like fishways, fish lifts, fish ladders, eel ladders, trapping and sorting facilities, fish hatcheries, intake screening facilities, fish collection systems, and downstream fish passage systems. Several examples of projects are given below.

Fish trap and haul

Kleinschmidt has been working with the US Army Corps of Engineers (USACE) since 2015 on an innovative fish passage design at the Mud Mountain Dam on the White River in Buckley, Washington. 

USACE had developed a preliminary design for the largest adult fish trap and haul facility in the US. However, it was applying standard fish trap technology involving vertical lifts and holding for manual sorting, which was being overwhelmed by the numbers of fish it was trying to handle.

Kleinschmidt proposed an unprecedented solution involving Archimedes screw lifts and flumes leading to transport trucks or a sampling facility, and then negotiated its acceptance with the National Marine Fisheries Service. The solution allows for continuously moving fish from pre-sort pools to the fish transport trucks while visually identifying and sorting fish without stopping them. Therefore, there are no traps, lifts, or intermediate pools to get overloaded.

The continuous lifting and passing of fish directly to the transport trucks, while visually sorting the fish in motion, allowed the USACE to construct a trap and haul facility that can sort and transport up to 60,000 adult salmon in 24 hours with a reduced number of people required, as compared to traditional manual handling and sorting of each fish. 

Kleinschmidt also assisted the USACE with engineering support during construction of the project providing real-time answers to questions that could otherwise have led to increased construction costs or delays if not addressed in a timely manner.

Opal Springs fish passage project

In response to the presence of reintroduced steelhead (which is threatened under the Endangered Species Act) and salmon into the Upper Deschutes Basin, the Deschutes Valley Water District (DVWD) needed a way to reduce regulatory risk at its existing 4.3MW Opal Springs Hydroelectric Project on the Crooked River in Oregon

Fish passage was not required as part of the original project, and the existing Federal Energy Regulatory Commission (FERC) licence expires in 2032. DVWD was concerned about ESA aspects of both upstream and downstream passage because anadromous fish are being reintroduced into the Deschutes basin. Bull trout (also threatened under the Endangered Species Act) are present in the project area as well.

Kleinschmidt negotiated a multi-party settlement agreement and subsequently developed a non-capacity amendment with FERC seeking authorisation to:

  • Construct a fish ladder.
  • Increase the normal surface elevation of the run-of-river project.
  • Implement an adaptive management programme to ensure ESA coverage. 

Kleinschmidt developed an environmental assessment to address FERC’s National Environmental Policy Act requirements, helped to raise external funding to assist with construction, and oversaw a value engineering process to bring down construction costs.

By negotiating settlement agreement with agencies and NGOs, DVWD was able to manage risk associated with implementing fish passage. Screening of intakes and other modifications of project operations were avoided, while the adaptive management approach ensures ESA compliance and limits risk of further costly fish protection measures. 

The increase in pool elevation also provides additional generation potential to partially offset capital costs; provides an enhanced ability to move water around the project to maximise fish passage success; and avoided major dam safety considerations of having to breach the existing dam to accommodate fish passage.

The project was granted Low Impact Hydropower Institute certification in 2019 and was also awarded the Environmental Business Journal Achievement Award for Hydropower Projects in 2019.

Kleinschmidt says it is proud to have supported DVWD and all project partners though the development of this important project, which will reconnect over 190km of habitat for anadromous and native migratory fish species. This collaborative effort brought many diverse interests together and overcame multiple regulatory, funding, and engineering challenges.

River restoration

Decommissioning of the Howland Dam and construction of the fish bypass channel were integral components of one of the largest river restoration projects in the US. These actions were implemented through a FERC order approving the Penobscot River Restoration Trust (PRRT)’s applications to surrender hydropower licences for the Howland Project and two other schemes on the Penobscot River in Maine.

PRRT retained Kleinschmidt to prepare final design plans for the proposed bypass channel and decommissioning of the powerhouse, complete the geotechnical exploration and design, and conduct an environmental investigation relative to soils management.

The nature-like fish bypass channel extends approximately 304m and consists of a broadly sweeping meander bend, with a radius of approximately 121m. It includes a multi-stage cross-section, with a 7.9m wide (top width) low flow channel that sweeps to the outside of the bend, and a mildly sloping high flow overbank area that extends to the inside of the bend. 

The Kleinschmidt team and PRRT coordinated with project partners and federal and state regulatory agencies via regular meetings and correspondence to develop the design.

Commissioning of the channel was completed in the fall of 2015 with full site restoration completed in the spring of 2016. 

Alaska Alaskan Steeppass fish ladder at Webber Pond Dam on Seven Mile Brook in Maine. Designed by Kleinschmidt Associates for the Maine Department of Marine Resources
Entrance Fishway entrance and fish lift at confidential northeast client. Designed by Kleinschmidt Associates
Howland Nature-like Fishway at Howland Dam on the Piscataquis River in Maine. Designed by Kleinschmidt Associates for the Penobscot River Restoration Trust


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