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ALASKA: Making Big Strides for Fish Passage in Alaska
Alaska Region, August 20, 2013
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A fish passage barrier and road maintenance nightmare on Coal Creek, a tributary to the Little Susitna River.
A fish passage barrier and road maintenance nightmare on Coal Creek, a tributary to the Little Susitna River. - Photo Credit: USFWS/Katrina Mueller
Of all the Pacific salmon, coho spend the longest time in freshwater as juveniles and use nearly all accessible waterbodies in a watershed before migrating to sea.
Of all the Pacific salmon, coho spend the longest time in freshwater as juveniles and use nearly all accessible waterbodies in a watershed before migrating to sea. - Photo Credit: USFWS/Katrina Mueller
Service Fish Passage Engineer/ Hydrologist Bill Rice flags flood evidence downstream of a restored crossing in the riparian zone of a Mat-Su salmon stream after a major 2012 flood event.
Service Fish Passage Engineer/ Hydrologist Bill Rice flags flood evidence downstream of a restored crossing in the riparian zone of a Mat-Su salmon stream after a major 2012 flood event. - Photo Credit: USFWS/Katrina Mueller
Coho salmon that have returned to spawn in Mat-Su waters are
followed closely by hungry Dolly Varden char. Tens of thousands of coho are harvested in the Mat-Su Borough every year, supporting the region’s largest sport fishery.
Coho salmon that have returned to spawn in Mat-Su waters are followed closely by hungry Dolly Varden char. Tens of thousands of coho are harvested in the Mat-Su Borough every year, supporting the region’s largest sport fishery. - Photo Credit: USFWS/Anderson

Nationally, habitat fragmentation and loss are primary drivers in the decline of freshwater and anadromous fish. Seemingly mundane culverts that channel small streams under roads are a major culprit. The majority of traditional round culverts, typically undersized relative to a stream’s width and placed at or above grade, impede fish movement by causing jump, velocity, depth, turbulence, and/or behavioral barriers. The negative impacts of poor fish passage where roads cross streams impacts people too—our economy (nationally, fish fuel a multi-billion industry), our roads, and flood abatement capacity.

 

The U.S. Fish and Wildlife Service’s Fish Passage Program is addressing this important issue by investing funding and technical assistance into projects that improve fish passage at dams and culverts (an estimated 74,000 dams and many more culverts span the nation’s streams, rivers, and lake outlets). In Alaska, Fish Passage Program staff are working collaboratively with partners to install under-road crossings that mimic the natural stream and are fish-friendly for weak-swimmers like juvenile coho salmon and Arctic grayling. These fish-friendly crossings also reduce flood damage and support jobs, revenues, and ways of living associated with fisheries and other free flowing river-based recreation.

While Alaska may seem pristine to the casual observer, habitat fragmentation and loss has and will continue to occur. For example, in southcentral Alaska’s fast-developing Matanuska-Susitna Borough (MSB), ~70% of the 567 fish bearing road-stream crossings evaluated to date by the Alaska Department of Fish and Game (ADFG) prevent salmon from reaching spawning and nursery habitats. Seven Mat-Su salmon populations are currently designated as “stocks of concerns” by the State of Alaska in this region and failing to meet escapement goals for each of the last four years also means that Little Susitna River coho salmon qualify for stock of concern status. Associated sportfishing closures and restrictions on commercial fishing in Cook Inlet have raised concern among anglers, businesses, fisheries managers, and other stakeholders.

Over the past 10 years, the Service and other salmon stakeholders have invested over $6 million in projects to improve passage at over 80 sites where roads cross salmon streams in the MSB. These projects restored access to well-over 100 miles of historic spawning and rearing habitat. The improved crossings are also proving to be immensely valuable from a road maintenance and public safety perspective. For example, all of the restored crossings survived the September 2012 100-year flood event while other unimproved crossings failed, causing road closures, road erosion, and other damage. Many of these upgraded crossings would likely have been compromised had the original culverts not been replaced.

According to Jim Jenson, MSB’s Director of Operations and Maintenance, “the fish passage culverts definitely lowered the potential for failure on many roads during these last [2012] floods.”

While these restoration actions are timely, perhaps the single most important cost effective action taken in this region to address fish passage problems is the MSB’s recent adoption of fish passage design standards for road-stream crossings. As restoration work continues, preventing the creation of new fish passage barriers is a key part of the overall strategy developed by the Service, the MSB and the Mat-Su Basin Salmon Habitat Partnership to help sustain healthy salmon populations in the MSB and reduce expensive restoration costs.

Adoption of the new standards marks the first amendment to the Mat-Su’s Subdivision Design and Construction Manual since 1991—it previously had no standards in place for designing and constructing culverts and bridges where roads cross anadromous waters. The MSB Assembly has identified the protection of fish and fish habitat as a legislative priority and continues to identify fish passage needs as a priority in state capital funding requests. In so doing, the MSB becomes the third community in Alaska to prioritize fish passage within road-stream crossing design standards. (Anchorage was the first to adopt specific fish passage standards in 2007; Kenai Peninsula in 2008).

“Adoption of these new standards brings the Mat-Su Borough in line with the Kenai Peninsula Borough and Anchorage in having local culvert standards for fish passage,” explained Frankie Barker, Environmental Planner with the MSB.

Facilitated by the MSB’s Public Works Department, the new design standards were developed by an interagency, public/private workgroup of engineers (including the Service’s fish passage engineer) and biologists. The standards include accommodation of at least the 100-year flood and the use of stream simulation and hydraulic methods that ensure crossings do not interfere with the movement of juvenile salmon, flood and debris conveyance, and sediment transport.

Over the next year, the Service will coordinate with the MSB, ADFG, and the State’s National Flood Insurance Program Coordinator to conduct workshops for contractors, developers, public works staff and others that focus on how to implement the new standards.

Implementing these standards will help reduce damage to private property and public roads that can occur during flood events, making installation of fish-friendly crossings when new roads are constructed a proactive means to save taxpayers’ money and improve public infrastructure and safety. Ultimately, fish-friendly crossings will help keep fish habitat and the growing community of Mat-Su connected, no matter what the weather.


Contact Info: Katrina Mueller, 907-786-3637, katrina_mueller@fws.gov



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