The Eklutna River () is approximately long and is located in the Southcentral region of the

U.S. state In the United States, a state is a constituent political entity, of which there are 50. Bound together in a political union, each state holds governmental jurisdiction over a separate and defined geographic territory where it shares its sover ...

Alaska Alaska ( ; russian: Аляска, Alyaska; ale, Alax̂sxax̂; ; ems, Alas'kaaq; Yup'ik: ''Alaskaq''; tli, Anáaski) is a state located in the Western United States on the northwest extremity of North America. A semi-exclave of the U.S., ...

. A portion of the

river A river is a natural flowing watercourse, usually freshwater, flowing towards an ocean, sea, lake or another river. In some cases, a river flows into the ground and becomes dry at the end of its course without reaching another body of wate ...

flows through a canyon up to deep, emptying into the

Knik Arm Knik Arm ( Dena'ina: ''Nuti'') is a waterway into the northwestern part of the Gulf of Alaska. It is one of two narrow branches of Cook Inlet, the other being Turnagain Arm. Knik Glacier empties into the Knik Arm. The Port of Anchorage is loc ...

Cook Inlet Cook Inlet ( tfn, Tikahtnu; Sugpiaq: ''Cungaaciq'') stretches from the Gulf of Alaska to Anchorage in south-central Alaska. Cook Inlet branches into the Knik Arm and Turnagain Arm at its northern end, almost surrounding Anchorage. On its sou ...

approximately northeast of

Anchorage Anchorage () is the largest city in the U.S. state of Alaska by population. With a population of 291,247 in 2020, it contains nearly 40% of the state's population. The Anchorage metropolitan area, which includes Anchorage and the neighboring Ma ...

. This degraded

anadromous Fish migration is mass relocation by fish from one area or body of water to another. Many types of fish migrate on a regular basis, on time scales ranging from daily to annually or longer, and over distances ranging from a few metres to thousan ...

stream historically originated from

Eklutna Lake Eklutna Lake ( Dena'ina: ''Idlu Bena'') is a lake in the Municipality of Anchorage, Alaska, near the village of Eklutna.Eklutna Glacier. Eklutna River is now fed primarily by groundwater before being joined by Thunderbird Creek.Eklutna Hydroelectric Project. (2020, September). FINAL Initial Information Package: 1991 Fish & Wildlife Agreement Implementation. McMillen Jacobs Associates. Retrieved from: https://mk0eklutnahydro42mjh.kinstacdn.com/wp-content/uploads/2020/10/200928-Eklutna-IIP_FINAL.pdf Thunderbird Creek, which enters the south bank about upstream from where the river exits the canyon and forms an

alluvial fan An alluvial fan is an accumulation of sediments that fans outwards from a concentrated source of sediments, such as a narrow canyon emerging from an escarpment. They are characteristic of mountainous terrain in arid to semiarid climates, but a ...

. Due to water impoundments on the Eklutna River for power generation, Thunderbird Creek is currently the main source of water in the lower portion of the Eklutna River. The river is located entirely within the limits of the Municipality of Anchorage.

Upper dam

Military expansion in Anchorage during the 1940s stressed the capacity of the Eklutna power generation system and it was upgraded several times. In 1948 the Bureau of Reclamation recommended the construction of Upper Eklutna Dam to raise the level of Eklutna Lake to an elevation of above sea level with a tunnel intake at . Construction was completed in 1955. The new system replaced the aging storage dam at the lake outlet with a new dam that diverted water through a long, diameter concrete lined tunnel with a capacity of to a turbine house on the south bank of the

Knik River The Knik River ( Dena'ina: ''Skitnu''; Ahtna: ''Scitna’'') is a 25-mile-long (40 km) river in the U.S. state of Alaska. Its source is at Knik Glacier, from which it flows northwest and west and empties into the head of Cook Inlet's Kn ...

. The dam, as modified, is an earth- and rock-filled structure, long and contains approximately of material. This new plant used essentially the entire storage capacity of Eklutna Lake and no water was made available to operate the existing plant at Eklutna. The 1964

Good Friday earthquake The 1964 Alaskan earthquake, also known as the Great Alaskan earthquake and Good Friday earthquake, occurred at 5:36 PM AKST on Good Friday, March 27.

severely damaged the dam. Because of this, a new storage dam was built downstream from the existing storage dam at the lake outlet. The new Eklutna Dam (referred to as the Upper Dam) is an earth and rockfill structure long and high containing of material. The spillway is a rectangular concrete conduit through the dam with an uncontrolled overflow crest. The maximum capacity of the spillway is . There are no

outlet works A gatehouse, gate house, outlet works or valve house for a dam is a structure housing sluice gates, valves, or pumps (in which case it is more accurately called a pumping station). Many gatehouses are strictly utilitarian, but especially in the ni ...

through the dam, as the power tunnel serves in that capacity. As the Upper Dam impounds 100% of the flow from Eklutna Lake, the river's volume immediately downstream is zero.

Lower dam

Anchorage was largely

electrified Electrification is the process of powering by electricity and, in many contexts, the introduction of such power by changing over from an earlier power source. The broad meaning of the term, such as in the history of technology, economic history ...

by the late 1920s, but as demand increased, Eklutna was selected as a power source because of the

hydroelectric Hydroelectricity, or hydroelectric power, is electricity generated from hydropower (water power). Hydropower supplies one sixth of the world's electricity, almost 4500 TWh in 2020, which is more than all other renewable sources combined and ...

potential of the river, then known as Eklutna Creek, and Eklutna Lake. In 1927, the City of Anchorage contracted with the Anchorage Light and Power Company to construct what is now called the Old Eklutna Hydroplant. Construction included a low-head storage dam at the outlet of Eklutna Lake and a high concrete arch diversion dam (known as the Lower Dam) in the river canyon downstream of the lake. The diversion dam diverted water through a 1/4 mile-long tunnel to a turbine house near the village of

Eklutna Eklutna (; Dena'ina: ''Idlughet''; Ahtna: ''Zdlaaygha'') is a native village within the Municipality of Anchorage in the U.S. state of Alaska. The Tribal Council estimates the population at 70; many tribal members live in the surrounding communit ...

. Since its construction, the Lower Eklutna Dam had been a barrier to fish passage. When the Upper Dam was brought online, the Lower Dam was shut down as a result and the Lower Eklutna Dam was allowed to fill with gravel. No longer operational, this dam gradually backfilled upstream for with of sediment. In 2018 the old dam was removed entirely as part of a restoration project.

Lower dam removal

Eklutna Inc. raised $7.5 million for the removal of the Lower Eklutna dam to restore fish and wildlife habitat and fish passage in this section of the Eklutna watershed. After the dam was removed in the summer of 2018, Eklutna Inc. began their mandated 3-year post-project monitoring. These monitoring efforts are presently ongoing in partnership with the

Alaska Department of Fish and Game The Alaska Department of Fish and Game (ADF&G) is a department within the government of Alaska. ADF&G's mission is to protect, maintain, and improve the fish, game, and aquatic plant resources of the state, and manage their use and development in ...

. The removal of the Lower Eklutna dam was funded largely by the

Conservation Fund The Conservation Fund is a U.S. nonprofit organization with a dual charter to pursue environmental preservation and economic development. From 2008–2018, it has placed more than 500,000 acres under conservation management through a program wh ...

, but had many other contributors including

Trout Unlimited Trout Unlimited (TU) is a US non-profit organization dedicated to the conservation of freshwater streams, rivers, and associated upland habitats for trout, salmon, other aquatic species, and people. It is headquartered in Arlington, Virginia. Th ...

, the Open Rivers Fund of Resources Legacy Fund,

Patagonia Patagonia () refers to a geographical region that encompasses the southern end of South America, governed by Argentina and Chile. The region comprises the southern section of the Andes Mountains with lakes, fjords, temperate rainforests, and gl ...

, New Belgium Brewing, the Marnell Company, the Rasmusson Foundation, the Alaska Community Foundation, the M.J. Murdock Trust, the

National Fish and Wildlife Foundation The National Fish and Wildlife Foundation (NFWF) is an American foundation that was chartered by Congress in 1984 to increase the resources available for the conservation of the nation's fish, wildlife, plants and habitats. Authority The Natio ...

through its Alaska Fish and Wildlife Fund,

ConocoPhillips ConocoPhillips Company is an American multinational corporation engaged in hydrocarbon exploration and production. It is based in the Energy Corridor district of Houston, Texas. The company has operations in 15 countries and has production in ...

SPIRIT of Conservation Program,

Wells Fargo Wells Fargo & Company is an American multinational financial services company with corporate headquarters in San Francisco, California; operational headquarters in Manhattan; and managerial offices throughout the United States and intern ...

, th
Pacific Coastal Salmon Recovery Fund
(PCSRF), a congressional grant managed by NOAA Fisheries West Coast Region.

1991 Fish & Wildlife Agreement

In 1997 the Purchasers (Chugach Electric Association, Municipal Light and Power L&P and Matanuska Electric Association EA of the Eklutna Hydroelectric Project signed the 1991 Fish & Wildlife Agreement. This agreement "commits the Purchasers to fund studies to determine impacts and propose measures for protection, mitigation, and enhancement of fish and wildlife affected by the projects", with the goal of informing the

Governor of Alaska A governor is an administrative leader and head of a polity or political region, ranking under the head of state and in some cases, such as governors-general, as the head of state's official representative. Depending on the type of political r ...

on their designation of a Fish and Wildlife Program for the Eklutna Project. The governor must have this proposal by the year 2024 (25 years after the Eklutna Project transaction date) and have completed the new program's implementation by 2032.US Department of Energy, Alaska Power Administration. (1992). Divesture Summary Report: Sale of Eklutna and Snettisham Hydroelectric Projects. Retrieved from: https://mk0eklutnahydro42mjh.kinstacdn.com/wp-content/uploads/2019/05/1992-Divestiture-Summary-Report.pdf Research to assess current status and causes of fish and wildlife degradation are ongoing.

Water Rights in the Eklutna Watershed

The Native Village of Eklutna (NVE) has applied for three different water rights permits. Together the three segments would encompass three miles of the Lower Eklutna River above the confluence with Thunderbird Creek and to the outlet of the river into Knik Arm, as well as Thunderbird Creek itself. These permits would support fish and wildlife by reserving in-stream flow.

Salmon in the Eklutna Watershed

When the Lower Eklutna dam was constructed there was no consideration for its effects on fish and wildlife. It was later determined that the dam blocked existing sockeye from the accessing their spawning grounds within the greater Eklutna watershed. As late as the mid-1980s native land-locked sockeye (also known as Kokanee) were observed within Eklutna Lake and are assumed to be remnants of the

extirpated Local extinction, also known as extirpation, refers to a species (or other taxon) of plant or animal that ceases to exist in a chosen geographic area of study, though it still exists elsewhere. Local extinctions are contrasted with global extinct ...

sockeye population.US Army Corps of Engineers SACE (2011). Eklutna River aquatic ecosystem restoration technical report: Eklutna River, Eklutna, Alaska. Unpublished report prepared for U.S. Army Corps of Engineers, PO Box 6898, JBER, Anchorage, Alaska 99506-0898. Retrieved from: https://mk0eklutnahydro42mjh.kinstacdn.com/wp-content/uploads/2020/03/USACE-2011-Eklutna-River-Aquatic-Ecosystem-Restoration-Technical-Report-1.pdf Presently, five species of salmon return to the Lower Eklutna River and spawn primarily in its main tributary, Thunderbird Creek ite Salmon smolts, namely Chinook (''

Oncorhynchus tshawytscha The Chinook salmon (''Oncorhynchus tshawytscha'') is the largest and most valuable species of Pacific salmon in North America, as well as the largest in the genus ''Oncorhynchus''. Its common name is derived from the Chinookan peoples. Other ve ...

'') and Coho ( ''Oncorhynchus kisutch''), have been observed using the Lower Eklutna River habitat above its confluence with Thunderbird Creek, as far upstream as the dam removal site. There has not been spawning activity observed above the confluence and it is likely that spawning gravels in this portion of the watershed would freeze during the winter due to low flow. In September 2021, for the first time in 92 years, water began flowing from the lake down the natural course of the river. It is hoped that returning flow to the upper river will lead to the return of salmon spawning there. The process of regulating the flow and establishing an optimal level could take several years.Irby, Marlise
‘Go With the Flow’ event to release water from Eklutna Lake into the Eklutna River

KTUU KTUU-TV (channel 2) is a television station in Anchorage, Alaska, United States, affiliated with NBC. It is owned by Gray Television alongside dual CBS/MyNetworkTV affiliate KAUU (channel 5). Both stations share studios on East 40th Avenue in ...

/Alaska's News Source, Sep. 16, 2021

References

External links

Eklutna Hydro
{{authority control Rivers of Alaska Rivers of Anchorage, Alaska