Eklutna River facts for kids

The Eklutna River is about 11.8 miles (19 km) long. It is found in the Southcentral part of Alaska, a state in the United States. Part of the river flows through a deep canyon, up to 400 feet (122 m) deep. It then flows into the Knik Arm of Cook Inlet, which is about 17 miles (27 km) northeast of Anchorage.

This river used to get its water from Eklutna Lake, which is fed by Eklutna Glacier. However, because of dams built for power, the Eklutna River now mostly gets its water from underground sources. It then joins Thunderbird Creek. Thunderbird Creek flows into the river about 0.6 miles (1 km) upstream from where the river leaves the canyon and spreads out into a flat, fan-shaped area called an alluvial fan. Since the Eklutna River's water is used for making electricity, Thunderbird Creek is now the main water source for the lower part of the river. The entire river is located within the city limits of Anchorage.

Dams on the Eklutna River

The Eklutna River has been used to create electricity for many years. This led to the building of two main dams: the Upper Dam and the Lower Dam.

The Upper Dam

During the 1940s, Anchorage grew a lot, especially with military bases. This meant the city needed more electricity. So, the power system at Eklutna was improved several times. In 1948, the U.S. government agency called the Bureau of Reclamation suggested building a new dam, known as the Upper Eklutna Dam. This dam would raise the water level of Eklutna Lake to 875 feet (267 m) above sea level.

Construction of the Upper Dam finished in 1955. This new system replaced an older dam at the lake's exit. The new dam sent water through a 4.5-mile (7.2 km) long tunnel, which was 9 feet (2.7 m) wide. This tunnel carried water to a power station on the Knik River. The dam itself is made of earth and rocks, measuring 555 feet (169 m) long. This new power plant used almost all the water from Eklutna Lake. This meant no water was left for the older power plant that used to operate at Eklutna.

In 1964, a very strong earthquake, known as the Good Friday earthquake, badly damaged the dam. Because of this, a new storage dam was built a bit downstream from the damaged one. This new Upper Dam is 815 feet (248 m) long and 51 feet (16 m) high. It has a concrete spillway, which is a channel for extra water to flow over. This spillway can handle a lot of water, about 3,315 cubic feet per second (94 m³/s). Since the Upper Dam holds back all the water from Eklutna Lake, the river right below it has no water flowing in it.

The Lower Dam

By the late 1920s, most of Anchorage had electricity. As the city grew, people looked for more ways to make power. The Eklutna River, then called Eklutna Creek, and Eklutna Lake were perfect for making hydroelectric power (electricity from moving water).

In 1927, the City of Anchorage hired a company to build what is now called the Old Eklutna Hydroplant. This project included a small dam at the exit of Eklutna Lake. It also had a 68-foot (21 m) high concrete arch dam, known as the Lower Dam. This Lower Dam was built in the river canyon about 8 miles (13 km) downstream from the lake. It sent water through a quarter-mile long tunnel to a power station near the village of Eklutna.

Since it was built, the Lower Eklutna Dam stopped fish from moving up and down the river. When the Upper Dam started working, the Lower Dam was shut down. Over time, the Lower Eklutna Dam filled up with about 230,000 cubic yards (176,000 m³) of gravel and sediment. It was no longer working. In 2018, this old dam was completely removed as part of a project to help the river.

Removing the Lower Dam

Eklutna Inc., a local Native corporation, raised $7.5 million to remove the Lower Eklutna Dam. The goal was to help fish and wildlife by letting them move freely through this part of the Eklutna watershed. After the dam was taken out in the summer of 2018, Eklutna Inc. started a three-year project to watch and study the river. They are still working with the Alaska Department of Fish and Game on this.

Many groups helped fund the removal of the Lower Eklutna Dam. The main supporter was The Conservation Fund. Other important helpers included Trout Unlimited, the Open Rivers Fund, Patagonia, New Belgium Brewing, the Rasmusson Foundation, and the National Fish and Wildlife Foundation.

Agreement for Fish and Wildlife

In 1997, the companies that buy power from the Eklutna Hydroelectric Project signed an agreement. This agreement, from 1991, states that these companies will pay for studies. These studies look at how the power project affects fish and wildlife. They also suggest ways to protect and improve the environment.

The goal is to give information to the Governor of Alaska. The Governor will then create a special Fish and Wildlife Program for the Eklutna Project. This proposal must be ready by 2024, and the new program should be fully working by 2032. Research is still happening to understand the current state of fish and wildlife and what causes any problems.

Water Rights in the Eklutna Area

The Native Village of Eklutna (NVE) has asked for three special permits for water rights. These permits would cover three miles of the Lower Eklutna River. This includes the area above where it meets Thunderbird Creek, all the way to where the river flows into Knik Arm. The permits also cover Thunderbird Creek itself. These permits would help protect fish and wildlife by making sure enough water stays in the river.

Salmon in the Eklutna River

When the Lower Eklutna Dam was built, no one thought about how it would affect fish and wildlife. Later, it was found that the dam stopped sockeye salmon from reaching their spawning grounds (places where they lay eggs) in the Eklutna area. Even in the mid-1980s, some sockeye salmon that were trapped in Eklutna Lake (also called Kokanee) were seen. These were likely the last of the sockeye population that used to live there.

Today, five types of salmon return to the Lower Eklutna River. They mostly lay their eggs in Thunderbird Creek, which is the river's main branch. Young Chinook and Coho salmon have been seen using the Lower Eklutna River habitat. They travel upstream from where it meets Thunderbird Creek, as far as where the dam used to be. However, salmon have not been seen laying eggs above this meeting point. It is likely that the gravel beds in this part of the river would freeze in winter because there isn't enough water flow.

See also

• Eklutna, Alaska
• List of rivers of Alaska