Lake Aldwell is a reservoir

Reservoir

A reservoir , artificial lake or dam is used to store water.Reservoirs may be created in river valleys by the construction of a dam or may be built by excavation in the ground or by conventional construction techniques such as brickwork or cast concrete.The term reservoir may also be used to...

 located about 4.9 miles (7.9 km) from the mouth of the Elwha River

Elwha River

The Elwha River is a -long river located on the Olympic Peninsula in the U.S. state of Washington. From its source at Elwha snowfinger in the Olympic Range of Olympic National Park it flows generally north to the Strait of Juan de Fuca. Most of the river is contained within Olympic National Park...

 on the Olympic Peninsula

Olympic Peninsula

The Olympic Peninsula is the large arm of land in western Washington state of the USA, that lies across Puget Sound from Seattle. It is bounded on the west by the Pacific Ocean, the north by the Strait of Juan de Fuca, and the east by Puget Sound. Cape Alava, the westernmost point in the contiguous...

 in the state of Washington. The reservoir was created in 1913 behind the Elwha Dam

Elwha Dam

The Elwha Dam is a 108-ft high dam located in the United States, in the state of Washington, on the Elwha River approximately upstream from the mouth of the river on the Strait of Juan de Fuca. The dam was built under the direction of Thomas Aldwell...

. The Elwha Dam blocks 70+ miles of fish habitat for Pacific Salmon and Steelhead within Olympic National Park.

Fish population

Lake Aldwell is home to a population of kokanee

Kokanee

Kokanee is a word from the Okanagan language referring to land-locked lake populations of Sockeye salmon . It may also refer to:* Kokanee Range, a subrange of the Selkirk Mountains in British Columbia, Canada...

 sockeye salmon

Sockeye salmon

Sockeye salmon , also called red salmon or blueback salmon in the USA, is an anadromous species of salmon found in the Northern Pacific Ocean and rivers discharging into it...

 from Indian Creek

Indian Creek (Elwha River)

Indian Creek is a tributary of the Elwha River located in Washington in the United States.Indian Creek flows from Lake Sutherland into Lake Aldwell. Historically, Indian Creek supported runs of several anadromous salmon and trout species, including all five species of Pacific Salmon...

 and Lake Sutherland

Lake Sutherland

Lake Sutherland is located on the Olympic Peninsula about west of Port Angeles, Washington. The lake is located just to the east of Lake Crescent. Lake Sutherland drains into Indian Creek, which is a tributary of the Elwha River....

 which, unable to access the Pacific Ocean

Pacific Ocean

The Pacific Ocean is the largest of the Earth's oceanic divisions. It extends from the Arctic in the north to the Southern Ocean in the south, bounded by Asia and Australia in the west, and the Americas in the east.At 165.2 million square kilometres in area, this largest division of the World...

 use the reservoir as their "ocean" during their adult lives. These salmon access the reservoir via Indian Creek and spawn in Lake Sutherland, just below Lake Crescent

Lake Crescent

Lake Crescent is a deep lake located entirely within Olympic National Park in Clallam County, Washington, United States, approximately west of Port Angeles, Washington on U.S. Route 101 and nearby to the small community of Piedmont...

. The lake also contains landlocked bull trout

Bull trout

The bull trout, Salvelinus confluentus, is a char of the family Salmonidae native to northwestern North America. Historically, S. confluentus has been known as the "Dolly Varden" , but was re-classified as a separate species in 1980. Bull trout are listed as a threatened species under the U.S....

, rainbow trout

Rainbow trout

The rainbow trout is a species of salmonid native to tributaries of the Pacific Ocean in Asia and North America. The steelhead is a sea run rainbow trout usually returning to freshwater to spawn after 2 to 3 years at sea. In other words, rainbow trout and steelhead trout are the same species....

, and a population of introduced eastern brook trout

Brook trout

The brook trout, Salvelinus fontinalis, is a species of fish in the salmon family of order Salmoniformes. In many parts of its range, it is known as the speckled trout or squaretail. A potamodromous population in Lake Superior are known as coaster trout or, simply, as coasters...

.

Ecosystem restoration

In 2012, the Elwha Ecosystem Restoration

Elwha Ecosystem Restoration

The Elwha Ecosystem Restoration Project in the United States is the largest dam removal project in history and the second largest ecosystem restoration project in the history of the National Park Service, after the Restoration of the Everglades...

 project will remove the Elwha Dam

Elwha Dam

The Elwha Dam is a 108-ft high dam located in the United States, in the state of Washington, on the Elwha River approximately upstream from the mouth of the river on the Strait of Juan de Fuca. The dam was built under the direction of Thomas Aldwell...

 and will begin to restore the fisheries of the river. Lake Aldwell will be drained. Immediately afterwards, revegetation crews will plant native vegetation to stabilize the slopes from erosion and speed up ecological restoration. It is expected that the fish populations that reside above the lake will return to their original anadromous lifestyle shortly thereafter.