A dam is a barrier that stops or restricts the flow of surface water or underground streams. Reservoirs created by dams not only suppress floods but also provide water for activities such as irrigation, human consumption, industrial use, aquaculture, and navigability. Hydropower is often used in conjunction with dams to generate electricity. A dam can also be used to collect or store water which can be evenly distributed between locations. Dams generally serve the primary purpose of retaining water, while other structures such as floodgates or levees are used to manage or prevent water flow into specific land regions.
The Elwha River is a 45-mile (72 km) river on the Olympic Peninsula in the U.S. state of Washington. From its source at Elwha snowfinger in the Olympic Mountains, it flows generally north to the Strait of Juan de Fuca. Most of the river's course is within the Olympic National Park.
Condit Hydroelectric Project was a development on the White Salmon River in the U.S. state of Washington. It was completed in 1913 to provide electrical power for local industry, and is listed in the National Register of Historic Places as an engineering and architecture landmark.
The Eklutna River is approximately 11.8 miles (19.0 km) long and is located in the Southcentral region of the U.S. state of Alaska. A portion of the river flows through a canyon up to 400 feet (120 m) deep, emptying into the Knik Arm of Cook Inlet approximately 17 miles (27 km) northeast of Anchorage. This degraded anadromous stream historically originated from Eklutna Lake, which itself is fed by Eklutna Glacier. Eklutna River is now fed primarily by groundwater before being joined by Thunderbird Creek. Thunderbird Creek, which enters the south bank about 1 km (0.62 mi) upstream from where the river exits the canyon and forms an alluvial fan. 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.
The Elwha Dam was a 108-ft high dam located in the United States, in the state of Washington, on the Elwha River approximately 4.9 miles (7.9 km) upstream from the mouth of the river on the Strait of Juan de Fuca.
San Francisquito Creek is a creek that flows into southwest San Francisco Bay in California, United States. Historically it was called the Arroyo de San Francisco by Juan Bautista de Anza in 1776. San Francisquito Creek courses through the towns of Portola Valley and Woodside, as well as the cities of Menlo Park, Palo Alto, and East Palo Alto. The creek and its Los Trancos Creek tributary define the boundary between San Mateo and Santa Clara counties.
The environmental impact of reservoirs comes under ever-increasing scrutiny as the global demand for water and energy increases and the number and size of reservoirs increases.
Stream restoration or river restoration, also sometimes referred to as river reclamation, is work conducted to improve the environmental health of a river or stream, in support of biodiversity, recreation, flood management and/or landscape development.
Glines Canyon Dam, also known as Upper Elwha Dam, was a 210-foot (64 m) tall concrete arch dam that impounded Lake Mills reservoir on the Elwha River in Clallam County, Washington. As of 2015, it is the tallest dam ever to be intentionally breached.
Lake Mills was a reservoir in Olympic National Park, Washington, United States, that existed from 1927 to 2012. It was formed by the Glines Canyon Dam on the Elwha River and was located about 13 miles from the mouth of the river on the Olympic Peninsula.
Lake Aldwell was a reservoir located about 4.9 miles (7.9 km) from the mouth of the Elwha River on the Olympic Peninsula in the U.S. state of Washington. The reservoir was created in 1913 behind the Elwha Dam, which was fully removed in 2012. The Elwha Dam blocked at least 70 miles (110 km) of fish habitat for Pacific Salmon and steelhead within Olympic National Park.
A river is a natural freshwater stream that flows on land or inside caves towards another body of water at a lower elevation, such as an ocean, lake, or another river. A river may run dry before reaching the end of its course if it runs out of water, or only flow during certain seasons. Rivers are regulated by the water cycle, the processes by which water moves around the Earth. Water first enters rivers through precipitation, whether from the runoff of water down a slope, the melting of glaciers or snow, or seepage from aquifers beneath the surface of the Earth.
The Elwha Ecosystem Restoration Project is a 21st-century project of the U.S. National Park Service to remove two dams on the Elwha River on the Olympic Peninsula in Washington state, and restore the river to a natural state. It 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. The controversial project, costing about $351.4 million, has been contested and periodically blocked for decades. It has been supported by a major collaboration among the Lower Elwha Klallam Tribe, and federal and state agencies.
Searsville Dam is a masonry dam in San Mateo County, California, that was completed in 1892, one year after the founding of Stanford University, and impounds Corte Madera Creek to form a reservoir known as Searsville Reservoir or Searsville Lake. Searsville Dam is located in the Jasper Ridge Biological Preserve and is owned and operated by Stanford University. Neighboring cities include Woodside and Portola Valley, California.
The Lower Elwha Klallam Tribe is a federally recognized Native American nation in the Pacific Northwest of the United States. The tribe is part of the larger Klallam culture, part of the Coast Salish people.
Iron Gate Dam was an earthfill hydroelectric dam on the Klamath River in northern California, outside Hornbrook, California, that opened in 1964. The dam blocked the Klamath River to create the Iron Gate Lake Reservoir. It was the lowermost of a series of power dams on the river, the Klamath River Hydroelectric Project, operated by PacifiCorp. It also posed the first barrier to migrating salmon in the Klamath. The Iron Gate Fish Hatchery was placed just after the dam, hatching salmon and steelhead that were released back into the river.
The San Acacia Diversion Dam is a structure built in 1934 for the Middle Rio Grande Conservancy District (MRGCD) near to San Acacia, New Mexico, United States. It diverts water from the Rio Grande into irrigation canals.
Guadalupe Creek is a 10.5 miles (16.9 km) northward-flowing stream originating just east of the peak of Mount Umunhum in Santa Clara County, California, United States. It courses along the northwestern border of Almaden Quicksilver County Park in the Cañada de los Capitancillos before joining Los Alamitos Creek after the latter exits Lake Almaden. This confluence forms the Guadalupe River mainstem, which in turn flows through San Jose and empties into south San Francisco Bay at Alviso Slough.
Matilija Dam is a concrete arch dam in Ventura County, California, completed in 1947. Designed for water storage and flood control, it impounds Matilija Creek to create the Matilija Reservoir in the Los Padres National Forest, south of the Matilija Wilderness and north of Ojai.
