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80-577: Download coordinates as: The West Branch (or West Fork ) Feather River is a Lake Oroville tributary that flows generally north-to-south in the North Fork Feather Watershed near the watershed's drainage divide with the Mills-Big Chico Watershed and Upper Butte Watershed. Lake Oroville The lake is a popular nationally renowned bass fishing location, while coho salmon are stocked from

160-497: A fish ladder to the hatchery, which is located on the north bank of the Feather River. The hatchery produces 10 million salmon smolt , along with 450,000 trout smolt, to stock in the river each year. The salmon smolt are released in two runs, with 20% for the spring run and 80% for the fall run. This facility has been successful enough that concern exists that salmon of hatchery stock are outcompeting remaining wild salmon in

240-672: A 3 pounds (1.4 kg) white crappie. It is permitted all year long but a California sport fishing license is required. The California Office of Environmental Health Hazard Assessment (OEHHA) has developed a safe eating advisory for Lake Oroville based on levels of mercury or PCBs found in fish caught from this water body. Boating occurs year round, including waterskiing , wakeboarding , houseboats , PWC , and trolling . There are five multi-lane boat launch ramps. These are located at Bidwell Canyon, Loafer Creek, Spillway, Lime Saddle, Enterprise, Nelson Bar, Vinton Gulch, Foreman Creek, and Dark Canyon. Boat supplies and rentals are available on

320-445: A Mediterranean type climate with hot, dry summers and cool wet winters. A semi-permanent, high pressure area of the mid-Pacific Ocean dominates and controls the weather in northern California. During the summer this high-pressure cell pushes storm tracks into the north causing this hot dry summer. In winter, it moves south allowing storms to cross northern California bringing wetter and cooler winters. The annual average high temperature

400-562: A concrete secant cutoff wall for the emergency spillway. The cost estimate at this point is over $ 500 million. In October 2017, hairline cracks were found in the rebuilt spillway. Things that added to the cost included relocating power lines, dredging the river downstream of the dam, as well as the discovery that the bedrock under the spillway was weak, necessitating deeper excavations and more concrete. The DWR commissioned an independent board of consultants (BOC) to review and comment on repairs to Oroville Dam. Memoranda (reports) prepared by

480-408: A failure of the emergency spillway prompted an evacuation of downstream residents. Phase 1 of emergency spillway repairs was completed in 2017. The main spillway was successfully reconstructed by November 1, 2018. The lake offers multiple recreational activities for the public to participate in. The Lake Oroville Visitor Center has a museum, exhibits, videos and a store. People like to look through

560-415: A failure, known as 'loss of crest control'." FERC water agencies responsible for the cost of the upgrades said this was unnecessary and that concerns were overblown. In 2006, a senior civil engineer sent a memorandum to his managers stating, "The emergency spillway meets FERC's engineering guidelines for an emergency spillway", and "The guidelines specify that during a rare flood event, it is acceptable for

640-419: A minimum of 375,000 acre-feet (463,000,000 m ). Each day the allowable level within the range is recalculated using an index reflecting the watershed wetness and the anticipation of heavy runoff from incoming storms. As a wet season like 1997-98 progresses, the allowable storage tends to coincide with the maximum flood control pool. The reservoir operators must balance the conflicting objectives of controlling

720-594: A motion with the Federal Energy Regulatory Commission (FERC) urging federal officials to require that the dam's emergency spillway be armored with concrete, rather than remain as an earthen spillway, as it did not meet modern safety standards. "In the event of extreme rain and flooding, fast-rising water would overwhelm the main concrete spillway, then flow down the emergency spillway, and that could cause heavy erosion that would create flooding for communities downstream, but also could cause

800-461: A third-party expert to improve the safety of the river valve outlet system (RVOS) and make it operational again. In 2014, DWR embarked on an accelerated refurbishment program to respond to concerns about operational needs during the ongoing drought. The system was mostly refurbished and was used during 2014 and 2015 to meet Endangered Species Act temperature requirements for the Feather River. Some additional refurbishments were being made to portions of

880-544: Is 30.66 inches (779 mm); January is the wettest month at 5.71 inches (145 mm) and July the driest at 0.08 inches (2 mm). In 2015, Northern California experienced a drastic drought reducing the lake level to 39% capacity in January 2016. The year 2017 has made up for the five-year drought by having above-average precipitation. The excess of water created a new danger – see 2017 Oroville Dam crisis . In 2021, another drought affected California which resulted in

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960-409: Is 75.2 °F (24.0 °C) and annual average low is 49 °F (9 °C) with average temperature of 62.1 °F (16.7 °C). The coldest months are winter – December to January with average high 56 °F (13 °C) and low 38 °F (3 °C). The warmest months are in the summer – June, July, and August with average high 93 °F (34 °C). The average annual rainfall precipitation

1040-803: Is an earthen dam and is the tallest dam located in the United States , measuring over 770 ft (230 m) high and 6,920 ft (2,110 m) across. The dam was the largest earth-fill dam in the world until succeeded by Aswan High Dam in Egypt . It was built by the California Department of Water Resources as part of the California State Water Project . The dam houses the Edward Hyatt Powerplant , an underground hydro-electric plant that

1120-521: Is available. The pump-generators at Hyatt can lift up to 5,610 cubic feet per second (159 m /s) into Lake Oroville (with a net consumption of 519 MW), while the six turbines combined use a flow of 16,950 cu ft/s (480 m /s) at maximum generation. Since 1969, the Hyatt plant has worked in tandem with an extensive pumped-storage operation comprising two offstream reservoirs west of Oroville. These two facilities are collectively known as

1200-656: Is melting snow, occurring April 1 – July 31, and Lake Oroville receives about 40 percent of the annual total inflow. The lake's storage and releases are a key part of the hydropower and water-supply facilities of the Oroville Complex, the reason it's a pillar and major source of flexibility of the SWP. The downstream flow limits set by the USACE for Lake Oroville are 150,000 cu ft/s (4,200 m /s) north of Honcut Creek, 180,000 cu ft/s (5,100 m /s) above

1280-440: Is released. During the winter and early spring, Lake Oroville is required to have at least 750,000 acre⋅ft (240 billion US gal; 930 billion L), or a fifth of the reservoir's storage capacity, available for flood control. The dam is operated to maintain an objective flood-control release of 150,000 cubic feet per second (4,200 m /s), which may be further reduced during large storms when flows below

1360-683: Is the second-largest reservoir in California, after Shasta Lake . About one-third of the water released from the reservoir goes to uses between the Oroville and Sacramento–San Joaquin Delta. Lake Oroville plays an important role in flood management, water quality, and the health of fisheries affecting areas downstream like the Sacramento-San Joaquin River Delta. During the warm season, the primary source of streamflow

1440-407: The California State Water Project (SWP), one of two major projects passed that set up California's statewide water system . Construction was initiated in 1961, and despite numerous difficulties encountered during its construction, including multiple floods and a major train wreck on the rail line used to transport materials to the dam site, the embankment was topped out in 1967 and the entire project

1520-522: The Feather River ( 39°33′20″N 121°28′0″W  /  39.55556°N 121.46667°W  / 39.55556; -121.46667 ) and the now-inundated towns of Bidwell ( 39°33′25″N 121°27′56″W  /  39.55694°N 121.46556°W  / 39.55694; -121.46556 ) and Land ( 39°33′13″N 121°28′04″W  /  39.55361°N 121.46778°W  / 39.55361; -121.46778 ). Completed in 1968, Oroville Dam

1600-779: The Oroville–Thermalito Complex . Water is diverted into the upper Thermalito reservoir (Thermalito Forebay) via the Thermalito Diversion Dam on the Feather River. During periods of off-peak power use, surplus energy generated at Hyatt is used to lift water from Thermalito's lower reservoir (the Thermalito Afterbay) to the forebay, which releases water back into the afterbay to generate up to 114 MW of power at times of high demand. The Hyatt and Thermalito plants produce an average of 2,200 gigawatt hours (GWh) of electricity each year, about half of

1680-536: The San Joaquin Valley , as well as municipal and industrial water supplies to coastal Southern California , and has prevented large amounts of flood damage to the area—more than $ 1.3 billion between 1987 and 1999. The dam stops fish migration up the Feather River and the controlled flow of the river; as a result, the Oroville Dam has affected riparian habitat. Multiple attempts at trying to counter

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1760-538: The anadromous migrations of Chinook salmon and steelhead trout in the Feather River. In 1967, in an effort to compensate for lost habitat, the DWR and the California Department of Fish and Game completed the Feather River Fish Hatchery. The Fish Barrier Dam, built in 1962, intercepts salmon and trout before they reach the base of the impassable Thermalito Diversion Dam and forces them to swim up

1840-530: The 4.40 mi (7.08 km) serpentine river channel (Thermalito Diversion Pool) which extends from the river's source to the Thermalito Diversion Dam. Oroville Dam Oroville Dam is an earthfill embankment dam on the Feather River east of the city of Oroville, California , in the Sierra Nevada foothills east of the Sacramento Valley . At 770 feet (235 m) high, it is

1920-452: The BOC are posted at the DWR web site. The independent forensic team (IFT) was selected to determine the cause of the spillways incident, including effects of operations, management, structural design and geological conditions. According to its 2017–18 operations plan, the DWR maintained Lake Oroville at a lower-than-normal level to reduce the possibility that the spillway would have to be used

2000-689: The Division of Water Resources (now California Department of Water Resources , DWR) was carried out under an act of the California State Legislature in 1945. In 1951, California State Engineer A. D. Edmonston proposed the Feather River Project, the direct predecessor to the SWP, which included a major dam on the Feather River at Oroville, and aqueducts and pumping plants to transfer stored water to destinations in central and southern California. The proposed project

2080-440: The Feather River Fish Hatchery include Chinook salmon ( Oncorhynchus tshawytscha ) and steelhead trout (Oncorhynchus mykiss). Chinook salmon are supported by California streams. They display a wide array of life history patterns allowing them to live in the diverse, variable riverine and ocean environments. As anadromous fish, they migrate upstream as adults to spawn in freshwater streams, and as juveniles migrate downstream to

2160-586: The Feather River Fish Hatchery. This hatchery is a main component of Lake Oroville. The local indigenous tribe were the Konkow Maidu (translation is 'man') who originally settled the lake region and Feather River for many years. Today many of the small towns including Oroville were originally occupied by the Maidu people. In 2002, a Sonoma State study took archaeological inventory of the 15,476 acres (6,263 ha) of Lake Oroville to learn 250 sites are from

2240-499: The Feather River ecosystem. Before the Oroville Dam was constructed, a majority of the fish hatcheries were located on the eastern side of the mountain range (about 100 miles northeast of the hatchery's current location). The first hatchery was constructed in 1916, the Yuba River Shad Hatchery was built on the Feather River to stop the over fishing of shad in the lower Sacramento River. This effort failed, leading to

2320-615: The Feather's confluence with the Yuba River exceed 300,000 cubic feet per second (8,500 m /s). In the particularly devastating flood of 1997, inflows to the reservoir hit more than 331,000 cubic feet per second (9,400 m /s), but dam operators managed to limit the outflow to 160,000 cubic feet per second (4,500 m /s), sparing large regions of the Sacramento Valley from flooding. Oroville Dam completely blocks

2400-637: The Lake Oroville Visitors Center. The lake is fed by the North Fork, Middle Fork, West Branch and South Fork of the Feather River watershed. This watershed drains an area of 3,611 square miles (9,350 km ). The North Fork and Middle Fork Feather Rivers comprise 3,222 square miles (8,340 km ) of this area which includes portions of the foothill and mountain regions of the northern Sierra Nevada and southern Cascade Range. Storing over 3,500,000 acre-feet (4.3 × 10  m ), it

2480-500: The Oroville Dam site. The water rose behind the partially completed embankment dam and nearly overtopped it, while a maximum of 157,000 cu ft/s (4,400 m /s) poured from the diversion tunnels. This Christmas flood of 1964 was one of the most disastrous floods on record in Northern California, but the incomplete dam was able to reduce the peak flow of the Feather River by nearly 40%, averting massive damage to

West Branch Feather River - Misplaced Pages Continue

2560-409: The Oroville area in 1975 is believed to have been caused by induced seismicity from the weight of the Oroville Dam and reservoir on a local fault line. ) The embankment was finally topped out on October 6, 1967, with the last of 155 million short tons (140.6 million tonnes ) of material that took over 40,000 train trips to transport. On May 4, 1968, Oroville Dam was officially dedicated by

2640-535: The RVOS and were expected to conclude in early 2017. The spillway cracked in 2013. A senior civil engineer with the DWR was interviewed by the Sacramento Bee , and explained, "It’s common for spillways to develop a void because of the drainage systems under them", and "There were some patches needed and so we made repairs and everything checked out." In July 2015, the state Division of Safety of Dams inspected

2720-690: The SWP. Groundbreaking on the dam site occurred in May 1957 with the relocation of the Western Pacific Railroad tracks that ran through the Feather River Canyon. The Burns-Porter Act of the California Legislature, which authorized the SWP, was not passed until November 8, 1960, and only by a slim margin. Engineer Donald Thayer of the DWR was commissioned to design and head construction of Oroville Dam, and

2800-476: The area. Ten months later, four men died in a tragic accident on the construction rail line. On October 7, 1965, two 40-car work trains, one fully loaded and the other empty, collided head-on at a tunnel entrance, igniting 10,000 US gallons (38,000 L) of diesel fuel, completely destroying two locomotives. The burning fuel from the collision started a forest fire that burned 100 acres (40 ha) before it could be extinguished. The crash delayed construction of

2880-583: The crater in the main spillway was carried downstream, and caused damage to the Feather River Fish Hatchery due to high turbidity . Although engineers had hoped that using the damaged spillway could drain the lake enough to avoid use of the emergency spillway, they were forced to reduce its discharge from 65,000 cu ft/s (1,800 m /s) to 55,000 cu ft/s (1,600 m /s) due to potential damage to nearby power lines. Shortly after 8:00 pm on February 11, 2017,

2960-484: The current flood event and preparing for a possible future one. In February 2017, extreme precipitation and high spillway releases caused significant damage to the main concrete spillway. Due to this damage, releases were cut back and lake level increased to 101% of capacity, causing the emergency spillway to overflow for the first time in the Lake's history. Below the emergency spillway, severe erosion occurred, and fear of

3040-624: The dam began in 1957 to relocate what is now Highway 70 and the then Western Pacific (now Union Pacific ) Railroad. A few years later the partially completed dam checked flooding on the Feather River in December 1964. This saved the Sacramento Valley from flooding. Prior to impoundment by the Oroville Dam , the current main basin of Lake Oroville was the location of the confluence of the North Fork Feather River with

3120-424: The dam by a week while the train wreckage was cleared. Overall, 34 men died in the construction of the dam. Oroville Dam was designed to withstand the strongest possible earthquake for the region, and was fitted with hundreds of instruments that serve to measure water pressure and settlement of the earth fill used in its construction, earning it the nickname "the dam that talks back". (A M L 5.7 earthquake in

3200-617: The dam spillway visually "from some distance" and did not walk it. The rainy season of 2016–2017 was Northern California's wettest winter in over 100 years . Heavy rainfall resulted in record inflows from the Feather River, and the spillway was opened in January to relieve pressure on Oroville Dam. After a second series of heavy storms in February, the spillway flow was increased to 50,000 cu ft/s (1,400 m /s), and on February 7, DWR employees noticed an unusual flow pattern. This halted spillway outflow, and DWR brought engineers onto

3280-432: The dam's impacts on fish migration have included the construction of a salmon / steelhead fish hatchery on the river, which began shortly after the dam was completed. In February 2017, the main and emergency spillways threatened to fail , leading to the evacuation of 188,000 people living near the dam. After deterioration of the main spillway largely stabilized and the water level of the dam's reservoir dropped below

West Branch Feather River - Misplaced Pages Continue

3360-401: The emergency spillway began carrying water for the first time since the dam's construction in 1968. The water flowed directly onto the earthen hillside below the emergency spillway, as designed. However, headward erosion of the emergency spillway threatened to undermine and collapse the concrete weir . On February 12, an evacuation was ordered for low-lying areas, due to possible failure of

3440-403: The emergency spillway to sustain significant damage." At around 7:30   am on July 22, 2009, several workers were deep below the reservoir operating flow controls to test a river valve chamber in the Oroville Dam. When the flow reached 85%, suction pulled a breakaway wall downstream into a 35-foot (11 m) diversion tunnel, cutting lights and nearly sending three workers to their deaths in

3520-422: The emergency spillway. The flow over the main spillway was increased to 100,000 cu ft/s (2,800 m /s) to try to slow erosion of the emergency spillway. By 8:00 pm on the evening of February 12, the increased flow had lowered the water level, causing the emergency spillway to stop overflowing. On February 14, the sheriff of Butte County lifted the mandatory evacuation order. On May 19, 2017,

3600-486: The following winter. In a second phase of spillway repairs in 2018–19, temporary repairs on the main spillway done during phase one were being torn out and replaced with steel-reinforced structural concrete. On April 2, 2019, due to heavy rainfall upstream, the DWR began releasing water over the newly reconstructed spillway at a rate of 8,300 cubic feet per second (240 m /s). Releases were increased to 25,000 cubic feet per second (710 m /s) on April 7 to test how

3680-409: The future. Due to the low precipitation in the catchment area, water levels were below normal beginning in 2020. In August 2021, the Hyatt power plant had to be shut down because the water level fell below its water inlets. After falling to a record low of 22% capacity by September 30, winter storms increased the lake level by December and the plant was restarted on January 4, 2022. Construction of

3760-442: The future. On November 1, 2017, DWR director Grant Davis said, "Lake Oroville's main spillway is indeed ready to safely handle winter flows if needed". While this completes phase 1 of the construction, there remained a phase 2 to be completed in 2018. The second phase would include rebuilding the top section of the spillway (which was not rebuilt this season), putting slabs over the roller compacted concrete section, and constructing

3840-643: The hatchery closure, because the Shad's first run did not produce enough eggs and the river had a light run. The main goal of Domingo Springs, built in 1916, was to supply fish to the lakes and streams in Lassen National Park and the surrounding area. In 1937 floods damaged the hatchery and eventually was abandoned. The next phase, built near Clio in Plumas County, was a 60 trout hatchery building and employee cabins that operated for 30 years. In 1953

3920-400: The highly fertile Central Valley . However, after the end of World War II in 1945, the state experienced an economic boom that led to rapid urban and commercial growth in the central and southern portions of the state, and it became clear that California's economy could not depend solely on a state water system geared primarily towards agriculture. A new study of California's water supplies by

4000-488: The lake level falling to 35% of its capacity in July. In August, the Hyatt hydroelectric plant was turned off for the first time when levels fell near the minimum necessary to generate power (640 feet (200 m) above sea level). The loss of power could cause an increased number of rolling blackouts during the summer heat wave. Operations resumed in January 2022 following significant rainfall in December. The species raised at

4080-706: The mouth of the Yuba River, and 320,000 cu ft/s (9,100 m /s) south of the Bear River. The Federal Energy Regulatory Commission (FERC) licenses hydroelectric facilities such as the Edward Hyatt Power Plant at Oroville Dam. California's Department of Water Resources and stakeholders recently participated in a six-year renewal process for a 50-year hydroelectric license for the Oroville Facilities. This agreement commits

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4160-476: The ocean but return to the rivers to start the lifecycle again. The Hyatt Generating–Pumping Plant source water for the Feather River is released from two discharge tunnels at up to 17,500 cu ft/s (500 m /s) during peak demand and "little or no release the remainder of the day". The power plant also routinely draws up to 5,610 cu ft/s (159 m /s) of Feather River water for "pumpback" into Lake Oroville. Hyatt releases are stored in

4240-627: The ocean, where they grow into mature adults. There are seventeen distinct runs of Chinook salmon recognized in California, classified into six major groups or evolutionarily significant units. Currently, these are a Species of Concern under the Federal Endangered Species Act. The hatchery spawn, rear and release the Fall and Spring Run Chinook salmon of local origin. The trout, being an anadromous form of rainbow trout, spawn for multiple years in rivers and creeks, transition into

4320-627: The power necessary to drive the pumps that lift the water in the aqueduct from the delta into the valley, and then from the valley over the Tehachapi Mountains into coastal Southern California. Water and power from the dam contribute to the irrigation of 755,000 acres (306,000 ha) in the arid San Joaquin Valley Westside and municipal supplies to some 25 million people. At least 2.8 million acre⋅ft (910 billion US gal; 3.5 trillion L) of water

4400-572: The prehistoric era relating to the Native American life along the Feather River and an additional 478 sites dating to the Gold Rush . These sites included open-air residential sites, caves and rockshelters, limited lithic scatters, rock art, quarries and workshops, bedrock milling sites and cemetery areas. Natives' lives were disrupted by gold discovery in 1848 and the miners infiltrated their lands. In April 1848, only three months after gold

4480-401: The primary work contract was awarded to Oro Dam Constructors Inc., a joint venture led by Oman Construction Co. Two concrete-lined diversion tunnels, each 4,400 ft (1,341 m) long and 35 ft (11 m) in diameter, were excavated to channel the Feather River around the dam site. One of the tunnels was located at river level and was to carry normal water flows, while the second one

4560-511: The roaring current. One of the workers who was badly injured survived by clinging to a bent rail, where he was struck by tools and equipment being sucked into the tunnel. He was hospitalized for four days with head trauma, a broken leg and arm, cuts, and bruises. The California Division of the Occupational Health and Safety Administration (Cal OSHA) concluded opening the valves without an energy-dispersion ring, which reportedly

4640-605: The south end of the Lake at Bidwell Marina or the north end at Lake Oroville Marina. Visitors can rent kayaks, canoes, sailboats, paddleboats and more at the Forebay Aquatic Center located at the North Forebay. Another major activity is camping by using the campground, floating campsites, boat-in camps, or equestrian campsites. A key component of Lake Oroville is the hatchery that manages thriving populations of Chinook salmon and steelhead trout for

4720-449: The spillway failure, including a faulty drainage system, variations in concrete thickness, and corrosion in the structure's rebar". For 2018 the DWR planned to demolish and reconstruct the portion of the spillway which was undamaged by the flood, but which also has been identified as structurally defective. In addition, crews worked to extend a cutoff wall under the emergency spillway to prevent erosion should that structure be used again in

4800-445: The spillway performed in higher flows. They were decreased to 15,000 cubic feet per second (420 m /s) on April 9. The DWR released an assessment, dated October 1, 2020, concluding that Oroville Dam was suitable for continued safe and reliable operation. Meanwhile, the Federal Energy Regulatory Commission has demanded that California submit a plan by September 2022, for addressing the issue of greater amounts of rain predicted in

4880-450: The spillway to inspect its integrity. The engineers found a large area of concrete and foundation erosion. This erosion feature was too massive to repair without diverting water to the emergency spillway, and halted outflow along the main spillway for a period to fix the hole. High inflows to Lake Oroville forced dam operators to continue using the damaged spillway, causing additional damage. The spillway hole continued to grow. Debris from

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4960-464: The spillway was shut down for the summer, to allow demolition and repair work to begin. The total cost of the repair was projected to exceed $ 400 million, with the $ 275 million primary contract awarded to Kiewit Construction . FEMA was expected to cover a large portion of the expenses. According to an independent forensics team led by John France, the exact cause of the spillway failure remains uncertain, though they identified "24 possible causes for

5040-428: The state of California. Among the notable figures present were California governor Ronald Reagan , who spoke, Chief Justice (formerly California governor) Earl Warren , Senator Thomas Kuchel , and California Representative Harold T. "Bizz" Johnson . The dedication was accompanied by a week of festivities in nearby Oroville, attended by nearly 50,000 people. On October 17, 2005, three environmental groups filed

5120-441: The state to: restore salmon and steelhead habitat, improved river recreation and community benefits, and a fish passage study to determine and launch a project to enhance passage in the Feather and surrounding river basins. Due to federal flood control requirements, by mid-October each year, the lake's storage must be reduced to a specified level within the range of a maximum flood control pool of 750,000 acre-feet (0.93 km ) and

5200-409: The tallest dam in the U.S. and serves mainly for water supply, hydroelectricity generation, and flood control. The dam impounds Lake Oroville , the second-largest reservoir in California, capable of storing more than 3.5 million acre-feet (1.1 × 10 ^  US gal; 4.3 × 10  m ). Built by the California Department of Water Resources , Oroville Dam is one of the key features of

5280-587: The top of the emergency spillway, the evacuation order was lifted. The main spillway was reconstructed by November 1, 2018, and water releases were successfully tested, up to 25,000 cu ft/s (710 m /s), during April 2019. In 1935, work began on the Central Valley Project , a federal water project that would develop the Sacramento and San Joaquin River systems for irrigation of

5360-642: The total power produced by the SWP's eight hydroelectric facilities. Water released from Oroville Dam travels down the Feather River before joining with the Sacramento River , eventually reaching the Sacramento-San Joaquin Delta , where the SWP's California Aqueduct diverts the fresh water for transport to the arid San Joaquin Valley and Southern California. Oroville–Thermalito hydroelectric facilities furnish about one-third of

5440-479: The two high-powered telescopes on the 47-foot tall tower to see the lake, Sierra Nevada, valley, foothills, and the Sutter Buttes mountain range. Fishing is described as outstanding at Lake Oroville State Recreation Area. People can fish for largemouth, smallmouth, and spotted bass, Chinook, catfish, mackinaw, sturgeon, white crappie and brown trout. The largest mackinaw caught was 19 pounds (8.6 kg) and

5520-474: The underground Edward Hyatt Pump-Generating Plant was finished shortly after the completion of Oroville Dam. At the time, it was the largest underground power station in the United States, with three 132- megawatt (MW) conventional turbines and three 141 MW pump-generators for a total installed capacity of 819 MW. The Hyatt Powerplant is capable of pumping water back into Lake Oroville when surplus power

5600-615: The west side of Table Mountain Boulevard includes: spawning room, hatchery and rearing ponds. Salmon spawning operations can be observed mid-September until mid-November, but fish are present in the rearing ponds all year. Annually on the 4th Saturday of September the Oroville Salmon Festival occurs at the hatchery and downtown Oroville. It is known as the only California salmon festival where personnel work Chinook salmon to harvest and fertilize eggs. Lake Oroville has

5680-464: The work was outdated so the operation was abandoned, creating a 14-year gap in hatchery work. The Department of Water Resources built the Oroville Dam in 1961 that altered the river flow so DWR built the present hatchery with the Department of Fish and Wildlife. The dam blocked salmon and steelhead access to upstream spawning areas, so to further mitigate fisheries impacts, a barrier and ladder system

5760-441: Was absent, "created water flow with such great turbulence that it blocked an air vent and created a vacuum". It sanctioned the DWR with six citations, including five classified as serious, and the department was initially fined $ 141,375. Two of the "serious" citations were overturned on appeal. This river valve system was one of the first parts of the dam to be built when the dam project started in 1961, because its initial purpose

5840-584: Was built that allows adult salmon and steelhead to be captured at the Feather River Fish Hatchery. Today the hatchery is managed by the California Department of Fish and Wildlife raising spring and fall-run Chinook salmon and steelhead along the Feather River, directly below Lake Oroville. The hatchery is divided into two sections. The first section located on the east side of Table Mountain Boulevard includes: fish barrier dam, observation platform and underwater viewing. The second section located on

5920-491: Was completed in 1967. Six generators are used to provide a maximum generating capacity of 819 MW. Lake Oroville and Oroville Dam are part of the Oroville–Thermalito Complex , a water infrastructure complex including the Hyatt Powerplant, Thermalito Diversion Dam and Powerplant, the Feather River Fish Hatchery, Thermalito Power Canal, Thermalito Forebay, Thermalito Pumping-Generating Plant, Thermalito Afterbay, and

6000-525: Was constructed to move earth and rock to the dam site. An average of 120 train cars ran along the line each hour, transporting fill that was mainly excavated from enormous piles of hydraulic mining debris that was washed down by the Feather River after the California Gold Rush . On December 22, 1964, disaster nearly struck when the Feather River, after days of heavy rain, reached a peak flow of 250,000 cu ft/s (7,100 m /s) above

6080-412: Was discovered at Sutter's Mill , John Bidwell found gold on the Feather River at a spot known today as the town of Bidwell Bar. Bidwell began to work the claim using local Konkow Maidu workers. Due to the rapidly spreading news of the California strikes, in under a year California's non-native population climbed from 20,000 to 100,000. By 1850, Butte County alone supported 3,052 miners. Construction on

6160-406: Was only to be used during floods. In May 1963, workers poured the last of 252,000 cu yd (6.8 million cu ft; 193,000 m ) of concrete that comprised the 128 ft (39 m) high cofferdam , to protect the construction site from floods. This structure later served as an impervious core for the completed dam. With the cofferdam in place, an 11-mile (18 km) rail line

6240-494: Was ready for use in 1968. The dam began to generate electricity shortly afterwards with completion of the Edward Hyatt Power Plant , then the country's largest underground power station . Since its completion in 1968, the Oroville Dam has allocated the flow of the Feather River from the Sacramento-San Joaquin Delta into the SWP's California Aqueduct , which provides a major supply of water for irrigation in

6320-495: Was strongly opposed by voters in Northern California and parts of Southern California that received water from the Colorado River , but was supported by other Southern Californians and San Joaquin Valley farmers. However, major flooding in the 1950s prompted the 1957 passage of an emergency flood-control bill that provided sufficient funding for construction for a dam at Oroville – regardless of whether it would become part of

6400-407: Was to divert the river while the dam was under construction. After that, it served various purposes, including as a possible emergency release valve. Since the accident, DWR had implemented a standing order that prohibited the operation of the river outlet system and significantly limited access to the river valve chamber. Following the accident, DWR entered into a 2012 agreement with Cal OSHA to hire

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