# Edward C Hyatt

CAISO Conventional Hydroelectric, Hydroelectric Pumped Storage · https://askthegrid.com/assets/facilities/edward-c-hyatt

Edward C Hyatt is a battery energy storage facility with 644.1 MW of EIA-reported nameplate capacity in Butte County, California, registered as EIA Plant ID 437. California Department of Water Resources is the public owner or developer; California Dept. of Water Resources is the registered plant entity or operator. The Oroville pumped-storage scheme was the first such facility constructed in California and was described by the California Department of Water Resources as one of the largest in the United States. Edward Hyatt Powerplant was also identified as the largest underground powerplant in the United States and received the American Society of Civil Engineers’ 1969 Outstanding Engineering Achievement recognition.

## Key facts

- Technology: Conventional Hydroelectric, Hydroelectric Pumped Storage
- Power capacity: 644.1 MW
- Operating status: operating

## Grid and market context

- ISO/RTO: CAISO
- Balancing authority: CISO (CAISO)
- Substation: 230 kV bus of the Table Mountain substation
- Point of interconnection: 230 kV bus of the Table Mountain substation
- Transmission owner: Pacific Gas and Electric Company
- Interconnection voltage: 230 kV

## Source-backed facts

- Owner logo domain: water.ca.gov — California Department of Water Resources · confidence: high
- Identifiers: [{"value":"437","system":"EIA plant code"},{"value":"CISO","system":"CAISO balancing authority"},{"value":"CAISO","system":"CAISO market"},{"value":"4753","system":"FERC EIA generator record"},{"value":"Generator 2","system":"EIA generator ID"},{"value":"4778","system":"FERC EIA generator record"},{"value":"Generator 4","system":"EIA generator ID"},{"value":"4826","system":"FERC EIA generator record"},{"value":"Generator 6","system":"EIA generator ID"},{"value":"449","system":"CAISO participating resource ID"},{"value":"ER15-227-000","system":"FERC docket"}] — MBR | Index · confidence: medium
- Identifiers: [{"value":"437","system":"EIA plant code"},{"value":"CISO","system":"CAISO balancing authority"},{"value":"CAISO","system":"CAISO market"},{"value":"4753","system":"FERC EIA generator record"},{"value":"Generator 2","system":"EIA generator ID"},{"value":"4778","system":"FERC EIA generator record"},{"value":"Generator 4","system":"EIA generator ID"},{"value":"4826","system":"FERC EIA generator record"},{"value":"Generator 6","system":"EIA generator ID"},{"value":"449","system":"CAISO participating resource ID"},{"value":"ER15-227-000","system":"FERC docket"}] — MBR | Index · confidence: medium
- Identifiers: [{"value":"437","system":"EIA plant code"},{"value":"CISO","system":"CAISO balancing authority"},{"value":"CAISO","system":"CAISO market"},{"value":"4753","system":"FERC EIA generator record"},{"value":"Generator 2","system":"EIA generator ID"},{"value":"4778","system":"FERC EIA generator record"},{"value":"Generator 4","system":"EIA generator ID"},{"value":"4826","system":"FERC EIA generator record"},{"value":"Generator 6","system":"EIA generator ID"},{"value":"449","system":"CAISO participating resource ID"},{"value":"ER15-227-000","system":"FERC docket"}] — Resource category and phase · confidence: medium
- Identifiers: [{"value":"437","system":"EIA plant code"},{"value":"CISO","system":"CAISO balancing authority"},{"value":"CAISO","system":"CAISO market"},{"value":"4753","system":"FERC EIA generator record"},{"value":"Generator 2","system":"EIA generator ID"},{"value":"4778","system":"FERC EIA generator record"},{"value":"Generator 4","system":"EIA generator ID"},{"value":"4826","system":"FERC EIA generator record"},{"value":"Generator 6","system":"EIA generator ID"},{"value":"449","system":"CAISO participating resource ID"},{"value":"ER15-227-000","system":"FERC docket"}] — Source · confidence: medium
- Official project url: https://water.ca.gov/programs/state-water-project/swp-facilities/oroville — Oroville · confidence: high
- Owner name: California Department of Water Resources — Edward C. Hyatt Pumped Storage hydroelectric plant · confidence: medium
- Description: Edward C Hyatt is a 644.1 MW hydroelectric and pumped-storage plant in Butte County, California, near Oroville. The facility is an underground hydroelectric pumping-generating plant operated by the California Department of Water Resources and connected to the CAISO-managed grid. Construction began in 1964 and was completed in 1967; EIA/FERC records identify six generating units, with units 2, 4, and 6 individually recorded at 97.7 MW. — Oroville · confidence: medium
- Description: Edward C Hyatt is a 644.1 MW hydroelectric and pumped-storage plant in Butte County, California, near Oroville. The facility is an underground hydroelectric pumping-generating plant operated by the California Department of Water Resources and connected to the CAISO-managed grid. Construction began in 1964 and was completed in 1967; EIA/FERC records identify six generating units, with units 2, 4, and 6 individually recorded at 97.7 MW. — Hyatt Powerplant at Oroville Dam Resumes Operation · confidence: medium
- Description: Edward C Hyatt is a 644.1 MW hydroelectric and pumped-storage plant in Butte County, California, near Oroville. The facility is an underground hydroelectric pumping-generating plant operated by the California Department of Water Resources and connected to the CAISO-managed grid. Construction began in 1964 and was completed in 1967; EIA/FERC records identify six generating units, with units 2, 4, and 6 individually recorded at 97.7 MW. — MBR | Index · confidence: medium
- Description: Edward C Hyatt is a 644.1 MW hydroelectric and pumped-storage plant in Butte County, California, near Oroville. The facility is an underground hydroelectric pumping-generating plant operated by the California Department of Water Resources and connected to the CAISO-managed grid. Construction began in 1964 and was completed in 1967; EIA/FERC records identify six generating units, with units 2, 4, and 6 individually recorded at 97.7 MW. — MBR | Index · confidence: medium
- Identifiers.3: {"value":"4753","system":"FERC EIA generator record"} — MBR | Index · confidence: medium
- Identifiers.4: {"value":"Generator 2","system":"EIA generator ID"} — MBR | Index · confidence: medium
- Identifiers.5: {"value":"4778","system":"FERC EIA generator record"} — MBR | Index · confidence: medium
- Identifiers.6: {"value":"Generator 4","system":"EIA generator ID"} — MBR | Index · confidence: medium
- Identifiers.7: {"value":"4826","system":"FERC EIA generator record"} — MBR | Index · confidence: medium
- Identifiers.8: {"value":"Generator 6","system":"EIA generator ID"} — MBR | Index · confidence: medium
- Identifiers.9: {"value":"449","system":"CAISO participating resource ID"} — Resource category and phase · confidence: medium
- Identifiers.10: {"value":"ER15-227-000","system":"FERC docket"} — Source · confidence: medium
- Parties.0: {"relationship":"Owner and operator","name":"California Department of Water Resources","official_url":"https://water.ca.gov/"} — Edward C. Hyatt Pumped Storage hydroelectric plant · confidence: medium
- Parties.1: {"relationship":"Balancing authority and market operator","name":"California Independent System Operator","official_url":"https://www.caiso.com/"} — Hyatt Powerplant at Oroville Dam Resumes Operation · confidence: high
- Parties.3: {"relationship":"Turbine supplier","name":"Voith Hydro Holding","official_url":"https://www.voith.com/"} — Power plant profile: Edward C Hyatt, US · confidence: medium
- Commercial operation date: 1968 — 14 energy · confidence: medium
- Product url: https://www.voith.com/corp-en/products-services/hydropower-components/turbines.html — Turbines & shut-off valves | Voith · confidence: medium
- Kind: hydro — Oroville - California Department of Water Resources · confidence: high
- Description: Edward C Hyatt is a 644.1 MW underground hydroelectric pumping-generating facility in Butte County, California, with six EIA-recorded generating units. It is part of the Oroville-Thermalito State Water Project complex and is operated by the California Department of Water Resources. Construction began in 1964 and was completed in 1967; EIA and commercial-operation records place unit commissioning during 1968-1969, with commercial operation reported in February 1969. The cited project histories document DWR ownership and operation but do not identify an acquisition, sale, predecessor owner, or sale consideration. In 2001, DWR refurbished pump-turbine equipment on Units 2, 4, and 6; the work was characterized as modernization without expansion. — Oroville · confidence: medium
- Description: Edward C Hyatt is a 644.1 MW underground hydroelectric pumping-generating facility in Butte County, California, with six EIA-recorded generating units. It is part of the Oroville-Thermalito State Water Project complex and is operated by the California Department of Water Resources. Construction began in 1964 and was completed in 1967; EIA and commercial-operation records place unit commissioning during 1968-1969, with commercial operation reported in February 1969. The cited project histories document DWR ownership and operation but do not identify an acquisition, sale, predecessor owner, or sale consideration. In 2001, DWR refurbished pump-turbine equipment on Units 2, 4, and 6; the work was characterized as modernization without expansion. — Source · confidence: medium
- Description: Edward C Hyatt is a 644.1 MW underground hydroelectric pumping-generating facility in Butte County, California, with six EIA-recorded generating units. It is part of the Oroville-Thermalito State Water Project complex and is operated by the California Department of Water Resources. Construction began in 1964 and was completed in 1967; EIA and commercial-operation records place unit commissioning during 1968-1969, with commercial operation reported in February 1969. The cited project histories document DWR ownership and operation but do not identify an acquisition, sale, predecessor owner, or sale consideration. In 2001, DWR refurbished pump-turbine equipment on Units 2, 4, and 6; the work was characterized as modernization without expansion. — Pump-Turbine Refurbishment, Units 2,4, and 6 Hyatt Powerplant · confidence: medium
- Quality notes: ["EIA Plant 437 records six operational units totaling 644.1 MW; nearby Thermalito facilities are separate assets in the Oroville-Thermalito complex.","Construction completion is reported as 1967 by DWR, while EIA/FERC generator records place individual units online across 1968-1969 and a commercial-plant profile reports February 1969 as the commercial-operation date.","The 2001 CEQA notice describes replacement of turbine runners, wicket gates, wear rings, and appurtenances on Units 2, 4, and 6, expressly characterizing the work as modernization with no expansion of use.","No retirement, sale, acquisition, predecessor-owner, portfolio-transaction value, or separate repowering transaction is identified in the cited project records."] — Source · confidence: high
- Quality notes: ["EIA Plant 437 records six operational units totaling 644.1 MW; nearby Thermalito facilities are separate assets in the Oroville-Thermalito complex.","Construction completion is reported as 1967 by DWR, while EIA/FERC generator records place individual units online across 1968-1969 and a commercial-plant profile reports February 1969 as the commercial-operation date.","The 2001 CEQA notice describes replacement of turbine runners, wicket gates, wear rings, and appurtenances on Units 2, 4, and 6, expressly characterizing the work as modernization with no expansion of use.","No retirement, sale, acquisition, predecessor-owner, portfolio-transaction value, or separate repowering transaction is identified in the cited project records."] — Pump-Turbine Refurbishment, Units 2,4, and 6 Hyatt Powerplant · confidence: high
- Quality notes: ["EIA Plant 437 records six operational units totaling 644.1 MW; nearby Thermalito facilities are separate assets in the Oroville-Thermalito complex.","Construction completion is reported as 1967 by DWR, while EIA/FERC generator records place individual units online across 1968-1969 and a commercial-plant profile reports February 1969 as the commercial-operation date.","The 2001 CEQA notice describes replacement of turbine runners, wicket gates, wear rings, and appurtenances on Units 2, 4, and 6, expressly characterizing the work as modernization with no expansion of use.","No retirement, sale, acquisition, predecessor-owner, portfolio-transaction value, or separate repowering transaction is identified in the cited project records."] — H-3 P-2100-185 | Federal Energy Regulatory Commission · confidence: high
- Financing summary: The documented construction financing was State Water Project power-revenue-bond financing, not sale consideration. A 50-year contract for Hyatt and Thermalito hydroelectric power was entered into in November 1967 between DWR and three major California investor-owned utilities; it supported the sale of $150 million of Series A revenue bonds on April 3, 1968, followed by an additional Series B issue sold on April 1, 1969. The historical record states that the two issues provided net proceeds to help finance project construction costs; no separate acquisition price or portfolio transaction value is disclosed. — Source · confidence: medium
- Timeline: [{"event":"Construction started","date":"1964","detail":"Excavation and construction began for the underground Hyatt Powerplant at Oroville."},{"event":"Construction completed","date":"1967","detail":"DWR’s State Water Project development timeline records completion of the Hyatt Powerplant in 1967."},{"event":"Power-sales contract","date":"1967-11","detail":"DWR entered a 50-year contract for hydroelectric power generated by the Hyatt and Thermalito powerplants with three major California investor-owned utilities."},{"event":"First unit recorded online","date":"1968-03","detail":"EIA-derived plant records identify the first unit as online on March 1, 1968."},{"event":"Series A revenue bonds sold","date":"1968-04-03","detail":"DWR sold $150 million of Series A revenue bonds backed by the Oroville power-sales arrangement."},{"event":"Commercial operation","date":"1969-02","detail":"A project operating record reports February 1969 as the commercial-operation date; EIA/FERC records place individual generator operation across 1968-1969."},{"event":"Series B revenue bonds sold","date":"1969-04-01","detail":"DWR sold an additional Series B revenue-bond issue to support State Water Project power-facility construction financing."},{"event":"Pump-turbine refurbishment","date":"2001-03-05","detail":"DWR filed a CEQA notice for refurbishment of Units 2, 4, and 6, including replacement of turbine runners, wicket gates, wear rings, and related appurtenances. The notice classified the work as modernization without expansion."},{"event":"Drought-related outage","date":"2021-08-05","detail":"DWR took Hyatt Powerplant offline because of historically low Lake Oroville levels during the statewide drought."},{"event":"Generation resumed","date":"2022-01-04","detail":"DWR announced resumed hydropower generation, initially using one generating unit and supplying power to the California Independent System Operator-managed grid after completing major maintenance while the plant was offline."},{"event":"Acquisition, sale, and retirement status","date":null,"detail":"The cited project histories identify DWR as the owner and operator and describe State Water Project construction, but do not document an acquisition, sale, predecessor owner, sale consideration, or retirement event."}] — Source · confidence: medium
- Timeline: [{"event":"Construction started","date":"1964","detail":"Excavation and construction began for the underground Hyatt Powerplant at Oroville."},{"event":"Construction completed","date":"1967","detail":"DWR’s State Water Project development timeline records completion of the Hyatt Powerplant in 1967."},{"event":"Power-sales contract","date":"1967-11","detail":"DWR entered a 50-year contract for hydroelectric power generated by the Hyatt and Thermalito powerplants with three major California investor-owned utilities."},{"event":"First unit recorded online","date":"1968-03","detail":"EIA-derived plant records identify the first unit as online on March 1, 1968."},{"event":"Series A revenue bonds sold","date":"1968-04-03","detail":"DWR sold $150 million of Series A revenue bonds backed by the Oroville power-sales arrangement."},{"event":"Commercial operation","date":"1969-02","detail":"A project operating record reports February 1969 as the commercial-operation date; EIA/FERC records place individual generator operation across 1968-1969."},{"event":"Series B revenue bonds sold","date":"1969-04-01","detail":"DWR sold an additional Series B revenue-bond issue to support State Water Project power-facility construction financing."},{"event":"Pump-turbine refurbishment","date":"2001-03-05","detail":"DWR filed a CEQA notice for refurbishment of Units 2, 4, and 6, including replacement of turbine runners, wicket gates, wear rings, and related appurtenances. The notice classified the work as modernization without expansion."},{"event":"Drought-related outage","date":"2021-08-05","detail":"DWR took Hyatt Powerplant offline because of historically low Lake Oroville levels during the statewide drought."},{"event":"Generation resumed","date":"2022-01-04","detail":"DWR announced resumed hydropower generation, initially using one generating unit and supplying power to the California Independent System Operator-managed grid after completing major maintenance while the plant was offline."},{"event":"Acquisition, sale, and retirement status","date":null,"detail":"The cited project histories identify DWR as the owner and operator and describe State Water Project construction, but do not document an acquisition, sale, predecessor owner, sale consideration, or retirement event."}] — Source · confidence: medium
- Timeline: [{"event":"Construction started","date":"1964","detail":"Excavation and construction began for the underground Hyatt Powerplant at Oroville."},{"event":"Construction completed","date":"1967","detail":"DWR’s State Water Project development timeline records completion of the Hyatt Powerplant in 1967."},{"event":"Power-sales contract","date":"1967-11","detail":"DWR entered a 50-year contract for hydroelectric power generated by the Hyatt and Thermalito powerplants with three major California investor-owned utilities."},{"event":"First unit recorded online","date":"1968-03","detail":"EIA-derived plant records identify the first unit as online on March 1, 1968."},{"event":"Series A revenue bonds sold","date":"1968-04-03","detail":"DWR sold $150 million of Series A revenue bonds backed by the Oroville power-sales arrangement."},{"event":"Commercial operation","date":"1969-02","detail":"A project operating record reports February 1969 as the commercial-operation date; EIA/FERC records place individual generator operation across 1968-1969."},{"event":"Series B revenue bonds sold","date":"1969-04-01","detail":"DWR sold an additional Series B revenue-bond issue to support State Water Project power-facility construction financing."},{"event":"Pump-turbine refurbishment","date":"2001-03-05","detail":"DWR filed a CEQA notice for refurbishment of Units 2, 4, and 6, including replacement of turbine runners, wicket gates, wear rings, and related appurtenances. The notice classified the work as modernization without expansion."},{"event":"Drought-related outage","date":"2021-08-05","detail":"DWR took Hyatt Powerplant offline because of historically low Lake Oroville levels during the statewide drought."},{"event":"Generation resumed","date":"2022-01-04","detail":"DWR announced resumed hydropower generation, initially using one generating unit and supplying power to the California Independent System Operator-managed grid after completing major maintenance while the plant was offline."},{"event":"Acquisition, sale, and retirement status","date":null,"detail":"The cited project histories identify DWR as the owner and operator and describe State Water Project construction, but do not document an acquisition, sale, predecessor owner, sale consideration, or retirement event."}] — Pump-Turbine Refurbishment, Units 2,4, and 6 Hyatt Powerplant · confidence: medium
- Timeline: [{"event":"Construction started","date":"1964","detail":"Excavation and construction began for the underground Hyatt Powerplant at Oroville."},{"event":"Construction completed","date":"1967","detail":"DWR’s State Water Project development timeline records completion of the Hyatt Powerplant in 1967."},{"event":"Power-sales contract","date":"1967-11","detail":"DWR entered a 50-year contract for hydroelectric power generated by the Hyatt and Thermalito powerplants with three major California investor-owned utilities."},{"event":"First unit recorded online","date":"1968-03","detail":"EIA-derived plant records identify the first unit as online on March 1, 1968."},{"event":"Series A revenue bonds sold","date":"1968-04-03","detail":"DWR sold $150 million of Series A revenue bonds backed by the Oroville power-sales arrangement."},{"event":"Commercial operation","date":"1969-02","detail":"A project operating record reports February 1969 as the commercial-operation date; EIA/FERC records place individual generator operation across 1968-1969."},{"event":"Series B revenue bonds sold","date":"1969-04-01","detail":"DWR sold an additional Series B revenue-bond issue to support State Water Project power-facility construction financing."},{"event":"Pump-turbine refurbishment","date":"2001-03-05","detail":"DWR filed a CEQA notice for refurbishment of Units 2, 4, and 6, including replacement of turbine runners, wicket gates, wear rings, and related appurtenances. The notice classified the work as modernization without expansion."},{"event":"Drought-related outage","date":"2021-08-05","detail":"DWR took Hyatt Powerplant offline because of historically low Lake Oroville levels during the statewide drought."},{"event":"Generation resumed","date":"2022-01-04","detail":"DWR announced resumed hydropower generation, initially using one generating unit and supplying power to the California Independent System Operator-managed grid after completing major maintenance while the plant was offline."},{"event":"Acquisition, sale, and retirement status","date":null,"detail":"The cited project histories identify DWR as the owner and operator and describe State Water Project construction, but do not document an acquisition, sale, predecessor owner, sale consideration, or retirement event."}] — Hyatt Powerplant at Oroville Dam Resumes Operation · confidence: medium
- Timeline.0: {"event":"Construction started","date":"1964","detail":"Excavation and construction began for the underground Hyatt Powerplant at Oroville."} — Source · confidence: high
- Timeline.1: {"event":"Construction completed","date":"1967","detail":"DWR’s State Water Project development timeline records completion of the Hyatt Powerplant in 1967."} — Source · confidence: high
- Timeline.2: {"event":"Power-sales contract","date":"1967-11","detail":"DWR entered a 50-year contract for hydroelectric power generated by the Hyatt and Thermalito powerplants with three major California investor-owned utilities."} — Source · confidence: medium
- Timeline.4: {"event":"Series A revenue bonds sold","date":"1968-04-03","detail":"DWR sold $150 million of Series A revenue bonds backed by the Oroville power-sales arrangement."} — Source · confidence: high
- Timeline.6: {"event":"Series B revenue bonds sold","date":"1969-04-01","detail":"DWR sold an additional Series B revenue-bond issue to support State Water Project power-facility construction financing."} — Source · confidence: high
- Timeline.7: {"event":"Pump-turbine refurbishment","date":"2001-03-05","detail":"DWR filed a CEQA notice for refurbishment of Units 2, 4, and 6, including replacement of turbine runners, wicket gates, wear rings, and related appurtenances. The notice classified the work as modernization without expansion."} — Pump-Turbine Refurbishment, Units 2,4, and 6 Hyatt Powerplant · confidence: high
- Timeline.8: {"event":"Drought-related outage","date":"2021-08-05","detail":"DWR took Hyatt Powerplant offline because of historically low Lake Oroville levels during the statewide drought."} — Hyatt Powerplant at Oroville Dam Resumes Operation · confidence: high
- Timeline.9: {"event":"Generation resumed","date":"2022-01-04","detail":"DWR announced resumed hydropower generation, initially using one generating unit and supplying power to the California Independent System Operator-managed grid after completing major maintenance while the plant was offline."} — Hyatt Powerplant at Oroville Dam Resumes Operation · confidence: high
- Timeline.10: {"event":"Acquisition, sale, and retirement status","date":null,"detail":"The cited project histories identify DWR as the owner and operator and describe State Water Project construction, but do not document an acquisition, sale, predecessor owner, sale consideration, or retirement event."} — Oroville · confidence: medium
- Timeline.10: {"event":"Acquisition, sale, and retirement status","date":null,"detail":"The cited project histories identify DWR as the owner and operator and describe State Water Project construction, but do not document an acquisition, sale, predecessor owner, sale consideration, or retirement event."} — H-3 P-2100-185 | Federal Energy Regulatory Commission · confidence: medium
- Commercial parties.0: {"relationship":"Owner and operator","name":"California Department of Water Resources","detail":"Operates Edward C Hyatt as a State Water Project facility and holds the documented project ownership and Feather River Project license relationship.","official_url":"https://water.ca.gov/"} — H-3 P-2100-185 | Federal Energy Regulatory Commission · confidence: medium
- Commercial parties.1: {"relationship":"Balancing authority and market operator","name":"California Independent System Operator","detail":"Manages the California electrical grid to which Hyatt generation was supplied when operations resumed in January 2022.","official_url":"https://www.caiso.com/"} — Hyatt Powerplant at Oroville Dam Resumes Operation · confidence: high
- Commercial parties.3: {"relationship":"Turbine supplier","name":"Voith Hydro Holding","detail":"A project profile identifies Voith Hydro Holding as the supplier of three 97.8 MW turbines for the hydroelectric project.","official_url":"https://www.voith.com/"} — Power plant profile: Edward C Hyatt, US · confidence: medium
- Quality notes.1: Construction completion is reported as 1967 by DWR, while EIA/FERC generator records place individual units online across 1968-1969 and a commercial-plant profile reports February 1969 as the commercial-operation date. — Source · confidence: high
- Quality notes.2: The 2001 CEQA notice describes replacement of turbine runners, wicket gates, wear rings, and appurtenances on Units 2, 4, and 6, expressly characterizing the work as modernization with no expansion of use. — Pump-Turbine Refurbishment, Units 2,4, and 6 Hyatt Powerplant · confidence: high
- Quality notes.3: No retirement, sale, acquisition, predecessor-owner, portfolio-transaction value, or separate repowering transaction is identified in the cited project records. — Oroville · confidence: medium
- Quality notes.3: No retirement, sale, acquisition, predecessor-owner, portfolio-transaction value, or separate repowering transaction is identified in the cited project records. — H-3 P-2100-185 | Federal Energy Regulatory Commission · confidence: medium

## Timeline

- 1964 — Construction started
  Excavation and construction began for the underground Hyatt Powerplant at Oroville.
  Source: Oroville (https://water.ca.gov/programs/state-water-project/swp-facilities/oroville)
- 1967 — Construction completed
  DWR’s State Water Project development timeline records completion of the Hyatt Powerplant in 1967.
  Source: Source (https://cawaterlibrary.net/wp-content/uploads/2020/10/DWR-News-SWP-Past-Present-Future-2006.pdf)
- 2001-03-05 — Pump-turbine refurbishment
  DWR filed a CEQA notice for refurbishment of Units 2, 4, and 6, including replacement of turbine runners, wicket gates, wear rings, and related appurtenances. The notice classified the work as modernization without expansion.
  Source: Pump-Turbine Refurbishment, Units 2,4, and 6 Hyatt Powerplant (https://ceqanet.lci.ca.gov/2001038094)
- 2021-08-05 — Drought-related outage
  DWR took Hyatt Powerplant offline because of historically low Lake Oroville levels during the statewide drought.
  Source: Hyatt Powerplant at Oroville Dam Resumes Operation (https://water.ca.gov/News/News-Releases/2022/Jan-21/Hyatt-Powerplant-at-Oroville-Dam-Resumes-Operation)
- 2022-01-04 — Generation resumed
  DWR announced resumed hydropower generation, initially using one generating unit and supplying power to the California Independent System Operator-managed grid after completing major maintenance while the plant was offline.
  Source: Hyatt Powerplant at Oroville Dam Resumes Operation (https://water.ca.gov/News/News-Releases/2022/Jan-21/Hyatt-Powerplant-at-Oroville-Dam-Resumes-Operation)

## Sources

- [California Department of Water Resources](https://water.ca.gov/) — water.ca.gov · tier regulatory
- [MBR | Index](https://mbrweb.ferc.gov/SearchlkpEIA/Index?page=96) — mbrweb.ferc.gov · tier regulatory
- [MBR | Index](https://mbrweb.ferc.gov/SearchlkpEIA/Index?page=97) — mbrweb.ferc.gov · tier regulatory
- [Resource category and phase](https://bpmcm.caiso.com/Lists/PRR%20Details/Attachments/1067/Resource%20category%20and%20phase_by%20resource%20ID_CAISO.XLSX) — bpmcm.caiso.com · tier other
- [Source](https://www.caiso.com/documents/dec29_2014_order_certificatesofconcurrence_cdwragreements_er15-322.pdf) — caiso.com · tier other
- [Oroville - California Department of Water Resources](https://water.ca.gov/programs/state-water-project/swp-facilities/oroville) — water.ca.gov · tier regulatory
- [Edward C. Hyatt Pumped Storage hydroelectric plant](https://www.gem.wiki/Edward_C._Hyatt_Pumped_Storage_hydroelectric_plant) — gem.wiki · tier other
- [Hyatt Powerplant at Oroville Dam Resumes Operation](https://water.ca.gov/News/News-Releases/2022/Jan-21/Hyatt-Powerplant-at-Oroville-Dam-Resumes-Operation) — water.ca.gov · tier regulatory
- [Power plant profile: Edward C Hyatt, US](https://www.power-technology.com/data-insights/power-plant-profile-edward-c-hyatt-us/) — power-technology.com · tier other
- [Source](https://www.caiso.com/documents/iso_responses-comments-preliminarypolicy-driven-economicassessment.pdf) — caiso.com · tier other
- [14 energy](https://www.buttecounty.net/DocumentCenter/View/2393/Energy-PDF) — buttecounty.net · tier other
- [H-3 P-2100-185 | Federal Energy Regulatory Commission](https://www.ferc.gov/media/h-3-p-2100-185) — ferc.gov · tier regulatory
- [Turbines & shut-off valves | Voith](https://www.voith.com/corp-en/products-services/hydropower-components/turbines.html) — voith.com · tier other
- [Source](https://cawaterlibrary.net/wp-content/uploads/2020/10/DWR-News-SWP-Past-Present-Future-2006.pdf) — cawaterlibrary.net · tier other
- [Pump-Turbine Refurbishment, Units 2,4, and 6 Hyatt Powerplant](https://ceqanet.lci.ca.gov/2001038094) — ceqanet.lci.ca.gov · tier regulatory
- [Source](https://cawaterlibrary.net/wp-content/uploads/2023/10/Bulletin-No.-200-1174.pdf) — cawaterlibrary.net · tier other
- [17 F.P.C. 262, 1957 WL 4171 DEPARTMENT OF WATER RESOURCES OF THE STATE OF CALIFORNIA, PROJECT NO. 2100 ORDER ISSUING](https://www.waterboards.ca.gov/water_issues/programs/cannabis/docs/ferc_license/ferc_p2100_feather_river.pdf) — waterboards.ca.gov · tier regulatory
- [Oroville Facilities (P-2100)](https://water.ca.gov/Programs/State-Water-Project/SWP-Facilities/Oroville/HLPCO-Oroville-Facilities-Project-2100) — water.ca.gov · tier regulatory
- [Source](https://www.ferc.gov/sites/default/files/2020-06/P-2100-182-EA.pdf) — ferc.gov · tier regulatory
- [APPENDIX A: Reliability Assessment Results](https://www.caiso.com/documents/decision_2011-12transmissionplan-appendixa-mar2012.pdf) — caiso.com · tier other

## Data quality

- EIA Plant 437 records six operational units totaling 644.1 MW; nearby Thermalito facilities are separate assets in the Oroville-Thermalito complex. The 2001 CEQA notice describes replacement of turbine runners, wicket gates, wear rings, and appurtenances on Units 2, 4, and 6, expressly characterizing the work as modernization with no expansion of use. No retirement, sale, acquisition, predecessor-owner, portfolio-transaction value, or separate repowering transaction is identified in the cited project records.

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Canonical page: https://askthegrid.com/assets/facilities/edward-c-hyatt

Source: Ask the Grid — https://askthegrid.com/