# Big Creek 3 CAISO Conventional Hydroelectric · https://askthegrid.com/assets/facilities/big-creek-3 Big Creek 3 is a hydroelectric facility with 174.5 MW of EIA-reported nameplate capacity in Fresno County, California, registered as EIA Plant ID 319. Southern California Edison Co owns and operates the plant. Constructed in 1923, Big Creek Powerhouse No. 3 was the largest hydroelectric generating plant in the western United States at the time. It was later expanded to five generating units and remains part of Southern California Edison’s Big Creek Hydroelectric System. Commercial operation began in 1923. caiso-gen-319 · 220 kV · Southern California Edison Company. ## Key facts - Technology: Conventional Hydroelectric - Power capacity: 174.5 MW - Commercial operation: 1923 - Operating status: operating ## Grid and market context - ISO/RTO: CAISO - Balancing authority: CISO - Transmission owner: Southern California Edison Company ## Source-backed facts - Owner logo domain: sce.com — Big Creek Watershed | SCE · confidence: medium - Identifiers: [{"value":"319","system":"EIA plant ID"},{"value":"120","system":"FERC project number"},{"value":"P-120-020","system":"FERC docket"},{"value":"CISO","system":"Balancing authority"},{"value":"CAISO","system":"Power market / ISO-RTO"}] — Big Creek Hydroelectric System | California State Water Resources Control Board · confidence: medium - Identifiers: [{"value":"319","system":"EIA plant ID"},{"value":"120","system":"FERC project number"},{"value":"P-120-020","system":"FERC docket"},{"value":"CISO","system":"Balancing authority"},{"value":"CAISO","system":"Power market / ISO-RTO"}] — FR Doc E8-507 · confidence: medium - Official project url: https://www.sce.com/regulatory/regulatory-information/hydro-licensing/big-creek — Big Creek Hydro Licensing | Hydro Licensing | SCE · confidence: high - Owner name: Southern California Edison Company — Big Creek Hydroelectric System | California State Water Resources Control Board · confidence: high - Description: Big Creek 3 is an operating hydroelectric power plant in Fresno County, California, with 174.5 MW of EIA nameplate capacity and five generating units. The corresponding Big Creek No. 3 Hydroelectric Project, FERC Project No. 120, occupies approximately 508 acres of national forest land on the Upper San Joaquin River. Its facilities were constructed between 1923 and 1980, and the project is owned and operated by Southern California Edison. — Big Creek Hydroelectric System | California State Water Resources Control Board · confidence: medium - Description: Big Creek 3 is an operating hydroelectric power plant in Fresno County, California, with 174.5 MW of EIA nameplate capacity and five generating units. The corresponding Big Creek No. 3 Hydroelectric Project, FERC Project No. 120, occupies approximately 508 acres of national forest land on the Upper San Joaquin River. Its facilities were constructed between 1923 and 1980, and the project is owned and operated by Southern California Edison. — Federal Register :: Southern California Edison Company; Notice of Application and Amended Preliminary Draft Environmental Assessment Tendered for Filing With the Commission, and Establishing Procedual Schedule for Licensing and Deadline for Submission of Final Amendments · confidence: medium - Identifiers.1: {"value":"120","system":"FERC project number"} — Big Creek Hydroelectric System | California State Water Resources Control Board · confidence: high - Identifiers.2: {"value":"P-120-020","system":"FERC docket"} — FR Doc E8-507 · confidence: high - Parties.0: {"relationship":"Owner, operator, and FERC license applicant","name":"Southern California Edison Company","official_url":"https://www.sce.com"} — Big Creek Hydroelectric System | California State Water Resources Control Board · confidence: high - Parties.2: {"relationship":"Federal land administrator for project lands","name":"United States Forest Service, Sierra National Forest","official_url":"https://www.fs.usda.gov/sierra"} — Big Creek Hydroelectric System | California State Water Resources Control Board · confidence: high - Parties.3: {"relationship":"Federal hydropower licensing authority","name":"Federal Energy Regulatory Commission","official_url":"https://www.ferc.gov"} — Big Creek Hydroelectric System | California State Water Resources Control Board · confidence: medium - Parties.3: {"relationship":"Federal hydropower licensing authority","name":"Federal Energy Regulatory Commission","official_url":"https://www.ferc.gov"} — Big Creek Hydro Licensing | Hydro Licensing | SCE · confidence: medium - Interconnection: Southern California Edison transmission and distribution system — 11351 · confidence: medium - Unit configuration: Reservoir-storage hydroelectric plant with one powerhouse and five turbine-generator units — 11351 · confidence: high - Power mw: 174.5 — 11351 · confidence: medium - Unit count: 5 — 11351 · confidence: high - Construction scope: Big Creek No. 3 consists of Dam 6, water-conveyance penstocks, three construction adits, and Powerhouse No. 3. The powerhouse contains five turbine/generator units; the documented construction sequence added Unit 4 in 1948 and Unit 5 in 1980. Historical equipment records identify three initial Francis turbines supplied by Wellman-Seaver-Morgan, Westinghouse main generators for Units 1–3, and two 600-hp Pelton station-service wheels. — Big Creek Hydroelectric System | California State Water Resources Control Board · confidence: medium - Product url: https://www.voith.com/corp-en/products-services/hydropower-components/turbines.html — Big Creek 3, US · 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 — Big Creek Hydroelectric System | California State Water Resources Control Board · confidence: high - Product family: Francis-type reaction turbines — Turbines & shut-off valves | Voith · confidence: high - Significance: Constructed in 1923, Big Creek Powerhouse No. 3 was the largest hydroelectric generating plant in the western United States at the time. It was later expanded to five generating units and remains part of Southern California Edison’s Big Creek Hydroelectric System. — Source · confidence: high - Description: Big Creek 3 is a conventional reservoir-storage hydroelectric plant in Fresno County, California, with one powerhouse, Dam 6 and forebay, a water-conveyance system, and five turbine-generator units. EIA records report 174.5 MW of nameplate capacity, while the FERC licensing record describes 174.45 MW of installed operating capacity. Southern California Edison owns and operates the project, which transmits its generation to SCE’s system and participates in the CAISO market. The powerhouse was constructed in 1923, expanded with a fourth unit in 1948 and a fifth unit in 1980, and has not been identified as retired or fully repowered. — FR Doc E8-507 · confidence: medium - Quality notes: ["Capacity figures differ slightly by source and measurement: EIA reports 174.5 MW, the FERC application reports 174.45 MW installed operating capacity, and the California Water Board page reports 165.375 MW of authorized capacity.","The 1917 transaction was a merger or consolidation involving Pacific Light and Power rather than a separately documented cash sale of Big Creek No. 3; no acquisition consideration was disclosed in the cited records.","The 2021 failure of field poles on Big Creek 3 Unit 3 caused an unplanned outage and refurbishment work. It was not reported as a unit retirement; the EIA record lists five operational generators.","The initial-unit dates in the historical record vary slightly in narrative accounts, so the timeline uses the consistently supported 1923 commissioning year except where later expansion years are explicit."] — Big Creek Hydroelectric System | California State Water Resources Control Board · confidence: medium - Quality notes: ["Capacity figures differ slightly by source and measurement: EIA reports 174.5 MW, the FERC application reports 174.45 MW installed operating capacity, and the California Water Board page reports 165.375 MW of authorized capacity.","The 1917 transaction was a merger or consolidation involving Pacific Light and Power rather than a separately documented cash sale of Big Creek No. 3; no acquisition consideration was disclosed in the cited records.","The 2021 failure of field poles on Big Creek 3 Unit 3 caused an unplanned outage and refurbishment work. It was not reported as a unit retirement; the EIA record lists five operational generators.","The initial-unit dates in the historical record vary slightly in narrative accounts, so the timeline uses the consistently supported 1923 commissioning year except where later expansion years are explicit."] — Source · confidence: medium - Quality notes: ["Capacity figures differ slightly by source and measurement: EIA reports 174.5 MW, the FERC application reports 174.45 MW installed operating capacity, and the California Water Board page reports 165.375 MW of authorized capacity.","The 1917 transaction was a merger or consolidation involving Pacific Light and Power rather than a separately documented cash sale of Big Creek No. 3; no acquisition consideration was disclosed in the cited records.","The 2021 failure of field poles on Big Creek 3 Unit 3 caused an unplanned outage and refurbishment work. It was not reported as a unit retirement; the EIA record lists five operational generators.","The initial-unit dates in the historical record vary slightly in narrative accounts, so the timeline uses the consistently supported 1923 commissioning year except where later expansion years are explicit."] — Section 4.32 General Information · confidence: medium - Financing summary: The 1917 Pacific Light and Power–Southern California Edison consolidation was accomplished through a stock swap; no sale price or acquisition consideration for Big Creek No. 3 was disclosed. For FERC Project 120, SCE reported project net investment of $37,174,159 as of 2005-12-31, estimated annual direct operations and maintenance expenses of $6,750,857, and approximately $5,310,000 in license-application costs through December 2006. SCE’s application used a 10.00% cost-of-capital assumption comprising 3.14% long-term debt, 0.75% preferred equity, and 6.11% common equity, and stated that no special financing was needed for major new development. Separately, Pacific Light and Power recapitalized and sold new bonds in late 1909 to fund the broader Big Creek project, but the bond amount was not disclosed and was not specific to Powerhouse No. 3. — Source · confidence: medium - Financing summary: The 1917 Pacific Light and Power–Southern California Edison consolidation was accomplished through a stock swap; no sale price or acquisition consideration for Big Creek No. 3 was disclosed. For FERC Project 120, SCE reported project net investment of $37,174,159 as of 2005-12-31, estimated annual direct operations and maintenance expenses of $6,750,857, and approximately $5,310,000 in license-application costs through December 2006. SCE’s application used a 10.00% cost-of-capital assumption comprising 3.14% long-term debt, 0.75% preferred equity, and 6.11% common equity, and stated that no special financing was needed for major new development. Separately, Pacific Light and Power recapitalized and sold new bonds in late 1909 to fund the broader Big Creek project, but the bond amount was not disclosed and was not specific to Powerhouse No. 3. — Section 4.32 General Information · confidence: medium - Quality notes.0: Capacity figures differ slightly by source and measurement: EIA reports 174.5 MW, the FERC application reports 174.45 MW installed operating capacity, and the California Water Board page reports 165.375 MW of authorized capacity. — Source · confidence: medium - Quality notes.1: The 1917 transaction was a merger or consolidation involving Pacific Light and Power rather than a separately documented cash sale of Big Creek No. 3; no acquisition consideration was disclosed in the cited records. — FR Doc E8-507 · confidence: high - Quality notes.1: The 1917 transaction was a merger or consolidation involving Pacific Light and Power rather than a separately documented cash sale of Big Creek No. 3; no acquisition consideration was disclosed in the cited records. — Big Creek Hydroelectric System | California State Water Resources Control Board · confidence: high - Quality notes.2: The 2021 failure of field poles on Big Creek 3 Unit 3 caused an unplanned outage and refurbishment work. It was not reported as a unit retirement; the EIA record lists five operational generators. — Source · confidence: medium - Quality notes.3: The initial-unit dates in the historical record vary slightly in narrative accounts, so the timeline uses the consistently supported 1923 commissioning year except where later expansion years are explicit. — Source · confidence: medium - Quality notes.3: The initial-unit dates in the historical record vary slightly in narrative accounts, so the timeline uses the consistently supported 1923 commissioning year except where later expansion years are explicit. — Do · confidence: medium - Timeline.1: {"event":"Acquisition and merger","date":"1917-06","detail":"Southern California Edison consolidated with or acquired Pacific Light and Power, the predecessor Big Creek developer and owner. Historical records describe the transaction as a merger accomplished through a swap of PLP and SCE stock; the cited records do not disclose separate consideration for Big Creek No. 3."} — Source · confidence: high - Timeline.2: {"event":"Powerhouse construction and initial commercial operation","date":"1923","detail":"Big Creek Powerhouse No. 3 was constructed and its first three generating units were placed on SCE’s lines during 1923. The historical record identifies the powerhouse as the largest hydroelectric generating plant in the western United States at that time."} — Source · confidence: medium - Timeline.3: {"event":"Unit 4 expansion","date":"1948-04","detail":"A fourth generating unit was added to Powerhouse No. 3 and began commercial operation in 1948; SCE historical material identifies April 28 as the commercial-operation date."} — Source · confidence: medium - Timeline.3: {"event":"Unit 4 expansion","date":"1948-04","detail":"A fourth generating unit was added to Powerhouse No. 3 and began commercial operation in 1948; SCE historical material identifies April 28 as the commercial-operation date."} — Do · confidence: medium - Timeline.4: {"event":"Final powerhouse expansion","date":"1978-1980","detail":"The powerhouse exterior was expanded between 1978 and 1980 in accordance with the original expansion plan."} — Source · confidence: high - Timeline.5: {"event":"Unit 5 expansion","date":"1980","detail":"The fifth generating unit was added in 1980, bringing the plant to its current five-unit configuration."} — Source · confidence: high - Timeline.6: {"event":"Turbine runner replacement","date":"1982","detail":"The turbine runners for Units 1 and 3 were replaced with cast stainless-steel runners."} — Section 4.32 General Information · confidence: high - Timeline.7: {"event":"FERC relicensing application","date":"2007-02-23","detail":"Southern California Edison filed a new-license application for Big Creek No. 3, FERC Project No. 120. The existing project was described as one powerhouse, Dam 6 and forebay, a water-conveyance system, and five turbine-generator units."} — FR Doc E8-507 · confidence: high - Timeline.8: {"event":"Generator rewind","date":"2010","detail":"The Unit 5 generator was rewound by General Electric. This was maintenance work rather than a full plant repowering."} — Source · confidence: high - Timeline.9: {"event":"Unit 3 unplanned outage","date":"2021-10-27","detail":"Big Creek 3 Unit 3 experienced an unplanned outage after generator field poles failed. SCE subsequently planned field-pole refurbishment and stator inspection work."} — Source · confidence: high - Timeline.10: {"event":"Retirement and repowering status","date":null,"detail":"The cited records do not identify a retirement or full repowering of Big Creek 3. EIA-derived plant data lists all five generators as operational."} — Source · confidence: medium - Commercial parties.0: {"relationship":"Owner, operator, and FERC license applicant","name":"Southern California Edison Company","detail":"SCE owns and operates Big Creek No. 3, filed the FERC Project 120 license application, and is responsible for project maintenance and capital work.","official_url":"https://www.sce.com"} — Big Creek Hydroelectric System | California State Water Resources Control Board · confidence: high - Commercial parties.3: {"relationship":"Federal hydropower licensing authority","name":"Federal Energy Regulatory Commission","detail":"FERC administers the license for Big Creek No. 3, FERC Project No. 120.","official_url":"https://www.ferc.gov"} — FR Doc E8-507 · confidence: high - Commercial parties.4: {"relationship":"Federal land administrator","name":"United States Forest Service, Sierra National Forest","detail":"Project facilities occupy approximately 508 acres of national forest land administered by the Forest Service.","official_url":"https://www.fs.usda.gov/sierra"} — Big Creek Hydroelectric System | California State Water Resources Control Board · confidence: medium - Interconnection voltage kv: 220 — Big Creek Hydroelectric System, Vincent 220kV Transmission Line, 224-mile transmission line extending from Big Creek to Antelope Substation, Big Creek, Fresno County, CA · confidence: medium ## Timeline - 1923 — Powerhouse construction and initial commercial operation Big Creek Powerhouse No. 3 was constructed and its first three generating units were placed on SCE’s lines during 1923. The historical record identifies the powerhouse as the largest hydroelectric generating plant in the western United States at that time. Source: Source (https://tile.loc.gov/storage-services/master/pnp/habshaer/ca/ca3600/ca3676/data/ca3676data.pdf) - 1978-1980 — Final powerhouse expansion The powerhouse exterior was expanded between 1978 and 1980 in accordance with the original expansion plan. Source: Source (https://tile.loc.gov/storage-services/master/pnp/habshaer/ca/ca3600/ca3676/data/ca3676data.pdf) - 2007-02-23 — FERC relicensing application Southern California Edison filed a new-license application for Big Creek No. 3, FERC Project No. 120. The existing project was described as one powerhouse, Dam 6 and forebay, a water-conveyance system, and five turbine-generator units. Source: FR Doc E8-507 (https://downloads.regulations.gov/FERC-2008-0086-0001/content.htm) - 2021-10-27 — Unit 3 unplanned outage Big Creek 3 Unit 3 experienced an unplanned outage after generator field poles failed. SCE subsequently planned field-pole refurbishment and stator inspection work. Source: Source (https://docs.cpuc.ca.gov/PublishedDocs/SupDoc/A2305010/6063/508571821.pdf) ## Sources - [Big Creek Watershed | SCE](https://www.sce.com/about-sce/community/camp-edison/big-creek) — sce.com · tier other - [Big Creek Hydroelectric System | California State Water Resources Control Board](https://www.waterboards.ca.gov/waterrights/water_issues/programs/water_quality_cert/big_creek/big_creek_120.html) — waterboards.ca.gov · tier regulatory - [FR Doc E8-507](https://downloads.regulations.gov/FERC-2008-0086-0001/content.htm) — downloads.regulations.gov · tier regulatory - [Big Creek Hydro Licensing | Hydro Licensing | SCE](https://www.sce.com/regulatory/regulatory-information/hydro-licensing/big-creek) — sce.com · tier other - [Federal Register :: Southern California Edison Company; Notice of Application and Amended Preliminary Draft Environmental Assessment Tendered for Filing With the Commission, and Establishing Procedual Schedule for Licensing and Deadline for Submission of Final Amendments](https://www.federalregister.gov/documents/2007/03/13/E7-4477/southern-california-edison-company-notice-of-application-and-amended-preliminary-draft-environmental) — federalregister.gov · tier regulatory - [11351](https://www.govinfo.gov/content/pkg/FR-2007-03-13/pdf/E7-4478.pdf) — govinfo.gov · tier regulatory - [Source](https://waterboards.ca.gov/waterrights/water_issues/programs/water_quality_cert/big_creek/big_creek_120.html) — waterboards.ca.gov · tier regulatory - [BIG CREEK HYDROELECTRIC SYSTEM](https://www.sce.com/sites/default/files/inline-files/2000_iip.pdf) — sce.com · tier other - [Source](https://tile.loc.gov/storage-services/master/pnp/habshaer/ca/ca3600/ca3676/data/ca3676data.pdf) — tile.loc.gov · tier regulatory - [Big Creek 3, US](https://www.power-technology.com/marketdata/big-creek-3-us/) — power-technology.com · tier other - [Turbines & shut-off valves | Voith](https://www.voith.com/corp-en/products-services/hydropower-components/turbines.html) — voith.com · tier other - [Source](https://docs.cpuc.ca.gov/PublishedDocs/SupDoc/A2305010/6063/508571821.pdf) — docs.cpuc.ca.gov · tier regulatory - [Section 4.32 General Information](https://www.sce.com/sites/default/files/inline-files/p120bc3_initialstatement_and_exhibitsad_and_h.pdf) — sce.com · tier other - [Source](https://sce.com/regulatory/regulatory-information/hydro-licensing/big-creek) — sce.com · tier other - [Big Creek Hydroelectric System, Vincent 220kV Transmission Line, 224-mile transmission line extending from Big Creek to Antelope Substation, Big Creek, Fresno County, CA](https://www.loc.gov/pictures/item/ca4237/) — loc.gov · tier regulatory - [Source](https://www.caiso.com/documents/meteringexemptionlistingreport2021.pdf) — caiso.com · tier other - [2026 NQC List](https://www.caiso.com/documents/net-qualifying-capacity-report-for-compliance-year-2026.xlsx) — caiso.com · tier other ## Data quality - Capacity figures differ slightly by source and measurement: EIA reports 174.5 MW, the FERC application reports 174.45 MW installed operating capacity, and the California Water Board page reports 165.375 MW of authorized capacity. The 1917 transaction was a merger or consolidation involving Pacific Light and Power rather than a separately documented cash sale of Big Creek No. 3; no acquisition consideration was disclosed in the cited records. The 2021 failure of field poles on Big Creek 3 Unit 3 caused an unplanned outage and refurbishment work. It was not reported as a unit retirement; the EIA record lists five operational generators. The initial-unit dates in the historical record vary slightly in narrative accounts, so the timeline uses the consistently supported 1923 commissioning year except where later expansion years are explicit. --- Canonical page: https://askthegrid.com/assets/facilities/big-creek-3 Source: Ask the Grid — https://askthegrid.com/