# Dion R Holm CAISO Conventional Hydroelectric · https://askthegrid.com/assets/facilities/dion-r-holm Dion R Holm is a hydroelectric facility with 180.2 MW of EIA-reported operating capacity in Tuolumne County, California, registered as EIA Plant ID 380. City & County of San Francisco is the registered plant entity or operator. Holm is the largest of the three hydroelectric powerhouses in San Francisco’s Hetch Hetchy Power System. Its two vertical-shaft, turbine-driven generators are each rated at 82,500 kVA. ## Key facts - Technology: Conventional Hydroelectric - Power capacity: 180.2 MW - Operating status: operating ## Grid and market context - ISO/RTO: CAISO - Balancing authority: California Independent System Operator (CAISO/CISO) - Transmission owner: City & County of San Francisco ## Source-backed facts - Owner logo domain: sfpuc.gov — Hetch Hetchy Power System · confidence: medium - Identifiers: [{"value":"380","system":"EIA plant ID"},{"value":"380_G_1","system":"EPA ORIS/EIA generator unique ID"},{"value":"380_G_2","system":"EPA ORIS/EIA generator unique ID"},{"value":"459","system":"CAISO resource ID — HOLM HYDRO UNIT 2"},{"value":"462","system":"CAISO resource ID — HOLM HYDRO UNIT 1"}] — Plant Name Unique ID ORIS Code AZNM_AZ_Coal Steam... · confidence: medium - Identifiers: [{"value":"380","system":"EIA plant ID"},{"value":"380_G_1","system":"EPA ORIS/EIA generator unique ID"},{"value":"380_G_2","system":"EPA ORIS/EIA generator unique ID"},{"value":"459","system":"CAISO resource ID — HOLM HYDRO UNIT 2"},{"value":"462","system":"CAISO resource ID — HOLM HYDRO UNIT 1"}] — Resource category and phase · confidence: medium - Description: Dion R Holm is a 180.2 MW hydroelectric power plant in Tuolumne County, California, with two generating units. The Dion R. Holm Powerhouse was built in 1960 at the downstream end of Cherry Power Tunnel and generates electricity from water released from Lake Lloyd. It is one of three hydroelectric powerhouses in the SFPUC's Hetch Hetchy Power System and is fed from Lake Eleanor and Cherry Lake. — 150079 - PUC Ltr 112414 · confidence: medium - Description: Dion R Holm is a 180.2 MW hydroelectric power plant in Tuolumne County, California, with two generating units. The Dion R. Holm Powerhouse was built in 1960 at the downstream end of Cherry Power Tunnel and generates electricity from water released from Lake Lloyd. It is one of three hydroelectric powerhouses in the SFPUC's Hetch Hetchy Power System and is fed from Lake Eleanor and Cherry Lake. — Hetch Hetchy Power System · confidence: medium - Parties: [{"relationship":"Owner (through SFPUC)","name":"City and County of San Francisco","official_url":"https://www.sfpuc.gov/"},{"relationship":"Operator","name":"San Francisco Public Utilities Commission (SFPUC)","official_url":"https://www.sfpuc.gov/"}] — Power plant profile: Dion R Holm, US · confidence: medium - Parties: [{"relationship":"Owner (through SFPUC)","name":"City and County of San Francisco","official_url":"https://www.sfpuc.gov/"},{"relationship":"Operator","name":"San Francisco Public Utilities Commission (SFPUC)","official_url":"https://www.sfpuc.gov/"}] — Hetch Hetchy Power System · confidence: medium - Identifiers.1: {"value":"380_G_1","system":"EPA ORIS/EIA generator unique ID"} — Plant Name Unique ID ORIS Code AZNM_AZ_Coal Steam... · confidence: medium - Identifiers.2: {"value":"380_G_2","system":"EPA ORIS/EIA generator unique ID"} — Plant Name Unique ID ORIS Code AZNM_AZ_Coal Steam... · confidence: medium - Identifiers.3: {"value":"459","system":"CAISO resource ID — HOLM HYDRO UNIT 2"} — Resource category and phase · confidence: medium - Identifiers.4: {"value":"462","system":"CAISO resource ID — HOLM HYDRO UNIT 1"} — Resource category and phase · confidence: medium - Parties.0: {"relationship":"Owner (through SFPUC)","name":"City and County of San Francisco","official_url":"https://www.sfpuc.gov/"} — Power plant profile: Dion R Holm, US · confidence: medium - Parties.0: {"relationship":"Owner (through SFPUC)","name":"City and County of San Francisco","official_url":"https://www.sfpuc.gov/"} — Hetch Hetchy Power System · confidence: medium - Parties.1: {"relationship":"Operator","name":"San Francisco Public Utilities Commission (SFPUC)","official_url":"https://www.sfpuc.gov/"} — Hetch Hetchy Power System · confidence: medium - Construction scope: Built in 1960, the Dion R. Holm Powerhouse is fed by a six-mile pressure tunnel from Cherry Dam and contains two vertical-shaft, turbine-driven generators rated at 82,500 kVA each. The documented Holm Unit 2 rehabilitation includes 13.8-kV equipment upgrades, addition and integration of a generator breaker, replacement of two 13.8-kV feed breakers and the Unit 2 main control board, plus integration of exciter, governor, and Generator 2 PLCs into the existing SCADA system. — ch Hetchy Capital Improvement Programs Het Quarterly Report – Fiscal Year 2020-2021 · confidence: high - Product url: https://www.andritz.com/products-en/group/products/turbines-hydropower — Power plant profile: Dion R Holm, US · confidence: medium - Product url: https://www.andritz.com/products-en/group/products/turbines-hydropower — Turbines for hydropower plants · confidence: medium - Product family: ANDRITZ hydropower turbines — Turbines for hydropower plants · confidence: medium - Equipment models.0: {"manufacturer_domain":"andritz.com","product_url":"https://www.andritz.com/products-en/group/products/turbines-hydropower","count":2,"unit_mw":87.6,"name":"ANDRITZ Hydro turbine"} — Turbines for hydropower plants · confidence: medium - Description: Dion R Holm is an operating 180.2 MW conventional hydroelectric plant in Tuolumne County, California, with two generating units. The City and County of San Francisco owns the Hetch Hetchy Power System through the San Francisco Public Utilities Commission (SFPUC), which operates the system. The powerhouse is located downstream of Cherry Power Tunnel and is fed by water from Lake Eleanor and Cherry Lake. It began commercial operation in 1960 and was named for former San Francisco City Attorney Dion R. Holm in 1967. — Hetch Hetchy Power System · confidence: medium - Description: Dion R Holm is an operating 180.2 MW conventional hydroelectric plant in Tuolumne County, California, with two generating units. The City and County of San Francisco owns the Hetch Hetchy Power System through the San Francisco Public Utilities Commission (SFPUC), which operates the system. The powerhouse is located downstream of Cherry Power Tunnel and is fed by water from Lake Eleanor and Cherry Lake. It began commercial operation in 1960 and was named for former San Francisco City Attorney Dion R. Holm in 1967. — 150079 - PUC Ltr 112414 · confidence: medium - Description: Dion R Holm is an operating 180.2 MW conventional hydroelectric plant in Tuolumne County, California, with two generating units. The City and County of San Francisco owns the Hetch Hetchy Power System through the San Francisco Public Utilities Commission (SFPUC), which operates the system. The powerhouse is located downstream of Cherry Power Tunnel and is fed by water from Lake Eleanor and Cherry Lake. It began commercial operation in 1960 and was named for former San Francisco City Attorney Dion R. Holm in 1967. — Hetch Hetchy Text FINAL.qxd · confidence: medium - Quality notes: ["No separate acquisition, sale, predecessor owner, sale consideration, or portfolio transaction is identified for this exact plant; the historical record instead describes municipal development and continuing City/SFPUC ownership and operation.","The 2015 Series A financing covered multiple Hetchy Power rehabilitation projects. The disclosed $32.025 million original par amount and $30.2 million of project-fund proceeds are bond-issue figures, not a Holm-only allocation or sale value.","Holm Unit 2 is described as receiving reliability and efficiency improvements, including replacement of supporting components and auxiliary systems; the available record does not characterize this work as a full repowering or retirement.","The 180.2 MW figure is the plant-level EIA capacity. The SFPUC history separately reports generator ratings in kVA, so those ratings are not converted into an additional MW figure here."] — Hetch Hetchy Power System · confidence: medium - Quality notes: ["No separate acquisition, sale, predecessor owner, sale consideration, or portfolio transaction is identified for this exact plant; the historical record instead describes municipal development and continuing City/SFPUC ownership and operation.","The 2015 Series A financing covered multiple Hetchy Power rehabilitation projects. The disclosed $32.025 million original par amount and $30.2 million of project-fund proceeds are bond-issue figures, not a Holm-only allocation or sale value.","Holm Unit 2 is described as receiving reliability and efficiency improvements, including replacement of supporting components and auxiliary systems; the available record does not characterize this work as a full repowering or retirement.","The 180.2 MW figure is the plant-level EIA capacity. The SFPUC history separately reports generator ratings in kVA, so those ratings are not converted into an additional MW figure here."] — Green Bond Report · confidence: medium - Quality notes: ["No separate acquisition, sale, predecessor owner, sale consideration, or portfolio transaction is identified for this exact plant; the historical record instead describes municipal development and continuing City/SFPUC ownership and operation.","The 2015 Series A financing covered multiple Hetchy Power rehabilitation projects. The disclosed $32.025 million original par amount and $30.2 million of project-fund proceeds are bond-issue figures, not a Holm-only allocation or sale value.","Holm Unit 2 is described as receiving reliability and efficiency improvements, including replacement of supporting components and auxiliary systems; the available record does not characterize this work as a full repowering or retirement.","The 180.2 MW figure is the plant-level EIA capacity. The SFPUC history separately reports generator ratings in kVA, so those ratings are not converted into an additional MW figure here."] — Hetch Hetchy Text FINAL.qxd · confidence: medium - Financing summary: For original development, a $54 million bond issue was approved on November 8, 1955, to construct the Canyon and Cherry River power projects, which included the Cherry Powerhouse project. For later rehabilitation, SFPUC issued tax-exempt Power Revenue Bonds, 2015 Series A, on May 20, 2015; the issue had $32.025 million of original par and generated $30.2 million in project-fund proceeds. The 2015 financing supported rehabilitation of SFPUC Hetch Hetchy facilities, including the Holm Unit 2 improvement program, and was not sale consideration or a portfolio transaction value. — Hetch Hetchy Text FINAL.qxd · confidence: medium - Financing summary: For original development, a $54 million bond issue was approved on November 8, 1955, to construct the Canyon and Cherry River power projects, which included the Cherry Powerhouse project. For later rehabilitation, SFPUC issued tax-exempt Power Revenue Bonds, 2015 Series A, on May 20, 2015; the issue had $32.025 million of original par and generated $30.2 million in project-fund proceeds. The 2015 financing supported rehabilitation of SFPUC Hetch Hetchy facilities, including the Holm Unit 2 improvement program, and was not sale consideration or a portfolio transaction value. — Source · confidence: medium - Financing summary: For original development, a $54 million bond issue was approved on November 8, 1955, to construct the Canyon and Cherry River power projects, which included the Cherry Powerhouse project. For later rehabilitation, SFPUC issued tax-exempt Power Revenue Bonds, 2015 Series A, on May 20, 2015; the issue had $32.025 million of original par and generated $30.2 million in project-fund proceeds. The 2015 financing supported rehabilitation of SFPUC Hetch Hetchy facilities, including the Holm Unit 2 improvement program, and was not sale consideration or a portfolio transaction value. — Green Bond Report · confidence: medium - Timeline: [{"event":"Original development financing approved","date":"1955-11-08","detail":"A $54 million bond issue was approved to construct the Canyon and Cherry River power projects."},{"event":"Cherry Power and Eleanor-Cherry tunnel construction started","date":"1957-08-30","detail":"Construction began on the Cherry Power and Eleanor-Cherry tunnels that serve the Cherry/ Holm hydroelectric development."},{"event":"Cherry Powerhouse construction began","date":"1958-09-16","detail":"Construction of the Cherry Powerhouse began."},{"event":"Power and water tunnels completed","date":"1960-06-17","detail":"The Cherry Power and Eleanor-Cherry tunnels were completed."},{"event":"Commercial operation began","date":"1960-08-01","detail":"The Cherry Powerhouse began commercial operation; the facility was later known as Dion R. Holm Powerhouse."},{"event":"Powerhouse renamed","date":"1967-08-25","detail":"The powerhouse was named after Dion R. Holm, a former San Francisco City Attorney and Hetch Hetchy counsel."},{"event":"Rehabilitation financing issued","date":"2015-05-20","detail":"SFPUC issued its tax-exempt Power Revenue Bonds, 2015 Series A, including proceeds for rehabilitation of Hetch Hetchy hydropower facilities and the Holm Unit 2 improvement program."},{"event":"Cherry Tunnel rehabilitation improved powerhouse production","date":null,"detail":"Mitchell Engineering rehabilitated the Cherry Tunnel rock trap and reported that the work improved power production from the powerhouse by 10 percent; the project page does not provide a completion date."}] — Hetch Hetchy Text FINAL.qxd · confidence: medium - Timeline: [{"event":"Original development financing approved","date":"1955-11-08","detail":"A $54 million bond issue was approved to construct the Canyon and Cherry River power projects."},{"event":"Cherry Power and Eleanor-Cherry tunnel construction started","date":"1957-08-30","detail":"Construction began on the Cherry Power and Eleanor-Cherry tunnels that serve the Cherry/ Holm hydroelectric development."},{"event":"Cherry Powerhouse construction began","date":"1958-09-16","detail":"Construction of the Cherry Powerhouse began."},{"event":"Power and water tunnels completed","date":"1960-06-17","detail":"The Cherry Power and Eleanor-Cherry tunnels were completed."},{"event":"Commercial operation began","date":"1960-08-01","detail":"The Cherry Powerhouse began commercial operation; the facility was later known as Dion R. Holm Powerhouse."},{"event":"Powerhouse renamed","date":"1967-08-25","detail":"The powerhouse was named after Dion R. Holm, a former San Francisco City Attorney and Hetch Hetchy counsel."},{"event":"Rehabilitation financing issued","date":"2015-05-20","detail":"SFPUC issued its tax-exempt Power Revenue Bonds, 2015 Series A, including proceeds for rehabilitation of Hetch Hetchy hydropower facilities and the Holm Unit 2 improvement program."},{"event":"Cherry Tunnel rehabilitation improved powerhouse production","date":null,"detail":"Mitchell Engineering rehabilitated the Cherry Tunnel rock trap and reported that the work improved power production from the powerhouse by 10 percent; the project page does not provide a completion date."}] — Green Bond Report · confidence: medium - Timeline: [{"event":"Original development financing approved","date":"1955-11-08","detail":"A $54 million bond issue was approved to construct the Canyon and Cherry River power projects."},{"event":"Cherry Power and Eleanor-Cherry tunnel construction started","date":"1957-08-30","detail":"Construction began on the Cherry Power and Eleanor-Cherry tunnels that serve the Cherry/ Holm hydroelectric development."},{"event":"Cherry Powerhouse construction began","date":"1958-09-16","detail":"Construction of the Cherry Powerhouse began."},{"event":"Power and water tunnels completed","date":"1960-06-17","detail":"The Cherry Power and Eleanor-Cherry tunnels were completed."},{"event":"Commercial operation began","date":"1960-08-01","detail":"The Cherry Powerhouse began commercial operation; the facility was later known as Dion R. Holm Powerhouse."},{"event":"Powerhouse renamed","date":"1967-08-25","detail":"The powerhouse was named after Dion R. Holm, a former San Francisco City Attorney and Hetch Hetchy counsel."},{"event":"Rehabilitation financing issued","date":"2015-05-20","detail":"SFPUC issued its tax-exempt Power Revenue Bonds, 2015 Series A, including proceeds for rehabilitation of Hetch Hetchy hydropower facilities and the Holm Unit 2 improvement program."},{"event":"Cherry Tunnel rehabilitation improved powerhouse production","date":null,"detail":"Mitchell Engineering rehabilitated the Cherry Tunnel rock trap and reported that the work improved power production from the powerhouse by 10 percent; the project page does not provide a completion date."}] — Cherry Tunnel | MITCHELL ENGINEERING · confidence: medium - Commercial parties: [{"relationship":"Owner, through SFPUC","name":"City and County of San Francisco","detail":"The City owns the Hetch Hetchy Power System, of which Holm is one of three hydroelectric powerhouses.","official_url":"https://www.sf.gov/"},{"relationship":"Operator","name":"San Francisco Public Utilities Commission (SFPUC)","detail":"SFPUC owns and operates all aspects of the Hetch Hetchy Power System and operates the Holm facility for the City and County of San Francisco.","official_url":"https://www.sfpuc.gov/"},{"relationship":"Project-finance issuer","name":"San Francisco Public Utilities Commission (SFPUC)","detail":"SFPUC issued the Power Revenue Bonds, 2015 Series A, whose proceeds financed rehabilitation of Hetch Hetchy hydropower facilities, including Holm Unit 2 improvements.","official_url":"https://www.sfpuc.gov/"},{"relationship":"Cherry Tunnel rehabilitation contractor","name":"Mitchell Engineering","detail":"Mitchell Engineering performed rock-trap rehabilitation work in the Cherry Tunnel, which serves the powerhouse’s power-generation and water-delivery functions; the project owner was identified as San Francisco Public Utilities (Hetch Hetchy).","official_url":"https://www.mitchell-engineering.com/"}] — Hetch Hetchy Power System · confidence: medium - Commercial parties: [{"relationship":"Owner, through SFPUC","name":"City and County of San Francisco","detail":"The City owns the Hetch Hetchy Power System, of which Holm is one of three hydroelectric powerhouses.","official_url":"https://www.sf.gov/"},{"relationship":"Operator","name":"San Francisco Public Utilities Commission (SFPUC)","detail":"SFPUC owns and operates all aspects of the Hetch Hetchy Power System and operates the Holm facility for the City and County of San Francisco.","official_url":"https://www.sfpuc.gov/"},{"relationship":"Project-finance issuer","name":"San Francisco Public Utilities Commission (SFPUC)","detail":"SFPUC issued the Power Revenue Bonds, 2015 Series A, whose proceeds financed rehabilitation of Hetch Hetchy hydropower facilities, including Holm Unit 2 improvements.","official_url":"https://www.sfpuc.gov/"},{"relationship":"Cherry Tunnel rehabilitation contractor","name":"Mitchell Engineering","detail":"Mitchell Engineering performed rock-trap rehabilitation work in the Cherry Tunnel, which serves the powerhouse’s power-generation and water-delivery functions; the project owner was identified as San Francisco Public Utilities (Hetch Hetchy).","official_url":"https://www.mitchell-engineering.com/"}] — Source · confidence: medium - Commercial parties: [{"relationship":"Owner, through SFPUC","name":"City and County of San Francisco","detail":"The City owns the Hetch Hetchy Power System, of which Holm is one of three hydroelectric powerhouses.","official_url":"https://www.sf.gov/"},{"relationship":"Operator","name":"San Francisco Public Utilities Commission (SFPUC)","detail":"SFPUC owns and operates all aspects of the Hetch Hetchy Power System and operates the Holm facility for the City and County of San Francisco.","official_url":"https://www.sfpuc.gov/"},{"relationship":"Project-finance issuer","name":"San Francisco Public Utilities Commission (SFPUC)","detail":"SFPUC issued the Power Revenue Bonds, 2015 Series A, whose proceeds financed rehabilitation of Hetch Hetchy hydropower facilities, including Holm Unit 2 improvements.","official_url":"https://www.sfpuc.gov/"},{"relationship":"Cherry Tunnel rehabilitation contractor","name":"Mitchell Engineering","detail":"Mitchell Engineering performed rock-trap rehabilitation work in the Cherry Tunnel, which serves the powerhouse’s power-generation and water-delivery functions; the project owner was identified as San Francisco Public Utilities (Hetch Hetchy).","official_url":"https://www.mitchell-engineering.com/"}] — Cherry Tunnel | MITCHELL ENGINEERING · confidence: medium - Timeline.0: {"event":"Original development financing approved","date":"1955-11-08","detail":"A $54 million bond issue was approved to construct the Canyon and Cherry River power projects."} — Hetch Hetchy Text FINAL.qxd · confidence: high - Timeline.0: {"event":"Original development financing approved","date":"1955-11-08","detail":"A $54 million bond issue was approved to construct the Canyon and Cherry River power projects."} — Green Bond Report · confidence: high - Timeline.0: {"event":"Original development financing approved","date":"1955-11-08","detail":"A $54 million bond issue was approved to construct the Canyon and Cherry River power projects."} — Source · confidence: high - Timeline.1: {"event":"Cherry Power and Eleanor-Cherry tunnel construction started","date":"1957-08-30","detail":"Construction began on the Cherry Power and Eleanor-Cherry tunnels that serve the Cherry/ Holm hydroelectric development."} — Hetch Hetchy Text FINAL.qxd · confidence: high - Timeline.2: {"event":"Cherry Powerhouse construction began","date":"1958-09-16","detail":"Construction of the Cherry Powerhouse began."} — Hetch Hetchy Text FINAL.qxd · confidence: high - Timeline.3: {"event":"Power and water tunnels completed","date":"1960-06-17","detail":"The Cherry Power and Eleanor-Cherry tunnels were completed."} — Hetch Hetchy Text FINAL.qxd · confidence: high - Timeline.4: {"event":"Commercial operation began","date":"1960-08-01","detail":"The Cherry Powerhouse began commercial operation; the facility was later known as Dion R. Holm Powerhouse."} — Hetch Hetchy Text FINAL.qxd · confidence: high - Timeline.5: {"event":"Powerhouse renamed","date":"1967-08-25","detail":"The powerhouse was named after Dion R. Holm, a former San Francisco City Attorney and Hetch Hetchy counsel."} — Hetch Hetchy Text FINAL.qxd · confidence: high - Timeline.6: {"event":"Rehabilitation financing issued","date":"2015-05-20","detail":"SFPUC issued its tax-exempt Power Revenue Bonds, 2015 Series A, including proceeds for rehabilitation of Hetch Hetchy hydropower facilities and the Holm Unit 2 improvement program."} — Green Bond Report · confidence: high - Timeline.6: {"event":"Rehabilitation financing issued","date":"2015-05-20","detail":"SFPUC issued its tax-exempt Power Revenue Bonds, 2015 Series A, including proceeds for rehabilitation of Hetch Hetchy hydropower facilities and the Holm Unit 2 improvement program."} — Source · confidence: high - Timeline.7: {"event":"Cherry Tunnel rehabilitation improved powerhouse production","date":null,"detail":"Mitchell Engineering rehabilitated the Cherry Tunnel rock trap and reported that the work improved power production from the powerhouse by 10 percent; the project page does not provide a completion date."} — Cherry Tunnel | MITCHELL ENGINEERING · confidence: medium - Commercial parties.0: {"relationship":"Owner, through SFPUC","name":"City and County of San Francisco","detail":"The City owns the Hetch Hetchy Power System, of which Holm is one of three hydroelectric powerhouses.","official_url":"https://www.sf.gov/"} — Hetch Hetchy Power System · confidence: medium - Commercial parties.1: {"relationship":"Operator","name":"San Francisco Public Utilities Commission (SFPUC)","detail":"SFPUC owns and operates all aspects of the Hetch Hetchy Power System and operates the Holm facility for the City and County of San Francisco.","official_url":"https://www.sfpuc.gov/"} — Hetch Hetchy Power System · confidence: high - Commercial parties.2: {"relationship":"Project-finance issuer","name":"San Francisco Public Utilities Commission (SFPUC)","detail":"SFPUC issued the Power Revenue Bonds, 2015 Series A, whose proceeds financed rehabilitation of Hetch Hetchy hydropower facilities, including Holm Unit 2 improvements.","official_url":"https://www.sfpuc.gov/"} — Source · confidence: high - Commercial parties.2: {"relationship":"Project-finance issuer","name":"San Francisco Public Utilities Commission (SFPUC)","detail":"SFPUC issued the Power Revenue Bonds, 2015 Series A, whose proceeds financed rehabilitation of Hetch Hetchy hydropower facilities, including Holm Unit 2 improvements.","official_url":"https://www.sfpuc.gov/"} — Green Bond Report · confidence: high - Commercial parties.3: {"relationship":"Cherry Tunnel rehabilitation contractor","name":"Mitchell Engineering","detail":"Mitchell Engineering performed rock-trap rehabilitation work in the Cherry Tunnel, which serves the powerhouse’s power-generation and water-delivery functions; the project owner was identified as San Francisco Public Utilities (Hetch Hetchy).","official_url":"https://www.mitchell-engineering.com/"} — Cherry Tunnel | MITCHELL ENGINEERING · confidence: medium - Quality notes.0: No separate acquisition, sale, predecessor owner, sale consideration, or portfolio transaction is identified for this exact plant; the historical record instead describes municipal development and continuing City/SFPUC ownership and operation. — Hetch Hetchy Power System · confidence: medium - Quality notes.0: No separate acquisition, sale, predecessor owner, sale consideration, or portfolio transaction is identified for this exact plant; the historical record instead describes municipal development and continuing City/SFPUC ownership and operation. — Hetch Hetchy Text FINAL.qxd · confidence: medium - Quality notes.1: The 2015 Series A financing covered multiple Hetchy Power rehabilitation projects. The disclosed $32.025 million original par amount and $30.2 million of project-fund proceeds are bond-issue figures, not a Holm-only allocation or sale value. — Green Bond Report · confidence: high - Quality notes.1: The 2015 Series A financing covered multiple Hetchy Power rehabilitation projects. The disclosed $32.025 million original par amount and $30.2 million of project-fund proceeds are bond-issue figures, not a Holm-only allocation or sale value. — Source · confidence: high - Quality notes.2: Holm Unit 2 is described as receiving reliability and efficiency improvements, including replacement of supporting components and auxiliary systems; the available record does not characterize this work as a full repowering or retirement. — Green Bond Report · confidence: medium - Quality notes.2: Holm Unit 2 is described as receiving reliability and efficiency improvements, including replacement of supporting components and auxiliary systems; the available record does not characterize this work as a full repowering or retirement. — 150079 - PUC Ltr 112414 · confidence: medium ## Timeline - 1960-08-01 — Commercial operation began The Cherry Powerhouse began commercial operation; the facility was later known as Dion R. Holm Powerhouse. Source: Hetch Hetchy Text FINAL.qxd (https://www.sfpuc.gov/sites/default/files/about-us/HH_historybook-2005.pdf) - 1967-08-25 — Powerhouse renamed The powerhouse was named after Dion R. Holm, a former San Francisco City Attorney and Hetch Hetchy counsel. Source: Hetch Hetchy Text FINAL.qxd (https://www.sfpuc.gov/sites/default/files/about-us/HH_historybook-2005.pdf) ## Sources - [Hetch Hetchy Power System](https://www.sfpuc.gov/about-us/our-systems/hetch-hetchy-power-system) — sfpuc.gov · tier regulatory - [Plant Name Unique ID ORIS Code AZNM_AZ_Coal Steam ...](https://downloads.regulations.gov/EPA-HQ-OAR-2003-0079-1030/content.pdf) — downloads.regulations.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 - [Power plant profile: Dion R Holm, US](https://www.power-technology.com/data-insights/power-plant-profile-dion-r-holm-us/) — power-technology.com · tier other - [150079 - PUC Ltr 112414](https://sfgov.legistar.com/View.ashx?M=F&ID=3479201&GUID=4152AFC5-80A0-4C0B-81C5-13631A6C10F5) — sfgov.legistar.com · tier other - [Hetch Hetchy Text FINAL.qxd](https://www.sfpuc.gov/sites/default/files/about-us/HH_historybook-2005.pdf) — sfpuc.gov · tier regulatory - [ch Hetchy Capital Improvement Programs Het Quarterly Report – Fiscal Year 2020-2021](https://www.sfpuc.gov/sites/default/files/documents/FY20-21_HHCIP_Qtrly_Report_1-4.pdf) — sfpuc.gov · tier regulatory - [Turbines for hydropower plants](https://www.andritz.com/products-en/group/products/turbines-hydropower) — andritz.com · tier other - [Green Bond Report](https://www.sfpuc.gov/sites/default/files/about-us/policies-reports/FY24_PowerGBR.pdf) — sfpuc.gov · tier regulatory - [Source](https://www.sfpuc.gov/sites/default/files/about-us/policies-reports/FY24_PowerEnterprise-AnnualDisclosure.pdf) — sfpuc.gov · tier regulatory - [Cherry Tunnel | MITCHELL ENGINEERING](https://www.mitchell-engineering.com/projects/sf-ba/n-cal/cherry-tunnel/) — mitchell-engineering.com · tier other - [How Drinking Water Powers San Francisco – SFPUC](https://waterpowersewer.wordpress.com/2019/09/26/how-drinking-water-powers-san-francisco/) — waterpowersewer.wordpress.com · tier other - [150079 - PUC Ltr 112414](https://sfgov.legistar.com/View.ashx?GUID=4152AFC5-80A0-4C0B-81C5-13631A6C10F5&ID=3479201&M=F) — sfgov.legistar.com · tier other ## Data quality - No separate acquisition, sale, predecessor owner, sale consideration, or portfolio transaction is identified for this exact plant; the historical record instead describes municipal development and continuing City/SFPUC ownership and operation. The 2015 Series A financing covered multiple Hetchy Power rehabilitation projects. The disclosed $32.025 million original par amount and $30.2 million of project-fund proceeds are bond-issue figures, not a Holm-only allocation or sale value. Holm Unit 2 is described as receiving reliability and efficiency improvements, including replacement of supporting components and auxiliary systems; the available record does not characterize this work as a full repowering or retirement. The 180.2 MW figure is the plant-level EIA capacity. The SFPUC history separately reports generator ratings in kVA, so those ratings are not converted into an additional MW figure here. --- Canonical page: https://askthegrid.com/assets/facilities/dion-r-holm Source: Ask the Grid — https://askthegrid.com/