Garrison Hydroelectric Power Dam -- Riverdale ND USA
N 47° 30.125 W 101° 25.836
14T E 316955 N 5263824
When Garrison Dam was built in 1960, its hydroelectric power station was state-of-the-art. 47 years later, the components were enlarged and replaced with state-of-the-art components
Waymark Code: WM17GCT
Location: North Dakota, United States
Date Posted: 02/17/2023
Views: 1
The small transformer house next to the much larger Garrison Dam Hydroelectric Powerhouse served its purpose well for over 40 years, but was obsolete by 2007, when a new project was awarded to replace and upgrade the obsolete transformers with 21st century equipment.
From the Hydroview Industry publication: (
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"U.S. awards Garrison Dam hydro project transformers contract
By -
4.7.2010
The U.S. Army Corps of Engineers awarded a contract for replacement transformers and and site modifications at the 517.8-MW Garrison Dam hydro project on the Missouri River in Garrison, N.D.
The $4.9 million contract was awarded to Texas-based IES Commercial Inc.
The Corps’ Omaha District hired L&S Electric in 2007 to retrofit governors at the hydroelectric project.
The transformer work is to include removal of six single-phase 115-kV GSU transformers, reconstruction of the transformer deck to accommodate two new 115-kV three-phase GSU transformers, removal and replacement of the isolated phase bus, replacement of oil-filled high-voltage cables with solid-dielectric high-voltage cables, replacement of the generator neutral grounding system, installation of a transformer deluge and containment system, replacement of transformer controls and relaying, replacement of the annunciation system, and synchronization of potential transformers."
From the US Army Corps of Engineers Omaha District website, some history of Garrison Dam: (
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"Since its opening in 1960, Garrison Dam has provided the hydropower and flood control potential envisioned by Colonel Pick and others who directed its development. USACE has worked with the Bureau of Reclamation to use Garrison pool to irrigate 250,000 acres. The Garrison Dam has also provided a steady flow of water for navigation as well as generating hydropower.
The power plant has five generating units that produce an annual average 2.6 million mega-watt hours of electricity, valued in excess of $39 million in revenue. Electricity is transmitted from the power plant through seven transmission lines to various substations and is marketed by Western Area Power Administration."