- Start
- Jun 3, 202690% CONFIDENCEfrom the source
Gross Dam Raise Tops Out at 470 Feet
- Denver Water placed the final load of roller-compacted concrete on 3 June 2026, bringing Gross Dam to 470 feet, about 130-131 feet higher, the tallest dam in Colorado[2][3]
- RCC was placed over three years to raise, thicken and lengthen the dam; more than 744,000 cu yd of RCC and 59,000 cu yd of conventional facing concrete had been placed by June 2026[2][3]
- One more foot of conventional protective concrete over the next year gives a final height of 471 feet[2][3]
- The project is designed to nearly triple Gross Reservoir's capacity and raise Denver Water's storage by 11%; program manager Jeff Martin said the gravity-to-arch dam transformation had not been done before anywhere in the world[3]
- Kiewit still has the crest, spillway, stilling basin and mechanical, electrical, instrumentation and security works to finish; overall completion is expected October 2027[2]
References 386% CONFIDENCE
The first entry is always the pin's source. Overall confidence is a weighted average of how firmly each reference supports the start and end times used above; a reference counts half as much for every 180 days older than the newest.
- [1]90%youtube.com/watch?v=5uh6qLtPpV8youtube.com· Posted Sep 14, 2026· Starts Jun 3, 2026 ✓· 36% of score
Happened as dated, per the source: "workers placed the final load of roller-compacted concrete on the top of the dam, bringing Gross Dam to a height of 470 feet."
- [2]78%Gross Reservoir dam raise hits major construction milestonewaterpowermagazine.com· Added Sep 14, 2026· 36% of score
Water Power Magazine corroborates the June 2026 milestone, reporting the contractor "completed all roller compacted concrete (RCC) placement" bringing the dam to 470 feet, with only structural concrete and mechanical work remaining before full completion expected by October 2027.
- [3]92%Gross Dam construction milestonedenverwater.org· Published Jul 20, 2026· 29% of score
Denver Water's own account confirms "On June 3, 2026, workers placed the final load of roller-compacted concrete on the top of the dam, bringing Gross Dam to a height of 470 feet" - matching the pin's stored date exactly.
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United States Bureau of Reclamation
