Photos: Dillon Reservoir aerials, July 2021

This page features drone-captured imagery of Dillon Reservoir in Summit County, Colorado.

Created by a 231-foot-tall earth-fill dam, Dillon Reservoir contains over 250,000 acre-feet of water when at full capacity. The reservoir supplies water to Denver and its neighboring cities by diverting water from the Blue River Basin under the Continental Divide through the Harold D. Roberts Tunnel.

Dillon Reservoir was built to accommodate the growing water needs of Denver, although getting the water across the Divide was no simple task. The fully lined, 23.3-mile tunnel took 20 years to complete, with construction beginning in 1942 and ending just before the reservoir’s completion in 1963. The inner diameter of Roberts Tunnel is 10.25 feet, which allows for a flow of up to 1,020 cubic feet per second. On average, around 60,000 acre-feet of water passes through the tunnel annually.

Dillon Reservoir became the largest water storage facility owned and operated by Denver Water—Colorado’s oldest and largest water utility. Each year, Dillon Reservoir provides about 40% of the water used by Denver Water’s 1.3 million customers.

Learn more:

DateJuly 2021
LocationDillon Reservoir, Colorado (map)
CreditTed Wood/The Water Desk
RightsFree to reuse under Creative Commons license.

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