Water for a growing city
Cheesman Dam was created at the beginning of the 20th century to provide water for the industrial and population growth of Denver. To grow, frontier Denver needed 200 gallons a day for each resident and more for industry and electrical power. As consulting engineer James D. Schuyler observed: "If Denver depended on Cherry Creek alone, her future water supply would be somewhat precarious."
The decisive moment came as the turn of the century approached. "Boosters" were eager to see Denver become the major city between Chicago and the Pacific. If they succeeded, Denver would be unique — a landlocked metropolis without even river access to the sea.
It also was the era of Teddy Roosevelt, Frederick L. Olmsted and John Muir, the beginnings of the National Parks, U.S. Forest Service and the Sierra Club. "Conservation" was rising to public consciousness, and the idea of preserving our natural heritage while adapting the land to our needs was in the air.
From the founding of the city of Denver in 1859, water companies had jockeyed to control the precious commodity which was, quite literally, a "life or death" proposition. As a folk saying in the San Luis Valley put it, "No agua, no vida." Water rights were appropriated, ditches were dug and wagons were hauled to provide a week's worth of water to homeowners.
It was an approach that served the needs of a tiny ambitious town, but it was not an approach that lent itself to building a city on the plains.
Storage needed
Then in 1878, John Wesley Powell published his Report on the Lands of the Arid Region, arguing that water storage was necessary for urbanizing "the Great American Desert." Powell's examples were drawn from Utah data, but civic leaders eager to secure Denver's future were listening. It became clear that Denver needed a major reservoir. But where should it be built?
The first plan was to build Strong Reservoir, contained by two earthen dams below Deer Creek, nestled against a hogback west of today's Colorado 121. The two proposed dams would have been huge: 275 feet high, 1,000 feet thick. A conduit would have brought water from the South Platte; another would have carried the water to the city, totaling 150 miles of pipe.
Work began in 1889, and in 1892, Frank Leslie's Illustrated Weekly enthused over the monumental project, which would have held about 30,000 acre-feet of water. It was an ambitious project – two enormous piles of earth, blocking the cut that feeds Little Deer Creek into the South Platte. At 1,000-feet thick, the "footprint" of each dam would have been more than three times the size of the final design for Cheesman. But the total storage capacity of the two dams together would have been less than half what Cheesman could hold.
Important fishing trip
In 1893, this project was replaced with a visionary alternative: a 200-foot wonder that would hold almost 80,000 acre-feet of water. The water would be enough to fill a swimming pool extending from Denver's City Park to Alameda Avenue and from Colorado Boulevard to Broadway, 10 feet deep. The lead engineer of the Strong project, C. P. Allen, had taken a fishing expedition up the South Platte River, above the confluence of the north and south forks of the South Platte and a few miles upriver from present-day Deckers. While fishing, he found a canyon that would become the model for western dam sites: deep and narrow, with huge potential storage above it. One dam, considerably smaller than the proposed Strong Dam, could hold more than twice the storage.
Strong Reservoir was abandoned. Crews assembled in the mountains fifty miles outside of Denver and began construction in the South Platte canyon. When the record floodwaters of 1900 wrecked their work, they started again with a new design, controversial but better suited to the rough handling they could expect from the South Platte. Five years later, water spilled over the top of Cheesman Dam.