Denver Water will be closing Cheesman Canyon, which includes the upper and lower Gil Trail, from Monday, Sept. 10, through Thursday, Sept. 13, to test the new valve system at Cheesman Dam. During the testing, the South Platte River flows in Cheesman Canyon will reach as high as 760 cubic feet per second. Currently, the flows are around 250 cubic feet per second.
“These conditions are too dangerous for recreation activities, especially fishing,” said Neil Sperandeo, manager of recreation. “The good news is that the high flows will flush sediment out of the river, improving the conditions for aquatic life.”
Denver Water is coordinating the testing with Colorado Parks and Wildlife and area fishing clubs. Fluctuating flows will be noticeable for 12 miles down the South Platte River from the canyon.
The new valves were installed as part of a project to upgrade the dam, which was built in 1905. This two-and-a-half year, $18.3 million project began in 2010, and included a specialized diving operation to install underwater valves.
The dam’s valve system controls the amount of water flowing from the reservoir into the South Platte River.