In 1891, Larimer County Water Supply Company filed on the water flowing from Never Summer Range to the Grand (now Colorado) River. The company planned to construct a “snow ditch” to carry water to Long Draw Creek and then to the Poudre River. Water Supply and Storage Company took over the project in 1895, and the result was the first major diversion of water from the Colorado River.
The first stage of the process was constructing the Specimen ditch in 1898, which was a starter ditch that first delivered water in 1900. William Rist surveyed the main system of the Grand River Ditch. Between 1901 and 1911, the WSSC and engineer James H. Andrews constructed the main section of Grand River Ditch using manual labor and mules. Laborers included Japanese and Mexican workers. The system captured water from Bennett Creek, Ludy Creek, Lulu Creek, Sawmill Creek, Little Dutch Creek, Middle Dutch Creek, Big Dutch Creek, Lost Creek, and Mosquito Creek.
Between 1911 and 1934, the WSSC enlarged and improved the ditch to five feet wide at bottom, and eight to ten feet wide at the top, with a carrying capacity of 125 cubic feet per second. In 1935, Gordon Construction Company was awarded a contract to lengthen the ditch as far as Baker Creek. James H. Andrews served as engineer on this extension project. In 1915, Congress created Rocky Mountain National Park, and by 1937 when the ditch was finally completed, most of it fell within the park boundary. The ditch was now capable of carrying 360 cubic feet of water per second.
In 1974, WSSC sealed the ditch with a membrane liner, and in 1977 demolished the old wooden flume and replaced it with a CMP pipe. On August 12, 1975, Grand River Ditch was nominated for the National Register of Historic Places because of its significance as the largest early diversion projects from the Colorado River to the South Platte River.[1. tanley R. Case, The Poudre: A Photo History (Bellvue, CO: Stanley R. Case, 1995), 223-231; Howard Ensign Evans and Mary Alice Evans, Cache La Poudre: The Natural History of a Rocky Mountain River (Niwot, CO: University Press of Colorado, 1991), 46-47; Norman Walter Fry, Cache La Poudre: “The River” As Seen from 1889, Second Printing, 24; William R. Kelly, A Compilation and Comment on Fifty Years, 1870-1920: I. Engineers and Ditch Men Developed on the Cache la Poudre, 1870-1920. II. “Ditch Men”, Water Hunters of That Fifty Years, Not Engineers, (not published, 1967), 13.]