Big Cottonwood Creek is located in the Wasatch Mountains just east of Salt Lake City. It is part of the Big Cottonwood Creek Watershed, which ranges in elevation from 5,000 to 10,500 feet with the headwaters around 9,600 feet. The creek flows through the Big Cottonwood Canyon in a westerly direction until it emerges into Salt Lake Valley about from its highest source. Thence its course is northwesterly through Cottonwood Heights, Holladay, and Murray, Utah for a little over twenty-four miles miles from the headwaters (39 km) until it empties into the Jordan River about south of Salt Lake City. The water eventually flows into the Great Salt Lake. In the summer, its waters are all used for irrigation purposes. From its source to its original outlet in the Jordan River is about twenty-six miles. Hydrology The creek flows from around at the headwaters to around when it reaches the confluence with the Jordan River. The stream flows northwest as it leaves the headwaters near the Brighton Ski Resort and then travels southwest about halfway down the canyon near Reynolds Gulch. At the base of the canyon, the stream leaves the Uinta-Wasatch-Cache National Forest, and a portion of the flow enters the Big Cottonwood Treatment Plant to provide municipal drinking water. At this point, the stream again flows northwest until the confluence with the Jordan River around the Murray area. Rock glaciers, which are high elevation rock landforms, exist throughout the upper reaches of the canyon. Their bedrock commonly consists of Paleozoic quartzites and carbonates, Mesozoic mets-sedimentary and meta-volcanic rocks, and Cenozoic granitic and gneissic intrusions. These rock glaciers create mountain reservoirs, which are very significant as Utah is prone to severe and extreme droughts. These reservoirs allow the formation and accumulation of ice that is better insulated against rapid changes in air temperature and weather. They are able to sustain very stable conditions. They hold a large amount of water in the Big Cottonwood Watershed. The source waters at the top of the canyon begin near the Brighton Ski Resort and flow from Silver Lake, Twin Lakes Reservoir, Lake Mary, Lake Martha, Lake Catherine, and Dog Lake. Additionally, precipitation and many tributaries along the canyon contribute to Big Cottonwood Creek's water volume. Brighton receives over of precipitation annually, most in the form of snow. 400 inches of total annual snowfall is measured. The average water yield of Big Cottonwood