The Colorado River, Mojave language 'Aha Kwahwat, Spanish: Río Colorado (Red River),[2] is a river in the Southwestern United States and northwestern Mexico, approximately 2,330 kilometers (1,450 mi) long, draining a part of the arid regions on the western slope of the Rocky Mountains. The natural course of the river flows from 25 km (16 mi) north of Grand Lake, Colorado into the Gulf of California between the Baja California peninsula and mainland México. Due to large irrigation diversions for California's Imperial Valley through the All - American Canal, and to a much lesser extent irrigation diversions for Arizona, the river is severely dewatered below Yuma, Arizona, resulting in it no longer consistently reaching the Gulf and Sea of Cortez.
The watershed of the Colorado River covers 629,100 km2 (242,900 sq mi) in parts of seven U.S. states and two Mexican states. Total flows of the river range from 113 m3/s (4,000 cu ft/s) in droughts to 28,000 m3/s (990,000 cu ft/s) in severe floods. With the construction of massive power dams on the lower course of the river, flows of over 2,000 m3/s (71,000 cu ft/s) are unusual. The mean flow of the river was 620 m3/s (22,000 cu ft/s) during the period between 1903-34. From 1951-80, the average flow was less than 110 m3/s (3,900 cu ft/s).
Historically the flow was much higher before water usage began in the basin.
Source: http://en.wikipedia.org/wiki/Colorado_River
