<P> The compact was the fruit of several years of negotiations among the states . The seven states had previously formed the League of the Southwest in 1917 to promote development along the river . In 1921 , Congress authorized the states to enter into a compact for allocation of the river resources . The agreement was approved by Congress in 1922 , the same year it was signed . Colorado River Compact was signed by the delegates from the seven Colorado River Basin states : Wyoming , Colorado , Utah and New Mexico were designated Upper Basin states and California , Arizona and Nevada as the Lower Basin states . This compact determined that the water would be shared equally among the upper and lower basin states . Prior to the compact , the name of the river was standardized along its length . Previously the portion of the river upstream from its confluence with the Green River had been known locally as the `` Grand River '' . The change was opposed by many local residents in Utah and Colorado , and the new name was enforced locally by acts of the state legislatures in both states in the early 1920s . One of the major concerns both today and back in the 1920s was the expanding population , and this increased the demand for water , particularly in California . In more recent years , mainly because of Las Vegas , Nevada has been looking for more use of the Colorado River . </P>
who decides where the water from the colorado river goes
Wyoming Colorado Utah New Mexico California Arizona Nevada