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WATER EDUCATION AND INSTITUTIONAL DEVELOPMENTLong-term planning investments payingdividends: the Colorado River Basin WaterSupply and Demand StudyCarly Jerla, Co-Study Manager and Ken Nowak, Bureau of Reclamation; Kay Brothers, Co-Study Manager,Southern Nevada Water Authority consultant; Armin Munevar, CH2M Hill; Les Lampe, Black & Veatch;David Groves and Jordan Fischbach, RAND CorporationFlowing more than 2,300 km from source to sea, theColorado River drains a basin of about 637,000 squarekilometres, covering roughly a twelfth of the contiguousUnited States. The watershed includes parts of seven US states(Arizona, California, Colorado, Nevada, New Mexico, Utah andWyoming) and two states in northern Mexico (Baja Californiaand Sonora).About 40 million people depend on drinking water from theColorado River and its tributaries. Additionally, the river irrigatesnearly 5.5 million acres (2.2. million hectares) of farmland and fuelshydropower facilities that generate more than 4,200 megawatts ofpower. It is the force that carved the Grand Canyon and is the lifebloodfor more than 20 Native American tribes and communities,seven national wildlife refuges, four national recreation areas, andeleven national parks.Because the Colorado supports such diverse resources, managingthe river has become a complex, multi-objective exercise thatinvolves stakeholders and resource management entities such as thefederal Government, Native American tribes and communities, stateagencies, municipalities and agricultural districts, advocacy groups,non-governmental organizations and local governments. It is inevitablethat these interests often are in conflict – managing the riverequitably requires a strong commitment by all parties.Reservoir management largely falls within the purview of theSecretary of the US Department of the Interior, and the Bureauof Reclamation (Reclamation) is the agency designated to act onthe Secretary’s behalf. Reclamation is the largest wholesale watersupplier in the United States, and numerous Reclamation projectsare located in the Colorado River basin, including Glen CanyonDam and Hoover Dam, which are effectively bookends for theGrand Canyon. As the water master for much of the river corridor,Reclamation is charged with advancing sound management of thisessential resource.Broad water conflicts began to emerge in the Colorado River basinin the early 1900s. Over the century that followed, entities associatedwith the river struck numerous compacts, treaties, settlementsand other agreements – some amicably and some through hardfoughtlitigation. Collectively, these comprise the ‘Law of the River’.The core of the Law of the River is a series of apportionments withinthe United States, and between the United States and Mexico, whichdate back over half a century. Unfortunately, theseagreements were based on a limited flow record thatdoes not reflect the river’s long-term average annualyield. As apportionments continued to develop, sizeabledams and their associated reservoirs were constructedalong the river to buffer the significant variability inyear-to-year flow. Since the early 1950s, there have beena number of years when the annual water use in theColorado River basin exceeded the yield; these shortageswere avoided only through the stored water. In thisregard, the Colorado River is unique – the river’s totalstorage capacity is about four times the mean annualnatural yield of the river basin.The Colorado River basinSource: Bureau of Reclamation[ 115 ]