27 May 2009
United States Balances Competing Needs for Colorado River Water
Methods for negotiating water demands developed over time
Littleton, Colorado — In the arid western United States, water is vital and scarce. Constant, competing demands for water must be met by the Colorado River. Water from the Colorado River affects more than 26 million people — it is used by industries, for hydroelectric power generation, for recreation and mineral production, plus for the needs of livestock and wildlife. About 1.6 million hectares (4.5 million acres) of agricultural land in Mexico and the United States are irrigated from this river.
“It is a big balancing act” to try to satisfy the competing users and interests that need Colorado River water, Robert King, chief of interstate streams with the Utah Division of Water Resources, told America.gov. Simply stated, there is not enough water in the river system to satisfy all the demand, he said.
From a huge drainage basin covering almost 632,000 square kilometers (244,000 square miles), the Colorado River supplies water to Mexico, 10 American Indian tribes and parts of seven states: Arizona, California, Colorado, Nevada, New Mexico, Utah and Wyoming.
Within each state, the highest priority for using river water goes to the oldest claims for water rights, which is referred to as “first in time, first in right,” or prior appropriation. “First priority usually goes to agricultural users for irrigation, as [modern] cities came last and therefore often have the lowest priority,” Terry Fulp, the U.S. Bureau of Reclamation’s deputy regional director for the lower Colorado region, told America.gov.
THE LAW OF THE RIVER
To help resolve disagreements among states and to share water with Mexico, a complex legal framework has been established over the years, known as “The Law of the River.” This framework includes numerous compacts, federal laws, court decisions, contracts, regulatory guidelines and a treaty that regulate the use and management of the Colorado River.
“The river is managed according to a set of laws [and legal agreements] that has evolved over time and that keeps evolving,” Bob Walsh, Bureau of Reclamation spokesman for the lower Colorado region, told America.gov.
The cornerstone of the Law of the River is the Colorado River Compact of 1922, which was negotiated by the seven Colorado River Basin states and the federal government. The compact split the river system into an upper basin (containing Arizona, Colorado, New Mexico, Utah and Wyoming) and a lower basin (containing Arizona, California, Nevada, New Mexico and Utah). Due to geography, three states are in both basins.
The compact was intended to resolve disputes among states in the upper basin, where most of the river’s water originates, and the lower basin, where most of the water demands developed and continue to grow from an ever-increasing population.
Although the agreement isn’t perfect, “all seven states realize the compact is valuable for all of us,” Pat Tyrrell, Wyoming state engineer, told America.gov. “If it was thrown out, there would be chaos.”
The compact began the complicated process of determining each state’s allotment of water. “Unfortunately, at that time the [river’s] annual flow was over-estimated, which has led to a water supply/demand imbalance in the basin,” Walsh said.
Each year, 20,352 million cubic meters (16.5 million acre-feet) of water is allocated to the seven states and Mexico. “However, over the past 100-plus years of record, the average runoff into Lake Powell [that is available to distribute] has only been about 15 million acre-feet [18,502 million cubic meters] a year,” Walsh said. “This means the Colorado River is [over-allocated], a condition exacerbated in recent years by a major drought.”
To share the Colorado River with Mexico, the Mexican Water Treaty of 1944 committed 1,850 million cubic meters (1.5 million acre-feet] of water to Mexico annually. The United States has met its obligations to this southern neighbor since that time.
TODAY’S RIVER MANAGEMENT
Modern development of the river began in the early 1900s, when the federal government started building dams, reservoirs and canals in the river basin to store, control and deliver water, and to generate hydroelectric power. Today, this river system is carefully operated, to the point where most water levels are monitored hourly, and, for example, flows from Hoover Dam can be adjusted every four seconds to meet fluctuating power demands, Fulp said.
In the lower basin, the Bureau of Reclamation serves as the “water master” on behalf of the U.S. secretary of the interior, managing the lower river and its reservoirs to meet water and power delivery obligations, provide flood control, enhance outdoor recreation opportunities and protect endangered species and native habitat.
In the upper basin, Arizona, Colorado, New Mexico, Utah and Wyoming are represented on the Upper Colorado River Commission, which has the authority to oversee the river in this region.
Throughout the entire river management process, “there is a heavy emphasis on negotiation and consultation” with all involved groups, Walsh said.
More information about the river is available at the Bureau of Reclamation’s upper Colorado River and lower Colorado River Web sites.
