AN ACTION PROGRAM FOR CONSERVING WATERS OF THE COLORADO RIVER, USA Abstract The Colorado is one of the world's great rivers o One of the longest on the North American Continent, it rises in the Rocky Mountains of the United States of America 14,000 feet above sea level, and flows 1,400 miles south­ westwardly through deep canyons and across desert valleys, to empty into the Gulf of California on the Pacific Ocean. The Colorado River has been manls lifeline in the southwest since he settled in the basin 2,000 years ago. The river continues to be a lifeline, but the demands of an exploding population have placed new strains on the stream's insufficient water supply. The Federal Government established the Colorado River Indian Reservation in 1865 near Parker, Arizona. And 2 years later, a white man named Jack Swilling diverted water from the Salt River to grow food and forage near Phoenix, Arizona. The Federal Reclamation development of the Colorado River Basin began in 1903, a year after passage of the National Reclamation Act, with authorization of the Salt River Project in central Arizona. The Yuma Project, authorized in 1904, became the first Reclamation project on the lower Colorado River. Multipurpose Hoover Dam, completed in 1935, controlled the Colorado River for the first time. This pioneer or forerunner of the great Reclamation dams serves a multiplicity of purposes, including flood control, improvement of navigation and river regulation, water storage for irrigation, domestic and industrial uses, hydroelectric power generation, recreation, fish and wild­ life benefits, and sediment control. Hoover Damqs control of the Colorado River made it possible to construct the All-American Canal System and other projects downstream. Hoover Dam stood for many years as the only major storage structure on the river. Completion of Glen Canyon Dam, 370 miles upstream, in 1964 has afforded additional and similarly effective control. Glen Canyon Dam is the backbone of the revenue-producing Colorado River Storage Project, authorized in 1956. Other storage units of this project are Flaming Gorge Dam on the Green River, Navajo Dam on the San Juan River, both completed, and three dams on the Gunnison River, two of which are under construction. The project's hydroelectric powerplants will have 1.3 million kilowatts of installed capacity. There are 28 participating irrigation proj­ ects, now in all stages from early planning to completion, which will benefit nearly 1.5 million acres of land in the project area. The inadequacy of the Colorado River to meet the water needs of the Colorado River Basin has highlighted the need to seek new sources of water, and to conserve that now available. Accordingly, the Department of the Interior has proposed the Pacific Southwest Water Plan, which calls for conservation and development of water resources on a regional basis. The plan recommends a 5-State regional complex of dams, hydroelectric plants, aqueducts, canals, water salvage, and conservation programs. Meanwhile, the Bureau of Reclamation is active in water salvage and conservation programs such as channelization, phreatophyte eradication, evaporation control studies, groundwater recovery, and sea water desalinization studies. All of these programs are aimed at the conservation and utilization of e~ery available drop of water in the Colorado River Basin. 2 AN ACTION PROGRAM FOR CONSERVING WATERS OF THE COLORADO RIVER, USA Paper by Assistant Commissioner Gilbert C. Stamm, Bureau of Reclamation, United States Department of the Interior, for presentation at Sixth Regional Conference on Water Resources Development, sponsored by the Economic Commission for Asia and the Far East, Bangkok, Thailand, November 12-19, 1964 Historical The Colorado River in North America--like the Mekong River in Southeast Asia--is one of the great rivers of the world. Both are lifelines--the Colorado River to the Pacific Southwestern United States of America and the Mekong River to the Asian States, This paper is about the Colorado River--the old and the new in its million-year history. The Colorado River is one of the longest rivers on the North American Continent. It rises in the snowcapped mountains of the northcentral part of the State of Colorado at an altitude of 14,000 feet, and zigzags southwestwardly for 1,400 miles to pour into the Gulf of California. The Colorado River's basin covers 242,000 square miles in the United States, or one-twelfth of the country's continental land area, and 2,000 square miles in Mexico. Parts of seven large Western States drain into this mighty river system. Through the ages, the river has slashed great gorges and chasms like world- famous Grand Canyon--a titanic cleft 217 miles long, from 4 to 18 miles wide, and a mile deep. From lofty mountain tops and through deep canyons, the river makes its way across desert plains bordered by mountain ranges--the hottest, driest region in the United States, where temperatures run as high as 125 degrees Fahrenheit, and rainfall as low as an average of 3 inches a year. Man's trek to the banks of the Colorado River and its tributaries began 2,000 years ago. The Ho-ho-kam Indians (meaning people who are gone) settled in the Salt River Valley of Arizona along the banks of the Salt and Gila Rivers, tributaries to the Colorado River. When the Spaniards arrived centuries later looking for gold and new territories to claim, they found dried-up canals and other remains of this ancient civilization. The Ho-ho-kam had left. Why? Perhaps their brush dams on the Salt and Gila Rivers could not control the floods and store water for their crops; or, it might have been because their lands became waterlogged. Historians just don't know. The Spaniards found Indians living along the Colorado River and its tribu­ taries. These Indians--who are believed to have migrated to the North American mainland from Asia many centuries ago--planted corn, squash, and other seeds along the riverbanks, letting spring floods irrigate and sprout them. Later on in the summer these early settlers dipped water from the streams to hand-irrigate their meager crops. Man's dependence on the Colorado River has grown with migration from east to west, across the North American continent. Colorado River water has been a major determining factor in the rapid population and industrial growth of the Colorado River Basin States into which several thousand people are pouring daily. This growth has far outstripped the Colorado River Basin's water supply and that supply which one day seemed limitless is now being overdrawn. Today, more than 10 million people in the basin depend on water and power benefits from the Colorado River. The river annually irrigates more than a million acres of farmland, generates nearly 2 5 billion kilowatt-hours of hydroelectric energy, and provides vast bodies of water for recreation, fish and wildlife. First Irrigation Step by step over the last 100 years, man has put to use the Colorado River's water. The river's development, as we know it today, began in 1865 when the United States Congress established the Colorado River Indian Reservation on the lower river to provide for settlement of several tribes. Meanwhile, a pioneer named Jack Swilling in 1867 dug a ditch from the Salt River through what is now the heart of Phoenix, Arizona, and irrigated a sizeable acreage of food and fiber. Some years later, in the early 1880's, Thomas H. Blythe established the white man's first irrigation development in the Palo Verde Valley of California on the Colorado River. Near the turn of the century, private irrigators diverted Colorado River water to Imperial Valley in California through the old Alamo River bed which ran in part through Mexico. At this same time, settlers along the Colorado and Gila Rivers near Yuma, Arizona, were irrigating adjacent flood plain lands from those streams and more remote areas from wells. But farming was uncertain, and often disastrous. These streams were often rivers of mud when spring floods swept away farms and towns. Conversely, they became rivers of dust when they dried to a trickle in the late summer and fall. Then, crops, livestock, and man thirsted, suffered and often died. Without upstream control, there was either too much or too little water. 3 Though underdeveloped and erratic, the muddy Colorado River was manls life­ line in this arid area. He settled out the red mud and drank the water. He diverted the river--mud and all--onto his fields. He learned how the river got its name "Colorado," meaning "red." Federal Development Began in 1902 It took a great catastrophe to spur man to push for control of the Colorado River. In 1905, the river broke through its banks below the Mexican border and for 2 years flowed unchecked into Imperial Valley of southern California-­ forming the Salton Sea which still exists as mute testimony to the river's vagaries. Similar tragedies--resulting in great losses of life and property-­ occurred elsewhere on the river and its tributaries. Settlers pleaded for help--for protection against the river. Many people in authority heard them--understood their problems. Among these was President Theodore Roosevelt, 26th President of the United States. The settlers, however, lacked the money and knowledge to build the dams and canals needed to give them a year-round regulated water supply. Congress, therefore, in 1902 provided the means for furnishing both money and technical assistance by passing the Reclamation Act. The Act, amended since to encompass all of the multipurposes of water resources development, launched the Federal Reclamation program. The Salt River Project in central Arizona on the Gila River, a tributary of the lower Colorado River, was authorized a year later and construction followed.