Contested Waters: An Environmental History of the Colorado River

3: Saving the River The Environmental Movement

61 Saving the River The Environmental Movement In 1963, the eleven-year Supreme Court case Arizona v. California finally ended, seemingly resolving the last major conflict in a forty-year struggle over sharing the Colorado River. Yet before Arizona could finally tap the main stream, a young and growing environmental movement challenged the entire policy of western water development . The river itself was becoming a power player in the struggle over water as its deteriorating riparian ecosystem began demanding attention. Western water users reluctantly moved away from big dams and project building toward preservation and restoration policies. One of the sharpest realities water users gradually faced was the fact of scarcity. For all the divisions and negotiated allocations , there was simply not enough water. Altered River Environment Overmanymillennia,thepowerfulflowoftheColorado River carved out many canyons along its path on its nearly 3 saving the river 62 1,500-mile journey to the sea. At first, the only canyon anyone knew much about was the Grand Canyon, first sighted by Europeans in the sixteenth century. Later, in the 1920s, Bureau of Reclamation engineers paid considerable attention to Black Canyon and Boulder Canyon along the present-day California-Arizona border as potential sites for the first large dam on the river. There are many more canyons, however, all of them beautiful in their own ways. The first canyon beneath the river’s headwaters in the Rocky Mountains of Colorado is Little Yellowstone Canyon. Named after a similar canyon in Wyoming’s Yellowstone National Park, the river carved this canyon out of volcanic ash and lava layers. Then the river passes through a string of other canyons—Byers, Gore, Glenwood,DeBeque,Ruby,andWestwater—beforereachingCanyonlandsNational Park and then Lake Powell, the now flooded Glen Canyon. Below Glen Canyon the river enters Marble Canyon just before entering the Grand Canyon and then exiting through Boulder Canyon, now part of Lake Mead. Hoover Dam stands astride Black Canyon, and below it the river naturally ran through a lower course and historically wandered over a larger floodplain. Although today the river is tightly channeled and reduced to a small stream by the time it reaches the US-Mexico border, the Colorado once flowed into a large delta area full of rich marshes that provided habitat for many species of fish and birds. The part of the delta that remains must be artificially enhanced with water, usually salty agricultural runoff. In earlier times, the delta regularly experienced a tidal bore or wave when tides in the Gulf of California sent seawater partway up the mouth of the Colorado River around Montague Island at the mouth of the delta. This island is an active breeding ground for at least seven species of waterbirds. The delta region as a whole was home to a large variety of wildlife species, but today some of them are gone, and at least five are listed as endangered: the desert pupfish, Yuma clapper rail, delta clam, vaquita porpoise, and bobcat. Along its length, humans have harnessed the Colorado with seven major dams on the main stem and dozens more on its tributaries. From north to south, these dams are the Glen Canyon, Hoover, Davis, Parker, Imperial, Laguna, and Morelos. Above Glen Canyon in the upper basin, the Aspinall Unit on the Gunnison River has three dams: Blue Mesa, Morrow Point, and Crystal. On the Green River in northeastern Utah is Flaming Gorge Dam and its large reservoir. Navajo Dam bridges the San Juan River in New Mexico. While many other tributaries and their dams all contribute to the storage and diversion of Colorado River water, these major dams are the ones that have contributed the most to the changing river ecosystem. Probably the most significant impact of damming the Colorado River is on its fish species. Ecologically isolated from other watersheds, the Colorado was once home saving the river 63 to perhaps sixteen species found nowhere else.1 These fish are usually not considered valuable or desirable for human consumption, as are trout and salmon, but some were heavily fished and appreciated as recently as the 1930s. The Colorado pikeminnow (previously named squawfish) is the largest fish in the river and at one time served as a major food supply for native communities and later European arrivals.2 The pikeminnow is at the top of the food chain, and its decline indicates two primary problems . First, if a top predator declines, it indicates...