Although salmon are a magnificent icon for watershed health in the Pacific Northwest, the razorback sucker and friends don't have quite the same stage-presence in parts of Colorado and Utah. Nevertheless, four endangered species of fish may lead to serious changes in water and land management practices in the Upper Colorado River basin. A recovery program that has been underway for more than a decade is attempting to take a comprehensive view of basin-wide water management and land-use practices could be altered to restore populations of these fish.
Two species native to the upper Colorado River, humpback chub and Colorado River squawfish (now pikeminnow), have been considered endangered since the 1960s and received more formal protection with the passage of the Endangered Species Act (ESA) in 1973. Federal endangered species listings followed for the bonytail in 1980 and for the razorback sucker in 1991. Utah and Colorado designated all four species as endangered in the 1970s. These fish evolved in the Colorado River basin and do not exist elsewhere. The present populations and ranges of these fish are small compared to the situation a century ago. No bonytail have been caught in the wild for several years. The rapid decline of these fish is blamed on fragmentation of habitat by dams, reduction of streamflow by diversions, and introduction of more than 40 species of non-native fish.
Initial piecemeal efforts to protect these fish were judged to be ineffective. A coordinated approach called the "Upper Colorado Endangered Fish Recovery Program" began in 1988. The key players in this program are the U.S. Fish and Wildlife Service; Bureau of Reclamation; Western Area Power Administration; states of Colorado, Utah, and Wyoming; Colorado Water Congress; Utah Water Users Association; Wyoming Water Development Association; Colorado River Energy Distributors Association, The Nature Conservancy, and Environmental Defense Fund. The program's annual funding of $2 million to $13 million has been allocated mainly to analysis of water availability for instream flow protection, restoration of wetlands, construction of fish bypasses, and hatchery programs.
One of the major components of the program has been the identification of critical habitat for the four species. A basin-wide analysis was conducted to determine which portions of the Upper Colorado River basin were essential to fish survival and recovery. Critical habitat was defined as all areas within the 100-year flood plain that provide the following attributes: sufficient quality and quantity of water needed by the fish at different life stages; spawning, nursery, feeding, and rearing sites; and an adequate food supply and other biological characteristics. A formal designation of 1,980 miles of the Colorado River and its tributaries as critical habitat was made in 1994. The four fish have similar habitat requirements, and the reaches of critical habitat overlap. However, the razorback sucker has the most extensive requirements, accounting for 87 percent of the total. Rules affecting critical habitat only apply on federal lands or areas of private property where there is some type of federal involvement. Examples of such involvement include Corps of Engineers permits for modifications of channels or wetlands or loans for soil conservation or agricultural improvements.
One type of aquatic-habitat restoration project is reconnecting the main channel with its flood plain and wetlands. The Fish and Wildlife Service estimates that half of the original wetlands of Colorado have been destroyed and about a third have been lost in Utah and Wyoming. Stream-side wetlands and side channels have been diked and drained to increase agricultural acreage. These areas were important to rearing young fish in a food-rich and predator-poor environment. Some of the dikes that isolated the river from its natural flood plain are being removed. Re-establishment of riparian vegetation has yet to be undertaken at any substantial scale. Conservation easements have been purchased to maintain or restore some riparian areas.
Another major effort of the recovery program involves altering water management. One segment of this work changes the operating rules of federal dams in an attempt to mimic natural streamflow patterns. The natural hydrographs of the Colorado River and most of its tributaries have been greatly altered by an extensive network of water management structures. Fish that evolved under the seasonal cycle of spring high flows and winter low flows apparently have had trouble adapting to the altered flow regime. Decreases in peak flows have also caused geomorphic changes in some channel segments that may be unfavorable to the endangered fish. The high degree of control over water in the Colorado River system now permits many options to create streamflow regimes that can be favorable to the fish. Changes in dam structure and operations can also restore the temperature regime of a river that may have been artificially cooled by releasing water from the lowest depths of a reservoir. Each federal water project in the basin is being evaluated for its contributions to the cumulative alterations of flow. In April 1999, the Fish and Wildlife Service found that the recovery program was a "reasonable and prudent alternative" for the operation of some 200 water projects.
Some dams in critical habitat are being considered for removal. For example, three dams in a 15-mile-long segment of the Colorado above its confluence with the Gunnison River are believed to restrict a large area of critical habitat. In 1998, the Grand Valley Irrigation Company dam was partially breached and a side channel for fish passage was installed. The Price-Stubb dam has been inoperable for 80 years and may be completely removed, except for portions of the foundation necessary to minimize channel erosion. The third dam in this series is being studied for options to allow fish passage.
Other water management work establishes instream-flow water rights for the fish. This process is particularly challenging in Colorado where water demand and water law limit the opportunity to designate water for environmental purposes. A few applications for instream water rights by the Colorado Water Conservation Board have been successful, but there has been intense opposition to these applications from water development interests. More than 150 objections were made regarding one filing, which was subsequently withdrawn in February 1999. Maintaining water availability for fish has been easier downstream. A few years ago, the state of Utah agreed to reserve its unused portion of Colorado River water to maintain favorable flows for the endangered fish. Utah has been using only about 900,000 acre-feet of its 1.4 million acre-foot allocation under the 1922 Colorado River compact. The legalities of this agreement are not clear.
From a watershed perspective, the most encouraging prospect of the Upper Colorado River Recovery Program has been the gradual shift from incremental, isolated actions to recognition of the Upper Colorado River basin as an integrated system. The Bureau of Reclamation is making progress toward managing its complex network of water projects within the basin systematically for improved efficiency for agricultural users and for the benefit of the endangered fish.
Colorado Department of Natural Resources
Upper Colorado River Recovery Program
U.S. Bureau of Reclamation ‚ Upper Colorado Region
