Federal government has large role
Colorado’s water law, which is premised on the Prior Appropriation Doctrine, was developed by California’s gold mining 49ers. To sluice the gold from streams, miners needed water. Those getting there first were granted the first – or senior – right.
Brought to Colorado when gold deposits in river beds were found here in the late 1850s, that system of appropriating a scarce resource was refined. The allocation system is similar to systems of water appropriation used in other arid Western states. It is quite unlike water allocation systems in states where water is more plentiful.
Federal involvement in Colorado is seen in several ways. First, it has been a referee. Seven major rivers originate in Colorado. As early as 1890, Kansas was grumbling about Colorado farmers taking all the water from the Arkansas. Dozens of lawsuits have been filed in litigation involving that and other rivers during the last century. Now interstate water compacts govern all the major rivers.
Of particular note is the 1922 Colorado River Compact. The compact divided water between the upper and lower basins, but it assumed far more annual flows in the river than has been the case. Annual average yield is now estimated at six million acre-feet, rather than the earlier, more optimistic 7.5 million acre-feet.
Meanwhile, California has taken more than its share, and Colorado has taken less. With Colorado there is a distinct and powerful fear that California, in particular, may try to circumvent the compact provisions by exerting its will through Congress.
A second federal involvement has been as a major financier of reclamation projects. Efforts to benefit Eastern Slope farms by diverting water from streams ranging from Grand Lake to Aspen have been aided by generous financing arrangements of the federal government. To a much smaller degree, Denver’s trans-basin diversions have also been aided by federal subsidies.
Since the last of the major diversions was completed in the 1960s, the federal government’s role has reversed, attempting to keep water in streams on the Western Slope. This is seen in two ways.
First, the federal government more actively has been asserting that its various lands, including national parks and forests, implicitly have rights to water that originates on them.
One facet of this assertion is something called bypass flows. When issuing special-use permits for diversions and other projects on federal land, federal officials claim the authority to require some water be left in streams. Colorado insists it has sole authority to regulate water flows, even on federal lands. Water managers fear that if the federal government wants large amounts, this can upset the whole prior appropriations system.
Second, more directly and with clear authority derived under the Endangered Species Act, the federal government has insisted that sufficient volumes of water be allowed to flow in the Colorado River and key tributaries for a 15-mile stretch in the Grand Junction area. Those water volumes are needed to maintain viable populations of four species of indigenous fish listed as endangered.
On the South Platte River, the federal government is asking for flows to recover populations of two endangered species, whooping cranes and piping plovers. They are found primarily in Nebraska.