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Click to close Image by: photos.com Click to close Image by: Christina Nealson View from Jackson Gulch Reservoir looking downstream toward the Mancos Valley. Click to close Image by: Christina Nealson Felicity Broennan Click to close Image by: Christina Nealson Map showing the Mancos River Watershed where river restoration work is being done (in pink) on a local level. Click to close Image by: Christina Nealson Dick White

If Major John Wesley Powell saw the way people are managing rivers today, he would be smiling. Powell felt that there was a limited role for the federal government in the development of the arid regions, where federal science and money would help local interests make the management decisions that were best for them and for their rivers.

Now Powell's dream is coming true. The era of massive federal reclamation projects is long over. We are replacing titanic, river-destroying federal schemes like Glen Canyon Dam with modest, river-restoring projects like those currently under way in the Mancos River watershed near Mesa Verde National Park.

With a changing climate that will demand more work from less water, a new movement, watershed management, has quietly taken those projects' place. We are dealing with the salty problems associated with such things as Mancos Shale. And we are learning the importance of eliminating salt-tolerant invasive trees like tamarisk and Russian olive, which crowd out more wildlife-friendly natives like cottonwood and willow.

Local groups in the Four Corners are part of the movement. Take, for example, the tiny Mancos River watershed, where river users are learning to be more efficient with the water while also improving water quality and working to restore it to an ecologically healthy condition. In doing so, they are helping the United States honor the terms of the 1927 Colorado River Compact, which requires the U.S. to deliver both a certain quantity and quality of water to Mexico via California.

Mancos Shale

The 116-mile long Mancos River begins its rise on the western flanks of Colorado's La Plata Mountains. From there it flows fast, incising steep canyons on the Colorado Plateau as it wends its way south and west through Montezuma County before eventually joining the San Juan River in northwestern New Mexico on the Navajo Reservation. It drains an area of 800 square miles. Annual precipitation at the upper end averages 40 inches, most of it in the form of snow; at the lower end, annual precipitation averages 8 inches.

Before the Mancos River slows through the flat stretches of the Mancos Valley, where it encounters the problematic Mancos Shale, the river is diverted in various ways. Part of the river disappears into a pipeline that provides drinking water for Mesa Verde. The west branch of the Mancos flows into Jackson Gulch Reservoir, where it is stored behind a simple, earth-fill dam that the Bureau of Reclamation built in 1949. That dam, along with a few others, feeds the irrigation systems in the valley below.

As the Mancos flows, the river and its tributaries accumulate salt from upstream irrigation projects. The history of this issue dates back to Native American arid-land farming practices. They learned to build dams at the top of a watershed to divert water from streams and rivers into ditches that fed flood-irrigation systems. When excess water returned from the fields to the rivers, it occasionally created new wetland corridors along rivers whose once-meandering flows had diminished into a single channel because of the upstream diversions. However, if the return flow passed through shale-derived soils, the working water acquired heavy loads of dissolved salts. These salts pose serious problems for downstream users whose crops cannot tolerate salty water. The most notorious of these salty soils is Mancos Shale.

The salty water eventually becomes part of the Colorado River - the source that delivers water to Mexico at the California border. In the past, the Bureau of Reclamation would have built an expensive, energy-consuming desalinization plant in southern California with an operating cost of $400 per ton of salt, according to BuRec figures. Compare that to the operating cost of $36 to $44 per ton for desalinization at the headwaters of the Colorado River and it makes economic sense to address the salt problem at its sources. Starting at the headwaters also provides related cultural and ecological benefits to much-abused rivers and streams.

When Powell arrived in the Southwest after the Civil War, he admired the Native Americans' engineering and how the Mormon irrigation colonies of Utah had adapted Native American ways to build a small-scale, watershed-based irrigation system. So when Powell became the head of the U.S. Geological Survey, he drew on their experiences. In doing so, he recommended to Congress a scientific and environmental approach to the development of arid lands. Discarding the artificial grid that produced geometric peculiarities like the Four Corners, Powell fought in vain for an alternative arrangement based on ascending scales of watersheds. An example would draw political borders by following the way the water from the Mancos River rises in Southwest Colorado, feeds into the San Juan River in New Mexico and then finally joins the Colorado River in Utah.

Getting a baseline

Powell's grin was a long-time coming. Too much salt in the Colorado River was one of the main reasons for the recent change in the scale of the federal government's role. Influential interests, ranging from the government of Mexico to environmentalists to farmers in southern California's Imperial Valley, demanded cleaner water. Power companies also joined the change. Generators need clean water for their cooling towers and for making the steam that drives turbines.

After more than a century of irrigation, the EPA and others began to ask questions about the health of the entire Mancos River watershed, starting with the river corridor. Because of its leadership, we are learning that river restoration works best on a local watershed scale.

Now, the Natural Resource Conservation Service (NRCS) is making federal grants available to Four Corners groups like the Mancos Soil Conservation District to take on changes. Jack Burk and Dick White are members of this district. They hired their neighbor Felicity Broennan to write a grant to get funding for a baseline study completed by Dr. Peter Stacey with the University of New Mexico. Stacey is an expert in determining the health of the much-abused rivers of the Southwest. The result is his report, "Functional Assessment of the Mancos River Watershed."

Broennan owns property along the Mancos River below White's Lazy F/W Ranch. She knew money was available from NRCS and the Colorado Water Conservation Board, so she forged public-private partnerships of diverse parties to work together on common interests.

"I live here on the river," says Broennan. "I love participating in the health of my community."

Because less than 10 percent of the Mancos watershed is in private lands, Broennan had to gain the cooperation of a complex network of local, state, federal and tribal entities. As it turned out, she had plenty of company in the Mancos Valley, which has a population of about 2,500 people. Though there is plenty of irrigation water in the valley, there is limited water available for domestic uses. In the land of Mancos Shale, drinking water must be piped directly from the mountains, because the salt content of ground water makes it unfit for human use. Drilling a well is not a solution.

Changing irrigation practices

It is one thing to assess the health of the tiny Mancos River, and quite another to address the salt issue and the health of the entire Colorado River. Yet various Mancos watershed groups found a partial solution: get federal help to build a five-mile-long pipeline system that will improve irrigation practices and thereby reduce the salt at its source. Funding for the salinity-reducing pipeline project goes to the local irrigation ditch company. NRCS contracts with the ditch company and monitors construction of the pipeline. The source of the money is an excise tax on utility companies downstream on the Colorado River.

The pipeline has helped. The former irrigation system on White's Lazy F/W ranch included some ditches that were built in 1878. Operation and maintenance for flood irrigation require heavy manual labor. But now that the new buried pipeline has replaced the ditches, White has the water pressure to drive an efficient network of irrigation sprinklers that he can run and service himself.

"Opening a valve is easier than lifting a shovel," White says.

This is an important consideration in maintaining the health of a ranching community whose members are mostly on the far side of 50 years old. If they can't stay in the hay business, then developers will find a way to access the high-quality water that is essential to subdivide these open lands. And if the culture of irrigated agriculture declines, then residents near little watersheds such as the Mancos River will not be able to defend themselves and their water against rapacious downstream users.

Stacey's study shows that the Mancos River watershed is well worth restoring and preserving. This was especially true in comparison with similar-sized rivers throughout the Southwest. His database on all regional rivers allows him to draw such conclusions. This suggests that it is in the public interest to identify and support the people and land uses presently at work in the valley. His science backs up what the locals already seem to know about the ecological value of preserving the Mancos Watershed: the ecological foundation is there because the river corridor is basically healthy. The challenge is learning how to keep it that way.

"I'm for keeping the Mancos Valley green," White says. He is doing his part by fencing his cattle away from riparian zones on his property and doggedly overseeing the construction of the pipeline project. White also is giving a conservation easement to the Montezuma Land Conservancy, based in Cortez, Colo., and is creating an agricultural easement over another part of the ranch, meaning that it will always stay undeveloped and in hay production.

White strongly supports Stacey's study because it provides quantitative ways of measuring the river's working condition and its ecological health. These measures stack up against the scores for an ideal system unimpacted by development. They provide a guide for restoration, or they deliver a pat on the back where no action is needed. And they provide a critical baseline against which citizens can monitor future changes.

Obviously, there also is room for improvement. Instead of waving a finger at the entire watershed, Stacey can look at each of the stretches of rivers he studied and suggest changes landowners and managers can make. For example, road building and water diversions impair the river's proper, meandering function. Beavers can be pests, but especially in the upper reaches of the Mancos watershed, the relatively simple business of allowing beavers to recolonize the river would provide a simple, natural solution to problems created by decades of channelization. Likewise, where bulldozers have built levees to control flow, the river has in turn cut a formidable sluiceway that does not serve wildlife well. Stacey identified such stretches, suggesting that adding woody debris would improve fish-friendly conditions like critical underbank cover around deep pools and riffles.

What you get in return

Return flows from more than 130 years of irrigation provide interesting challenges and opportunities. In many places along the river, return flows maintain vigorous riparian vegetation, including critical wet meadows and moist soil conditions. Nevertheless, during the height of irrigation season, some stretches of the river go dry. This drying out also occurred during pre-European times, with the important difference that the pre-development river had deep pools where fish and other aquatic creatures could retreat. Such pools could be recreated, whether by bulldozer or by beaver. Obviously, the pipeline-related efficiencies will lessen some of the return flows. Where that happens, the pipeline can simply deliver water for ecological purposes.

The pipeline project treats 7,000 acres in the Mancos Valley. Ten delivery pipelines and 60 new irrigation systems remove 12,000 tons of salt per year. Further, ranchers have enhanced or established 354 acres of wildlife and wetland habitat. Landowners and ditch companies contribute 25 percent of the project's cost. One result of the project is 50 percent more productivity with less water use.

South of the town of Mancos, there is an old Mormon cemetery. A marker commemorates "the Beacon on the Hill," a building where lonely settlers could socialize during the early years. Visible from the entire valley, it radiated hope. John Wesley Powell would have smiled on the hopeful Mancos Valley.

Tom Wolf's latest book, Arthur Carhart: Wilderness Prophet (The University Press of Colorado), will publish in spring, 2008.