One man's salt must not burden another man's water
by Tom Wolf
The era of massive federal reclamation projects is long over, yet a changing climate will demand more work from less water. And so a new movement — watershed management — has quietly taken the place of building the big dams.
Visit the tiny town of Mancos near Mesa Verde National Park in southwest Colorado to see the new, watershed-way of doing business up and down the Colorado River, where one man's salt used to burden another man's water.
When irrigation water passes through shale-derived soils, the water acquires heavy loads of dissolved salts. The most notorious of these salty soils is Mancos Shale. In resourceful Mancos, however, local groups are using their own funds and federal grants to restore damaged rivers to healthy ecological conditions. The source of the federal matching money is an excise tax on utility companies downstream on the Colorado River. Generators need clean water for their cooling towers and for making the steam that drives turbines. Other influential interests are also demanding less salty water, ranging from the government of Mexico and environmentalists to farmers in southern California's Imperial Valley. Thanks to the leadership of the Environmental Protection Agency, we're learning that river restoration works best on a local watershed scale. And now the Natural Resource Conservation Service is making federal grants available to local groups such as the Mancos Soil Conservation District.
In the past, the Bureau of Reclamation would have built an expensive energy-consuming desalinization plant in southern California. According to BuRec figures, the cost of desalinization in California would be $400 per ton of salt. The cost of desalinization at the headwaters of the Colorado River is about $40 per ton. So 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.
The locals in Mancos are building a pipeline system that will improve irrigation practices and thereby reduce the salts at their source. The Natural Resource Conservation Service contracts with the local ditch company and monitors construction of the pipeline. Landowners and ditch companies contribute 25 percent of the project's cost.
The project treats 7,000 acres in the Mancos Valley, helping to remove 12,000 tons of salt per year, thanks to 10 buried delivery lines and 60 new irrigation systems. What's more, ranchers have enhanced or established 354 acres of wildlife and wetland habitat. This is an important consideration, according to Dr. Peter Stacey of the University of New Mexico, who has done ecological studies of the project.
The Mancos River is only 116 miles long, though 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, where the Mancos River joins the San Juan River in northwestern New Mexico on the Navajo Reservation, annual precipitation averages only 8 inches.
How does the project work? Consider the traditional irrigation system on Dick White's ranch near Mancos. Some of the ditches on the Lazy F/W were built in 1878. Operation and maintenance for flood irrigation require heavy manual labor, but thanks to the new, buried pipeline that has replaced the ditches, White now has the gravity-powered water pressure to drive an efficient network of irrigation sprinklers that he can run and service himself. Sprinklers are a lot more efficient and easier on the soil than flood irrigation.
"Opening a valve is easier than lifting a shovel," White says. "I want to keep the Mancos Valley green, but I can't do it alone."
This is an important consideration in maintaining the health of a ranching community whose members are mostly on the far side of 50. If they can't stay in the hay business, then developers will find a way to access the water that is essential to subdivide these open lands. And if the culture of irrigated agriculture declines, then little watersheds like the Mancos will not be able to defend themselves and their water against rapacious downstream users.
Rancher White has done his part in many ways. In addition to donating a conservation easement to the local land trust, White has given an agricultural easement over another part of the ranch, meaning that it will always stay undeveloped and in hay production.
South of Mancos, there is an old cemetery. A bronze marker commemorates "the Beacon on the Hill," a community building where lonely settlers socialized during the early years. Visible from the entire valley, it radiated hope. It still does.
Tom Wolf is a contributor to Writers on the Range, a service of High Country News (hcn.org). He is a writer in Mancos, Colorado.© High Country News