Putting water to work: small-scale hydropower eyed for electricity, irrigation.

• Author: Best, Allen
• Position: ENERGY REPORT

GRAVITY BEING WHAT IT IS, any water flowing between Colorado's highest and lowest points--a range of 11,124 feet --has great embedded energy. The question is whether that energy can be throttled and put to use.

The answer, of course, is yes. Early gold-seekers used hydraulic mining to blast apart hillsides. Later, turbines were installed in many dams to produce electricity.

And now come new efforts across Colorado to further yoke the power of falling water. One such example is near Yampa, a town between Vail and Steamboat Springs. The site is just a few miles from where the Bear River takes a sharp turn and becomes the Yampa River. On his ranch, Gary Clyncke decided three years ago to use the 126-foot drop in elevation of his irrigation water to power a new center-pivot irrigation system.

Clyncke's hydro-mechanical center-pivot doesn't produce electricity. It does, however, preclude the need for stringing up power lines to operate the center-pivot sprinklers. The sprinkler system, in turn, saves water--which is worth money. The 90 acres were previously irrigated with flood irrigation from ditches s pread across the field of timothy, brome and clover several inches thick. Center-pivot irrigation requires just one-sixth the water.

That savings motivated Clyncke to invest in center-pivot. This hydromechanical system cost $13,000, of which $6,000 came from the Natural Resources Conservation Service, a federal agency. That left Clyncke a cost of $7,000. Payback on that investment is achieved in three years.

Federal aid is motivation, at least in part, because of concerns about salinity. When large volumes of water are applied to fields in flood irrigation, the water picks up salts that are then returned to creeks and rivers. It's a major problem on the Western Slope, where water can be used two times for flood irrigation before it enters Utah. Downstream in California's Imperial Valley, an important source of food for the nation, some fields have become so salty they have been abandoned.

One of the most saline areas is in the Uncompahgre Valley, where Delta, Montrose and Paonia are located. An ancient sea left salts and the element of selenium in unusually large quantities in the Mancos shale. Both are harmful to endangered fish downstream in the Colorado River. "Anything you can do that helps with salinity also helps with selenium, and vice versa," says "Dev" Carey, manager of the Delta Conservation District.

Saving money is a strong argument...