By Christina B. Farnsworth. Builders throughout the Southwest must control dust or be in violation of air pollution standards. And most control dust by spraying water as they grade. In many areas, such as Coachella Valley, Calif.--home to Palm Springs, Palm Desert, and Indian Wells--no dust control means no grading permit. One of the earliest signs that cuts in Colorado River water delivery will hurt the building industry is the denial to start grading at Sun City Shadow Hills in Coachella Valley. The 31 percent reduction in Colorado River water delivery caused the Coachella Valley Water District to deny the development water for dust control.