1. Research Leader, USDA-ARS, U.A. Arid-Land Agricultural Research Center, 21881 N. Cardon Lane, Maricopa, AZ 85239 (corresponding author). E-mail: bclemmens@uswcl.ars.ag.gov; formerly, Laboratory Director, U.S. Water Conservation Lab., ARS-USDA, 4331 East Broadway Rd., Phoenix, AZ 85239.
2. Senior Hydraulic Engineer, WEST Consultants, Inc., 960 W. Elliot Rd., Ste. 201, Tempe, AZ 85284.