1. Research Hydraulic Engineer, U.S. Arid Land Agricultural Research Center, USDA-ARS, 21881 N. Cardon Ln., Maricopa, AZ 85138 (corresponding author).
2. Senior Hydraulic Engineer, WEST Consultants, Inc. 8950 So. 52nd St. Suite 210, Tempe, AZ 85284.
3. Research Hydraulic Engineer, U.S. Arid Land Agricultural Research Center, USDA-ARS, 21881 N. Cardon Ln., Maricopa, AZ 85138.