1. Water Resources Engineer, Dept. of Civil and Environmental Engineering, Univ. of California, Davis, One Shields Ave., Davis, CA 95616 (corresponding author).
2. Distinguished Professor, Dept. of Civil and Environmental Engineering, Univ. of California, Davis, One Shields Ave., Davis, CA 95616.
3. Engineer, Tucson Water, 201 N Stone Ave., Tucson, AZ 85726.