1. Associate Professor, Dept. of Landscape Architecture, Univ. of Illinois, 611 E. Loredo Taft Dr., Champaign, Il 61820 (corresponding author).
2. Professor, Dept. of Agricultural and Consumer Economics, Univ. of Illinois, 1301 W. Gregory Dr., Rm. 431, Urbana, Illinois 61801.
3. Principal, Director of Water Resources Engineering, Conservation Design Forum, 35 W. First St., Elmhurst, IL 60126.