Design, application, and interpretation of a three-tiered sampling framework as a strategy for eliciting public participation in planning and program implementation is presented, with emphasis on implications for federal programs which mandate citizen participation (for example, Level B planning of Water Resources Planning Act, Federal Water Pollution Control Amendments). The three-tiered survey procedure was used in the Lake Champlain Basin Study, which dealt with development and implementation of long-range programs for conservation and development and use of water and land resources in a mixed rural/urban area of uneven socioeconomic status. Study goals were a broader data base, a representative basin constituency, and identification of and relative importance of basin issues; the tiers were high school, key informant, and organizational surveys. The seven basic categories of environmental concern ranked by respondents were land use, wetland issues, water pollution, socioeconomic issues, recreation, energy, planning/management. Results show that the research design gave representative groups a systematic opportunity to respond to issues and that the public did respond and rank priority issues. It is predicted that treating informant groups as constituencies will achieve a new dimension of coordinated integrated planning, which addresses the real complexities of preparing environmental plans likely to receive public understanding and support. (RS)