Nonpoint Source (NPS) assessment, planning, and control programs to protect lakes top short of addressing the cumulative impacts of incremental development. Taken separately, each lakeside dwelling may appear acceptable; cumulatively such developments accelerate eutrophication. A new development may provide the infrastructure or precedent for additional development, and equity becomes a planning issue. The Clean Water Act touches on cumulative impacts in provisions dealing with antidegradation, load allocations and permits. Certain federal/state laws to protect envirionmentaliy-sensitive areas can also be interpreted to cover cumulative impacts. This paper explores the limits to which federal/state environmental laws and local planning and zoning can be used to handle the cumulative impacts of development on lakes. More use can be made of federal authorities, especially now that the Clean Water Act Amendments direct more attention to nonpoint source control. Comprehensive state and local land use planning and regulation needs to be strengthened. THis paper outlines a planning framework to consider cumulative impacts in planning and land use decisions to respect a lake's finite capacity. Comprehensive planning will develop the data and assumptions about environmental constraints and development activities needed to refine the framework and lend legitimacy; in turn, this framework can strengthen comprehensive planning.