The problems associated with urban development and its resultant effects on environmental quality present increasingly complex decisions for elected and technical officials. Current approaches to modeling often result in the development of models which are too complex to be understood and require such long time periods to be modified that by the time the model is operational the problem has changed. A modular modeling framework is proposed which considers land use, runoff, and water quality and connects these factors to a budgetary function. In addition, the modular configuration facilitates the process of modifying components of the model in response to a changing problem environment. In order to test the feasibility of the proposed modeling approach, the model is applied to the Upper South River watershed, Waynesboro, Virginia. The following three alternative development plans are evaluated: 1. To permit no additional population growth and preserve the area for agriculture and recreation. 2. To permit concentrated development in the form of two new communities each with a population of three thousand persons. 3. To increase the population by three thousands persons but to allow development to continue to follow the existing pattern of urban sprawl. The study concludes by stating that if zoning ordinances and comprehensive plans focus on consolidating development within the framework of existing water and sewer networks, the cost of providing the sewer network for Alternative 2 will be ten million dollars less than Alternative 3 for the same increase in population. / Ph. D.