The Surface Water Treatment Rule under the Safe Drinking Water Act requires that all surface water sources used for drinking water must be filtered, unless the purveyor can demonstrate that the water is of such high quality that filtration is not required. The New York City Department of Environmental Protection (DEP) operates the New York City water supply system and is taking actions to ensure that the water supplied from the Catskill -- Delaware system remains of high enough quality to maintain an avoidance of filtration determination granted by the Environmental Protection Agency (EPA). New watershed rules and regulations have been adopted to govern land development activities, and to address pollutants that may be carried into the water supply system with storm water runoff from new impervious surfaces.

This paper presents an overview of the pollution threats presented by new land development, outlines the evolution of the regulatory requirements controlling storm water management, and attempts an assessment of the effectiveness of the current regulatory initiatives. A land development scoring system is proposed to measure the rate of storm water management implementation and the impacts of the new regulations. The result of the research demonstrates that insufficient time has passed since the adoption of the watershed rules and regulations to allow a proper measure of their effectiveness. Finally, the land development scoring system is proposed as a simplified method for use by the DEP in monitoring the effect of the regulations as future land development activities take place.