In an effort to improve ambient water quality in the numerous estuaries within Beaufort County, ATM is reassessing and updating the County’s Stormwater Management Plan. ATM’s work for this effort began with collection and review of a 10 years of GIS, database and aerial photography data ranging from land growth patterns to water quality data. After completing the data collection and review efforts, ATM updated the County’s GIS mapping and applied the results to update existing stormwater models to present-day conditions utilizing the ICPR and Water Quality models. Stormwater runoff and water quality statistics were compared from previous models for both the present and future land-use conditions to develop a decision making tool for the County so capital improvements can be implemented regionally in a manner that results in the biggest improvements. In conjunction with this effort ATM also worked with the County to develop methods to track and assure compliance with the County’s MS4.