This webcast will highlight effective tools communities can apply to minimize the impact of land development on their streams, lakes and estuaries. It will begin by showing how impervious cover (IC) is used as a key index of watershed development. Next, current research will be reviewed on the strong relationship between IC and more than twenty indicators on aquatic quality. This emerging research provides the technical foundation for the Impervious Cover Model (ICM) which will be discussed at length. The remainder of the webcast will review the eight tools localities can apply to protect their sub watersheds-watershed planning, natural area conservation, buffers, better site design, erosion and sediment control, storm water management practices, non-storm water discharges and watershed stewardship.