Geographic Information Systems (GIS) has emerged as a critical tool for conducting stormwater investigations. Watershed Consulting Associates, LLC utilizes the most current GIS software available, ArcGIS 10, to support runoff modeling and analysis. GIS is also indispensable for mapping, analyzing, and managing stormwater infrastructure; a requirement for municipalities now facing MS4 permitting or other larger facilities with drainage infrastructure. Watershed Consulting Associates has extensive experience in mapping drainage infrastructure, stormwater outfalls, subwatersheds, impervious areas, and assembling data into a GIS database to be utilized for improved and more productive stormwater management, and to meet applicable regulatory requirements.