The objective in developing any GIS is to answer questions related to specific data. The challenge is integrating data with programming and field collection techniques to help increase efficiency and get answers. This becomes increasingly important when the mission is to inventory one of the nation's largest storm water systems. Incorporating these project-specific techniques provides cost-effective and efficient methods that are essential to the successful implementation of a GIS. This paper focuses on the techniques necessary in the development of a storm water GIS and how questions related to municipal NPDES storm water permitting are answered.