Land development has led to excessive drainage of stormwater runoff into our rivers and streams. Proper planning of the drainage has not been a common practice and as a result urban flooding problems are common. Municipal, county and district stormwater agencies are faced with the challenge of developing plans to resolve existing and future flood problems. As an environmental engineering company, CH2M Hill has been involved with many watershed flood evaluation and remediation projects. In recent years, procedures and macros have been developed using GIS and hydrologic and hydraulic models. The integration of these tools has served to streamline the evaluation process and increase the depth and breadth of analysis. The basic tasks that have evolved from our project experience include; development of the GIS database, preparation of model input from the GIS data (cutting cross sections), modeling the future flood events, interpolating and mapping flood surfaces from the model output, and developing remediation alternatives. This presentation will provide an overview of the basic project tasks while focusing on the procedures and macros developed to cut cross sections and interpolate flood surfaces.