Environmental mitigation of storm water run off from highways and bridges is becoming a critical part of every new project. When deciding which projects should be constructed first, it is necessary to determine which project provides the best return on investment. Determining environmental benefits has been difficult because it is hard to place a dollar value to reducing or eliminating pollution. The goal of this research was to establish a scientifically justifiable approach for evaluating the benefits of environmental enhancement. The report documents the literature review and the Condition Indexing methodology adopted. A support program was developed for Windows 95 and NT operating systems that enables users to quickly evaluate and compare projects. The final result is a B/C ratio for each project. Since the costs associated with construction are well known, the gross benefit can also be determined.