Impact of Alternative Storm Water Management Approaches on Highway Infrastructure: Project Task Reports - Volume 2

Highway infrastructure represents a substantial portion of the total impervious areas that generate runoff water. Because of long winters in congested areas that require frequent applications of de-icing materials, much of the runoff has the potential for affecting downstream water quality. However, storm water management techniques themselves have the potential for compromising the integrity of adjacent highways when they result in significant increases of water content in the soil beneath the roadway.

Because of impacts and the costs associated with construction and maintenance, any storm water management system needs to be assessed before any decisions are made regarding new highway development or redevelopment. The authors consider Best Management Practices (BMPs) as they relate to the most commonly used storm water management approaches including dry ponds, wet ponds, infiltration trenches, infiltration basins, constructed wetlands, grassed swales, bioretention cells, sand filters and porous pavements. They provide a framework for considering cost of practices, negative impact on infrastructure, results from a BMP-related survey of highway design and maintenance professionals and cost-estimation formulas for each of the most commonly used storm water management approaches in urban Minnesota.