Natural Infrastructure

In Philadelphia; Chicago; Portland, Oregon; and Milwaukee, water managers are trying to implement green infrastructure solutions or low-impact development practices. A number of these techniques are in use, including green roofs, rain barrels, rain gardens, vegetated curb extensions, porous pavement, urban reforestation, and even constructed or restored wetlands or wet meadows. The aim of these practices is to retain water on site, allowing for infiltration and evapotranspiration, thereby reducing runoff and allowing for removal of unwanted pollutants.

Increasingly, communities are relying on the “natural infrastructure” as a least-cost approach to protecting surface water quality, which can generate multiple benefits such as habitat preservation, carbon sequestration, and aesthetics. Utilizing such green or natural infrastructure means less hard or gray infrastructure and reduced energy intensity, too. This trend is spreading with respect to wastewater and stormwater management in more and more utilities and communities across the country. This is especially true with respect to “urban wet weather” issues, which involve CSOs, stormwater runoff, and conventional point-source or end-of-the-pipe discharges. Increasingly, communities are meeting these challenges through a watershed approach which employs green or nonstructural approaches in tandem with traditional hard or gray infrastructure.