The benefits of replacing outdated and overwhelmed urban sanitary and storm sewer systems with green stormwater infrastructure may extend far beyond water quality. New research by U.S. Forest Service scientists and partners found reduced narcotics possession occurring within a half-mile of Philadelphia’s new green stormwater infrastructure projects.

The article, “The impact of green stormwater infrastructure installation on surrounding health and safety,” recently appeared in the American Journal of Public Health. The articles states that narcotics possession after green stormwater infrastructure construction at treatment sites was 18% to 27% lower than at matched control sites. By contrast, there was a citywide 65% increase in narcotics possession between 2000 and 2012.

The research included both green stormwater infrastructure installations that had been built by 2012 and, as control sites, locations where green stormwater infrastructure had been proposed but not yet constructed. Researchers compared crime data for both control sites and green infrastructure sites.

Why specifically narcotics possession? “That was a surprise,” said Michelle Kondo, a research hydrologist with the U.S. Forest Service’s Northern Research Station and the article’s lead author. “Police officers tell us that it could be an example of the ‘broken window’ theory. Green infrastructure and regular maintenance is making the area look cared for and less abandoned and thus less hospitable to criminal activity.”