Performance of green infrastructure

Last month Salem experienced what some have called a 100-year storm event, with more than 6.5" of rainfall in 48 hours. Combined with melting from recent snowfall, the storm caused all sorts of chaos in town -- street closures all over the place, evacuations, and flooding.

The entrance to Pringle Creek Community during a storm, where conventional city street meets porous street.

Here at Pringle Creek Community it was just another regular day. Despite all the rain, not one of our homes flooded during the storm, a storm that shut down most of Salem. There was no impact to homeowners or businesses here whatsoever — people came and went, Café was open, we held meetings, normal day. Flowing water on the surface of the street never exceeded 1” deep at any intersection, hardly an inconvenience for anyone, and before we knew it, the water had completely vanished while the rest of the city remained underwater.

BEFORE SHOT: the peak of the storm, January 19th, showing surface flows as designed.

AFTER SHOT: the next morning, January 20th, all gone!

Vegetated detention swales along Lindburg slow
and allow water to percolate naturally.

This is the beauty of the natural system, which distributes stormwater impact across the land, allowing it to trickle down as it normally would in a meadow or a field. Through a combination of all-porous streets, limited impervious surfaces, lots of trees and open space, greenroofs, rainwater harvesting, and vegetated rain gardens, our green infrastructure knocked the socks off conventional stormwater management systems in nearby neighborhoods -- gutters and storm pipes tend to be the first to fail, blocked by debris or submerged under the water table with no where to go.


The result of all of this is that even in tough sites, where the water table is known to be seasonally high (adjacent to the creek), green infrastructure can work even in the most tested of circumstances, with tremendous benefit to aquatic ecosystems.