Designing for stormwater, naturally.

07.2014Design, Ideas

By Claudia Saladin

“April showers bring May flowers” goes the saying. But often those showers also bring flooding and “combined sewer overflow events,” where stormwater mixes with untreated sewage in old combination sewers and flows untreated into our rivers and streams. These problems have increased over time through an abundance of paving and buildings, too little green space, and too little thought given to what happens to the water when it rains.

Flooding from stormwater can pose serious public safety problems, in addition to contributing to poor water quality and the degradation of our streams and rivers. Until recently the way to deal with these issues was to build a giant pond, typically on the perimeter of the property. Often acres of woodlands, nature’s best stormwater management device, are cut down to make room for detention ponds. They collect all the stormwater from a site into one place, allowing it to flow into rivers and streams over time rather than all at once. Because they are periodically inundated with large volumes of dirty, polluted water, they have to been fenced in and warning signs posted.

Increasingly, designers and planners are turning to something called “green infrastructure.” Green infrastructure—which includes rain gardens, green roofs and porous pavers—seeks to address stormwater through many small interventions closer to the site where rain falls. It seeks to mimic the way natural systems deal with stormwater by using plants and soils, and encouraging infiltration on site.

Perhaps most important from a design and place-making perspective is that green infrastructure can be integrated into the design of public and private spaces. For instance, rain garden tree planters located along streets, rather than off to the side, can provide shade and beauty as well as stormwater mitigation. Rather than being dangerous and fenced off, they can serve as amenities that also screen and slow traffic. Interventions like these make a street a place in the city and not only a way of getting from point A to point B.

Green infrastructure presents new challenges for designers, contractors and regulators. It requires us to work and collaborate in new interdisciplinary ways. The results, however, are worth the challenges.

To learn more about some of Strada’s green infrastructure projects, please see Rivers Casino and Riverfront Park, Bakery Square Master Plan, and Dick’s Sporting Goods.

Top image: The top photo illustrates how green infrastructure helps screen traffic and create safe pedestrian places, in addition to mitigating stormwater impacts. (http://www.asla.org/greenstreet/img/GreenStreetBagbySt-1.jpg)