Planning for the HOTTER future
October 12, 2013Designing Tomorrow’s Cities Today
October 25, 2013by Jeffrey Harlan, LEED AP
It was a strange sound to hear walking along Solana Beach’s Cedros Avenue just before midnight.
I had just left the club where Steve Earle and The Dukes left my ears buzzing, but instead of a quiet hum in the night air, the loud, constant rush of water streaming down the street’s gutters accompanied my walk. Two hours of rain (an unseasonable surprise) moved quickly by my feet and disappeared into the darkened mouths of the city’s stormdrains.
We often see stormwater as it wipes across our windshields, sheets down roadways, or pools at the bottom of a hillside. But we rarely hear it. Listening to the rainwater reminded me how important it is to design our communities to conserve this valuable resource, especially in Southern California.
In urban areas, where the amount of developed land and supporting infrastructure (including streets and highways, sidewalks, and parking lots) significantly outnumbers preserved open space, the impact of stormwater is particularly acute. According to the Natural Resources Defense Council, urban stormwater runoff deposits almost 10 trillion gallons of polluted water into our country’s coasts and waterways annually. Not surprisingly, the US Environmental Protection Agency reported in its last Clean Watersheds Needs Survey (2008) that local governments need to invest more than $42 billion over the next twenty years to address the nation’s aging stormwater infrastructure (and nearly $64 billion to address combined stormwater-sewer system overflows).
Traditional city systems, gray infrastructure, treat stormwater like a nuisance to be abated by the quickest means necessary. Curbs, gutters, stormdrains, and pipes were designed to take this resource—which collects trash, bacteria, oil and grease, metals, and other pollutants—away from our homes, buildings, parks, and streets and conveyed to the nearest body of water. We built complex and costly systems to flush, literally, one of our most precious assets down the nearest drain.
More recently, however, communities have recognized the value of incorporating ecological design principles into a wide range of development projects, resulting in a new approach called green infrastructure. Rather than engineer a solution to pipe water and move it away quickly, we now focus on using vegetation and designing natural processes that capture, detain, and filter stormwater so that it can be harvested, recycled, or conserved to recharge our groundwater supplies.
Whether it’s retrofitting parking lot, renovating a streetscape, or creating a civic park space, planners and designers employ a range of site-specific, low-impact development strategies to better manage stormwater. Bioswales, permeable paving, bioretention ponds, constructed wetlands, greenroofs, and rain gardens are but a few examples of design strategies that have become mainstream. Creating the right solution, of course, depends on an individual site’s condition, climate, soils, and design program.
I’m not the only one to hear the siren’s call of stormwater. This month, Chicago Mayor Rahm Emmanuel announced the city will invest $50 million in water infrastructure spending over the next five years to improve stormwater management. Chicagoans stand to reap the community health benefits offered by green infrastructure, such as reducing flood risk and greenhouse gases, improving air quality and property aesthetics, providing habitat for urban wildlife, and mitigating the urban heat island effect.
So during the next rainstorm, take a closer look at the path your stormwater follows in your neighborhood. Better yet, listen carefully and maybe you’ll hear the quiet melody of nature soaking up and storing water.
References:
US Environmental Protection Agency, Clean Watersheds Needs Survey (2008)