By CATHERINE SENGEL/ecoRI News contributor
A 1968 song-lyric complaint that, “they paved paradise and put up a parking lot” spoke more to the aesthetic blight of asphalt burying jungle than the cascade of natural destruction scientists now see as its byproduct.
In the 40 years since songwriter Joni Mitchell took us for a ride in her “Big Yellow Taxi,” society has learned there are consequences to covering nature with surfaces that can’t absorb water. Research has shown a strong correlation between pollutant loads, stormwater flows, and runoff from asphalt and concrete.
“There are certain consequences of removing natural soil and permeable lands and replacing it with impervious surfaces that shed water that need to be managed better,” said James Houles, program manager for the UNH Stormwater Center at the University of New Hampshire.
The path to reclaiming paradise, however, can begin at home.
In much the same way that a neighbor who dumps trash in your yard or onto your street degrades your property and the neighborhood, the water that leaves your property infringes on not only your neighbors but also on the environment. Off roofs, patios, concrete walkways and asphalt driveways streams wastewater carrying chemicals, fertilizers, debris, oil and pollutants into storm drains that feed into wetlands, streams, watersheds, rivers and, eventually, the sea.
“The real issue is not so much unpaving, but managing the runoff from your property to at least what it would have been had it not been developed,” said Thomas Ballestero, director of the UNH Stormwater Center. “It’s instructive just to see how water flows through your property, as an introduction to the water cycle. Learn from the way nature has processed waste for hundreds of thousands of years before development.”
The UNH Stormwater Center and the Environmental Protection Agency (EPA) offer tips to channel its movement:
Use natural areas, natural vegetation and native soil to filter and manage stormwater in ways similar to what nature designed to help rebalance some of the impacts of pavement.
Install rain barrels to repurpose runoff from roofs. Position rain gardens to catch rainwater, feed vegetation and provide habitat for insects and birds.
Find ways to divert water coming off gutters onto lawns, gravel and permeable surfaces, rather than down driveways and onto streets.
When updating surroundings, make informed decisions about the latest advances in technology and resurfacing materials. Replace concrete and asphalt with wood mulch, gravel or pavers over a bed of well-drained soil or sand that allows rainwater to soak into the ground.
Brake up compacted soil and add shredded leaf mulch to help retain water.
When disposing of household products that contain chemicals, such as insecticides, pesticides, paint, solvents, used motor oil and other auto fluids, don't pour them down drains.
Use pesticides and fertilizers sparingly. Excess fertilizers and pesticides applied to lawns and gardens wash off and pollute streams. In addition, yard clippings and leaves can wash into storm drains and contribute nutrients and organic matter to streams. Use organic mulch or safer pest control methods whenever possible. And don't overwater your lawn.
Compost or mulch yard waste. Don’t leave it in the street or sweep it into storm drains or streams.
“We’ve come around to now recognizing that these natural systems enjoy more respect,” Houle said.
From the early days of the nation’s industrialization well into the 1950s and ’60s, waterways were considered infrastructure — a convenient dumping ground for raw sewage and waste. The Clean Water Act of 1977 answered calls for more aesthetically pleasing rivers and ponds, closer to their natural state and more conducive to recreational activities.
We didn’t know what we had until it was gone. Well into the 1980s, stomwater runoff was still being drained into waterways. Change has been driven by regulations in response to some external force of “natural events,” such as recurring flooding, polluted rivers no longer safe for swimming and fishing, beach closings because of bacterial outbreaks and runoff from fertilized fields negatively affecting agriculture.
In addition to making changes at home, municipalities need to incorporate newer technologies as a routine practice when updating catch basins and improving roadways. For example, replacing curbs that are rounded and shed water with curb medians that are depressed and receive water.
In this growing field there is still much work to be done. The challenge is to demonstrate the economic, environmental and social benefits of such practices as low-impact development.
A 2007 report by the EPA titled “Reducing Stormwater Costs through Low Impact Development (LID) Strategies and Practices” compared LID costs with conventional stormwater management and found “with a few exceptions, total LID capital costs were lower than conventional methods, with savings ranging from 15 to 80 percent.”
“Ten years ago when we started, stormwater was not something at the forefront of everbody’s attention,” Houle said. “Today it largely is. If you’re in front of a planning board, or you're trying to get a development through, stormwater is going to be a critical thing that you’re going to have to address.”
While progress has been made, change is slow, according to Houle.
“If you’re measuring along a spectrum of 0 to 100 percent, maybe we’re at a two percent level right now,” he said. “We still have 98 percent of the way to go, but compared to 18 years ago, we’re much farther ahead. We don’t hear questions around do these systems perform. It’s a growing field for sure, but there’s still a lot of work to be done. ... It’s really incumbent that everyone does their fair share.”
Editor’s note: A workshop titled “Cost Effective Green Infrastructure in the Blackstone River Watershed” is scheduled for June 15 in Millville, Mass. The workshop is being sponsored by several organizations and businesses, including the Horsley Witten Group Inc.