A natural solution green infrastructure is transforming stormwater management for the 21st century.

• Author: Iarrapino, Anthony

"We can design our built environment in a way that mimics nature and restores the ability of the landscape to soak up precipitation and filter out pollutants before the runoff reaches our waterways."

When rainwater falls over undeveloped land, it runs o into our rivers, streams, and lakes. Its route to get there can be circuitous, with most runoff absorbed and filtered by woods, meadows, and fields before it ever reaches a waterway.

However, in many parts of New England, those woods have been cut down, meadows paved over, and fields replaced with shopping centers and other commercial development. All that pavement and hard surface is watertight, so instead of being slowly absorbed, rain gushes off of it down gutters, into the sewer, and straight into the nearest watercourse.

Historically, moving water quickly from rooftop to river seemed like an efficient and effective way to deal with big storms. The problem, says CLF Senior Attorney Anthony larrapino, "is that huge volumes now flow across these hard surfaces, which end up being a big collecting plate for dirt, gas, oil, sediment, nutrients, and other pollutants." The result: many New England waterways that are polluted, their fish and other wildlife devastated, their water unsafe to swim in or drink.

For much of the past 25 years, managing stormwater meant trying to collect it to avoid causing larger floods, with little focus on pollution control or understanding of the natural flow of waterways.

Today, pipes and sewers are inadequate to deal not only with the pollutants pouring into our waters, but also the higher frequency and intensity of storms due to climate change.

CLF and its partners, including the Environmental Protection Agency (EPA), are championing a new approach to managing stormwater, one that puts nature back into the picture. "Green" infrastructure (in contrast to the "gray" infrastructure of pipes and sewers) "is about trying to design our built environment in a way that restores the ability of the landscape to soak up precipitation and filter out pollutants before the runoff reaches our waterways," explains larrapino.

Unlike pipes and sewers, green infrastructure-generally involves tactfully siting a small number of elements and complementing them with the landscape," says Wendi Goldsmith, President and CEO of Bioengineering Group in Salem, Massachusetts, and co-author of Bioengineering Case Studies. These elements could include a green roof on an office building, a rain...