Clean Water In the News

In a recent demonstration, workers drove a cement truck full of water and dumped the contents on a new driveway at New London Hospital. Instead of flooding the property, the water rolled down the roadway until it reached a brand new parking lot.

"It was like being at the beach where the wave comes up onto the sand and just drops into the sand," said Lori Underwood, the hospital's senior director of planning and projects. "It didn't go more than a foot into the porous concrete until it was all absorbed. It was amazing, and it was a lot of water."

The hospital chose a cutting edge product for its parking lot, designed to absorb storm water into the ground. Conventional road surfaces send water cascading downhill, where it often runs into streams and lakes, carrying dirt and sediment. The hospital's lot is an experiment to see whether a porous concrete surface will hold up to the same wear and tear while preventing the kind of runoff that can cause environmental damage.

The town of New London hopes that more developers will invest in products like porous concrete, to reduce erosion and protect the health of its waterways. That's why the planning board has passed new regulations requiring developers to minimize their impact on storm water runoff.

The new rules, which affect new subdivisions and commercial site plan reviews, will not reach every new home or renovation in the town. But town planners hope that by asking some of its builders to think about the effect of their projects on the waterways, they can encourage every builder to do the same.

The new rules require buildings or additions to compensate for any runoff they create from impervious surfaces, like roofs or driveways, by installing porous materials on their land to help it absorb the water. The standard requires that the total volume of the water running off the property stay the same.

The upside, many environmentalists say, is that reducing runoff will protect bodies of water and will protect properties downhill in the case of extreme rain or flooding, which the state has seen increase in recent years.

The downside is that these materials cost more. Underwood said the hospital estimates that the porous lot cost about 20 percent more than a conventional one. Peter Stanley, New London's zoning administrator, said that compliance for most homeowners would cost about a fraction of their septic system, or a couple of thousand dollars.

"It can work. You can have both things. You can have development, and you can protect the environment," Stanley said. "It costs a little more."

Environment New Hampshire, an advocacy group that has applauded the New London project, said it is focusing now on persuading neighboring towns to adopt similar rules, with an eye toward protecting Lake Sunapee. Newbury, which also borders the lake, is considering new zoning regulations for next year's town meeting.

"In Lake Sunapee, storm water runoff hasn't had as many impacts yet," said Kathryn Fox, the preservation associate at the organization. "It still has relatively good water quality and is relatively pristine."