Porter: Irene and Flood Protection
08/21/12 5:55PM By Louis Porter
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(Host) One year ago, when Tropical Storm Irene hit, the destruction wrought along Vermont's rivers was tragic. But Lake Champlain Lakekeeper Louis Porter of the Conservation Law Foundation says some extraordinary and wonderful things happened as well - some of which have taken us some time to understand.
(Porter) All across our state the natural landscapes that Vermonters inherited and preserved in turn protected them from what would otherwise have been even more devastation from Tropical Storm Irene.
In places where rivers still had access to flood plains, the waters spread out and their force was dissipated. This kept many buildings, roads and bridges from being completely annihilated. And some places had culverts and bridges sized to accommodate the larger deluges. They survived, while neighboring older and smaller culverts and bridges were simply washed away.
What happened along Otter Creek shows the benefits of protecting and preserving our natural defenses against floods.
Upstream in Rutland, where the city and the river back up against the slopes of the Green Mountains with little access to a flood plain, the river's volume leapt up by nearly twenty fold in a day. The crest came and went suddenly.
But 30 or so miles down the river in Middlebury, the story was different. Nearly a week after Irene had passed by, water still roared under the massive stone bridge at the heart of the town. The crest there came days after it reached Rutland, and instead of seeing a drastic and dangerous increase in volume, Middlebury residents saw Otter Creek grow at a slower and safer pace. It receded gradually over most of September.
The difference was due to acres of swamps, with tall trees emerging from beds of cattails, and broad floodplains with comparatively little development on the riverbanks. These natural features functioned, as nature intended, like a massive sponge, sopping up, slowing down and weakening the flood's destructive force.
The wetlands and floodplains provided us with a valuable service- but one that we've never bothered to tally in our system of economic accounting.
That's about to change. Under a law passed this year, the University of Vermont's Gund Institute for Ecological Economics is studying how to add the benefits of systems, like the flood protection, nature provides, to how the state measure's economic activity - and to subtract the loss of them as well.
"If we want to keep these ecosystem services," says Eric Zencey, coordinator for Gund's Genuine Progress Indicator Project, "we have to start valuing them, and taking their value into account in our economic decision making."
Gross State Product, the current system of measuring the economy, is "literally perverse," Zency says. And he adds "as all the damage from Irene gets repaired, the expenditure shows up as a net gain, even though we aren't actually making any economic progress."Especially after Irene, we know that the key to flood protection lies in giving rivers room to move, keeping flood plains intact and building roads and bridges that are ready for our new climate. We're still learning how to count up the real, tangible savings the wetlands provided along Otter Creek and other flood-prone rivers, lakes, and ponds across the state. But if we don't, we may find we didn't know what we had until it is gone.