Mary M. Fuqua
The strong summer thunderstorm is a mixed blessing. It brings welcome cooling on a hot day and revives the drooping flowers and vegetables in our gardens. But much of the downpour becomes stormwater - the rain that falls on our roofs, driveways and other impervious surfaces and runs off into storm sewers and ultimately into our lakes and streams, carrying with it whatever it has picked up along the way. Runoff from just one roof in Bennington, the One World Conservation Center’s, illustrates the volume from a single storm. In a 1" rainstorm, our 2520-square-foot roof will produce 1575.8 gallons of run-off, water that would have flowed across Route 7 and into Jewett Brook until we built rain gardens to catch it.
Rain runoff has been a concern since humans began living in villages. Stormwater engineering emerged as housing became more concentrated and impervious surfaces were used in the construction of settlements.
The palace of King Knossos at Crete is a fine example of a system to divert stormwater. It dates to about 2000 BC - long before the better-known sewerage and stormwater systems of the classical Greeks and Romans. Today our cities and towns, farms and industries are exponentially larger than their ancient predecessors and the "stuff" the stormwater picks up is far more dangerous -- oil and grease from parking lots, fertilizers from farms and gardens, chemicals and pesticides from homes, industry and public areas along with soil and bird droppings. These items, even the soil, become pollutants once in our waterways.
Stormwater causes damage wherever it occurs. In undeveloped areas, the force of the water erodes stream channels and destroys habitats for fish and other creatures. In our towns and cities, our built environment magnifies the run-off and our activities create a dangerous mix of pollutants. Toxic substances and heavy metals can kill fish and may be harmful to humans even in small amounts. More commonly, stormwater changes the ecology of a stream, often at the cost of displacing its native plants and fish. Stormwater, warmed as it flows over roofs and paved surfaces, can raise the water temperature in a stream to levels that are harmful to trout. The dirt it carries clouds the water and fertilizers cause excessive plant growth, which in turn depletes the oxygen the fish need.
Stormwater is a major concern from Washington State, where one-third of the pollution in Puget Sound is from stormwater, to Maine, where the City of Portland has proposed a new fee for impervious surfaces. In Vermont, the pollution of Lake Champlain grabs headlines. Though the direct discharge of untreated sewage has been stopped for nearly 20 years, the lake now suffers from "nutrient pollution," phosphorus in the run-off from farms and stormwater from the cities along the shore. The blue-green algae blooming every summer in Lake Champlain are a visible reminder that excess nutrients support unwanted vegetation. A new state stormwater permit, introduced in 2012, establishes standards that apply to cities from St. Albans to Rutland whose stormwater flows into the Lake.
Bennington’s stormwater, too, runs into our streams, some directly and some through the town’s stormwater drains. Happily, our streams get good marks on the State of Vermont’s report card on the state’s waterways (www.vtwaterquality.org/mapp/docs/mp_2012). Only two streams are listed as impaired: Barney Brook, with sediment and iron, and Jewett Brook, which needs further assessment for warm water temperature. For purposes of this essay, the Hoosick River, contaminated with PCB.s, is not considered a Bennington waterway.
Let’s keep our waterways clean! Small changes, implemented town-wide, can assure that they remain in good condition. You can help - here is the top six list of measures all of us can take.
* Keep the outflow of your downspouts away from the storm drains. In a heavy storm, one spout can drain as much as 12 gallons per minute. Redirect this water to a garden or grassy area that will soak up the water.
* Use lawn fertilizers, pesticides and herbicides sparingly. Don’t apply them immediately before a predicted storm.
* Maintain your car or truck and recycle used oil and antifreeze. Don’t dump such chemicals in the storm drains, as they do not flow to the treatment plant.
* Wash your car on the lawn where the soapy water will soak in.
* Reduce impervious surfaces and direct runoff to vegetated areas.
* Pick up after your pet.
We at the One World Conservation Center have a vested interest in Jewett Brook, which flows through our Norman & Selma Greenberg Conservation Reserve. Our rain gardens do their small part to keep our stormwater out of it. We encourage interested visitors to visit after a storm to see how well our rain gardens pond up and then soak up the water from our roof. Even the torrents from Hurricane Irene did not spill over the berms and were absorbed within a couple days.
Mary M. Fuqua is the board chair of the One World Conservation Center.