STORMWATER

Another extended dry-spell… How can it rain in Madison, Rocky Hill and East Haddam and miss Old Saybrook? Our lawns are getting crispy and the forests are filled with kindling; could this be another sign of Global Warming? Didn’t we just experience a drought? And, what is going on with the tropical cyclones? When will southern New England suffer the wrath of Nature? So many different opinions, theories, ideas and attitudes…

We are always talking about the “greening” of our Town and yet, the concrete mixers never seem to stop. Conserve a tree; build a house. Ah, yes, the balance of conservation and development. This is a difficult and delicate situation. How much is too much? A group of New York City architects have proposed a new angle on stormwater mitigation. Installing one “green” roof does not have much of an effect; instead, they are proposing 662 acres of green roofs. The idea is to create a microclimate of moderated temperature, cooler in the summer; warmer in the winter. Green roofs absorb a tremendous volume of stormwater and provide an unexpected area to grow some food crops. Locally grown rooftop tomatoes! This sounds good to me.

In reality, we cannot do much about the weather; we just react to each event as it occurs. When needed, we re-direct traffic; deploy emergency vehicles, as needed, and may include snow plows, tree trimming equipment and bulldozers and backhoes. We can even hold back or divert some water with sandbags. Anyone remember the scenes in St. Louis, Mo. a few years ago? Sandbags holding back the Mississippi… It must have been frustrating. All this flooding was the result of too much rain with no place to go; stormwater flowing with a vengeance.

Buildings, pavement and sidewalks seem to dominate all town centers. Rain water flows along a curb and magically disappears through a grate; our job is done. Right? Finger-piers and bulkheads, with paved walkways and fencing, define a lot of our waterfront areas. Rain water forms puddles in the adjoining parking lot and eventually evaporates. So, what is the problem?

According to the EPA, 70% of the pollutants entering the marine ecosystem are from non-point source components. Runoff is the major constituent. That is the main reason that we have to close shellfish beds after one-inch of rain. Rain events, and the subsequent runoff, cause the spikes in bacteria levels in swimming areas. Notice that lake-settings are far more sensitive than the tidal areas. Tidal areas are flushed every six hours. Petroleum products deposited on parking lots and paved areas seem to continuously migrate toward the water. Low concentrations of oil products are hardly noticeable, always present.

Ironically, a major threat to our marine ecosystem is lurking on the side of our streets and highways. This is where the bacteria grow into colonies and eventually concentrate and transport into the surrounding waters. Roadways with a direct stormwater discharge need to employ fairly complex mitigation technologies. These devices will replace drainage culverts and are very expensive. Wherever possible, stormwater mitigation using native plants for nutrient uptake should be used. Retention and detention ponds are effective structures for reducing pollutant and nutrient impact on receiving water bodies. All new developments will have to provide EPA Phase II Stormwater technologies in their design proposals.

As an update, we have identified our stormwater sample locations and the Town has submitted Phase II sample results. From this data we will develop a baseline and begin watching for trends.

Steve Luckett

WPCA Coordinator