Rain, rain, rain. We experienced a wet and cold spring, and so far, are enjoying a wet summer, yet we have escaped the devasting floods experienced in sections of Vermont and New York. We are no strangers to rain in New England. Average annual precipitation for Scarborough is 45.6 inches. The National Weather Service has a thirty-year June average (1991 – 2020) of 4.15 inches of rain for Portland, Maine. In June 2023, Portland recorded 5.68 inches of rain. Not close to the historic wettest June on record of 10.86 inches in 1917 but never the less significant rainfall for the month.

This week I was walking on Sandi’s Trail along Silver Brook at Broadturn Farm and the normally small, moderately flowing stream was gushing. Water was pouring over the small waterfalls filling the brook from bank to bank. Our recent rainfall totals demonstrate one critical fact, we need natural areas – river flood plains and wetlands to absorb and store all the rain and snow from severe storms. Today, I will focus on flood storage as a function of wetlands/floodplains; in the future we can cover the many additional benefits of wetlands.

Natural systems are very good at absorbing floodwater and releasing it slowly back into a stream or river. Drive over the Nonesuch River on Route 1 or Gorham Road after a major storm and you will see the quantity of water dispersed into the natural floodplain. The United States Environmental Protection Agency estimates one acre of wetland can store between 1 and 1.5 million gallons of floodwater. As storms become more extreme and concentrated rainfall pushes our man-made drainage and stormwater systems to the brink, we will need these natural areas to pick up the slack.

There are more examples every day of communities restoring wetland and floodplains to protect buildings and other infrastructure. Even the champions of concrete and built solutions to environmental problems, the U.S. Army Corps of Engineers is realizing the cost effectiveness of nature. On the Charles River in Massachusetts, the Corps concluded that existing floodplain wetlands were so effective for flood control measures, the agency purchased and protected the wetlands rather than build expensive flood control structures in an effort to protect Boston from flooding.

Scarborough is home to five rivers and dozens of smaller brooks and streams. We are fortunate to have much of our natural buffers intact along these watercourses. However, each linear foot lost is a weakening in our ability to withstand major storm events. Overall, Maine has lost 20% of its historic wetlands from conversion to other uses. We are lucky that this is a low percentage compared to most states, for example, California tops the list with 91% wetland loss. Southern Maine, including Scarborough, is experiencing a higher loss rate than most of the State because of our pace of development. We can also add salt marshes to this list, such as Scarborough Marsh, anticipated to be negatively impacted from sea level rise. Scarborough Marsh and other salt marshes are an important defense against storm surge. The Scarborough Marsh and salt marshes are vital in slowing, storing, and buffering coastal storm impacts.

We can expect to see more severe weather in the future. Nature is often our best and most cost-effective approach to dealing with these storm events. Protecting floodplains and wetlands is a key strategy to protect communities in a changing world. We have made great progress in Scarborough but still have much more to do. On the upside, the rainy weather has spurred the growth of native grasses, ferns, and wildflowers, all beneficial for our wildlife populations.

For comments or questions, contact Andrew Mackie at amackie@scarboroughlandtrust.org

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