We All Live Downstream
What is a watershed? Where do we live within them? Why is the concept of a watershed important for conservation biologists and restoration ecologists? How to teach about watersheds in a meaningful way, without the helpful mountainous models we all encountered in school settings?
Our class began, as always, in our own backyard. To understand the complexity of human impacts on watersheds, I told the story of Stanley Brook in Seal Harbor, which experienced a pollution problem back in 2006. The issue brought together teams of concerned citizens, scientists, and town officials to identify the pollution source and develop a remedial plan. As a class, we walked in their shoes, making our own educated guesses as we learned more along the way; acting, as one participant noted, as “environmental detectives.”
Stanley Brook flowing through the middle of Seal Harbor Beach. On a sunny summer day, this beach is often crowded with swimmers. Younger children enjoy playing in the shallow stream.
Over a decade ago at Seal Harbor beach, a popular spot enjoyed by locals, tourists and children’s summer camps, swimmers began developing illnesses after contact with the water - ear infections, rashes, diarrhea - illnesses caused by exposure to bacteria. The problem was so bad that the town was forced to close the beach to public access.
I asked the Nature Links participants to imagine they were there, back in time, as citizens of Seal Harbor. What would be their first step in addressing this problem? How would they work towards reopening the beach?
If the beach was a closed system, finding the pollution source and fixing the problem would not be that difficult. However, no body of water is a closed system. Stanley Brook flows directly through Seal Harbor beach. Initial water quality tests found that bacterial readings were the highest in the mouth of the stream. This meant that the bacteria could have been introduced at any point upstream in the Stanley Brook watershed.
Time for some definitions: A watershed is the area of land where all of the water that drains off of it goes into the same place, such as a river, stream, lake or bay. Whatever happens upstream in a watershed ends up flowing downstream.
So the bacteria was flowing from somewhere in the watershed downstream to the beach. The next step in solving this issue? Gathering as much data as possible. To do this, a watershed survey was put together, for which citizens were trained to collect water samples at different points along Stanley Brook. As they did this, they collected other observational data for five types of pollution: bacterial, nutrient, sediment, toxic, and thermal.
An environmental restoration project of this scale requires collaboration and coordination between partners from different fields.
Survey results showing the different kinds of pollution found throughout the Stanley Brook Watershed.
At this point, our Nature Links class had some questions about these pollutants. Wasn’t the goal of the survey to locate high bacteria levels in the water? Why look at all these other pollution types? While high bacteria was the cause of the swimming illnesses plaguing beach-goers, other types of pollution were potentially the cause of the high bacteria. Thermal pollution that heats up a stream could create conducive conditions for bacterial reproduction. Extra nutrients introduced into the watershed, such as fertilizer runoff from lawns, could also potentially increase bacterial populations. These potential relationships between data sets are why scientists always seek to study a broad range of variables. The survey was not designed to only locate areas of high bacteria, but also to discover what was causing it.
Enterococcus is an indicator species of bacteria that is found in the gut of warm-blooded animals. The presence of enterococcus in water indicates contamination by fecal matter. High bacteria in swim areas is often caused by water fowl, beavers living upstream, or dogs visiting and defecating near the water.
Even though much of Stanley Brook passes through land protected by Acadia National Park, runoff from private homes finds its way down the watershed. During the course of the survey, a team of participants came across a major pollution source: broken above ground sewer lines. Surveyors soon after discovered that the breakage in these lines was not an isolated incident, but typically happened every year!
Broken sewer lines discovered in the Stanley Brook watershed. We are looking at raw sewage - poop! - flowing out of this pipe immediately near the brook.
After the results of the watershed survey were completed and published, an advocacy process began. Citizens called for improved public policy regarding private sewer systems. In 2007, a new ordinance for the town of Mount Desert was passed that:
Dictates that all above ground private sanitary sewers must be inspected on or before June 1st of each year
Requires conformance with local, state, and federal regulations
Addresses Sewer Pipe Materials and Installation (HDPE, PVC, Ductile Iron Pipe)
The effectiveness of this new ordinance was evident in the following years - bacterial levels steadily decreased. Seal Harbor Beach is still tested weekly for bacteria, and has not seen a pollution problem of this scale since.
The Stanley Brook Watershed Survey produced a report with all their findings that you can download here.
Everything upstream ends up downstream. We need to remember that we all live downstream and that our everyday activities can affect downstream waters.
