Coulbourn Mill Pond

Coulbourn Mill pond is a good observation spot for me because over a period of 24 years, I have personally witnessed the changes that have take place. They are not good. I can still picture the water of the pond when I was younger. It was very clear and fish could be caught any day of the spring and summer. There were always people out in kayaks or small boats chasing the perfect fishing spot. People would be sitting on their docks late into the evening just enjoying the natural beauty that accompanies a healthy water body. I imagine the pond was an even more popular spot before well before I was born. Local people who are much older than me must have a very different view of the pond. It might have even been healthier than I could ever imagine. I doubt that it will ever get back to that point again.

I have kayaked the full length of the pond many times over the past few years, enough to conclude that a strong case can be made that these waters are suffering hypoxia. All the properties surrounding the pond have at least a moderate slope leading into the pond. This gradient would promote the movement of nutrients into the pond.  Overabundance of nutrients in the water in turn inevitably creates nitrification, which is like a nutrient overdose for the habitat. All the extra nutrients allow the plants to grow excessively. The water is dense with aquatic plants, which is the main reason why I am point to hypoxia. These plants make paddling the pond extremely difficult. Each dip down into the water entangles the paddle, and each lift out of the water is weighed down by the plants tangled around the shaft. The plant appears to be the Brazilian elodea. It has the ability to overwhelm a pond with extremely dense areas of the vegetation. These plants do not have any rigid structures and sway with the movement of the water. It can produce through fragmentation and is very different to eradicate. There are also aquatic plants known as Fragrant Water Lilies sporadically spread about the pond. Their scientific name is Nymphaea odorata and are native to this area. They take up root in the silts on the bottom of the pond and have a long stalk that leads to the surface where the pad structure is located. The pad floats and is where the plant takes in sunlight. This area is often where you would find water frogs or even dragonflies sitting to take in the warmth of the sun. It can produce new plants through spreading seeds or even rhizomes. Rhizome is the ability of a plant to take up root from different parts of the plant. One could take part of the stalk and plant it down into the mud. This stalk would produce roots and form a new plant. It would be genetically identical to the original plant. This is a fascinating evolutionary adaption that is beneficial to the survival of the Water lily. There are times when the flowering portion of the plant may not be pollinated for one reason or another and its biological function of reproduction would not occur unless it had rhizomes. These aquatic plants are in love with this man made ecosystem. They thrive off all the abundant nutrients in the water. At this point in the process the plants are producing oxygen that is dissolved in the pond water. This is a good thing for any aquatic organisms and the ecosystem in general. The situation turns bad when these aquatic plants begin to die off and decompose. There is not enough dissolved oxygen in the water to facilitate the bacteria that help in the decomposition process. This is the point in which the water becomes hypoxic. There is no longer enough dissolved oxygen to support aquatic life. The pond is now a large dead zone from a fishermen’s perspective.

It could be better. Better management could help this aquatic ecosystem. Land management techniques need to be improved upon on the land surrounding the pond. These areas should refrain from using any fertilizers on their yards. This would reduce any excess nutrients from making their way into the water and causing excessive growth in the aquatic plants. Buffers could be created by planting native plants and trees around the pond. This would do great to suck up nutrients and hold onto sediments what would normally erode into the pond. The wood structures that separate water from land lining the edges of the pond could be reverted back to natural barriers. This would also help hold onto sediments, as well as allowing amphibians to enter and exit the pond with ease. Currently these creatures have very limited access to the shore line.

There is a dense mixture of debris covering the ground in between and around the trees. This layer is constructed of pine shads, leaves, dirt and sticks that have accumulated over the years. These materials all together are very good for the trees and other plants because it prevents water loss through evaporation. The soil beneath this layer will stay moist year round. It also can become very rich with nutrients as the materials decay and return nitrogen and carbon back to the Earth. These things if given enough time can also form good topsoil for future plants to take up root in. Well developed forests will have very thick layers of these materials. The farther you dig down, the more decomposed the materials will become. This is also where Earth Worms thrive. I have recently walked around in a forest that is owned and maintained by the Nature Conservatory not far from here that had a very thick forest floor. It was a well established forest that has trees over 75 years old with natural springs around the property. The floor is capable of soaking up all the rainfall and cleaning it through natural processes. The water will then reemerge somewhere else on the property as a spring with very clean water. This is why forests are vital to the prevention of erosion. The forests can handle very large sums of rainfall that would have normally pooled up on manmade surfaces and caused damage eventually. The lack of forested area along with the road way so very near the pond has created excessive erosion along the shore line. The banks are very steep with exposed roots winding their way through the open air. Without a large forest surrounding the pond there is no effective buffering system from contamination.

The pond faces the next challenge of contamination. The local ground water in the area near Coulbourn Mill pond is contaminated with a chemical called Trichloroethene (TCE). It is a solvent used in industrial processes and is not found naturally in the environment. It has been found to cause cancer, which makes its presence in the water supply a very bad thing. I personally drank from this contaminated water for the first 18 years of my life and so did countless other people. It is frustrating knowing the cause of this contamination is caused by humans and could have prevented. There is no telling when exactly the chemical reached the aquifer, but it is safer to assume it has been there throughout the duration of its use. There are a few possible sources of TCE and how it came to be in the water supply, but the State has not come to the conclusion at this time. I predict they never will for fear of being sued if it was from something state funded. The locals have their own prediction of the source of TCE and are most likely correct because of where the chemical has been found and who was using it 25 to 30 years ago.

The pond ecosystem needs its space in order for all the different ecological functions to take place. The human species has encroached on these systems not allowing them to function properly. Ponds have always been a sanctuary for organisms and plants to grow and reproduce. As much as non-migratory geese or duckweed, we humans are an invasive species disrupting the natural balance here. But if we think back farther, we find we are actually encroaching on an encroachment. The pond was not always a pond. It was once a slow meandering stream. The stream was the original natural state of this water body and undoubtedly thrived in its glory days before agriculture, industry and housing developments changed the face of the earth here. Humans then dammed the stream to create a mill pond. This new type of water body creates a new ecosystem in itself. Damming the stream was the first encroachment. But then land developers constructed houses and roads right up to the banks of the pond, which is the second encroachment. I can only imagine what the area would be like if the original stream was still there with no hard-scapes nearby . It might have been a thriving ecosystem or maybe even a great place to take a leisurely kayak trip on a nice summer day. If only we didn’t feel compelled to always dominate nature things might be different. The original damming of the pond was crucial to the survival of the early people settling the area. They were able to feed their families from the money made off the production of the mill. Now the pond serves no industrial function to the people so why must it remain dammed? The answer to this is could be many things but the obvious is the property value of the water front homes. Water will typically raise the property value of homes which is the goal of any homeowner.

Joshua Shrieves