Milky water slowly flowing down Great Meadow Stream


The water in Great Meadow Stream is especially milky below Pine Tree Road in Smithfield. 7 Lakes scientists believe the color is the result of algae dying in North Pond and entering the stream.

Since Friday, Aug. 19, milky, murky water has been observed above the North Pond dam and is slowly making its way down Great Meadow Stream. Today, that cloudy white water arrived at the Route 225 bridge. Current evidence and discussions with the Maine Department of Environmental Protection indicate this is likely a result of the dying algae bloom on North Pond. When algae die and decay, they can change the water to unnatural colors as the pigments they contain are released. Additionally, the decaying process consumes oxygen and can change the pH of the water. That leads to chemical reactions with the sediments on the stream’s bed that can cause color changes, as well.


There is little flow in Great Meadow Stream at the moment, so the discolored water is moving slowly downstream. The first reports of discolored water at the dam were on Friday, and water is only now arriving at 225. It likely will eventually arrive in North Bay on Great Pond. The lower half of Great Meadow Stream is winding and has a large wetland area that will likely slow and, to some extent, filter the water. However, discolored water may appear in the next week in North Bay near the mouth of Great Meadow Stream. Humans and pets should stay out of any discolored water; algal toxins can be released when the algae die. To date, no toxins have been detected in North Pond. A sample has been taken from Great Meadow Stream for toxin analysis.


7 Lakes Science Director Dr. Danielle Wain, left, and Assistant Lake Scientist Lizzy Gallagher taking samples from Great Meadow Stream on Tuesday, Aug. 23.

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