Roadways often contribute large amounts of sediment to lake watersheds. In northern New England, many private roadways (often referred to as camp roads) are poorly designed and maintained and are often in need of repair and continued maintenance. Types of roadway BMPs that will need to be installed in Salmon Falls headwater lakes watersheds include proper ditching, turnouts, proper crowning of roads, and proper installation of culverts.
When roadways contribute large amounts of sediment to lakes, they are also conveying large amounts of nutrients, specifically phosphorus, as well as pollutants like oil and gas. The continued input of nutrients to lakes increases the natural aging of a lake. More nutrients allow more algae to grow and often grow rapidly in the form of large algal blooms. These algal blooms can leave a clear, pristine lake with a layer of green plant matter and even scum on top.
But it doesn’t stop there. As the algae go through their life cycle, they eventually die and begin sinking to the bottom. During the sinking, bacteria consume the organic matter and consume large volumes of oxygen in the water. This can lead to oxygen depletion at depth which often leads to fish kills. The remaining algae settle on the bottom of the lake slowly filling in the lake and also providing an internal phosphorus source to the lake during periods of oxygen depletion. This scenario leads to more significant algal blooms in subsequent years.
Natural lake aging that takes centuries compared to lake aging that has been accelerated by land use. (Image from the US EPA Watershed Academy website: Issues in Ecology, Summer, 1998)
Through AWWA’s Salmon Falls Headwater Lakes Watershed Management Plan, several road construction projects were identified and have been completed. Please visit our current and future road projects on Lovell Lake, Great East Lake, and Wilson Lake.
Lovell Lake –Brackett Road
Great East Lake –Langley Shores Drive,
Wilson Lake –Hawk Road