A watershed is the area that "drains" into a lake, brook, stream, pond, reservoir, ocean or wetland. Wood cutting operations and development can change the lay of the land and natural drainage to cause water that drains downhill to pick up speed and carry silt into precious waterways. The trick around these natural resources is to slow the water speed and to filter it with natural riparian buffers that slow, retain or clean this water before it ends up where the fish live and you enjoy recreation. The drainage basin acts as a funnel and the water's course depends on the topography from adjacent watersheds, mountains, rolling fields. Exposed land that is not seeded down can have soil erosion from the water drainage and from wind. I grew up on a potato farm and loss of top soil is always a concern. Air harvesters that blow the dirt from the conveyors to the bulk body that holds the spuds that are destined for winter storage is just like loss of hair. Ledge or rock out croppings can show thru and suddenly there are spots of land in the field you can not plant on because the soil is gone. You could and farmers do scoop up soil from one area and over lay it on these ledge "bald spots".
I am president of the Drews Lake Owner's Association and we have worked hard to spot the erosion areas, studies the watershed that is roughly 19 miles large around the lake. The lake itself turns over, or "refreshes" every 13 months so new water with [potential for contanimants can change the overall health of a clean Maine lake. Erosion, silt, pollution from say a dairy farm's manure pile or fertilizer nitrogen can be toxic to a lake too. These elements along with man using weed and feed on lawns, or pressure treated arsenic laced docks and decks all contribute to the stability or decline of a lake. The pressure from pollution and silt destroys habitats, spawning beds and can cause fewer game fish and more rough fish. And the worse culprit to impact our lake enjoyment in Maine is too much weed and algae growth. The word milfoil is a scary one for southern Maine lakes that have out of control evasive plants life going wild. All land uses have the potential to add pollutants to Meduxnekeag (Drews) Lake or any precious natural resource.
A cutting operation in a woodlot five miles away can pollute a lake with silt, run off, phosphorus and other contaminants. Property culverts on roadways, proper grading of those roadways and installation of "punge pools" can help buffer a lake. The plunge pool is a series of rocked "holes" that fill up with run off during spring snow melting or heavy summer rains so that water does not race down a steep hill, taking dirt, debris from decaying leaves, etc into a body of water. The pools fill up, over flow and fill up the next hole to slow the water's speed and what it carries with it. Planting vegetation along the shoreline helps hold the soil in place and acts as a filter between land and waterway too. Maine lakes are a blessing, a privledge and we all need to be good stewards, passing them on to our kids in better shape than we received them if they are to be saved and preserved.