What is a Watershed?
A land area that contributes water, through run-off or subsurface infiltration and flow to a given point of drainage. A watershed is usually considered to be smaller than a basin. Smaller, contributory watersheds or subsurface watersheds, usually range from 12 to 15 square miles in size.
Mirror Lake drains to the Chubb River, then to the West Branch of the Ausable River, and on to Lake Champlain.
The Mirror Lake watershed can be described as having two very different parts. The first lies to the northeast of the lake and is characterized by heavily forested land, permeable surfaces, and a system of ponds and streams that help filter and slow drainage.
One part is urban and residential characterized by density of development and a high degree of impermeable surfaces. These characteristics are complicated by the steepness of the topography in much of the watershed. Mirror Lake’s outlet is at the southern end close to the municipal beach.
The urban/residential part of the watershed can be viewed as having three different categories of storm water impacts. The Mirror Lake Storm Water Action Plan of 2001 describes these as high density commercial, low density commercial, and residential.
