What is a Watershed?
In general terms, a watershed is an area of land upstream of a waterbody (a point in a stream or the outlet of a lake) in which all the surface water drains to the waterbody. A watershed is delineated by starting at the point in a stream or the outlet of a lake and following the highest elevation of land that divides the direction of flow until returning back to the point or outlet. Note: The U. S. Geological Services has a more technical definition of a watershed as part of their
hydrologic unit coding system.
New Hampshire consists of many interconnected watersheds of widely varying shapes and sizes. Every spot in the state is part of one or more watersheds. The watershed of a point in the Merrimack River as it enters Massachusetts contains all the lakes and streams (and all the watersheds of the lakes and streams) that eventually flow into the Merrimack above this point. The watershed of Profile Pond, located under the nose of the Old Man of the Mountain, is a relatively small area draining the steep slopes around it - and is also part of the Merrimack River watershed. Lake watersheds contain the watersheds of all lakes that drain to the downstream lake. For example, the watershed of Lake Winnipesaukee contains the watersheds of a number of lakes, including such lakes as Waukewan, Kanasatka and Wentworth. And Winnipesaukee is part of the watershed of Lake Winnisquam, which is in the Silver Lake, Tilton watershed - and all this is one small part of the Merrimack River watershed, which is part of the Gulf of Maine watershed, which is part of the Atlantic Ocean watershed.
[ Jackson Pond New Hampton Watershed Map Here ]
The above map depicts the watershed of Jackson Pond, located in New Hampton, NH. Notice that the watershed boundary crosses the outlet of Jackson Pond (the western end) and then connects all the high points (closed contour lines) surrounding the pond that divide the direction of flow to or away from the pond. The outlet waters of Sky Pond flow northward into Jackson Pond. This means that Sky Pond and its watershed is part of the Jackson Pond watershed. The Sky Pond watershed is also delineated and can be referred to as a sub-watershed of Jackson Pond.