Watershed Facts

Watershed FactsLake Winnipesaukee usually freezes in January to a depth of 3 to 4 feet.

General Facts

  • It is a 63 mile drive around Lake Winnipesaukee.
  • There are 365 islands in Lake Winnipesaukee; 274 of which are habitable.
  • Becky’s Garden is the smallest island on Lake Winnipesaukee having a 10 foot width on a good day.
  • Loon is the name of three different islands on Lake Winnipesaukee.


  • “Winnipiseogee” is the Native American name for Lake Winnipesaukee, which was the most common named used by the earliest New Hampshire English settlers. The most popular translation of the name is “Smile of the Great Spirit”.
  • The Lady of the Lake was constructed in Lakeport in 1849 and was the first boat built over 100 feet in length that provided mass transport on the lake.
  • The 780 ton MS Mount Washington, was assembled in 1939 from the 230-foot hull of the Lake Champlain Vessel Chateaugay. The Mount stops at Wolfeboro, Alton Bay, Weirs Beach, Meredith, and Center Harbor, from ice-out in spring until October 21st.
  • The islanders on Lake Winnipesaukee don’t have to come to the mainland to pick up their mail. The MS Mount Washington’s sister ship, the Sophie C, delivers mail to all inhabited islands.
  • The official Ice-Out on Lake Winnipesaukee is judged by when the MS Mt. Washington can successfully navigate its route.
  • Wolfeboro is the oldest summer resort town in the U.S.

Water Quality Facts

  • The water quality in Lake Winnipesaukee is considered fairly good, but poorer conditions do occur in localized sites.
  • Lake Winnipesaukee is considered an oligotrophic lake meaning the lake has high water clarity, limited plant growth, and relatively low nutrient inputs.
  • The parameters used to measure a lake’s trophic state are chlorophyll a, water transparency, and total phosphorus.
  • Phosphorus stimulates plant growth and contributes significantly to eutrophication, when the lake turns green due to algae growth. Water transparency measures water clarity, which is affected by algae growth in response to increases of phosphorus input.
  • The water in the lake’s numerous coves and bays does not readily mix with the rest of the lake, causing the water in these areas to be more susceptible to water quality problems.

Animal Facts

  • Otter, beaver, muskrat, mink, fisher, moose, deer, black bear, coyotes, and bobcats all can be seen in the Lakes Region.
  • The Lakes Region has one of the last known colonies of purple martins in the state, which nest in boxes provided by local residents.
  • Male loons return to their traditional nesting territory in the Lakes Region on the day of ice-out and are joined by a female.
  • Rainbow trout were introduced to Lake Winnipesaukee in 1990 and small mouth bass were introduced in 1860.

Lake Winnipesaukee Watershed Stats

Land Area

180,550 acres

Surface Water

55,685 acres

Total Watershed Area

236,225 acres

Surface Water

Lake Winnipesaukee

44,586 acres

Other Lakes, Ponds, Rivers

11,099 acres

Total Surface Water

55,685 acres

Land Area

Forested Land (88.5%)

159,799 acres

Cleared Land (8.3%)

14,993 acres

Wetlands (3.2%)

5,758 acres

Total Land Area

180,550 acres

Lake Winnipesaukee

Surface Area

72 sq. miles

Maximum Depth

180 feet

Average Depth

43 feet


625 billion gallons


504 feet

# of Habitable Islands


Length of Shoreline

240 miles

Lake Length

28 miles

Mean Discharge

534 cu. ft/second

Residence Time

5 years

Evaporation Rate


Trophic State


Watershed Facts

  • A watershed may be defined as the land area contributing water to a body of water or watercourse. The Lake Winnipesaukee Watershed covers 381 square miles.
  • A watershed is defined by topography. All water that falls onto a watershed flows to a common point, the lowest point, which could be a stream, river, lake, or pond. Sixteen (16) towns, eight of which have lake frontage, contain land within the watershed that contribute water to Lake Winnipesaukee.
  • Smaller watersheds draining only a few acres into a pond, may be part of a much larger watershed draining into a nearby river or lake. For example, Lake Waukewan in Meredith and Lake Wentworth in Wolfeboro are both part of the Winnipesaukee Watershed.
  • The Lakes Region consists of over 273 lakes and ponds.