Keeping Lake Winnipesaukee pure and healthy means measuring how well we're achieving that critical goal.


Assessing the health of the watershed includes more than just monitoring the water quality of the lake – land use changes, fish and wildlife populations, the occurrence and spread of invasive plants, and the frequency of algal blooms are all indicators of overall lake and watershed health.

Monitoring these changes is an important component of implementing the Lake Winnipesaukee management plans, and for tracking progress in meeting the water quality goals established by the subwatershed committees.


Lake monitoring has been conducted on Lake Winnipesaukee since the late 1970’s with the creation of the University of New Hampshire’s NH Lakes Lay Monitoring Program (LLMP). The LLMP is dedicated to preservation and sound management of lakes through citizen-based monitoring and research. Through its integration of research, outreach and teaching, the LLMP provides valuable data on the lakes of New Hampshire, broad community service and a unique opportunity for hands-on learning and employment of students. The program continues to receive local and national recognition as one of the leading lake monitoring programs in the country. The LLMP is administered jointly through the Cooperative Extension and the Center for Freshwater Biology at the University of New Hampshire.

While water quality data collected over the past two decades on Lake Winnipesaukee provides valuable information for long-term trend analysis, the location of sampling stations is not distributed evenly over the lake, nor is the frequency of sampling consistent. Much of this is due to the fact that the program is volunteer based, relying on active participation of lake residents, and the financial support of the local lake, homeowner, road association and conservation commission.

Another active lake monitoring program in the Winnipesaukee Watershed is the NH DES Volunteer Lake Assessment Program (VLAP). While not conducted on Lake Winnipesaukee itself, this program is conducted on several lakes and ponds within the watershed, such as Lake Waukewan, Wicwas Lake, Lake Winona, Rust Pond, and Lake Winnisquam. Information on the program can be found at NH DES VLAP website.

Interested in being a lake monitor or supporting continued water quality monitoring efforts? The Lake Winnipesaukee Watershed Association assists UNH LLMP in the coordination of lake and tributary monitoring on Winnipesaukee. Contact us at 603-581-6632 or email: for information on how you can help.


The currently active monitoring sites for Meredith Bay, Paugus Bay, and Saunders Bay are shown on our interactive map. In the future, this web site will have more of the water quality data collected by the Environmental Monitoring Database (EMD) of the NH Department of Environmental Services.


As part of the Management plan for Meredith, Paugus, Saunders Bay Subwatersheds, a water quality monitoring project was conducted in the three bays to acquire current data on water quality. Monitoring has continued in 2010 with a number of volunteers (the results will be posted here when they are available from UNH LLMP). Access the current water quality reports by clicking here:

2009 Meredith, Paugus, Saunders Bay Water Quality Report (PDF, 894kb)
2009 Tributary Monitoring Report (PDF, 721kb)

Photo by Boston Magazine

For those who want to learn more about water quality in general, the Field Guide to Aquatic Phenomena (PDF, 715kb) by the Maine DEP and the University of Maine is a public-friendly guide to understanding what causes different things we see on lakes, such as foam, algae and water quality changes.

The programs and sites listed below are great resources for learning more about monitoring and accessing data about water quality in Lake Winnipesaukee and in New Hampshire: