Monthly water quality testing and sample collection by WWN volunteers helps us monitor conditions in the lake to identify threats and assess long-term trends. It also formed the foundation for the Winnisquam Watershed Management Plan, and will aid in determining the impact of improvements made based on recomendations in that plan.

Lake Monitoring

Each summer Winnisquam Watershed Network volunteers conduct monthly water quality testing and sample collection at three deep-water stations and two shallower near-shore stations in the lake. Samples are transported to the NH Department of Environmental Services (NHDES) laboratory in Concord where they’re tested for color, chloride, chlorophyll-a, alkalinity, pH, total phosphorus and conductivity.

This program is part of the comprehensive Lake Winnisquam Tiered Monitoring Plan, which the WWN began implementing in 2017. It builds on the database previously established by several neighborhood groups on the lake through two volunteer monitoring programs, the University of NH Lakes Lay Monitoring Program (LLMP) and the NHDES Volunteer Lake Assessment Program (VLAP). The comprehensive program allows us to coordinate volunteers, share resources & equipment, and synchronize the sampling to allow for better comparability of the data generated.  See the most recent lake VLAP reports.

Tributary Monitoring

In the summer of 2018 the Winnisquam Watershed Network began implementing a tributary monitoring program as recommended by the Tiered Monitoring Plan. Tributary monitoring is conducted monthly throughout the summer months by WWN volunteers using protocols from the NHDES Volunteer Rivers Assessment Program (VRAP). The sampling is conducted at eight stream locations where water flows into Lake Winnisquam, and at one location at the outlet to Silver Lake. The samples are tested for dissolved oxygen, chloride, pH, turbidity, total phosphorus and conductivity.  In recent years, the VRAP program has helped us identify areas around the lake that need some attention. See the most recent tributary VRAP report.

What are we finding?

In general Lake Winnisquam has excellent water quality, with better than average water clarity and low phosphorus and dissolved organic matter. The impact of all the rain the summer of 2023 was evident in the data, with increased nutrient and sediment washoff leading to reduced water clarity and increased phosphorus levels observed at some of the in-lake stations. We need to remain vigilant. This is a continuation of a trend that started in the last couple of years, where the near-shore stations have indicated a decrease in clarity over time. The conductivity and chloride levels in our lake are on the rise, most likely from the urbanization of the watershed and in particular the use of road salt on impervious surfaces. This is a trend that’s been seen in freshwater bodies throughout the northeast, but seems to be a bit worse in Winnisquam.  Click here to see past lake water quality reports. Reports for 2023 will be posted as soon as they’re received.