Water Quality & Watershed Management

The Association works with the town of Wolfeboro, watershed property owners, and users to implement best management practices that improve water quality in the Wentworth-Crescent Watershed. Below are some of the resources that the Wentworth Watershed Association shares with the community in order to protect the water quality of the Wentworth-Crescent Watershed.

The Association collaborates with local and state agencies in the collection and use of scientific data to support the planning and implementation of stormwater mitigation efforts. These activities are best exemplified by the successful pursuit of four state grants – totaling more than $500,000 – that have been used to develop and initiate the implementation of a watershed-wide management plan. The grants were awarded by the NH Department of Environmental Services under Section 319 of the Clean Water Act to a partnership of the Association and the Town of Wolfeboro.

Water, Water, Water

The Wentworth-Crescent watershed has many attractive features, but the three most important are Water, Water and Water – Wentworth, Crescent and Sargent’s.

The WWA, in association with the University of New Hampshire Extension Service “Lay Lakes Monitoring Program” (LLMP), has an extensive water sampling effort designed to monitor water quality and to identify sources of potential contamination. Thanks to a number of WWA volunteers, recurring water samples are collected, frozen and sent to UNH for analysis. The LLMP has two parts:

Tributaries

Samples are collected periodically throughout the season from 25 tributaries that feed the lakes, usually on short notice within a small window of time following or during a rain event. This effort paid off recently when the source of an abnormally high phosphorus result in one tributary was tracked down and subsequently corrected.

In-Lake

Weekly samples are collected, May – September, from Fuller’s, Governor’s and Triggs in Lake Wentworth, and from Crescent Lake. We are currently in the process of looking for a 2021 volunteer or team for Sargent’s Pond. If you may be interested, please let us know.

The In-Lake results are published by UNH at https://extension.unh.edu/resources/index.cfm?e=app.llmp. The 2020 sampling results have not been published yet due to COVID-19 access restrictions at UNH, but we understand that they will be consistent with the 2019 observations.

The results show:

	Crescent	Fuller’s	Governor’s	Triggs
Clarity	Excellent	Excellent	Excellent	Excellent
Chlorophyll	Excellent	Excellent	Excellent	Excellent
Phosphorus	Excellent	Excellent	Excellent	Excellent
Deep Dissolved Oxygen	Not Assessed	Fair	Poor	Fair
Color	Slightly colored	Slightly tea colored	Slightly tea colored	Slightly tea colored
Alkalinity	Moderately vulnerable	Moderately vulnerable	Moderately vulnerable	Moderately vulnerable
pH	Optimal	Optimal	Optimal	Optimal
Conductivity	Some human influence	Some human influence	Some human influence	Some human influence

Long Term Trends:

• Clarity:
  • Crescent: Has remained relatively stable since 1984.
  • Wentworth: There has been a trend of decreasing transparency between 1985 and 2019.
• Color: Naturally occurring “tea” color is from the breakdown of soils and plant materials in the run off:
  • Crescent: Has displayed a trend of increasing color since 1986.
  • Wentworth: Has remained relatively stable since 1984.
• Chlorophyll: Is “Excellent” and has remained stable since 1985.
• Phosphorus: Is “Excellent” and has remained stable since 1985.
• Dissolved Oxygen: The deep water dissolved oxygen is important to the successful growth and reproduction of cold-water fish. Low oxygen occurs in lakes that are deep enough to stratify during the summer, preventing transportation of oxygen from the surface. Oxygen from the spring mixing is consumed by fish and bacteria that feed on algae that has died and settled to bottom.
  • Crescent: is not deep enough to stratify and is not tested.
  • Wentworth: Low levels of deep-water oxygen has been a long-term issue. It is a natural result There is no practical way to directly affect the oxygen level. The best practice is to limit algae growth by controlling phosphorus.

Submitted by John Buttrick, WWA LLMP coordinator