The communities of Moultonborough, Tuftonboro, and Wolfeboro are committed to keeping Winnipesaukee clean and healthy.



Lake Winnipesaukee is a 44,586-acre lake located in central New Hampshire (NH), with a 215,133-acre watershed area that includes the 29,870-acre Moultonborough Bay watershed and the 5,095-acre Winter Harbor watershed. The lake and its embayments are currently listed on the NHDES 303(d) List of Impaired Waters as impaired for primary contact recreation due to elevated levels of cyanobacteria hepatoxic microcystins. Gloeotrichia (Gloeotrichia echinulata) (a species of cyanobacteria) blooms have been observed in Winter Harbor, as well as other embayments on Lake Winnipesaukee, and represent a threat to water quality and lake health. A cyanobacteria warning for Winter Harbor was issued by NHDES from August 30, 2018 to September 21, 2018 when areas along the southern shoreline near Whitegate Road showed evidence of a Gloeotrichia bloom. Based on modeling and field surveying presented in this plan, both Moultonborough Bay and Winter Harbor are at risk for continued water quality degradation from future development under current zoning. The combined effects of increased development and climate change will likely continue to exacerbate the prevalence of potentially-toxic cyanobacteria in these waterbodies. It is therefore important to take proactive steps to manage and treat pollutants entering surface waters from existing and future point and nonpoint source (NPS) pollution in the Moultonborough Bay and Winter Harbor watersheds. These actions will ensure continued ecosystem health and recreational enjoyment by current and future generations. 

This plan was partially funded by a Watershed Assistance Grant for High Quality Waters from NHDES using Clean Water Act Section 319 funds from the USEPA, with additional financial and in-kind services provided by the Towns of Tuftonboro and Wolfeboro, residents, and stakeholders.  

The Moultonborough Bay and Winter Harbor Watershed Management Plan is the culmination of a major effort by many individuals who care about the long-term protection of water quality in the watershed. The plan provides a roadmap using the USEPA’s nine key planning elements for preserving and/or improving water quality and a mechanism for acquiring funding for implementation of management actions (e.g., Section 319 grants). USEPA requires that a watershed plan, or an acceptable alternative plan, be created so that communities become eligible for federal watershed assistance implementation grants. In addition, this plan sets the stage for ongoing dialogue among key stakeholders in the community and promotes coordinated action to address future development in the watershed. Plan success is dependent on the continued effort of volunteers, as well as a strong and diverse steering committee that meets regularly to review progress and make any necessary adjustments to the plan.

As part of the development of this plan, a build-out analysis, water quality and assimilative capacity analysis, and shoreline/watershed surveys were conducted (Section 3). Results of these efforts were used to run a linked watershed land-use, or Lake Loading Response Model (LLRM), that estimated the pre-development, current, and projected future amount of total phosphorus delivered to these two embayments from the watershed (Section 3.3). An Action Plan (Section 5.2) with associated timeframes, responsible parties, and estimated costs was developed based on feedback from the steering committee and the resultant annual average total phosphorus concentrations in the embayments. A public forum was initially scheduled to discuss the Action Plan and receive feedback from the community; however, this forum was canceled due to concerns with public gatherings in the face of COVID-19. The public forum was replaced with individual outreach to community members within the watershed and sharing of a homeowner’s guide to assist residents with the implementation of residential BMPs.


We have presented the water quality goals for Moultonborough Bay and Winter Harbor as two-fold.

Goal 1: To improve water quality in both Moultonborough Bay and Winter Harbor through a 5% reduction in current total phosphorus loads to meet an average seasonal (May 24-Sept 15) deep spot epilimnion concentration of 6.7 ppb and 5.9 ppb in Moultonborough Bay and Winter Harbor, respectively.

  • To maintain current water quality in Moultonborough Bay, 39 kg/yr of total phosphorus must be removed to offset the anticipated increase in annual inputs over the next 10 years plus an additional 148 kg/yr to meet the 5% reduction target. This sums to a reduction total of 187 kg/yr for Moultonborough Bay in the next 10 years.
  • To maintain current water quality in Winter Harbor, 4.7 kg/yr of total phosphorus must be removed to offset the anticipated increase in annual inputs over the next 10 years plus an additional 14 kg/yr to meet the 5% reduction target. This sums to a reduction total of 18.7 kg/yr for Winter Harbor in the next 10 years.

Goal 2: To assess the spatial and temporal distribution and causes of Gloeotrichia blooms observed in Lake Winnipesaukee (and most notably in the Winter Harbor basin) and determine geographically specific water quality objectives to reduce the occurrence of localized blooms.

  • Quantify (through enumeration and speciation) the presence of Gloeotrichia at nearshore sites in Moultonborough Bay and Winter Harbor during bloom events (including within column, surface scum, and benthic algae).
  • Identify long-term beach profiling sites to determine the contribution of shoreline erosion to localized total phosphorus concentrations in both Moultonborough Bay and Winter Harbor (Rando et. al., 2017).
  • Enhance water quality monitoring at nearshore sites with sampling in spring, summer, and fall to identify the seasonal effects of localized total phosphorus.


USEPA guidance lists nine components that are required within a watershed plan to restore waters impaired or likely to be impaired by NPS pollution. These guidelines highlight important steps in restoring and protecting water quality for any waterbody affected by human activities. The following locates and describes the nine required elements found within this plan:

A. Identify Causes and Sources: Section 3.5 highlights known sources of NPS pollution to Moultonborough Bay and Winter Harbor and describes the results of the watershed and shoreline surveys conducted in the summer and fall of 2019. These sources of pollution must be controlled to achieve load reductions estimated in this plan, as discussed in item (B) below. 

B. Estimate Phosphorus Load Reductions Expected from Planned Management Measures: described under (C) below: Sections 3.5 and 4.1.1 describe the calculation of pollutant load to Moultonborough Bay and Winter Harbor and the amount of reduction needed to meet the water quality goal. Section 4 describes how estimated phosphorus load reductions to Moultonborough Bay and Winter Harbor can be met using specific management measures, including structural Best Management Practices (BMPs) for existing development, non-structural BMPs for future development, and an adaptive management approach.  

C. Description of Management Measures: Sections 4 and 5.2 identify ways to achieve the estimated phosphorus load reduction and reach water quality targets. The Action Plan focuses on six major topic areas that address NPS pollution, including: water quality monitoring, watershed and shorefront BMPs, roads, municipal planning and conservation, and septic systems. Management options in the Action Plan focus on non-structural BMPs integral to the implementation of structural BMPs.

D. Estimate of Technical and Financial Assistance: Sections 5.1, 5.2, and 5.4 include a description of the associated costs, sources of funding, and primary authorities responsible for implementation. Sources of funding need to be diverse and should include local, state, and federal granting agencies (towns of Moultonborough, Tuftonboro, and Wolfeboro, NHDES, and USEPA), local groups (Lake Winnipesaukee Association (LWA)), private donations, and landowner contributions for BMP implementation on private property. The towns of Moultonborough, Tuftonboro, and Wolfeboro, and other core stakeholders, led by the LWA, should oversee the planning effort by meeting regularly and efficiently coordinating resources to achieve the Plan objectives.

E. Information & Education & Outreach: Sections 1.5 and 5.5 describe how the Education and Outreach component of the plan is already being or will be implemented to enhance public understanding of the project, because of leadership from the LWA and the three towns.

F. Schedule for Addressing Phosphorus Reductions: Section 5.2 provides a list of action items and recommendations to reduce the phosphorus load to Moultonborough Bay and Winter Harbor. Each item has a set schedule that defines when the action should begin and/or end or run through (if an ongoing activity). The schedule should be adjusted by a steering committee on an annual basis (see Section 4.3 on Adaptive Management).

G. Description of Interim Measureable Milestones: Section 5.3 outlines indicators of implementation success that should be tracked annually. The indicators are divided into three different categories: Environmental, Programmatic, and Social Indicators. Environmental indicators are a direct measure of environmental conditions, such as improvement in water clarity or reduced median in-lake phosphorus concentration. Programmatic indicators are indirect measures of restoration activities in the watershed, such as how much funding has been secured or how many BMPs have been installed. Social indicators measure change in social behavior over time, such as the number of new monitoring volunteers. 

H. Set of criteria: Sections 3.4 and 5.4 can be used to determine whether loading reductions are being achieved over time, substantial progress is being made towards water quality objectives, and if not, criteria for determining whether this plan needs to be revised.

I. Monitoring component: Section 5.2.1 of the Action Plan describes the long-term water quality monitoring strategy for Moultonborough Bay and Winter Harbor, the results of which can be used to evaluate the effectiveness of implementation efforts over time as measured against the criteria in (H) above. The goal of this plan is to improve water quality by lowering the median phosphorus concentration to eliminate the occurrence of cyanobacteria blooms. The success of this plan cannot be evaluated without ongoing monitoring and assessment and careful tracking of load reductions following successful BMP implementation projects.


The plan was developed through the collaborative efforts of numerous meetings, public presentations, and conference calls between FB Environmental Associates (FBE), the LWA, NHDES, the USEPA, representatives from the towns of Moultonborough, Tuftonboro, and Wolfeboro, and private landowners (see Acknowledgments). 

Five meetings were held over the duration of the plan development.  The following list does not include routine annual meetings conducted separately by LWA.

  • June 20, 2018: Held a project kick-off meeting with LWA, consultants, and steering committee members to review project objectives, timeline, and strategy.
  • March 6, 2019: LWA presented the revised landcover analysis, subwatershed delineation, and assimilative capacity to the steering committee.
  • September 19, 2019:  FBE met with the project steering committee to review the preliminary results of the LLRM and the results of the watershed and shoreline survey work completed in the summer of 2019. 
  • April 10, 2020: FBE and LWA met with the steering committee to review the final results of the LLRM and to present the conceptual design plans for the four identified candidate sites for BMP implementation projects. BMP implementation projects were presented by sub-contracting engineers, Horsley Witten Group (HWG).
  • September 24, 2020: The final public meeting to review the full plan was held on September 24, 2020 as a webinar.



Patricia Tarpey, Executive Director
Alison Baranovic, AmeriCorps for Lake Winnipesaukee Association
Gloria Norcross, AmeriCorps for Lake Winnipesaukee Association


David Ford, Public Works Director, Town of Wolfeboro
Bill Gassman, Conservation Commission, Town of Moultonborough
Lawrence Gil, Conservation Commission, Town of Tuftonboro
Peter Glick, Board Member, Lake Winnipesaukee Association and Resident of Tuftonboro
Ellen Laase, Resident of Tuftonboro
Francis Laase, Resident of Tuftonboro
Amy Lindamood, Moultonborough Planning Board
Bill Marcussen, Board of Select, Town of Tuftonboro
Warren Muir, Conservation Commission, Town of Wolfeboro
Linda Murray, Board of Select, Town of Wolfeboro
Marie Samaha, Town of Moultonborough
Brian Sanford, Conservation Commission Chair, Town of Moultonborough
Robert Simmonds, Resident of Wolfeboro
Steve Wingate, Conservation Commission Chair, Town of Tuftonboro


Forrest Bell, Principal, FB Environmental Associates
Richard Brereton, Ph.D., Water Resources Scientist, FB Environmental Associates
Christine Bunyon, Project Scientist, FB Environmental Associates
Laura Diemer, Project Manager and Environmental Monitoring Lead, FB Environmental Associates
Maggie Kelly, Project Scientist, FB Environmental Associates
Margaret Mills, Project Manager and Hydrologist, FB Environmental Associates – Project Lead
Kevin Ryan, Wetlands/Wildlife Ecologist and Ecological Services Lead, FB Environmental Associates
Antonia Sohns, Project Manager, FB Environmental Associates
Don Kretchmer, DK Water Resource Consulting
Renee Bourdeau, P.E., Water Resources Engineer, formerly of Horsley Witten Group
Richard Claytor, P.E., President, Horsley Witten Group
Brian Laverriere, Project Designer, Horsley Witten Group

Additional Partners

  • Jeffrey Marcoux, Watershed Supervisor, NHDES
  • Bob Craycraft, Center for Freshwater Biology, University of New Hampshire

Thank you all for your valuable input on this project!