LAKE WINNISQUAM
WATERSHED-BASED PLAN
PREPARED BY FB ENVIRONMENTAL ASSOCIATES & HORSLEY WITTEN GROUP
in cooperation with the Winnisquam Watershed Network, the New Hampshire Department of
Environmental Services, and the US Environmental Protection Agency
JULY2022 I FINAL
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LAKE WINNISQUAM WATERSHED-BASED PLAN
LAKE WINNISQUAM
WATERSHED-BASED PLAN
Prepared by FB ENVIRONMENTAL ASSOCIATES & HORSLEY WITTEN GROUP
in cooperation with the Winnisquam Watershed Network, the New Hampshire Department of
Environmental Services, and the US Environmental Protection Agency Region 1
WINNISQUAM
WATERSHED NIT WORK
FB
environmental
Horsley Witten Group M \
Cucfainah/a Cm/imnmanfa/ Qo/ii+if%r»c I
Sustainable Environmental Solutions
113 R2 Water Street • Exeter. NH • 03833
603-658-1660 • horsleywitten.com
JULY 2022 I FINAL
CONTACT
Lisa Eggleston, President
Winnisquam Watershed Network
P0 Box 502
Winnisquam, NH 03289
Funding for this project was provided in part by funds from the U, S, En vironmentai Protection Agency and the NH State
Conservation Committee Conservation Moose Plate Grant Program.
Cover Photo: Winnisquam Watershed Network
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LAKE WINNISQUAM WATERSHED-BASED PLAN
ACKNOWLEDGEMENTS
WINNISQUAM WATERSHED NETWORK
Lisa Eggleston, P.E., President
Dean Anson, Vice President
Richard Tracy, Secretary
Ed Stephenson, Treasurer
Cynthia O'Connell, Program Manager (Staff)
Melissa Macheras, Water Resources Intern (Staff)
Tom Camp, Director
Tony Carita, Director
Jim Chapman, Director
Bob Day, Director
Judy Hughes, Director
Katherine Keen, Director
Chuck Mitchell, Director
LOCAL CONSERVATION COMMISSIONS
Barbara Richter, Executive Director, NH Association of Conservation Commissions
Daniel Moore, Board of Directors, NH Association of Conservation Commissions
Lisa Morin, Laconia Conservation Commission - Member
Deborah Williams, Laconia Conservation Commission - Vice Chair
Dean Anson, Laconia Conservation Commission - Member
James Cropsey, Tilton Conservation Commission - Member
Chuck Mitchell, Tilton Conservation Commission - Member
James Gregorie, Meredith Conservation Commission - Treasurer
Scott Powell, Meredith Conservation Commission - Chair
Scott Rolfe, Belmont Conservation Commission - Co-chair
Ed Stephenson, Belmont Conservation Commission - Member
PLAN DEVELOPMENT COMMITTEE
Steve Winnett, EPA Contracting Officer; Regional TMDL Coordinator, US EPA Region 1
Mary Garren, TMDL and 303(d) Listing Coordinator for CT, US EPA Region 1
Steve Landry, NPS Program Supervisor, NH Department of Environmental Services
Jeff Marcoux, Watershed Supervisor, NH Department of Environmental Services
Lisa Eggleston, P.E., President, Winnisquam Watershed Network
Cindy O'Connell, Project Manager, Winnisquam Watershed Network
Melissa Macheras, Water Resources Intern, Winnisquam Watershed Network
Dean Anson, Laconia District Supervisor, Belknap County Conservation District; Vice President, Winnisquam
Watershed Network; Laconia Conservation Commission; Lakes Region Planning Commission Board
Lisa Morin, Program Coordinator, Belknap County Conservation District; Laconia Conservation Commission
Donna Hepp, Chairman, Belmont District Supervisor, Belknap County Conservation District
Dave Jeffers, Planner, Lakes Region Planning Commission
John Edgar, Community Development Director, Town of Meredith
Ken Kettenring, New Hampton Associate District Supervisor, Belknap County Conservation District
PatTarpey, Executive Director, Lake Winnipesaukee Association
Bree Rossiter, Conservation Program Manager, Lake Winnipesaukee Association
Scott Powell, President, Lake Wicwas Association
TECHNICAL STAFF
Forrest Bell, CEO/Owner, FB Environmental Associates
Laura Diemer, Project Manager, Environmental Monitoring Lead, FB Environmental Associates
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LAKE WINNISQUAM WATERSHED-BASED PLAN
Lori Kennedy, Senior Water Resources Engineer, Horsley Witten Group
Richard Claytor, P.E., President, Horsley Witten Group
Cayce Dalton, Project Manager, FB Environmental Associates
Maggie Kelly, Project Manager, FB Environmental Associates
Kevin Ryan, Wetlands/Wildlife Ecologist, Ecological Services Lead, FB Environmental Associates
Christine Bunyon, Project Scientist, FB Environmental Associates
In Memory of Toby Stover, TMDL and303(d) Listing Coordinator for NH; Regional
TMDL Alternative Restoration Plan Coordinator, US EPA Region 1
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LAKE WINNISQUAM WATERSHED-BASED PLAN
TABLE OF CONTENTS
Acknowledgements II
Table of Contents Iv
List of Abbreviations viii
Definitions x
Executive Summary xll
1 Introduction 1
1.1 Waterbody Description and Location 1
1.2 Watershed Protection Groups 2
1.3 Purpose and Scope 3
1.4 Community Involvement and Planning 3
1.4.1 Plan Development Meetings 4
1.4.2 Public Workshop 4
1.4.3 Public Surveys 4
1.4.4 Final Public Presentation 5
1.5 Incorporating EPA's Nine Elements 5
2 Assessment of Water Quality 6
2.1 Water Quality Summary 6
2.1.1 Water Quality Standards & Impairment Status 6
2.1.2 Water Quality Data Collection 7
2.1.3 Trophic State Indicator Parameters 9
2.1.4 Dissolved Oxygen & WaterTemperature 9
2.1.5 Cyanobacteria 10
2.1.6 Fish 13
2.1.7 Invasive Aquatic Species 13
2.2 Assimilative Capacity 13
2.3 Watershed Modeling 15
2.3.1 Lake Loading Response Model (LLRM) 15
2.3.2 Build-out Analysis 22
2.4 Water Quality Goal & Objectives 25
3 Pollutant Source Identification 27
3.1 Watershed Development 27
3.1.1 Development History of Lake Winnisquam 27
3.1.2 Watershed Assessments 29
3.1.3 Shoreline Survey 36
3.1.4 Soil&Shoreline Erosion 38
3.1.5 Wastewater 39
3.1.6 Fertilizers 41
3.1.7 Agriculture 41
3.1.8 Pets 42
3.1.9 Future Development 42
3.2 Potential Contamination Sources 42
3.2.1 Above and Underground Storage Tanks 43
3.2.2 Automobile Salvage Yards 43
3.2.3 Solid Waste Facilities 43
3.2.4 Hazardous Waste Sites 43
3.2.5 Local Potential Contamination Sources 43
3.2.6 NPDES Outfalls 43
3.2.7 Remediation Sites 43
3.3 Wildlife 45
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3.4 Climate Change 45
4 Management Strategies 46
4.1 Structural Nonpoint Source (NPS) Restoration 46
4.1.1 Watershed & Shoreline BMPs 46
4.1.2 Conceptual Designs for Select Priority Structural BMP Sites (2021) 48
4.2 Non-Structural Nonpoint Source (NPS) Restoration 52
4.2.1 Pollutant Reduction Best Practices 52
4.2.2 Stream Restoration 53
4.2.3 Zoning and Ordinance Updates 53
4.2.4 Land Conservation 57
4.2.5 Septic System Regulation 57
4.2.6 Sanitary Sewer System Inspections 57
4.2.7 Fertilizer Use Prohibition 58
4.2.8 Agricultural Practices 58
4.2.9 Pet Waste Management 58
4.2.10 Nuisance Wildlife Controls 59
4.3 Outreach & Education 59
4.4 Adaptive Management Approach 59
5 Action Plan 61
5.1 Action Plan 61
5.2 Pollutant Load Reductions 67
6 Plan Implementation & Evaluation 68
6.1 Plan Oversight 68
6.2 Estimated Costs 68
6.3 Funding Strategies 69
6.4 Monitoring Plan 71
6.5 Indicators to Measure Progress 71
Additional Resources 74
References 75
Appendix A: Public Workshop 77
Appendix B: Supporting Maps 30
Appendix C: BMP Matrix 90
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LAKE WINNISQUAM WATERSHED-BASED PLAN
List of Tables
Table 1. Cyanobacteria blooms occurring in the Lake Winnisquam watershed since 2006 11
Table 2. Aquatic life integrity (ALI) nutrient criteria ranges by trophic class in New Hampshire. TP = total phosphorus. Chl-a =
chlorophyll-a, a surrogate measure for algae 14
Table 3. Decision matrix for aquatic life integrity (ALI) assessment in New Hampshire. TP = total phosphorus. Chl-a =
chlorophyll-a, a surrogate measure for algae concentration 14
Table 4. Assimilative capacity (AC) analysis results for Lake Winnisquam, Lake Wicwas, and Lake Opechee. Chlorophyll-a
dictates the assessment results 14
Table 5. In-lake water quality predictions for Lake Wicwas, Lake Opechee, and Lake Winnisquam. TP = total phosphorus.
Chl-a = chlorophyll-a. SDT = Secchi disk transparency. Bloom Days represent average annual probability of chlorophyll-a
exceeding 10 ppb. Refer to FBE (2021a) 19
Table 6. Total phosphorus (TP) and water loading summary by model and source for Lake Winnisquam. Italicized sources
sum to the watershed load. Referto FBE (2021a) 20
Table 7. Amount of buildable land and projected buildings by zone in the direct Lake Winnisquam watershed in Belmont,
Gilford, Laconia, Meredith, New Hampton, Sanbornton, and Tilton, New Hampshire 23
Table 8. Compound annual growth rates for the seven municipalities within the direct watershed of Lake Winnisquam, used
for the TimeScope Analysis. 2020 data were not available for towns with populations less than 5,000 at the writing of this
plan. Data from US Census Bureau 24
Table 9. Summary of water quality objectives for Lake Winnisquam, Lake Wicwas, and Lake Opechee. Interim
goals/benchmarks are cumulative 26
Table 10. Estimated pollutant reduction for structural BMPs by sub-watershed. Only those sites with a measurable
reduction in pollutant loading from recommended remediation are included 35
Table 11. Average scores for each evaluated condition criterion and the average Shoreline Disturbance Score and average
Shoreline Vulnerability Score for Lake Winnisquam. Lower values indicate shoreline conditions that are effective at reducing
erosion and keeping excess nutrients out of the lake 37
Table 12. Summary of septic system data for properties along the shoreline of Lake Winnisquam. Note: The number of
shoreline parcels within 250 ft of Lake Winnisquam (and subsequent percentages) include vacant lots 40
Table 13. Top 24 high priority structural BMP sites in the Lake Winnisquam watershed 47
Table 14. Ordinance review summary of regulatory and non-regulatory tools for natural resource protection for the seven
watershed municipalities of the Lake Winnisquam watershed 55
Table 15. Action Plan for the Lake Winnisquam watershed 61
Table 16. Breakdown of phosphorus load sources to Lake Winnisquam and modeled water quality for current and target
conditions that meet the water quality goal (Objective 3) for Lake Winnisquam and that reflect all field identified red uction
opportunities in the watershed 67
Table 17. Estimated pollutant reduction (TP) in kg/year and estimated total and annual 10-year costs for implementation of
the Action Plan (Section 5) to meet the water quality goal and objectives for Lake Winnisquam. The light gray shaded
planning actions are necessary to achieve the water quality goal. Other planning actions are important but difficult to
quantify for TP reduction and costs, the latter of which were roughly estimated here as general placeholders 69
Table 18. Environmental, programmatic, and social indicators for the Lake Winnisquam Watershed-Based Plan.
Environmental indicator milestones determined from Assimilative Capacity Analysis in Section 2.2 and FBE (2021a).
Programmatic and social indicator milestones estimated from best professional judgement 72
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LAKE WINNISQUAM WATERSHED-BASED PLAN
List of Figures
Figure 1. Lake Winnisquam watershed basemap xv
Figure 2. Total annual precipitation (TOP) and annual max, average, and min of monthly air temperature (BOTTOM) from
1950 - 2020 for the Lake Winnisquam watershed area. Data collected from NOAA NCEI 1
Figure 3. Bathymetric map with water quality monitoring stations in the Lake Winnisquam watershed 8
Figure 4. Annual average epilimnetic total phosphorus (blue), chlorophyll-a (green), and water clarity (Secchi depth, black)
measured intermittently from 2011-2021 at three deep spot stations on Lake Winnisquam (from upstream to downstream):
Three Island (TOP), Pot Island (MIDDLE), and Mohawk Island (BOTTOM) 9
Figures. Dissolved oxygen (black) and temperature (blue) depth profiles for three deep spot stations on Lake Winnisquam
(ordered from upstream to downstream): Three Island (TOP), Pot Island (MIDDLE), and Mohawk Island (BOTTOM). Profiles
were measured once in 2012,2013,2016,2017, and 2018, and twice in 2020 during thermal stratification in summer. Dots
represent average values across sampling dates for each respective depth. Error bars represent standard deviation 10
Figure 6. Map of documented wild brooktrout occurrences. Courtesy of Trout Unlimited 12
Figure 7. Lake Winnisquam watershed (including Lake Wicwas and Lake Opechee but not including Lake Winnipesaukee)
land cover area by general category (agriculture, developed, forest, and water/wetlands) and total phosphorus (TP)
watershed load by general land cover type. This shows that developed areas cover 29% of the watershed and contribute
84% of the TP watershed load to Lake Winnisquam. Water/wetlands category does not include the lake areas 16
Figure 8. Summary of total phosphorus loading by major source for Lake Winnisquam. Refer to Table 6 for a breakdown.. 17
Figure 9. Map of current total phosphorus load per unit area (kg/ha/yr) for each sub-watershed in the Lake Winnisquam
watershed. Higher phosphorus loads per unit area are concentrated in the more developed southern portion of the
watershed. Refer to FBE (2021a) 21
Figure 10. Full build-out time projections for the direct Lake Winnisquam watershed in Belmont, Gilford, Laconia, Meredith,
New Hampton, Sanbornton, and Tilton, New Hampshire (based on compound annual growth rates reported in Table 8)... 24
Figure 11. Map depicting identified sites and features of note during the 2021 investigation of Hueber Brook in Belmont. .. 31
Figure 12. Map of documented and prioritized remediation sites in the Black Brook sub-watershed. Referto site photos on
the previous page as well as FBE (2022) for more details 34
Figure 13. Historical demographic data forthe municipalities of Belmont, Gilford, Laconia, Meredith, New Hampton,
Sanbornton, and Tilton in the Lake Winnisquam watershed. The population of this community has grown dramatically over
the last 50 years. *2020 official census data is only available for municipalities with populations greater than 5,000people,
as of the writing of this plan 42
Figure 14. Potential sources of contamination in the Lake Winnisquam watershed 44
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LAKE WINNISQUAM WATERSHED-BASED PLAN
LIST OF ABBREVIATIONS
ACRONYM DEFINITION
AC Assimilative Capacity
AIPC Aquatic Invasive Plant Control, Prevention and Research Grants
ACEP Agricultural Conservation Easement Program
ALI Aquatic Life Integrity
ARM Aquatic Resource Mitigation Fund
ARP Alternative Restoration Plan
BCCD Belknap County Conservation District
BMP Best Management Practice
CAGR Compound Annual Growth Rate
CHL-A Chlorophyll-a
CNMP Comprehensive Nutrient Management Plan
CSP Conservation Stewardship Program
CUM Cubic Meters
CWA Clean Water Act
CWP Center for Watershed Protection
CWSRF Clean Water State Revolving Fund
DO Dissolved Oxygen
DOS Division of Security and Emergency Management
DPW Department of Public Works
EPA United States Environmental Protection Agency
EQIP Environmental Quality Incentives Program
ESRI Environmental Systems Research Institute
FBE FB Environmental Associates
FT Feet
HA Hectare
HAB Harmful Algal Bloom
HW Horsley Witten Group
ILF In-Lieu Fee
KG Kilogram
LCHIP Land and Community Heritage Investment Program
LID Low Impact Development
LLMP Lay Lakes Monitoring Program
LLRM Lake Loading Response Model
LOPA Lake Opechee Preservation Association
LRPC Lakes Region Planning Commission
LWA Lake Winnipesaukee Association
LWCF Land and Water Conservation Fund
M Meter
NAWCA North American Wetlands Conservation Act
NERFG New England Forest and River Grant
NCEI National Centers for Environmental Information
NFWF National Fish and Wildlife Foundation
NH GRANIT New Hampshire Geographically Referenced Analysis and Information Transfer System
NHACC New Hampshire Association of Conservation Commissions
NHD National Hydrography Dataset
NHDES New Hampshire Department of Environmental Services
NHDOT New Hampshire Department of Transportation
NHFGD New Hampshire Fish and Game Department
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ACRONYM
DEFINITION
NHGS
New Hampshire Geological Survey
NHLCD
New Hampshire Land Cover Database
NOAA
National Oceanic and Atmospheric Administration
NPS
Nonpoint Source Pollution
NRCS
Natural Resources Conservation Service
NRI
Natural Resources Inventory
NWI
National Wetlands Inventory
PCR
Primary Contact Recreation
PCS
Potential Contamination Source
ppb, ppm
parts per billion, parts per million
PSU
Plymouth State University
QAPP
Quality Assurance Project Plan
RCCP
Regional Conservation Partnership Program
RCRA
Resource Conservation and Recovery Act
ROW
Right-of-Way
SADES
Statewide Asset Data Exchange System
see
State Conservation Committee
SCM
Stormwater Control Measure
SDT
Secchi Disk Transparency
TMDL
Total Maximum Daily Load
TP
Total Phosphorus
UNH
University of New Hampshire
USLE
Universal Soil Loss Equation
VLAP
Volunteer Lake Assessment Program
VRAP
Volunteer River Assessment Program
WBP
Watershed-Based Plan
WRBP
Winnipesaukee River Basin Program
WWN
Winnisquam Watershed Network
YR
Year
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LAKE WINNISQUAM WATERSHED-BASED PLAN
DEFINITIONS
Adaptive management approach recognizes that the entire watershed cannot be restored with a single restoration action
or within a short time frame. The approach provides an iterative process to evaluate restoration successes and challenges to
inform the next set of restoration actions.
Alternative Restoration Plan (ARP or 5-alt) is a voluntary plan for restoration developed in advance of a TMDL. These plans
are created to speed up the planning and restoration process to meet water quality standards. A full TMDL planning process
is not needed for Lake Winnisquam, so an ARP that demonstrates the practicality of meeting water quality standards in a
reasonable timeframe can be developed instead. When the plan is accepted by EPA, the waterbody will remain at Category 5
(needing a TMDL) but can be assigned a lower priority for TMDL development. If water quality degrades or remains unchanged
after 10 years (asset by this plan) or if implementation of the plan is not progressing during that time, then EPA may require
a full TMDL process. Many of the required planning elements for the ARP overlap with the nine planning elements for WBPs.
Anoxia is a condition of low dissolved oxygen (Generally accepted as less than 2 ppm of dissolved oxygen).
A real Water Load is the total annual flow volume reaching the waterbody divided by the surface area of the waterbody.
Assimilative Capacity is a lake's capacity to receive and process nutrients (phosphorus) without impairing water quality or
harming aquatic life.
Best Management Practices (BMPs) are conservation practices designed to minimize discharge of NPS pollution from
developed land to lakes and streams. Management plansshould include both non-structural (non-engineered) and structural
(engineered) BMPs for existing and new developmentto ensure long-term restoration success.
Build-out analysis combines projected population estimates, current zoning restrictions, and a host of additional
development constraints (conservation lands, steep slope and wetland regulations, existing buildings, soils with low
development suitability, and unbuildable parcels) to determine the extent of buildable areas in the watershed.
Chlorophyll-a (Chl-a) is a measurement of the green photosynthetic pigment found in all plants, including microscopic
plants such as algae. Measured in parts per billion or ppb, it is used as an estimate of algal biomass;the higher the Chl-a value,
the higherthe concentration of algae in the lake.
Clean Water Act (CWA) is a federal law administered by the United States Environmental Protection Agency (EPA) that
requires states to establish water quality standards and conduct assessments to ensure that surface waters are clean enough
to support human and ecological needs.
Cyanobacteria are photosynthetic bacteria that can grow prolifically as blooms when enough nutrients are available. Some
cyanobacteria can fix nitrogen and/or produce toxins, in particular microcystin, a hepatoxin that is highly toxic to humans
and other life forms.
Dimictic lakes mix twice peryear, typically in springand fall (see turnover).
Dissolved Oxygen (DO) is a measure of the amount of oxygen dissolved in water. Low oxygen can directly kill or stress
organisms and stimulate release phosphorus from bottom sediments.
Epilimnion is the top layer of lake water, the depth (or thickness) of which is directly affected by seasonal air temperature
and wind. This layer is well-oxygenated by wind and wave action.
Eutrophication is the process by which lakes become more productive overtime (oligotrophicto mesotrophicto eutrophic).
Lakes naturally become more productive or "age" over thousands of years. In recent geologic time, however, humans have
enhanced the rate of enrichment and lake productivity, speeding up this natural process to tens or hundreds of years.
Flushing rate is the amount of time water spends in a waterbody. It is calculated by dividing the inputs of water to the lake
(streams, groundwater, precipitation, etc.) by the volume of the waterbody. The flushing rate of a lake is the inverse of the
time that water spends in the lake, known as the retention time.
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Full build-out refers to the time and circumstances in which, based on a set of restrictions (e.g., environmental constraints
and current zoning), no more building growth can occur, or the point at which lots have been subdivided to the minimum size
allowed.
Hypolimnion is the bottom-most layer of the lake that experiences periods of low oxygen during stratification and is
commonly characterized bya lack of sunlight for photosynthesis.
Impervious surfaces refer to any surface that will not allow water to soak into the ground. Examples include paved roads,
driveways, parking lots, and roofs.
Internal Phosphorus Loading is the process whereby phosphorus bound to lake bottom sediments is released back into the
water column during periods of anoxia. The phosphorus can be used as fuel for plant and algae growth, creating positive
feed back to eutrophication with negative consequences.
Low Impact Development (LID) is an alternative approach to conventional site planning, design, and development that
reduces the impacts of stormwater by working with natural hydrology and minimizing land disturbance by treating
stormwater close to the source, and preserving natural drainage systems and open space, among other techniques.
Nonpoint Source (NPS) Pollution comes from diffuse sources throughout a watershed, such as stormwater runoff, seepage
from septic systems, and gravel road erosion. One of the major constituents of NPS pollution is sediment, which contains a
mixture of nutrients (like phosphorus) and inorganic and organic material that stimulate plant and algae growth.
Non-structural BMPs, which do not require extensive engineering or construction efforts, can help reduce stormwater runoff
and associated pollutants through operational actions, such as land use planning strategies, municipal maintenance
practices, and targeted education and training.
Oligotrophic lakes are less productive or have fewer nutrients (i.e., low levels of phosphorus and chlorophyll-a), deep Secchi
Disk Transparency readings (8.0 m or greater), and high dissolved oxygen levels throughout the water column. In contrast,
eutrophic lakes have more nutrients and are therefore more productive and exhibit algal blooms more frequently than
oligotrophic lakes. Mesotrophic lakes fall in-between with an intermediate level of productivity.
pH is the standard measure of the acidity or alkalinity of a solution on a scale of 0 (acidic) to 14 (basic).
Secchi Disk Transparency (SDT) is a vertical measure of the transparency of water (ability of light to penetrate water)
obtained by lowering a black and white disk into the water until it is no longer visible. Transparency is an indirect measure of
algal productivity and is measured in meters (m). A reading of less than 2 meters is generally considered a nuisance algal
bloom.
Structural BMPs, or engineered Best Management Practices, are often at the forefront of most watershed restoration projects
and help reduce stormwater runoff and associated pollutants.
Thermal stratification is the process whereby warming surface temperatures create a temperature and density differential
that separates the water column into distinct, non-mixable layers.
Total Phosphorus (TP) is one of the major nutrients needed for plant growth including algae. It is generally present in small
amounts (measured in parts per billion (ppb)) and usually limits plant growth in lakes.
Trophic State is the degree of eutrophication of a lake and is designated as oligotrophic, mesotrophic, or eutrophic.
Turnover is the process of complete lake mixing when cooling surface waters become denser and sink, especially during high
winds, forcing warmer, less-dense water to the surface. This process is critical for the natural exchange of oxygen and
nutrients between surface and bottom layers in the lake.
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LAKE WINNISQUAM WATERSHED-BASED PLAN
EXECUTIVE SUMMARY
As the fourth largest lake in New Hampshire at 4,249 acres, Lake Winnisquam is situated within the economically vital Lakes
Region of central New Hampshire and drains Lake Winnipesaukee through Paugus Bay and Lake Opechee via the
Winnipesaukee River. The direct watershed area of Lake Winnisquam spans portions of the municipalities of Meredith,
Laconia, Sanbornton, Belmont, Gilford, New Hampton, and Tilton and includes other important waterbodies such as Lake
Wicwas and Lake Opechee, along with major tributaries such as Black Brook, Chapman Brook, Dolloff Brook, Durgin Brook,
Durkee Brook, and Jewett Brook. From the outlet of Lake Winnisquam, water flows south to Silver Lake then west via the
Winnipesaukee River until it joins with the Pemigewasset Riverto form the Merrimack River in Franklin.
The Problem
Lake Winnisquam is classified as an oligotrophic, Class Bwaterbody in New Hampshire but was placed on the New Hampshire
Department of Environmental Services (NHDES) 303(d) List of Impaired Waters forthe designated use of Aquatic Life Integrity
(ALI) due to excessive turbidity coming from Hueber Brook, a small tributary to the southeast side of Lake Winnisquam off
Route 3 and near Sun Lake Drive. Elevated turbidity indicates that Lake Winnisquam is experiencing enhanced sedimentation
or infill of sediment and other materials from the landscape. Black Brook, a tributary to Lake Winnisquam, has been long
impacted by excessive sediment loading from the gravel roads throughout the sub-watershed, most especially Huse Rd,
Kaulback Rd, and Woodman Rd. This sediment load is transported out into Lake Winnisquam where a visible 300-ft radius
sediment delta has formed over the years. Sediment often transports nutrients such as phosphorus to surface waters.
Enhanced loading of phosphorus, a key limiting nutrient for growth in freshwater, to surface waters such as Lake Winnisquam
can stimulate excessive plant and algae growth and degrade water quality. Lake Winnisquam has already experienced
cyanobacteria bloom warnings, which were issued by NHDES in 2008 (28 days) and 2010 (43 days). NHDES issued a
cyanobacteria bloom alert on 6/27/22 forthe north end of Lake Winnisquam. Cyanobacteria concentrations were below the
advisory level and dissipated within a couple days.
Potential sources of phosphorus in the watershed impacting the lake's water quality include stormwater runoff from urban
areas, shoreline erosion, erosion from construction activities or other disturbed ground particularly along roads, excessive
fertilizer application, illicit connections, failed or improperly functioning septic systems, leaky sewer lines, unmitigated
agricultural activities, and pet, livestock, and wildlife waste. Over 100 problem sites were identified in the watershed during a
field survey, and the main issues found were unpaved road and ditch erosion; waterfront park and beach erosion; buffer
clearing; and untreated urban stormwater runoff. The model results revealed changes in phosphorus loading and in-lake
phosphorus concentrations over time from pre-development through future conditions, showing that the water quality of
Lake Winnisquam is threatened by current development activities in the watershed and will degrade further with continued
development in the future, especially when compounded by the effects of ongoing climate change.
The Goal
The purpose and overarching goal of the Lake Winnisquam Watershed-Based Plan (WBP) is to guide implementation
efforts over the next 10 years (2022-2031) to improve the water quality of Lake Winnisquam such that it meets state
water quality standards for the protection of ALI. Note: this plan covers only the direct Lake Winnisquam watershed area
located in Laconia, Gilford, Belmont, Tilton, Sanbornton, Meredith, and New Hampton. Restoration efforts for the larger Lake
Winnipesaukee watershed are being led by other local groups. In addition, two other lakes are located within the immediate
drainage area to Lake Winnisquam: Lake Wicwas and Lake Opechee. While not the focus of the plan, their water quality status
has a direct impact on the water quality of Lake Winnisquam, and thus secondary water quality objectives were set to improve
their water quality both for their own benefit and for the benefit of Lake Winnisquam. Monitoring of these two waterbodies
should continue and/or be expanded, and if water quality decline is evident, then development of individual plans may be
warranted in the future.
This goal will be achieved by accomplishing the following summarized objectives:
• OBJECTIVE 1: Reduce pollutant loading from Hueber Brook to remove Lake Winnisquam's impaired listing for ALI
due to excessive turbidity.
• OBJECTIVE 2: Mitigate (prevent or offset) anticipated additional pollutant loading from future development in the
watershed.
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• OBJECTIVE 3: Reduce pollutant loading from existing development in the watershed, especially in the Black Brook
sub-watershed.
The Solution
Through the efforts of many key watershed protection groups, including, but not limited to, the Winnisquam Watershed
Network (WWN), Belknap County Conservation District (BCCD), Lake Wicwas Association, Lake Opechee Preservation
Association (LOPA), Lake Winnipesaukee Association (LWA), Lakes Region Planning Commission (LRPC), NHDES, and
municipalities and their conservation commissions, much planning and restoration work to protect and restore Lake
Winnisquam's water quality has been accomplished in the watershed to date.
A watershed management plan for the Black Brook sub-watershed was completed in 2012. In 2017, WWN was formed in part
to unify monitoring and assessment efforts around Lake Winnisquam. The monitoring program was significantly revamped
and expanded to include more frequent sampling of the deep spot and key tributaries. In 2020, a shoreline survey of Lake
Winnisquam was completed by WWN volunteers, 11 stream crossing culvert assessments were completed by Trout Unlimited
in the Black Brook sub-watershed, septic system data in the shoreland zone were collected by WWN volunteers (and
separated out from sewered parcels), and funding from the US Environmental Protection Agency (EPA) was secured to
develop a WBP for Lake Winnisquam. As part of the development of the WBP, a build-out analysis, land-use model, water
quality and assimilative capacity analysis, and watershed survey were conducted to better understand the sources of
phosphorus and other pollutants to the lake. In addition, remaining stream crossing culverts in the watershed were assessed
in 2021 by Trout Unlimited and the NHDES Wetlands Mitigation Program; BCCD hired an engineer in 2021 to review and assess
sedimentation issues impacting Black Brook; BCCD teamed with Trout Unlimited to complete a large wood installation
stream restoration project in 2021 for a one mile segment of Black Brook; and BCCD hired a consultant in 2022 to perform a
quantitative evaluation and prioritization of 11 erosion sites in the Black Brook sub-watershed to serve as supporting
documentation for future grant funding applications.
Results from these analyses were used to determine recommended management strategies for the identified pollutant
sources in the watershed. An Action Plan was developed in collaboration with a plan development committee comprised of
the key watershed protection groups noted above. The following actions were recommended to meet the established water
quality goaland objectives for the Lake Winnisquam watershed:
WATERSHED STRUCTURAL BMPS: Sources of phosphorus from watershed development should be addressed through
installation ofstormwater controls,stabilization techniques, buffer plantings, etc. forstormwater infrastructure in the Hueber
Brook sub-watershed, the top 24 high priority sites (and the remaining 84 medium and low priority sites as opportunities
arise) identified during the watershed survey, including road erosion in the Black Brook sub-watershed, the 20 high impact
shoreline properties (as well as the 282 medium impact shoreline properties) identified during the shoreline survey, and any
new or redevelopment projects in the watershed with high potential for soil erosion.
MONITORING: A long-term waterquality monitoring plan is critical to evaluate the effectiveness of implementation efforts
over time. WWN, in concert with University of New Hampshire (UNH) Lay Lakes Monitoring Program (LLMP) and NHDES
Volunteer Lake Assessment Program (VLAP), has implemented the Lake Winnisquam Tiered Monitoring Plan since 2017
and should continue the annual monitoring protocol and consider incorporating additional monitoring
recommendations laid out in this plan.
EDUCATION AND OUTREACH: WWN and other key watershed protection groups should continue all aspects of their education
and outreach strategies and consider developing new ones or improving existing ones to reach more watershed residents.
Examples include providing educational materials to existing and new property owners, as well as renters, by distributing
them at various locations and through a variety of means, such as websites, newsletters, social media, community events, or
community gathering locations. Educational campaigns should include raising awareness of water quality concerns, septic
system maintenance, fertilizer and pesticide use, pet waste disposal, waterfowl feeding, invasive aquatic species, boat
pollution, shoreline buffer improvements, gravel road maintenance, and stormwater runoff controls.
OTHER ACTIONS: Additional strategies for reducing phosphorus loading to the lake include: revising local ordinancessuch as
setting low impact development (LID) requirements on new construction; identifying and replacing malfunctioning septic
systems; inspecting and remediating leaky sewer lines; using best practices for road maintenance and other activities
including municipal operations such as infrastructure cleaning; conserving large or connective habitat corridor parcels;
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LAKE WINNISQUAM WATERSHED-BASED PLAN
completing stream restoration projects; and improving agricultural practices. Future development should also be considered
as a pollutant source and potential threat to water quality. Lake Winnisquam is at risk for greater water quality degradation
because of new development in the watershed unless climate change resiliency and LID strategies are incorporated to
existing zoning standards.
The recommendations of this plan will be carried out largely by WWN with assistance from a diverse stakeholder group,
including representatives from the seven municipalities (e.g., select boards, planning boards), conservation commissions,
state and federal agencies or organizations, nonprofits, land trusts, schools and community groups, local business leaders,
and landowners. The cost of successfully implementing the plan is estimated at $2.1-$3.2 million over the next 10 or more
years in addition to the dedication and commitment of volunteer time and support to manage plan implementation.
However, many costs are still unknown or were roughly estimated and should be updated as information becomes available.
This financial investment can be accomplished through a variety of funding mechanisms via both state and federal grants, as
well as commitments from municipalities or donations from private residents. Of significant note, this plan meets the nine
planning elements required by the EPA, and eligible entities within the Lake Winnisquam watershed are now eligible for
federal watershed assistance grants.
Important Notes
The success of this plan is dependent on the continued effort of volunteers and a strong and diverse stakeholder group that
meets regularly to coordinate resources for implementation, review progress, and make any necessary adjustments to the
plan to maintain relevant action items and interim milestones. A reduction in nutrient loading is no easy task, and because
there are many diffuse sources of phosphorus reaching surface waters in the watershed, it will require an integrated and
adaptive approach across many different parts of the watershed community to be successful.
Each municipality will likely have a unique response or implementation approach to the recommendations in the Action Plan,
and thus, the execution of the actions may take a decentralized path. WWN and other local groups can work with each
municipality to provide support in reviewing and tailoring the recommendations to fit the specific needs of each municipality.
It should also be understood that the recommendations in this plan are idealized and, in some cases, may be difficult to
achieve given the physical and political realities of each municipality dealing with old infrastructure, lack of access to key
lakefront areas, and limited funding and staff capacity.
Finally, we all have a common responsibility to protect our lakes for future generations to enjoy. Private landowners arguably
hold the most power in making significant impact to restoring and maintaining excellent water quality in our lakes; however,
engaging private landowners as a single stakeholder group can be difficult and outreach efforts often have limited reach,
especially to those individuals who may require the most education and awareness of important water quality protection
actions. WWN and other key watershed protection groups will continue to engage the public as much as possible so that
private individuals can help review and implement the recommendations of this plan and protect the water quality of Lake
Winnisquam long into thefuture.
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LAKE WINNISQUAM WATERSHED-BASED PLAN
Base Map
Lake Winnisquam
Watershed Based
Management Plan
C3 Lake Winnisquam Watershed
] Town Boundary
State Road
Local Road
Private Road
— Unmaintained Road
Waterbody
Stream/River
Wetland
n ^ Conservation Land
(§) Beach
^ Farm
(•) Golf Course
@ Marina
Bathymetry (ft)
0-20
21-40
41-60
61 - 80
81 -100
101 -120
121 -140
141 -160
Study Area
Data Source: NH Granit,
NHD, NWI, ESRI
Coordinate System: NAD 1983
State Plane NH FIPS 2800 ft
Map Created By: C. Bunyon
FB Environmental
Date Created: 1/5/2021
Center Harbor
New Hampton
/Forest Pond
Meredith
'Lake Wicwas
Pickerel Pond
Lctke
Winnipesaukee
PauguS' '¦
Bay
Lake Winnisquam
Lake Opechee
Gilford
Lake Winnisquam
Outlet
Tilton
Lake
Northfield
Belmont
ESRI World Imagery
captured on 3/27/2020
0 0.5 1
I Miles
Gilmanton
Figure 1, Lake Winnisquam watershed basemap,
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LAKE WINNISQUAM WATERSHED-BASED PLAN
1 INTRODUCTION
1.1 WATERBODY DESCRIPTION AND LOCATION
As the fourth largest lake in the State of New Hampshire,
Lake Winnisquam is a 6.6-square-mile (4,249-acre) lake
with a 64-square-mile (40,694-acre) direct watershed area
(Figure 1) in the municipalities of Meredith (24%), Laconia
(23%), Sanbornton (21%), Belmont (16%), Gilford (9%),
New Hampton (5%), and Tilton (3%), The total watershed
area to Lake Winnisquam includes Lake Winnipesaukee via
Paugus Bay and the Winnipesaukee River (pictured right).
Other major waterbodies in the direct Lake Winnisquam
watershed include Lake Opechee (449 acres) and Lake
Wicwas (350 acres), along with major tributaries such as
Black Brook, Chapman Brook, Dolloff Brook, Durgin Brook,
Durkee Brook, and Jewett Brook. From the outlet of Lake
Winnisquam, waterflows south to Silver Lake then west via
the Winnipesaukee River until it joins with the
Pemigewasset River to form the Merrimack River in
Franklin, New Hampshire.
The Lake Winnisquam watershed is situated within a
temperate zone of converging weather patterns from the
hot, wet southern regions and the cold, dry northern
regions, which causes various natural phenomena such as
heavy snowfalls, severe thunder and lightning storms, and
hurricanes. The area experiences moderate to high rainfall
and snowfall, averaging 43 inches of precipitation annually
(data collected for the period 1950-2020 from the Lakeport
2, NH US weather station (USC00274480), with gaps
covered by the following weather stations: Lakeport, NH US
(USC00274475), Franklin Falls Dam, NH US (USC00273182),
and Plymouth, NH US (USC00276945) (Figure 2). Annual air
temperature (from average monthly data) generally ranges
from 20 °F to 70 °F with an average of 46 °F (NOAA NCEI,
2022).
The highest elevation in the watershed (about 1,480 feet
above sea level) is located between the Bald Ledge Scenic
Vista and the Sky Pond State Forest conservation areas in
New Hampton. Lake Winnisquam and the direct shoreline
area are situated at approximately 580 feet above sea level.
These elevation measurements were derived from digital
elevation models provided by NH GRANIT.
The watershed is characterized primarily by mixed forest
that includes both conifers (e.g., white pine and eastern
hemlock) and deciduous (e.g., beech, red oak, and maple)
tree species. Fauna that enjoy these forested resources
include land mammals (moose, deer, black bear, coyote,
bobcats, fisher, fox, raccoon, weasel, porcupine, muskrat,
mink, chipmunks, squirrels, snowshoe hares, and bats),
E60"
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13
2 50-
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cl
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to
=J 35-
\Sf>0 t.0*1"0 -£&
Average Maximum Minimum
Figure 2. Total annual precipitation (TOP) and annual max,
average, and min of monthly air temperature (BOTTOM) from
1950 - 2020 for the Lake Winnisquam watershed area. Data
collected from NOAA NCEI.
Paugus Bay
pechee Bay
Lake
Winnisquam
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LAKE WINNISQUAM WATERSHED-BASED PLAN
WINNISQUAM
WATERSHED NETWORK
belknap
county w*
conservation
district
water mammals (muskrat, otter, and beaver), land and water reptiles and amphibians (turtles, snakes, frogs, and
salamanders), various insects, birds (herons, loons, gulls, geese, multiple species of ducks1, wild turkeys, ruffed grouse,
cormorants, bald eagles, and song birds), and fish. The only recorded invasive aquatic plant species present in Lake
Winnisquam is variable milfoil (Myriophyllum heterophyllum) which became established in the lake in 1995. Invasive Chinese
mystery snails have also been recorded in Lake Winnisquam. Vigilant Weed Watchers and Lake Hosts are helping to keep the
lake free from additional invasive aquatic species.
1.2 WATERSHED PROTECTION GROUPS
The Winnisquam Watershed Network (WWN) serves as a non-profit lake association
for Lake Winnisquam and its surrounding watershed with the mission to "preserve
and protect Lake Winnisquam and its watershed now and for future generations."
With focuses on water quality monitoring and invasive species prevention and
control, the WWN helps educate members of the community and promote
management initiatives.
Belknap County Conservation District (BCCD) is one of 10 county conservation
districts in New Hampshire that operate as resource management agencies and a
subdivision of local governments. BCCD's mission is to " coordinate and implement
programs for education and on the ground work regarding conservation, use, and
development of soil, water, and related resources." BCCD works with farmers, forest
owners, landowners, schools, and municipalities to help protect and conserve the
area's natural resources through projects such as stream bed restoration, invasive
species management, and pollinator plantings. The BCCD is led by two paid staff and
a volunteer Board of Supervisors with representation from each municipality.
The Lake Wicwas Association serves as a non-profit lake association for Lake Wicwas
with the mission to "maintain and promote what's best for the health and
preservation of Lake Wicwas." They perform water quality monitoring, watches for
invasive species through the Lake Host and Weed Watcher programs and maintains
effective communication with lake residents to promote education and awareness of
lake protection initiatives. Their Conservation Committee actively pursues
watershed parcels for conservation.
The Lake Opechee Preservation Association (LOPA) was created to combat the issue
of invasive aquatic species in the lake, as well as to protect the overall health of the L LAKE WINNIPESAUKEE
watershed and water quality of the lake. The group plans to expand their activities to ;')\ ASSOCIATION
include water quality monitoring in the future. ty,*.-,/ j»/T-
The Lake Winnipesaukee Association (LWA) is a non-profit organization with the
mission of "protecting the water quality and natural resources of Lake Winnipesaukee and its watershed. Through
monitoring, education, stewardship, and utilizing science-guided approaches for lake management, LWA works to ensure
that Winnipesaukee's scenic beauty, wildlife habitat, water quality, and recreational potential continues to provide
enjoyment today and for the future." LWA serves the 14 communities located in Belknapand Carroll counties. LWA is led
by several paid staff and a volunteer Board of Directors.
The New Hampshire Association of Conservation Commissions (NHACC) works to provide educational assistance to
conservation commissions throughout New Hampshire (216 in total). As a non-profit organization, the NHACC's mission
is to instill responsible use of the available natural resources by promoting conservation and serving as the
communication link between conservation commissions, while providing technical support on the logistics of
conservation commission meetings and document language. Conservation commissions in the Lake Winnisquam
1 American black duck, black scoter, canvasback, common goldeneye, hooded merganser, long tailed duck, wood duck, red breasted merganser, northern
pintail, and mallard.
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LAKE WINNISQUAM WATERSHED-BASED PLAN
watershed include those from the municipalities of Tilton, Meredith, Laconia,
Belmont, Gilford, Sanbornton, and New Hampton.
Covering 31 communities, the Lakes Region Planning Commission (LRPC) is a
valuable resource to the WWN and the Lake Winnisquam watershed. The LRPC aids
communities with their local planning services in a targeted approach to protectthe
environment, while supporting local economies and cultural values.
The New Hampshire Department of Environmental Services (NHDES) works with
local organizations to improve water quality in New Hampshire at the watershed
level. NHDES works with communities to identify water resource goals and to
develop and implement watershed-based plans. This work is achieved by providing
financial and technical assistance to local watershed management organizations and
by investigating actual and potential water contamination problems, among other
activities.
1.3 PURPOSE AND SCOPE
The purpose and overarching goal of the Lake Winnisquam Watershed-Based Plan (WBP) is to guide implementation
efforts over the next 10 years (2022-2031) to improve the water quality of Lake Winnisquam such that it meets state
water quality standards for the protection of Aquatic Life Integrity (ALI). Note: this plan covers only the direct Lake
Winnisquam watershed located in Laconia, Gilford, Belmont, Tilton, Sanbornton, Meredith, and New Hampton. Restoration
efforts for the larger Lake Winnipesaukee watershed are being led by other local groups. In addition, two other lakes are
located within the immediate drainage area to Lake Winnisquam: Lake Wicwas and Lake Opechee. While not the focus of the
plan, their water quality status has a direct impact on the water quality of Lake Winnisquam, and thus secondary water quality
objectives were set to improve their water quality both for their own benefit and for the benefit of Lake Winnisquam.
Monitoring of these two waterbodies should continue and/or be expanded, and if water quality decline is evident, then
development of individual plans maybe warranted in the future.
As part of the development of this plan, a build-out analysis, land-use model, water quality and assimilative capacity
analysis, and shoreline and watershed surveys were conducted to better understand the sources of phosphorus and other
pollutants to the lake (Sections 2 and 3). Results from these analyses were used to establish the water quality goal and
objectives (Section 2.4), determine recommended management strategies for the identified pollutant sources (Section 4),
and estimate pollutant load reductions and costs needed for remediation (Sections 5 and 6). Recommended management
strategies involve using a combination of structural and non-structural Best Management Practices (BMPs), as well as an
adaptive management approach that allows for regular updates to the plan (Section 4). An Action Plan (Section 5) with
associated timeframes, responsible parties, and estimated costs was developed in collaboration with a plan development
committee (Section 1.4).
This plan meets the nine elements required by the United States Environmental Protection Agency (EPA) so that communities
become eligible for federal watershed assistance grants (Section 1.5). This plan is also considered a Total Maximum Daily
Load (TMDL) Alternative Restoration Plan (ARP or 5-alt), which is a voluntary plan for restoration developed in advance of a
TMDL. These plans are created to speed up the planning and restoration process to meet water quality standards. A full TMDL
planning process is not needed for Lake Winnisquam, so an ARP that demonstrates the practicality of meeting water quality
standards in a reasonable timeframe can be developed instead. When the plan is accepted by EPA, the waterbody will remain
at Category 5 (needing a TMDL) but can be assigned a lower priority for TMDL development. If water quality degrades or
remains unchanged after 10 years (as set by this plan) or if implementation of the plan is not progressing during that time,
then EPA may require a full TMDL process. Many of the required planning elements for the ARP overlap with the nine planning
elements for WBPs.
1.4 COMMUNITY INVOLVEMENT AND PLANNING
This plan was developed over a period of nearly two years through active collaboration among FB Environmental Associates
(FBE), Horsley Witten Group (HW), WWN, NHDES, EPA, BCCD, LWA, Lake Wicwas Association, LRPC, representatives from the
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LAKE WINNISQUAM WATERSHED-BASED PLAN
municipalities of Meredith, Laconia, Gilford, Belmont, Tilton, Sanbornton, and New Hampton, and private landowners (see
Acknowledgments).
1.4.1 Plan Development Meetings
Ten meetings were held over the duration of the plan's development. The following list does not include other smaller check-
in meetings conducted among project partners.
1. December 14,2020: EPA, NHDES, and the technical project staff (FBE, HW) held a logistics kickoff meeting to discuss
project roles, communications, and timeline for tasks and deliverables.
2. January 5, 2021: Key project team members, including WWN, EPA, NHDES, FBE, and HW held a content kickoff
meeting which walked through project tasks and the expected project timeline. Additional supporting organizations
attending included LWA and BCCD.
3. February 2,2021: WWN held a project kick-off meeting for local conservation com missions to attend and learn about
the plan and the project's objectives, technical partners, timeline, and strategy.
4. March 9,2021: The committee discussed the Quality Assurance Project Plan (QAPP) development and prepared for
the virtual public workshop.
5. April 6,2021: The committee discussed the outreach efforts for the upcoming public workshop and preparations for
watershed assessments by FBE and HW.
6. May 4, 2021: The committee discussed the upcoming virtual public workshop, including WWN's advertisement,
expected attendees, and break-out group facilitation. The committee also discussed the to-date work for the
watershed assessment (FBE), culvert assessments (Trout Unlimited), and septic system database (WWN).
7. June 1, 2021: The committee discussed survey responses associated with the public workshop. FBE presented
preliminary build-out results. HW and FBE provided an update on watershed assessments completed.
8. August 3, 2021: The committee walked through numerous task updates, including a summary of the public
workshop, FBE's review of environmental monitoring data to-date, the updated draft of the build-out report with
feedback from the watershed municipalities, and completed estimates of pollutant load reductions for the
watershed assessment sites.
9. December 7,2021: The committee discussed the completed land-use model by FBE and the recommended water
quality goal and specific objectives identified for Lake Winnisquam. WWN submitted a full proposal for a Section 319
Watershed Assistance Grant that focuses on remediating several identified watershed assessment sites.
10. March 1, 2022: The committee discussed final rounds of edits made for reports that inform the plan, including the
build-out analysis report, modeling report, water quality goal memorandum, public workshop summary, and
watershed assessments and NPS management measures technical memorandum.
1.4.2 Public Workshop
A virtual public workshop was held on May 18,2021 to introduce the project to the watershed community and solicit feed back
on local interests, values, and concerns related to water quality and practical solutions. The workshop was attended by 44
people, including 12 team members and stakeholders who served as presenters and facilitators. Key topics discussed
included land conservation and municipal planning, road erosion and maintenance, septic systems, stormwater
management, and other water quality concerns. Refer to Appendix A for a full summary of solicited feedback.
1.4.3 Public Surveys
WWN posted a survey online to gather local feedback on water quality perceptions, values, and interests in the watershed.
There were 133 respondents. Survey responses indicate that 50% of respondents live in the watershed year-round, most on
Lake Winnisquam. Most respondents felt that water quality was about the same or getting somewhat worse and that
maintaining excellent water quality was very important to them, valuing roughly equally recreational use, fishery health,
wildlife health, drinking water, and property value. Respondents identified stormwater runoff, fertilizers, septic systems, and
road salt as the largest perceived contributors to water quality degradation. About 57% of respondents were served by sewer;
most septic systems were around 20 years old; 60% pumped their septic system in last 3-5 years. About 42% of respondents
use fertilizer at least once per year on their lawn. About 92% of respondents supported land conservation to protect water
quality. Other specific environmental concerns that respondents listed included: density of waterfront homes, lack of
shoreline buffers, large tree removal, trash/litter, boat wakes generating shoreline erosion, boat and swimmer pollution at
the sandbar, winter road maintenance, loss of wetland habitat, light pollution, and dirt road erosion, among others.
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LAKE WINNISQUAM WATERSHED-BASED PLAN
With a rise in the number of boaters entering Lake Winnisquam each year, WWN is concerned about boaters launching from
private launches around the lake and bypassing the Lake Host Program inspection for invasives at the public launch. WWN
created a survey targeting Winnisquam boaters to determine where boaters were coming from and where they were
launching into the lake. There were 136 survey respondents, of which 48% were year-round and 52% were seasonal. Most of
the boaters used motor boats (90%) compared to jet skis (31%), sail boats (11%), and wake boats (10%). About 41% of the
boaters used the public launch, while 25% used private property, 19% used a marina, and 14% used a
neighborhood/association launch. Of the public boat launches and neighborhood/association launches listed in the survey,
most used the Laconia/Water Street launch with only a handful of respondents using Sunray Shore, Wildwood Shores,
Mallards Landing, Winnisquam Marine, Black Brook Rd, and Waldron Bay Owner's Association. Most boaters keep their boats
in the lake for the season (81%), while others launch their boats for day trips (12%) or short vacations (4%). While 84% of
boaters do not bring their boat to other lakes, about 6% of boaters do, including such waterbodies as Lake Winnipesaukee,
Rye Harbor, Lake George, Sarantac Lake, Beaver Lake, Merrimack River, Squam Lake, Arlington Pond, Lake Wicwas, Lake
Champlain, and Sunapee Lake. Most boaters reported draining and drying their boats prior to launching them, though 5%
were not familiar with the protocol.
1.4.4 Final Public Presentation
A final public presentation was held on June 7,2022 to summarize the analyses and recommendations detailed in the plan.
An opportunity for public feed back on the plan was offered. The presentation was attended by 26 people, including nine team
members and stakeholders on the committee.
1.5 INCORPORATING EPA'S NINE ELEMENTS
EPA guidance lists nine components that are required within a WBP to restore waters impaired or likely to be impaired by
nonpoint source (NFS) pollution. These guidelines highlight important steps in restoring and protecting water quality for
any waterbody affected by human activities. The nine required elements found within this plan are as follows:
A. IDENTIFY CAUSES AND SOURCES: Sections 2 and 3 highlight known sources of NPS pollution to Lake Winnisquam
and describe the results of the watershed survey and other assessments conducted in the watershed. These sources
of pollutants must be controlled to achieve load reductions estimated in this plan, as discussed in item (B) below.
B. ESTIMATE PHOSPHORUS LOAD REDUCTIONS EXPECTED FROM MANAGEMENT MEASURES: Sections 2 and 5
describe the calculation of pollutant load to Lake Winnisquam and theamountof reduction needed to meetthegoal.
C. DESCRIPTION OF MANAGEMENT MEASURES: Sections 4 and 5 identify ways to achieve the phosphorus load
reduction and water quality targets through general management strategies and specific action items in the Action
Plan. The Action Plan focuses on non-structural BMPs integral to the implementation of structural BMPs.
D. ESTIMATE OF TECHNICAL AND FINANCIAL ASSISTANCE: Sections 5 and 6 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, local groups, private donations, and
landowner contributions for implementation of the Action Plan.
E. EDUCATION & OUTREACH: Section 4 describes how the educational component of the plan is already being or will
be implemented to enhance public understanding of the project.
F. SCHEDULE FOR ADDRESSING PHOSPHORUS REDUCTIONS: Section 5 provides a list of action items and
recommendations to reduce the phosphorus load to Lake Winnisquam. 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
the WWN on an annual basis (see Section 4 on Adaptive Management).
G. DESCRIPTION OF INTERIM MEASURABLE MILESTONES: Section 6 outlines indicators along with milestones of
implementation success that should be tracked annually.
H. SET OF CRITERIA: Sections 2 and 6 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 6 describes the long-term water quality monitoring strategy for Lake
Winnisquam, 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 success of this plan cannot be evaluated without ongoing monitoring
and assessment and careful tracking of load reductions following successful BMP implementation projects.
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LAKE WINNISQUAM WATERSHED-BASED PLAN
2 ASSESSMENT OF WATER QUALITY
This section provides an overview of the past, current, and future state of water quality based on the water quality assessment
and watershed modeling, which identified pollutants of concern and informed the established water quality goal and
objectives for Lake Winnisquam.
2.1 WATER QUALITY SUMMARY
2.1.1 Water Quality Standards & Impairment Status
2.1.1.1 Designated Uses & Water Quality Criteria
The Clean Water Act (CWA) requires states to determine designated uses for all surface waters within the state'sjurisdiction.
Designated uses are the desirable activities and services that surface waters should be able to support and include uses for
aquatic life, fish consumption, shellfish consumption, drinking water supply, primary contact recreation (swimming),
secondary contact recreation (boating and fishing), and wildlife. Surface waters can have multiple designated uses. Primary
Contact Recreation (PCR) and ALI are the two major uses for lakes - ALI being the focus of this plan. In New Hampshire,
all surface waters are also legislatively classified as Class A or Class B, most of which are Class B (Env-Wq 1700). Lake
Winnisquam is classified as a Class B waterbody. Additionally, from 1974 to 2010, NHDES conducted surveys of lakes to
determine trophic state (oligotrophic, mesotrophic, oreutrophic). The trophic surveys evaluated physical lake features, as
well as chemical and biological indicators. For Lake Winnisquam, the trophic state was determined to be oligotrophic
during all four completed surveys (1980,1984,1994,2007) (NHDES, 2007). This means that in-lake water quality was consistent
with the standards for oligotrophic lakes.
Water quality criteria are then developed to protect designated uses, serving as a "yardstick" for identifying water quality
exceedances and for determining the effectiveness of state regulatory pollution control and prevention programs. Depending
on the designated use and type of waterbody, water quality criteria can become more or less strict if the waterbody is
classified as either Class A or B or as oligotrophic, mesotrophic, or eutrophic. To determine if a waterbody is meeting its
designated uses, water quality criteria forvarious parameters (e.g., chlorophyll-a, total phosphorus, dissolved oxygen, pH,
and toxics) are applied to the water quality data. If a waterbody meets or is better than the water quality criteria, the
designated use is supported. The waterbody is considered impaired for the designated use if it does not meet water quality
criteria. Water quality criteria for each classification and designated use in New Hampshire can be found in RSA 485 A:8, IV
and in the state's surface water quality regulations.
2.1.1.2 Antidegradation Provisions
The Antidegradation Provision (Env-Wq 1708) in New Hampshire's water quality regulations serves to protect or improve the
quality of the state's waters. The provision outlines limitations or reductions for future pollutant loading. Certain
development projects (e.g., projects that require Alteration of Terrain Permit or 401 Water Quality Certification) may be
subject to an Antidegradation Review to ensure compliance with the state's water quality regulations. The Antidegradation
Provision is often invoked during the permit review process for projects adjacent to waters that are designated impaired, high
quality, or outstanding resource waters. While NHDES has not formally designated high-quality waters, unimpaired waters
are treated as high quality with respect to issuance of water quality certificates. Antidegradation requires that a permitted
activity cannot use more than 20% of the remaining assimilative capacity of a high-quality water. This is on a parameter-by-
parameter basis. For impaired waters, antidegradation requires that permitted activities discharge no additional loading of
the impaired parameter.
2.1.1.3 Waterbody Impairment Status
According to New Hampshire's 2020-2022 303(d) List of Impaired Waters, Lake Winnisquam is impaired for ALI due to
excessive turbidity, which was documented at one location: the outlet area of Hueber Brook, a small tributary to the
southeast side of Lake Winnisquam off Route 3 and near Sun Lake Drive in Belmont. Excessive turbidity represents a threat to
water quality and lake health. The original impairment was determined in 2007 during reconstruction of Route 3 and Route
11 when a plume of sediment with turbidity exceeding 10 NTU after rain events was documented in the lake and coming from
Hueber Brook. Even with reconstruction of Route 3 and Route 11 complete, resampling of the area in 2015 revealed turbidity
still exceeding 10 NTU after rain events. The water quality criteria for turbidity must be met everywhere in the lake to be
considered attaining for ALI. Elevated turbidity indicates that Lake Winnisquam is experiencing enhanced sedimentation or
FB Environmental Associates & Horsley Witten Group
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LAKE WINNISQUAM WATERSHED-BASED PLAN
infill of sediment and other materials from the landscape, in this case washed in from Hueber Brook. Sediment often
transports nutrients such as phosphorus to surface waters. Enhanced loading of phosphorus to surface waters such as Lake
Winnisquam can stimulate excessive plant and algae growth and degrade water quality. Lake Winnisquam has already
experienced cyanobacteria bloom warnings, which were issued by NHDES in 2008 (28 days) and 2010 (43 days). NHDES issued
a cyanobacteria bloom alert on 6/27/22 for the north end of Lake Winnisquam. Cyanobacteria concentrations were below the
advisory level and dissipated within a couple days.
Lake Wicwas is currently listed on the NHDES 303(d) List of Impaired Waters for ALI due to low dissolved oxygen, which
is often indicative of enhanced nutrient loading from external watershed sources and/or internal sediment sources. Low
dissolved oxygen can release legacy phosphorus from bottom sediments and contribute to cyanobacteria blooms that
capitalize on available light and nutrients in the water column. NHDES issued cyanobacteria (Dolichospermum) bloom
warnings in August 2018 (14 days) and 2019 (6 days) for Lake Wicwas. Lake Opechee is currently not listed as impaired for
ALI (but is listed as impaired for PCR due to elevated £ coif). There was evidence of low oxygen (at 13 m and deeper) and
elevated hypolimnetic total phosphorus concentrations (at 15 m) in the 1979,1986, and 1999 NHDES Trophic Survey Reports
for Lake Opechee; thus, there is likely some internal loading occurring. Cyanobacteria bloom warnings were issued for Lake
Opechee in 2008 (37 days) for AnabaenaaX. Bond Beach, which represents localized blooms that should be tracked closely in
the future; a lake-wide cyanobacteria advisory was issued by NHDES in June 2022 (5 days) for Dolichospermum. The high
flushing rate of Lake Opechee due to the large incoming water volume from Lake Winnipesaukee through Paugus Bay helps
to mix the lake with lower concentration water than that coming from the direct watershed area to Lake Opechee in Laconia.
Much of the area in Laconia directly draining to Lake Opechee is already built-out but increasing the density of new or re-
development will have consequences for the water quality of Lake Opechee in the future, especially when compounded by
the effects of climate change.
2.1.2 Water Quality Data Collection
Prior to 2017, volunteers conducted monitoring on Lake Winnisquam as part of both the UNH Lay Lakes Monitoring
Program (LLMP) and NHDES Volunteer Lake Assessment Program (VLAP). LLMP monitoring was conducted almost every
yearfrom 1997-2016 during the summer months at four nearshore stations along the western shoreline of the lake
in Sanbornton and Meredith. VLAP monitoring (going back to 1987) was conducted at three deep spot stations near Three
Island, Pot Island, and Mohawk Island (Figure 3). NHDES also conducted monitoring of the three deep spot stations several
times as part of their lake trophic surveys (1980,1984,1994,2007). In 2017, the WWN met with the directors of both the LLMP
and VLAP programs and put together a tiered monitoring plan for the lake that allowed for better coordination of volunteers,
resources, and data.
Since 2017, the WWN, in collaboration with VLAP and LLMP, has been implementing the first tier of the monitoring plan,
conducting sampling at two of the nearshore stations and the three deep spot stations. VLAP monitors three deep spot
stations in Lake Winnisquam (Three Island, Pot Island, and Mohawk Island), and LLMP monitors two nearshore stations in
Lake Winnisquam (10 Waldron and 30 Bartlett), three to five times each summer for total phosphorus (epilimnion,
metalimnion, and hypolimnion), chlorophyll-a (composite or epilimnion), Secchi disk transparency, and dissolved oxygen-
temperature profiles. Samples are analyzed by the NHDES laboratory in Concord. Volunteers also collect additional Secchi
disk transparency readings at the three deep spot stations throughout the summer season. Dissolved oxygen-temperature
profiles for 2017-2019 were not collected except for two profiles, one in 2017 and one in 2018, at the Three Island deep spot
station.
In 2018, the WWN also added a tributary monitoring program using NHDES Volunteer River Assessment Program (VRAP)
protocols to monitor nine stations for total phosphorus two to three times each summer (Figure 3). The City of Laconia has
also monitored Jewett Brook under VRAP. Three stations (Jewett Brook, Black Brook, and Winnipesaukee River inlet to the
lake) have been monitored consistently in the last 10 years. The other seven stations include Lake Wicwas outlet, Durkee
Brook, Collins Brook, Chapman Brook (two branches), Durgin Brook, and the outlet of Lake Winnisquam.
Once each year, VLAP also monitors the deep spot, west cove, east cove, and the Route 104 inlet to Lake Wicwas in the
headwaters of the Lake Winnisquam watershed for total phosphorus, chlorophyll-a, Secchi disk transparency, and/or
dissolved oxygen-temperature profiles. VLAP collects up to six chlorophyll-a samples from Hunkins Pond. Dissolved oxygen
and temperature are also monitored at several other sites throughout the watershed and at beaches.
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LAKE WINNISQUAM WATERSHED-BASED PLAN
Lake Winnisquam
Water Quality
Monitoring Stations f New Hampton
¦—Study Area
NH
Legend
Monitoring Stations
• All Other Stations
A Lake Stations Used in Model
¦ Trib Stations Used in Model
Lake Winnipesaukee Watershed
Lake Winnisquam Watershed
Bathymetry (ft)
Rivers/Streams
Lakes/Ponds
Wetlands
' ] Towns
Source: NHD, NHDES, NHGRANIT
Projection: NAD 1983 State Plane NH FIPS 2800 Feet
Map Created By: FB Environmental Associates, Dec 2021
0.5 1 2
] Miles
$
Figure 3. Bathymetric map with water quality monitoring stations in the Lake Winnisquam watershed.
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LAKE WINNISQUAM WATERSHED-BASED PLAN
2.1.3 Trophic State Indicator Parameters
Total phosphorus, chlorophyll-a, and Secchi disk
transparency are trophic state indicators, or
indicators of biological productivity in lake
ecosystems. The combination of these parameters
helps determine the extent and effect of
eutrophication in lakes and helps signal changes in
lake water quality over time. For example, changes in
Secchi disk transparency may be due to a change in
the amount and composition of algae communities
(typically because of greater total phosphorus
availability) or the amount of dissolved or particulate
materials in a lake. Such changes are likely the result
of human disturbance or other impacts to the lake's
watershed.
Annual average water clarity at the three deep spot
stations on Lake Winnisquam range from the
shallowest of 5.6 m at Mohawk Island deep spot to
the deepest of 8.6 m at Pot Island deep spot (Figure
4), with overall average water clarity from 2011-2021
ranging from 6.2 m to 7.7 m at the three stations.
Annual average total phosphorus was highest at 13.0
ppb at Three Island deep spot in 2021 (possibly due
to the extreme wet summer generating runoff that
concentrated nutrient-laden sediment from the
upper watershed); otherwise, the three stations
range comparably similar from 6.7 ppb to 7.5 ppb for
overall average total phosphorus concentration from
2011-2021. Mohawk Island deep spot generally had
lower total phosphorus concentrations, likely due to
the diluting effects of the large volume of incoming
water from upstream waterbodies including Lake
Winnipesaukee (though Pot Island is also influenced
by Lake Winnipesaukee inflows). Annual average
chlorophyll-a was consistently and comparably low,
ranging from the lowest of 0.7 pb at Pot Island deep
spot to the highest of 3.8 ppb at Three Island deep
spot, with overall average chlorophyll-a from 2011-
2021 ranging from 1.5 ppb to 1.9 ppb at the three deep
spot stations.
2.1.4 Dissolved Oxygen & Water Temperature
A common occurrence in many New England lakes is
the depletion of dissolved oxygen in the deepest part
of lakes throughout the summer months, a natural
phenomenon in some dimictic lakes that is made
more severe by human disturbance. Chemical and
biological processes occurring in bottom waters
deplete the available oxygen throughout the summer,
and because these waters are colder and denser, the
Lake Winnisquam 3 Island Island Deep Spot
Lake Winnisquam Pot Island Deep Spot
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'—I «—I 1—1 •—I I—I T-H 1—I T-H 1—1 ("\| CN
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CNCNCvJCNrNlCMCNrMCMCNCM
Lake Winnisquam Mohawk Island Deep Spot
fNcjCNiCNirvicNC'jrsi
Total Phosphorus -•-Chlorophyll-a -•-Secchi Depth
Figure 4. Annual average epilimnetic total phosphorus (blue),
chlorophyll-a (green), and water clarity (Secchi depth, black)
measured intermittently from 2011-2021 at three deep spot
stations on Lake Winnisquam (from upstream to downstream):
Three Island (TOP), Pot Island (MIDDLE), and Mohawk Island
(BOTTOM).
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LAKE WINNISQUAM WATERSHED-BASED PLAN
oxygen cannot be replenished
through mixing with surface waters.
Dissolved oxygen levels below 5
ppm (and watertemperatureabove
24 °C) can stress and reduce habitat
for coldwater fish and other
sensitive aquatic organisms. In
addition, anoxia (dissolved oxygen
< 2 ppm) at lake bottom can result
in the release of sediment-bound
phosphorus (otherwise known as
internal phosphorus loading),
which can become a readily
available nutrient source for algae
and cya no bacteria. It is important
to keep tracking these parameters
to make sure the extent and
duration of low oxygen does not
change drastically because of
human disturbance in the
watershed, resulting in excess
phosphorus loading.
Figure 5 shows temperature and
dissolved oxygen profiles averaged
across sampling dates (2012-2020)
during thermal stratification in
summer (between spring and fall
turnover) for the three deep spot
stations on Lake Winnisquam. The
change in temperature, seen most
dramatically between 6 and 12 m
depth, indicates thermal
stratification in the watercolumn at
all three sites. Dissolved oxygen
levels did not fall below the 5 ppm
threshold at the most upstream
station, Three Island, indicating
good oxygenation throughout the
water column. Anoxia was
measured at both Pot Island and
Mohawk Island deep spots, though
only near the very bottom at Pot
Island. Mohawk Island deep spot
showed dissolved oxygen depleting
rapidly below the 5 ppm threshold
at 9 m and below the 2 ppm
threshold at 16 m.
o-
2-
4-
6-
£ 8
i/>
g 10
o
g 10
Dissolved Oxygen (ppm) / Temperature (°C)
5 10 15 20 25
w
w
h»H
h*H
h
h
I • 1
I—•—I I—*—I
I—• 1 I—•—I
I • 1 ' '
-H*H
I—«- H
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3 Island Deep Spot
Dissolved Oxygen (ppm) / Temperature (°C)
Dissolved Oxygen (ppm) / Temperature (°C)
5 10 15 20 25
Hr
• o
I • 1
I • 1
I • 1 I-
I • 1 I
H H
I-
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Dissolved Oxygen
Mohawk Island Deep Spot
Temperature
Figures. Dissolved oxygen (black) and temperature (blue) depth profiles for three deep
spot stations on Lake Winnisquam (ordered from upstream to downstream): Three
Island (TOP), Pot Island (MIDDLE), and Mohawk Island (BOTTOM). Profiles were
measured once in 2012, 2013, 2016, 2017, and 2018, and twice in 2020 during thermal
stratification in summer. Dots represent average values across sampling dates for each
respective depth. Error bars represent standard deviation.
2.1.5 Cyanobacteria
Nutrients such as phosphorus and nitrogen, as well as algae and cyanobacteria, naturally occur in the environment, including
lakes and tributaries and their contributing watersheds, and are essential to lake health. Under natural conditions, algae and
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LAKE WINNISQUAM WATERSHED-BASED PLAN
cyanobacteria concentrations are regulated by limited nutrient inputs and lake mixing processes that keep them from
growing too rapidly. However, human related disturbances, such as erosion, overapplied fertilizers, polluted stormwater
runoff, excessive domesticated animal waste, and inadequately treated wastewater, can dramatically increase the amount
of nutrients entering lakes and their tributaries. Excess nutrient loading to human-disturbed lake systems, in combination
with a warming climate, has fueled the increasing prevalence of Harmful Algal Blooms (HABs) or the rapid growth of algae
and cyanobacteria in lakes across the United States.
Cyanobacteria are small photosynthesizing, sometimes nitrogen-fixing, single-celled bacteria that grow in colonies in
freshwater systems. Cyanobacteria blooms can (but not always) produce microcystins and other toxins that pose a serious
health risk to humans, pets, livestock, and wildlife, such as neurological, liver, kidney, and reproductive organ damage,
gastrointestinal pain or illness, vomiting, eye, ear, and skin irritation, mouth blistering, tumor growth, seizure, or death.
Blooms can form dense mats or surface scum that can occur within the water column or along the shoreline. Dried scum
along the shoreline can harbor high concentrations of microcystins that can re-enter a waterbody months later.
Cyanobacteria blooms and their associated toxins have been recorded in the Lake Winnisquam watershed, including Lake
Winnisquam, Hunkins Pond, Lake Opechee, and Lake Wicwas (Table 1). Lake Winnisquam has experienced cyanobacteria
bloom warnings, which were issued by NHDES in 2008 (28 days) and 2010 (43 days). NHDES issued a cyanobacteria bloom
alert on 6/27/22 for the north end of Lake Winnisquam. The bloom appeared as diffuse green clouds or ribbons of material
suspended in the water along the shoreline. Cyanobacteria concentrations contained Dolichospermum but were below the
advisory level and dissipated within a couple days.
Cyanobacteria are becoming more prevalent in low-nutrient lake systems likely due to climate change warming effects (e.g.,
warmer water temperatures, prolonged thermal stratification, increased stability, reduced mixing, and lower flushing rates
at critical low-flow periods that allow for longer residence times) that allow cyanobacteria to thrive and outcompete other
phytoplankton species (Przytulska, Bartosiewicz, & Vincent, 2017; Paerl, 2018; Favot, et al., 2019). Many cyanobacteria can
regulate their buoyancy and travel vertically in the water column to maximize their capture of both sunlight and sediment
phosphorus (even during stratification and/or under anoxic conditions) for growth. In addition, some cyanobacteria can also
fix atmospheric nitrogen, if enough light, phosphorus, iron, and molybdenum are available for the energy-taxing process.
Some taxa are also able to store excess nitrogen and phosphorus intra-cellularly for later use under more favorable
conditions. Because of these traits and as climate warming increases the prevalence and dominance of cyanobacteria,
cyanobacteria are one of the major factors driving positive feed backs with lakeeutrophication and may be both accelerating
eutrophication in low-nutrient lakes and preventing complete recovery of lakes from eutrophic states (Dolman, et al., 2012;
Cottingham, Ewing, Greer, Carey, & Weathers, 2015). A better understanding of cyanobacteria's role in nutrient feedbacks will
be needed for better and more effective lake restoration strategies. However, we can substantially minimize conditions
favorable for blooms, such as reducing nutrient-rich runoff from the landscape during warm, sunny spells. Regulating water
level and flow also helps to either flush out blooms or limit upstream nutrient sources to stymie growth.
Table 1. Cyanobacteria blooms occurring in the Lake Winnisquam watershed since 2006.
Location
Date of
Advisory
Number of
Advisory Days
Species
Illness
Reported
Total Cell
Concentration
(cells/mL)
HUNKINS POND
7/20/2006
95
Anabaena
Unknown
>70,000 or >50%
LAKE WINNISQUAM
6/25/2008
28
Unidentified
Unknown
>70,000 or >50%
LAKE OPECHEE (BOND BEACH)
7/7/2008
37
Anabaena
Unknown
>70,000 or >50%
HUNKINS POND
8/21/2008
102
Anabaena
Unknown
>70,000 or >50%
LAKE WINNISQUAM (EPHRAIMS COVE)
9/19/2010
43
Anabaena
Unknown
58,459
HUNKINS POND
9/5/2014
25
Anabaena
Unknown
102,000
LAKE WICWAS
8/9/2018
14
Anabaena/Dolichospermum
Unknown
119,000
HUNKINS POND
6/26/2019
34
Anabaena/Dolichospermum
Unknown
611,000
HUNKINS POND
8/9/2019
19
Anabaena/Dolichospermum
Unknown
165,000
LAKE WICWAS
8/21/2019
6
Anabaena/Dolichospermum
Unknown
446,675
LAKE WINNISQUAM
6/27/2022
Alert Only
Dolichospermum
Unknown
<70,000
LAKE OPECHEE
6/27/2022
5
Dolichospermum
Unknown
73,133
FB Environmental Associates & Horsley Witten Group
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LAKE WINNISQUAM WATERSHED-BASED PLAN
Aherft
State
ParK
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Lake Winnisquam Watershed
Fish Survey Records
• Wild Brook Trout Documented
• Wild Brook Trout Not Documented
Figure 6. Map of documented wild brook trout occurrences. Courtesy of Trout Unlimited.
FB Environmental Associates & Horsley Witten Group
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LAKE WINNISQUAM WATERSHED-BASED PLAN
2.1.6 Fish
Fish are an important natural resource for sustainable ecosystem food webs and provide recreational opportunities. Lake
Winnisquam supports a thriving population of both cold and warm water species including but not limited to rainbow trout,
land locked salmon, lake trout, small and large mouth bass, eastern chain pickerel, brown bullhead, white perch, black
crappie, bluegill, rock bass, burbot, and American eel. A map of documented wild brook trout occurrences is shown in Figure
6. Fish species of concern include river herring (whose population is stocked by the New Hampshire Fish and Game
Department, NHFGD) in the Winnipesaukee River, as well as brown trout in Black Brook, Chapman Brook, Jewett Brook, and
Durgin Brook. Historically, the Lake Winnisquam watershed hosted an abundant rainbow smelt population that spawned in
the tributaries. Land use changes and sedimentation have since buried the cobble/gravel substrate needed to support egg
incubation in fish spawning areas. Each year, about 20,000 migrating adult herring and alewives are trapped at dams in
Massachusetts and transported to Lake Winnisquam where the adults spawn. At one time, Black Brook also supported a
commercial alewife fishery.
2.1.7 Invasive Aquatic Species
The introduction of non-indigenous invasive aquatic plant species to New Hampshire's waterbodies has been on the rise.
These invasive aquatic plants are responsible for habitat disruption, loss of native plant and animal communities, reduced
property values, impaired fishing and degraded recreational experiences, and high removal costs. Once established, invasive
species are difficult and costly to remove.
Variable milfoil [Myriophyllum heterophyllum) was first established in Lake Winnisquam around 1995 and was only managed
sporadically in a few areas until 2018 when WWN began actively managing milfoil and other invasive aquatic species through
several programs, including the NH Lakes' Lake Host Program, the NHDES Weed Watcher Program, and WWN's Milfoil
Management Program. Through the Lake Host Program, which WWN operates in cooperation with NH Lakes, trained Lake
Hosts inspect boats and trailers both entering and exiting Lake Winnisquam for invasive aquatic plants to prevent their
spread. The Weed Watcher Program uses trained volunteers to survey the near-shore areas of the lake for any invasive aquatic
plants. These survey efforts have identified previously unknown infestation areas that have since been eradicated. WWN
established the Milfoil Control Program for Lake Winnisquam in 2018 with funding from NHDES, local matches from the
municipalities of Meredith, Belmont, Tilton, Sanbornton, and Laconia, and donations from neighborhood associations and
WWN members. Under the leadership of WWN, milfoil management, including diver-assisted harvesting and herbicide
treatments, is done comprehensively lake-wide and according to a Long-Term Variable Milfoil Management /'/an first created
by NHDES in 2017 (with annual updates since) for Lake Winnisquam (NHDES, 2020). These survey efforts have identified
previously unknown infestation areas that have since been eradicated, treated with herbicide, or removed by divers and
monitored to detect any regrowth. At the end of the 2021 season, no milfoil was detected in Lake Winnisquam, which was
declared milfoil-free. Although milfoil will likely return in future years, the eradication monitoring efforts (Weed Watcher, Lake
Host) by WWN and volunteers followed by treatment of any infestation has proven to be effective and will continue each year.
Invasive Chinese mystery snails have also been recorded in Lake Winnisquam, but populations are low and are not actively
managed by any group.
2.2 ASSIMILATIVE CAPACITY
The assimilative capacity of a waterbody describes the amount of pollutant that can be added to a waterbody without causing
a violation of the water quality criteria. For oligotrophic waterbodies such as Lake Winnisquam and Lake Opechee, the water
quality criteria are set at 8 ppb for total phosphorus and 3.3 ppb for chlorophyll-a (Table 2). Each trophic state has a certain
phytoplankton biomass (chlorophyll-a) that represents a balanced, integrated, and adaptive community. Exceedances of the
chlorophyll-a criterion suggests that the algal community is out of balance. Since phosphorus is the primary limiting nutrient
for growth of freshwater algae (chlorophyll-a), phosphorus is included in this assessment process. NHDES requires 10% of the
difference between the best possible water quality and the water quality standard be kept in reserve; therefore, total
phosphorus and chlorophyll-a must be at or below 7.2 ppb and 3.0 ppb, respectively, to achieve Tier 2 High Quality Water
status. For mesotrophic waterbodies such as Lake Wicwas, the water quality criteria are set at 12 ppb for total phosphorus
and 5 ppb for chlorophyll-a (Table 2). The 10% reserve assimilative capacity for mesotrophic lakes is set at 11.6 ppb for total
phosphorus and 4.8 ppb for chlorophyll-a. Chlorophyll-a will dictate the final assessment if both chlorophyll-a and total
phosphorus data are available and the assessments differ (Table 3).
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LAKE WINNISQUAM WATERSHED-BASED PLAN
Results of the assimilative capacity analysis showed that Lake Winnisquam, Lake Wicwas, and Lake Opechee are classified as
Tier 2 high quality waters for their respective trophic class designations (Table 4). Tier 2 waters have one or more water quality
parameters that are better than the water quality standard and that also exhibit a reserve capacity of at least 10% of the
waterbody's total assimilative capacity.
Table 2. Aquatic life integrity (ALI) nutrient criteria ranges by trophic class in New Hampshire. TP = total phosphorus. Chl-a =
chlorophyll-a, a surrogate measure for algae.
Trophic State
TP (ppb)
Chl-a (ppb)
Oligotrophic
<8.0
<3.3
Mesotrophic
>8.0-12.0
>3.3-5.0
Eutrophic
>12.0-28.0
>5.0-11.0
Table 3. Decision matrix for aquatic life integrity (ALI) assessment in New Hampshire. TP = total phosphorus. Chl-a =
chlorophyll-a, a surrogate measure for algae concentration.
Nutrient Assessments
TP Threshold Exceeded
TP Threshold NOT Exceeded
Insufficient Info for TP
Chl-a Threshold Exceeded
Impaired
Impaired
Impaired
Chl-a Threshold NOT Exceeded
Potential Non-support
Fully Supporting
Fully Supporting
Insufficient Info for Chl-a
Insufficient Info
Insufficient Info
Insufficient Info
Table 4. Assimilative capacity (AC) analysis results for Lake Winnisquam, Lake Wicwas, and Lake Opechee. Chlorophyll-a
dictates the assessment results. Water quality data summarized from NHDES Environmental Monitoring Database (EMD) and
applied to state water quality standards described in NHDES (2022).
Parameter AC Threshold (ppb) Existing Mean WQ (ppb)*
Remaining AC (ppb)
Assessment Results
Lake Winnisquam - Three Island Deep Spot [WINTLACD]
Total Phosphorus 7.2 7.2
Chlorophyll-a 3.0 1.9
+0.0
+1.1
Tier2 (High Quality)
Lake Winnisquam - Pot Island Deep Spot [WINPLACD]
Total Phosphorus 7.2 7.5
Chlorophyll-a 3.0 1.7
-0.3
+1.3
Tier 2 (High Quality)
Lake Winnisquam - Mohawk Island Deep Spot [WINMBELD]
Total Phosphorus 7.2 6.7
Chlorophyll-a 3.0 1.5
+0.5
+1.5
Tier 2 (High Quality)
Lake Winnisquam - Aggregate Deep Spot Sites
Total Phosphorus 7.2 7.1
Chlorophyll-a 3.0 1.7
+0.1
+1.3
Tier 2 (High Quality)
Lake Wicwas - Deep Spot [WICMERD]
Total Phosphorus 11.6 7.5
Chlorophyll-a 4.8 4.0
+4.1
+0.8
Tier 2 (High Quality)
Lake Opechee - Lakeport, Winnipesaukee River Downstream of Dam [WIN-LP-2]
Total Phosphorus 7.2 6.3
Chlorophyll-a 3.0 1.3
+0.9
+1.7
Tier 2 (High Quality)
* Existing water quality data truncated to May 24-Sept 15 (though a few mid to late September samples were kept if thermal stratification
was still evident) in the previous 10 years (2011-2020) for composite, epilimnion, or upper samples (in order of priority on a given day). Data
were summarized by day, then month, then year using mean statistic.
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2.3 WATERSHED MODELING
LAKE WINNISQUAM WATERSHED-BASED PLAN
2.3.1 Lake Loading Response Model (LLRM)
Environmental modeling is the process of using mathematics to represent the natural world. Models are created to explain
how a natural system works, to study cause and effect, or to make predictions under various scenarios. Environmental models
range from very simple equations that can be solved with pen and paper, to highly complex computer software requiring
teams of people to operate. Lake models, such as the Lake Loading Response Model (LLRM), can make predictions about
phosphorus concentrations, chlorophyll-a concentrations, and water clarity under different pollutant loading scenarios.
These types of models play a key role in the watershed planning process. EPA guidelines for watershed plans require that
pollutant loads to a waterbody be estimated.
The LLRM is an Excel-based model that uses environmental data to develop a water and phosphorus loading budget for lakes
and their tributaries (AECOM, 2009). Water and phosphorus loads (in the form of mass and concentration) are traced from
various sources in the watershed through tributary basins and into the lake. The model incorporates data about watershed
and sub-watershed boundaries, land cover, point sources (if applicable), septic systems, waterfowl, rainfall, volume and
surface area, and internal phosphorus loading. These data are combined with coefficients, attenuation factors, and equations
from scientific literature on lakes, rivers, and nutrient cycles to generate annual average predictions2 of total phosphorus,
chlorophyll-a, Secchi disk transparency, and algal bloom probability. The model can be used to identify current and future
pollutant sources, estimate pollutant limits and water quality goals, and guide watershed improvement projects. A complete
detailing of the methodology employed for the Lake Winnisquam LLRM is provided in the Lake Winnisquam Lake Loading
Response ModelReport{V&E, 2021a).
2.3.1.1 Lake Morphometry & Flow Characteristics
The morphology (shape) and bathymetry (depth) of lakes and ponds are considered reliable predictors of water clarity and
lake ecology. Large, deep lakes are typically clearer than small, shallow lakes as the differences in lake area, number and
volume of upstream lakes, and flushing rate affect lake function and health.
The surface area of Lake Winnisquam is 4,249 acres (28 miles of shoreline) with a maximum depth of 174 feet (53 m) and
volume of 278,744,376 m3. The a real water load is 111 ft/yr (33.7 m/yr), and the flushing rate is 2.1 times per year. The
relatively high flushing rate of 2.1 means that the entire volume of Lake Winnisquam is replaced twice per year, allowing less
time for pollutants to settle in lake bottom sediments or be taken up by biota.
There are multiple dams in the watershed controlling water flow, including: (1) Lake Wicwas Dam at the lake outlet on Mill
Brook; (2) Winnipesaukee Lakeport Dam on the Winnipesaukee River between Paugus Bay and Lake Opechee; (3) Lake
Opechee Avery Dam on the Winnipesaukee River between Lake Opechee and Lake Winnisquam; (4) Holding Pond Dam on
Hunt Brook between Hunkins Pond and Lake Winnisquam (in the Chapman Brook drainage); and (5) Lochmere Dam atoutlet
from Lake Winnisquam.
2.3.1.2 Land Cover
Characterizing land cover within a watershed on a spatial scale can highlight potential sources of NPS pollution that would
otherwise go unnoticed in a field survey of the watershed. For instance, a watershed with large areas of developed land and
minimal forestland will likely be more at riskfor NPS pollution than a watershed with well-managed development and large
tracts of undisturbed forest, particularly along headwater streams. Land cover is also the essential element in determining
how much phosphorus is contributing to a surface water via stormwater runoff and baseflow.
Current land cover in the Lake Winnisquam watershed was determined by FBE and the LRPC, using a combination of the 2001
New Hampshire Landcover Database (NHLCD), ESRI World Imagery from March 27,2020, and Google Earth satellite imagery
from July 7, 2019. For more details on methodology, see the Lake Winnisquam Lake Loading Response Model Report
2021a). Final land cover is shown in Appendix B, Map B-l.
The direct Lake Winnisquam watershed (not including the Lake Winnipesaukee and Paugus Bay watersheds) is 35,648 acres,
not including the lake areas of Lake Wicwas, Lake Opechee, and Lake Winnisquam. Development accounts for 29% (10,392
2 The model cannot simulate short-term weather or loading events.
FB Environmental Associates & Horsley Witten Group
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LAKE WINNISQUAM WATERSHED-BASED PLAN
acres) of the watershed, while forested and natural areas account for 67% (23,703 acres). Wetlands and open water represent
1% (361 acres) of the watershed (Figure 7). Agriculture represents 3% (1,191 acres). Figure 7 shows a breakdown of land cover
by major category for the entire watershed (not including lake area), as well as total phosphorus load by major land cover
category (referto Section 2.3.1.4 or FBE, 2021a for details on methodology). Developed areas cover 29% of the watershed and
contribute 84% of the total phosphorus watershed load to Lake Winnisquam.
Developed areas within the Lake Winnisquam watershed are characterized by impervious surfaces, including areas with
asphalt, concrete, compacted gravel, and rooftops that force rain and snow that would otherwise soak into the ground to run
off as stormwater. Stormwater runoff carries pollutants to waterbodies that may be harmful to aquatic life, including
sediments, nutrients, pathogens, pesticides, hydrocarbons, and metals.
i Agriculture "Developed "Forest "Water/Wetlands "Agriculture "Developed "Forest "Water/Wetlands
Figure 7. Lake Winnisquam watershed (including Lake Wicwas and Lake Opechee but not including Lake Winnipesaukee)
land cover area by general category (agriculture, developed, forest, and water/wetlands) and total phosphorus (TP)
watershed load by general land cover type. This shows that developed areas cover 29% of the watershed and contribute 84%
of the TP watershed load to Lake Winnisquam. Water/wetlands category does not include the lake areas.
2.3.1.3 Internal Phosphorus Loading
Phosphorus that enters the lake and settles to the bottom can be re-released from sediment under anoxic conditions,
providing a nutrient source for algae, cyanobacteria, and plants. Internal phosphorus loading can also result from wind-
driven wave action or physical disturbance of the sediment (boat props, aquatic macrophyte management activities). Internal
loading estimates were derived from dissolved oxygen and temperature profiles taken at the deep spots of Lake Winnisquam
and Lake Wicwas from 2011-2020 (to determine average annual duration and depth of anoxia defined as <2 ppm dissolved
oxygen) and epilimnion/hypolimnion total phosphorus data taken at the deep spots of Lake Winnisquam and Lake Wicwas
from 2011-2020 (to determine average difference between surface and bottom phosphorus concentrations). These estimates,
along with anoxic volume and surface area, helped determine rate of release and mass of annual internal phosphorus load.
There were insufficient data to determine whether there is a significant internal phosphorus load to Lake Opechee.
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LAKE WINNISQUAM WATERSHED-BASED PLAN
2.3.1.4 LLRM Results
Overall, model predictions were in good agreement with observed data for total
phosphorus, chlorophyll-a, and Secchi disk transparency (Table 5). It is
important to note that the LLRM does not explicitly account for all the
biogeochemical processes occurring within a waterbody that contribute to
overall water quality and is less accurate at predicting chlorophyll-a and Secchi
disktransparency. For example, chlorophyll-a is estimated strictlyfrom nutrient
loading, but other factors strongly affect algae growth, including transport of
phosphorus from the sediment-water interface to the water column by
cyanobacteria, low light from suspended sediment, grazing by zooplankton,
presence of heterotrophic algae, and flushing effects from high flows. There
were insufficient data available to evaluate the influence of these other factors
on observed chlorophyll-a concentrations and Secchi disk transparency
readings.
Watershed runoff combined with baseflow (93%) was the largest phosphorus
loading contribution across all sources to Lake Winnisquam. The watershed
load (93%) includes the watershed loads from LakeWicwas (1%), LakeOpechee
and thus Lake Winnipesaukee via Paugus Bay (51%), and the direct land area to
Lake Winnisquam (41%) (Figure 8, Table 6). Atmospheric deposition (3%),
internal loading (2%), waterfowl (1%), and septic systems (1%) were relatively
minor sources. Development in the watershed is most concentrated around the
shoreline where septic systems or holding tanks are located within a short
distance to the water, leaving little horizontal (and sometimes vertical) space
for proper filtration of wastewater effluent. Improper maintenance or siting of
these systems can cause failures, which leach untreated, nutrient-rich
wastewater effluent to the lake. Nearly half of the shoreline area of Lake
Winnisquam is serviced by sewer systems, which also represent a potential vulnerability if the sewer systems are old or
damaged and leaking wastewater into groundwater near the lake. Note that septic systems are a relatively minor load to
Lake Winnisquam because 1) the estimate is only for those systems directly along the shoreline and potentially short-
circuiting minimally treated effluent to the lake and 2) much of the shoreline area is serviced by sewer which is not accounted
for in the model since the assumption is that the sewer lines are not leaking. The load from septic systems throughout the
rest of the watershed is inherent to the coefficients used to generate the watershed load.
Internal loading is currently a relatively minor source of phosphorus to Lake Winnisquam; however, locally significant internal
phosphorus loading is occurring in the Mohawk Island basin area and should be monitored closely, especially given that
cyanobacteria bloom warnings were issued for Lake Winnisquam in 2008 (28 days) and 2010 (43 days) with a brief alert issued
in June 2022. Internal loading is currently a significant source of phosphorus (23%) to LakeWicwas and may be driving recent
cyanobacteria (Dolichospermum) bloom warnings issued by NHDES in August 2018 (14 days) and 2019 (6 days). (Note: The
Lake Wicwas model estimated an average annual bloom probability of nine days at chlorophyll-a > 8 ppb and two days at
chlorophyll-a > 10 ppb.) The 2009 NHDES Lake Trophic Survey Report for Lake Wicwas noted that zooplankton abundance
was low which might otherwise help to keep phytoplankton at bay, depending on the palatabi lity of dominant cyanobacteria
species. Lake Wicwas is also highly colored (>30 CPU), which may help to block light at depth and limit phytoplankton growth.
However, anecdotal information from the Lake Wicwas Association indicates that the lake may be becoming clearer in recent
years and thus the 2009 color data may be outdated. The Lake Wicwas Association also noted that the lake is relatively shallow
with legacy loading from an old sawmill that was decommissioned around 1950 and from log sinking to protect the logs from
insects following the 1938 hurricane (5-10 logs continue to float to the surface each year). There were insufficient data to
assess whether internal loading is occurring in Lake Opechee. There was evidence of low oxygen (at 13 m and deeper) and
elevated hypolimnetic total phosphorus concentrations (at 15 m) in the 1979,1986, and 1999 NHDES Trophic Survey Reports:
thus, there is likely some internal loading occurring, but there were insufficient data to support an estimation for internal
loading. Cyanobacteria bloom warnings were issued for Lake Opechee in 2008 (37 days) for Anabaena at Bond Beach and
lake-wide in June 2022 (5 days) for Dolichospermum.
¦ ATMOSPHERIC DEPOSITION
¦ INTERNAL LOADING
¦ WATERFOWL
¦ SEPTIC SYSTEM
¦ WATERSHED LOAD - WICWAS
¦ WATERSHED LOAD -OPECHEE
WATERSHED LOAD - DIRECT
Figure 8. Summary oftotal phosphorus
loading by major source for Lake
Winnisquam. Refer to Table 6 for a
breakdown.
FB Environmental Associates & Horsley Witten Group
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LAKE WINNISQUAM WATERSHED-BASED PLAN
Normalizing for the size of a sub-watershed (i.e., accounting for its annual discharge and direct drainage area) better
high lights sub-watersheds with elevated pollutant exports relative to their drainage area. Sub-watersheds with moderate-to-
high phosphorus mass exported by area (> 0.20 kg/ha/yr) generally had more development (i.e., the southern portion of the
watershed around Laconia; Figure 9). Drainage areas directly adjacent to waterbodies have direct connection to the lakes
and are usually targeted for development, thus increasing the possibility for phosphorus export.
As part of the 2012 Black Brook Watershed Management Plan (AECOM, 2012), a portion of Lake Winnisquam was modeled
(excluded most downstream Mohawk Island basin). The 2012 model outputs generally agreed well with 2020 model outputs
when accounting for the differences in lake area modeled, annual precipitation, atmospheric deposition coefficient used,
waterfowl estimates or lack thereof, and attenuation assumptions. The 2020 model assumed default water and phosphorus
attenuation for longer stream networks such as Black Brook. The 2012 model assumed higher attenuation factors (more water
and phosphorus passed through) due to relatively steep, shallow, moderate-to poorly-drained soils in the watershed, which
accounted for the difference in total water and phosphorus load output from Black Brook between the two models.
Once the model is calibrated for current in-lake phosphorus concentration, we can then manipulate land cover and other
factor loadings to estimate pre-development loading scenarios (e.g., what in-lake phosphorus concentration was prior to
human development or the best possible water quality for the lake). Refer to FBE (2021a) for details on methodology. Pre-
development loading estimation showed that total phosphorus loading to Lake Winnisquam increased by 438%, from 1,385
kg/yr prior to European settlement to 7,458 kg/yr under current conditions (Table 6). These additional phosphorus sources
are coming from development in the watershed (especially from Lake Winnipesaukee, the direct shoreline of Lake
Winnisquam, the direct shoreline of Lake Opechee, Durkee Brook, and Jewett Brook), septic systems, atmospheric dust, and
internal loading (Table 6). Water quality prior to settlement was predicted to be excellent with extremely low phosphorus and
chlorophyll-a concentrations and high water clarity (Table 5).
We can also manipulate land cover and other factors to estimate future loading scenarios (e.g., what in-lake phosphorus
concentration might be at full build-out under current zoning constraints or the worst possible water quality for the lake).
Refer to FBE (2021a) and the 2021 Lake Winnisquam Direct Watershed Build-out Analysis Report (FBE, 2021b) for details on
methodology. Note: the future scenario did not assume a 10% increase in precipitation over the next century (NOAA Technical
Report NESDIS 142-1,2013), which would have resulted in a lower predicted in-lake phosphorus concentration; this is because
the model does not consider the rate and distribution of the projected increase in precipitation. Climate change models
predict more intense and less frequent rain events that may exacerbate erosion of phosphorus-laden sediment to surface
waters and therefore could increase in-lake phosphorus concentration (despite dilution and flushing impacts that the model
assumes).
Future loading estimation showed that total phosphorus loading to Lake Winnisquam may increase by 54%, from 7,455 kg/yr
under current conditions to 11,492 kg/yr at full build-out (2076) under current zoning for Lake Winnisquam (Table 6).
Additional phosphorus will be generated from more development in the watershed (especially from Lake Winnipesaukee, the
direct shoreline of Lake Winnisquam, Do I [off Brook3, and Jewett Brook), greater atmospheric dust, more septic systems, and
enhanced internal loading (Table 6). The total phosphorus load coming from the direct Winnipesaukee River sub-watershed
(excluding input from Lake Winnipesaukee) showed minimal change because the small sub-watershed in Laconia is already
largely built-out. The model predicted higher(worse) phosphorus (12.9 ppb), higher(worse) chlorophyll-a (3.6 ppb),and lower
(worse) water clarity (3.3 m) compared to current conditions for Lake Winnisquam (Table 5). Predicted water quality was
especially poor for Lake Wicwas, which would exhibit characteristics of a hypereutrophic lake that blooms throughout much
of the year (267 days; Table 5). Even if the internal phosphorus load to Lake Wicwas were eliminated (either via an in-lake
treatment or assuming the build-out assumptions are overestimating the predicted increase in total phosphorus load to the
lake), Lake Wicwas would still experience severely degraded water quality and be classified as a eutrophic lake.
3 Note that the predicted increase in total phosphorus load from Dolloff Brook may be overestimated due to build-out assumptions. The build-out analysis
for the portion of the Lake Winnisquam watershed in the Town of New Hampton (which feeds into Dolloff Brook and ultimately Lake Wicwas) did not account
for New Hampton's complex zoning standards that adjust the allowable lot size based on soil drainage class and slope, along with a more nuanced
"adjustment factor" for other considerations such as water supply and sewage disposal. Some of these standards were accounted for in areas with hydric
soils and steep slopes but not for the complex graduations of other soil and slope types. It is likely that accounting for this complex zoning would reduce the
number of projected buildings in the New Hampton portion of the study area and thus reduce the estimated phosphorus load increase to Lake Wicwas; the
significance of that reduction is unknown. Additionally, a 139-acre parcel along Dolloff Brook in New Hampton was recently put into conservation (and not
accounted for in the build-out analysis), which would further reduce the number of projected buildings.
FB Environmental Associates & Horsley Witten Group
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LAKE WINNISQUAM WATERSHED-BASED PLAN
Table 5. In-lake waterquality predictions for Lake Wicwas, Lake Opechee, and Lake Winnisquam. TP = total phosphorus. Chl-
a = chlorophyll-a. SDT = Secchi disk transparency. Bloom Days represent average annual probability of chlorophyll-a
exceeding 10 ppb. Refer to FBE (2021a).
Model Scenario
Median TP
Predicted Median
Mean Chl-
Predicted Mean
Mean
Predicted Mean
Bloom
(ppb)
TP (ppb)
a (ppb)
Chl-a (ppb)
SDT (m)
SDT (m)
Days
Lake Wicwas
Pre-Development
-
2.4
-
0.3
-
11.9**
0
Current-2020
9.6 (11.5)
12.1
4.0
3.3
4.2
3.4
2
Future (2076)
-
35.9
-
15.4
-
1.5
267
Lake Opechee
Pre-Development
-
1.6
-
0.2
-
16.3**
0
Current-2020
6.3 (7.5)
7.8
1.3
1.6
-
4.8
0
Future (2076)
-
11.8
-
3.1
-
3.5
2
Lake Winnisquam
Pre-Development
-
1.5
-
0.2
-
16.4
0
Current-2020
7.1 (8.5)
8.3
1.7
1.8
7.1
4.5
0
Future (2076)
-
12.9
-
3.6
-
3.3
4
"Mean TP concentration (first value) represents current in-lake epilimnion TP from observed data. Median TP concentration (second value in parentheses) represents 20%
greater than the observed mean value as the value used to calibrate the model. Most lake data are collected in summer when TP concentrations are typically lo wer than annual
average concentrations for which the model predicts. It was argued in the 2012 Black Brook Watershed Management Plan that the "average summer concentrations are likely
representative of annual average or average at spring overturn values"given the large and continuous load of phosphorus and water from the Winnipesaukee River. April2021
data collected at the three lake deep spots confirm minimal difference in average total water column phosphorus with average summer epilimnion phosphorus. However, for
this model, our modeled lake area included the Mohawk Island basin and its contributing sources, slightly lessening the total load percent contribution from the Winnipesaukee
River; in addition, the load contribution from the Winnipesaukee River flows through two large lakes (Paugus Bay and Lake Opechee) and may elevate phosphorus
concentrations in winter. More winter data would be needed to confirm.
**Hit Bottom
FB Environmental Associates & Horsley Witten Group
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LAKE WINNISQUAM WATERSHED-BASED PLAN
Table 6. Total phosphorus (TP) and water loading summary by model and source for Lake Winnisquam. Italicized sources
sum to the watershed load. Refer to FBE (2021a).
PRE-DEVELOPMENT
CURRENT (2020)
FUTURE (2076)
SOURCE
TP
%
WATER
TP
%
WATER
TP
%
WATER
(KG/YR)
(CU.M/YR)
(KG/YR)
(CU.M/YR)
(KG/YR)
(CU.M/YR)
LAKE WICWAS
ATMOSPHERIC
9.9
15%
897,352
15.6
5%
897,352
35.3
3%
897,352
INTERNAL
0.0
0%
0
78.8
23%
0
228.6
23%
0
WATERFOWL
8.5
13%
0
8.5
2%
0
8.5
1%
0
SEPTIC SYSTEM
0.0
0%
0
6.2
2%
5,243
9.3
1%
7,865
WATERSHED LOAD
48.6
72%
10,435,330
232.2
68%
10,318,434
713.7
72%
9,995,418
TOTAL LOAD TO LAKE
66.9
100%
11,332,682
341.2
100%
11,221,029
995.4
100%
10,900,635
LAKEOPECHEE
ATMOSPHERIC
12.1
1.4%
1,095,975
19.0
0.4%
1,095,975
43.2
0.7%
1,095,975
INTERNAL
0.0
0.0%
0
0.0
0.0%
0
0.0
0.0%
0
WATERFOWL
10.4
1.2%
0
10.4
0.2%
0
10.4
0.2%
0
SEPTIC SYSTEM
0.0
0.0%
0
9.7
0.2%
8,128
14.2
0.2%
11,910
WATERSHED LOAD
825.3
97.4%
488,213,857
4,216.3
99.2%
487,954,357
6,340.4
98.9%
487,855,167
Paugus Bay-Lake Winnipesaukee
799.1
94.3%
482,712,903
3,817.9
89.8%
482,712,903
5,792.6
91.2%
482,712,903
Direct Land Use Load
26.2
3.1%
5,500,954
398.4
9.4%
5,241,454
547.8
7.8%
5,142,264
TOTAL LOAD TO LAKE
847.7
100%
489,309,833
4,255.4
100%
489,058,460
6,408.2
100%
488,963,052
LAKE WINNISQUAM
ATMOSPHERIC
120.4
9%
10,913,507
189.1
3%
10,913,507
429.9
3%
10,913,507
INTERNAL
0.0
0%
0
112.7
2%
0
173.6
2%
0
WATERFOWL
103.2
7%
0
103.2
1%
0
103.2
1%
0
SEPTIC SYSTEM
0.0
0%
0
86.3
1%
71,094
98.5
1%
81,089
WATERSHED LOAD
1,161.9
84%
570,577,547
6,963.8
93%
568,655,087
10,686.7
93%
567,266,589
Lake Wicwas
20.4
1%
9,066,146
101.8
1%
8,976,823
293.5
3%
8,720,508
Lake Opechee
782.9
57%
489,309,833
3,814.7
51%
489,058,460
5,769.8
50%
488,963,052
Direct Land Use Load
358.6
26%
72,201,569
3,047.3
41%
70,619,804
4,623.4
40%
69,583,029
TOTAL LOAD TO LAKE
1,385.4
100%
581,491,054
7,455.2
100%
579,639,688
11,491.8
100%
578,261,186
FB Environmental Associates & Horsley Witten Group
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LAKE WINNISQUAM WATERSHED-BASED PLAN
Unnamed
Tributary
(North Trib)
Lake Wicwas
Direct
Total Phosphorus Load (kg/ha/yr)
o.oo-o.ii
0.12-0.19
0.20-0.31
0.32-0.47
0.47-0.83
Winnipesaukee
River
Figure 9. Map of current total phosphorus load per unit area (kg/ha/yr) for each sub-watershed in the Lake Winnisquam
watershed. Higher phosphorus loads per unit area are concentrated in the more developed southern portion of the
watershed. Refer to FBE (2021a).
FB Environmental Associates & Horsley Witten Group
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LAKE WINNISQUAM WATERSHED-BASED PLAN
2.3.2 Build-out Analysis
A full build-out analysis was completed for the direct Lake Winnisquam watershed for the municipalities of Belmont, Gilford,
Laconia, Meredith, New Hampton, Sanbornton, and Tilton (FBE, 2021b). A build-out analysis identifies areas with
development potential and projects future development based on a set of conditions (e.g., zoning regulations, environmental
constraints) and assumptions (e.g., population growth rate). A build-out analysis shows what land is available for
development, how much development can occur, and at what densities. "Full Build-out" is a theoretical condition
representing the moment in time when all available land suitable for residential, commercial, and industrial uses has been
developed to the maximum extent permitted by local ordinances and zoning standards. Local ordinances and zoning
standards are subject to change and the analysis requires simplifying assumptions and therefore the results of the build-out
analysis should be viewed as planning-level estimates only for potential future outcomes from development trends. For
example, current use (which lowers tax obligations on 10-acre or more parcels kept in a natural state) can be a deterrent to
development because of the tax burden when parcels are removed from current use status.
when all available land suitable for residential, commercial, and industrial uses has been
To determine where development may occur within the study area, the build-out analysis first subtracts land unavailable for
development due to physical constraints, including environmental restrictions (e.g., wetlands, conserved lands, hydric soils),
zoning restrictions (e.g., shoreland zoning, street Right-of-Ways (ROWs), and building setbacks), and practical design
considerations (e.g., lot layout inefficiencies) (Appendix B, Map B-2). Existing buildings also reduce the capacity for new
development.
Under current zoning regulations, 45% (15,027 acres) of the direct Lake Winnisquam watershed is buildable (Appendix B, Map
B-3). The greatest acreages of land available for development include the Forestry and Rural District of Meredith (1,822 acres),
the Forest Conservation Zone of Sanbornton (1,807 acres), and the Residential Rural Zone of Laconia (1,576 acres). New
Hampton's General Residential zone and Laconia's Commercial zone are the most vulnerable to increased development
potential with the highest percent increase from existing buildings to projected buildings at 2,461% and 1,500%, respectively
(Table 7). FBE identified 8,456 existing buildings within the watershed, and the build-out analysis projected that an additional
6,734 buildings could be constructed in the future, resulting in a total of 15,190 buildings in the watershed (Appendix B, Map
B-4). Currently, existing buildings are the densest along the shores of the lakes, as well as in Laconia. Major conservation lands
in the watershed restrict existing and future development in rural areas of the watershed.
FULL BUILD-OUT is a theoretical condition representing the moment in time
developed to the maximum extent permitted by local ordinances and zoning standards.
FB Environmental Associates & Horsley Witten Group
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LAKE WINNISQUAM WATERSHED-BASED PLAN
Table 7. Amount of buildable land and projected buildings by zone in the direct Lake Winnisquam watershed in Belmont,
Gilford, Laconia, Meredith, New Hampton, Sanbornton, and Tilton, New Hampshire.
Zone
Total Area
(Acres)
Buildable
Area
(Acres)
Percent
Buildable
Area
No.
Existing
Buildings
No.
Projected
Buildings
Total No.
Buildings
Percent
Increase
Belmont
Commercial
653
248
38
136
88
224
65
Residential - Multi Family
113
22
19
53
10
63
19
Residential - Single Family
2,040
939
46
836
541
1,377
65
Rural
2,647
1,413
53
524
289
813
55
Gilford
Industrial
119
42
35
15
20
35
133
Limited Residential
1,781
1,001
56
197
601
798
305
Natural Resource Residential
825
256
31
78
80
158
103
Professional Commercial
70
41
60
21
18
39
86
Single Family Residential
561
204
36
325
118
443
36
Laconia
Commercial
164
113
69
5
75
80
1,500
Industrial
103
76
74
16
90
106
563
Industrial Park
129
86
67
19
20
39
105
Residential Apartment
157
136
87
70
117
187
167
Residential Rural
3,500
1,576
45
574
444
1,018
77
Residential Single-Family District
2,101
479
23
3,030
193
3,223
6
Urban Commercial District
428
257
60
651
738
1,389
113
Meredith
Business Industrial District
14
5
37
7
3
10
43
Commercial District - Center
33
7
23
19
6
25
32
Forestry and Conservation
1,452
217
15
81
35
116
43
Forestry and Rural District
4,401
1,822
41
341
390
731
114
Residential District
1,133
605
53
186
337
523
181
Shoreline District
1,244
165
13
217
116
333
53
New Hampton
General Residential
2,178
1,143
52
57
1,403*
1,460
2,461
Sanbornton
Commercial (Lt. Manuf. Perm.)
123
45
36
60
57
117
95
Forest Conservation
3,563
1,807
51
121
204
325
169
General Agricultural
1,921
1,150
60
111
253
364
228
General Residence
1,141
720
63
180
246
426
137
Recreational
208
100
48
249
136
385
55
Tilton
Medium Density Residential District
7
2
27
2
2
4
100
Mixed Use District
26
1
2
40
1
41
3
Resort Commercial
419
174
42
210
70
280
33
Rural Agricultural
303
173
57
25
33
58
132
Total
33,555
15,027
45
8,456
6,734
15,190
80
* Note on New Hampton's number of projected buildings: It is likely that accounting for New Hampton's complex zoning that adjusts allowable lot size based
on soil drainage class and slope would reduce the number of projected buildings in the New Hampton portion of the study area; the significance of that
reduction is unknown. Additionally, a 139-acre parcel along DolloffBrook in New Hampton was recently put into conservation, which would further reduce
the number of projected buildings.
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LAKE WINNISQUAM WATERSHED-BASED PLAN
Three iterations of the TimeScope Analysis were run using compound annual growth rates (CAGR) for 20-, 30- and 50-year
periods from 1990-2010 (1.09%), 1980-2010 (1.65%), and 1960-2010 (2.61%), respectively (Table 8). Full build-out is projected
to occur in 2076 at the 20-year CAGR, 2057 at the 30-year CAGR, and 2044 for the 50-year CAGR (Figure 10). Note that the
growth rates used in the TimeScope Analysis are based on town- or city-wide census statistics but have been applied hereto
a portion of the municipalities. Also note that the population growth rate in these municipalities is decreasing, so the 20-year
estimate is likely more accurate than the 50-year estimate. Using census data to project population increase and/or
development has inherent limitations. For instance, the building rate may increase at a different rate than population such
as when considering commercial versus residential development. As such, the TimeScope Analysis might over or
underestimate the time required for the study area to reach full build-out. Numerous social and economic factors influence
population change and development rates, including policies adopted by federal, state, and local governments. The
relationships among the various factors may be complex and therefore difficult to model.
Table 8. Compound annual growth rates for the seven municipalities within the direct watershed of Lake Winnisquam, used
for the TimeScope Analysis. 2020 data were not available for towns with populations less than 5,000 at the writing of this
plan. Data from US Census Bureau.
Municipality
Compound Annual Growth Rate
50 yr. Avg. 1960-2010 30 yr. Avg. 1980-2010 20 yr. Avg. 1990-2010
Belmont
2.69%
2.03%
1.20%
Gilford
2.53%
1.30%
0.98%
Laconia
0.08%
0.08%
0.07%
Meredith
1.90%
0.99%
1.28%
New Hampton
1.86%
1.85%
1.50%
Sanbornton
2.51%
1.91%
1.65%
Tilton
1.03%
0.17%
0.48%
Combined
2.61%
1.65%
1.09%
Figure 10. Full build-out time projections for the direct Lake Winnisquam watershed in Belmont, Gilford, Laconia, Meredith,
New Hampton, Sanbornton, and Tilton, New Hampshire (based on compound annual growth rates reported in Table 8).
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LAKE WINNISQUAM WATERSHED-BASED PLAN
2.4 WATER QUALITY GOAL & OBJECTIVES
The model results revealed changes in total phosphorus loading and in-lake total phosphorus concentrations over time from
pre-development through future conditions, showing that the water quality of Lake Winnisquam, Lake Wicwas, and Lake
Opechee is threatened by current development activities in the watershed and will degrade further with continued
development in the future. We can use these results to make informed management decisions and set an appropriate water
quality goal for Lake Winnisquam, as well as Lake Wicwas and Lake Opechee. In-lake chlorophyll-a and total phosphorus
concentrations are currently meeting state water quality criteria which would indicate that there is reserve capacity for the
lakes to assimilate additional nutrients under a "business as usual" scenario. However, it is highly recommended that strong
objectives be established to protect the water quality of these lakes over the long term, especially given that these lakes are
not meeting other water quality criteria (e.g., turbidity, dissolved oxygen), are experiencing occasional cyanobacteria blooms,
and are threatened by new development. The water quality goal and objectives were set by the Plan Development Committee
with guidance from FBE.
The overarching goal of the Lake Winnisquam WBP is to improve the water quality of Lake Winnisquam such that it
meets state water quality standards for the protection of ALI. This goal will be achieved by accomplishing the following
objectives. Specific action items to achieve these objectives are provided in the Action Plan (Section 5). Refer to Section 5.2:
Pollutant Load Reductions for more details on linking the established water quality objectives and needed pollutant load
reductions with field-identified remediation opportunities.
• OBJECTIVE 1: Reduce pollutant loadingfrom Hueber Brook to improve in-stream and in-lake turbidity concentration
to <10 NTU. The drainage area of Hueber Brook is small and thus the possible pollutant sources from Hueber Brook
are few. An investigation by FBE of the Hueber Brook sub-watershed was completed and identified sources of
sedimentation to remediate. Meeting this objective will remove Lake Winnisquam's impaired listing for ALI due to
excessive turbidity.
• OBJECTIVE 2: Mitigate (prevent or offset) phosphorus loading from future development in the direct watersheds to
Lake Winnisquam, Lake Wicwas, and Lake Opechee to maintain in-lake total phosphorus concentration. The
estimated total phosphorus direct watershed load increase from new development by 2076 was predicted at 1,576
kg/yrfor Lake Winnisquam, 654 kg/yrfor Lake Wicwas, and 149 kg/yrfor Lake Opechee, equating to about 281 kg/yr,
117 kg/yr, and 27 kg/yr, respectively, in the next 10 years (by 2031). At a minimum, pollutant loading should be
prevented or offset by 281 kg/yr, 117 kg/yr, and 27 kg/yr from the direct watershed areas to Lake Winnisquam, Lake
Wicwas, and Lake Opechee, respectively, by 2031.
/Vote/Objective 2 does not account for the additional load expected from Lake Winnipesaukee by 2031 given that the
scope of management strategies for this plan is limited to the direct watershed of Lake Winnisquam. Other plans and
management strategies are currently being implemented for the Lake Winnipesaukee watershed that will likely
result in a lower-than-predicted increase in the total phosphorus load from Lake Winnipesaukee. Assuming an
estimated increase of 314 kg/yr in the total phosphorus load from Lake Winnipesaukee via Lake Opechee to Lake
Winnisquam in the next 10 years, the in-lake total phosphorus concentration for Lake Winnisquam may increase by
0.5 ppb, placing it within the 10% reserve assimilative capacity range. Because Lake Winnisquam is currently not
impaired for ALI due to either of the trophic indicators, we recommend that this objective be re-evaluated after5 and
10 years to determine the true increase in total phosphorus load from Lake Winnipesaukee and whether a more
stringent objective should beset.
• OBJECTIVE 3: Reduce phosphorus loading from existing development by 4% (260 kg/yr) to Lake Winnisquam Pot
Island Deep Spot [WINPLACD] to improve in-lake total phosphorus concentration to 7.2 ppb. Note: the target
pollutant load reduction was calculated as 4% of the total phosphorus load to Lake Winnisquam (including Lake
Winnipesaukee) minus the total phosphorus loads from the sub-watersheds of Chapman Brook, Durgin Brook, and
roughly 50% of Lake Winnisquam Direct due to their downstream proximity to WINPLACD. Meeting this objective
would be in addition to mitigation of the anticipated future phosphorus loading by 2031 (Objective 2) to achieve an
in-lake total phosphorus concentration of 7.2 ppb at WINPLACD. Even though the response indicator (chlorophyll-a)
meets ALI criteria, targeting additional pollutant load reductions to WINPLACD highlights the locally significant
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LAKE WINNISQUAM WATERSHED-BASED PLAN
sedimentation and nutrient loading coming from the nearby Black Brook sub-watershed, which is estimated to
contribute 151 kg/yr of phosphorus load to Lake Winnisquam.
The interim goals for each objective allow flexibility in re-assessing water quality objectives following more data collection
and expected increases in phosphorus loading from new development in the watershed over the next 10 or more years (Table
9). Understanding where water quality will be following watershed improvements compared to where water quality should
have been following no action will help guide adaptive changes to interim goals (e.g., goals are on track or goals are falling
short). If the goals are not being met due to lack of funding or other resources for implementation projects versus due to
increases in phosphorus loading from new development outpacing reductions in phosphorus loading from improvements to
existing development, then this creates much different conditions from which to adjust interim goals. For each interim goal
year, WWN should update the water quality data and model and assess why goals are or are not being met. WWN will then
decide on how to adjust the next interim goals to better reflect water quality conditions and practical limitations to
implementation.
Table 9. Summary of water quality objectives for Lake Winnisquam, Lake Wicwas, and Lake Opechee. Interim
goals/benchmarks are cumulative.
Water Quality Objective
Interim Goals/Benchmarks
2024
2026
2031
1. Reduce pollutant loading from Hueber Brook to improve in-stream and in-lake turbidity concentration to <10 NTU.
Remediate sources of
sediment to Hueber Brook
Remediate sources of sediment to
Hueber Brook; re-evaluate water quality
and track progress
Remediate sources of sediment to
Hueber Brook; re-evaluate water
quality and track progress
2. Mitigate (prevent or offset) pollutant loading from future development in the direct watersheds to Lake Winnisquam, Lake Wicwas, and Lake
Opechee to maintain in-lake total phosphorus concentration
Prevent or offset 70 kg/yr in TP
loading from new
development to Lake
Winnisquam
Prevent or offset 29 kg/yr in TP
loading from new
development to Lake Wicwas
Prevent or offset 8 kg/yr in TP
loading from new
development to Lake Opechee
Prevent or offset 141 kg/yr in TP loading
from new developmentto Lake
Winnisquam; re-evaluate water quality
and track progress
Prevent or offset 59 kg/yrinTP loading
from new developmentto Lake Wicwas;
re-evaluate water quality and track
progress
Prevent or offset 16 kg/yr in TP loading
from new developmentto Lake
Opechee; re-evaluate water quality and
track progress
Prevent or offset 281 kg/yrinTP
loading from new developmentto
Lake Winnisquam; re-evaluate
water quality and track progress
Prevent or offset 117 kg/yrinTP
loading from new developmentto
Lake Wicwas; re-evaluate water
quality and track progress
Prevent or offset 27 kg/yrinTP
loading from new developmentto
Lake Opechee; re-evaluate water
quality and track progress
3. Reduce pollutant loading from existing development by 4% (298 kg/yr) to Lake Winnisquam Pot Island Deep Spot [WINPLACD] to improve in-
lake total phosphorus concentration to 7.2 ppb.
Achieve 0.25% (16 kg/yr)
reduction in TP loading
Achieve 2% (130 kg/yr) reduction in TP
loading; re-evaluate water quality and
track progress
Achieve 4% (260 kg/yr) reduction in
TP loading; re-evaluate water
quality and track progress
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LAKE WINNISQUAM WATERSHED-BASED PLAN
3 POLLUTANT SOURCE IDENTIFICATION
This section describes sources of excess phosphorus to Lake Winnisquam. Sources of phosphorus to lakes can include
stormwater runoff, shoreline erosion, construction activities, fertilizers, illicit connections, failed or improperly functioning
septic systems, leaky sewer lines, fabric softeners and detergents in greywater, and pet, livestock, and wildlife waste. These
external sources of phosphorus to lakes can then circulate within lakes and settle on lake bottoms, contributing to internal
nutrient loads over time. Additional phosphorus sources can enter the lake from atmospheric deposition but are not
addressed here because of limited local management options. Wildlife is mentioned as a potential source but largely for
nuisance waterfowl such as geese or ducks that may be congregating in large groups because of human-related actions such
as feeding or having easy shoreline access (lawns). Climate change is also not a direct source but can exacerbate the impact
of the other phosphorus sources identified in this section and should be considered when striving to achieve the water quality
objectives.
3.1 WATERSHED DEVELOPMENT
NPS pollution comes from many diffuse sources on the landscape and is more difficult to identify and control than point
source pollution. NPS pollution can result from contaminants transported by overland runoff (e.g., agricultural runoff or
runoff from suburban and rural areas), groundwater flow, or direct deposition of pollutants to receiving waters. Examples of
NPS pollution that can contribute nutrients to surface waters via runoff, groundwater, and direct deposition include erosion
from disturbed ground or along roads, stormwater runoff from urban areas, malfunctioning septic systems, excessive
fertilizer application, unmitigated agricultural activities, pet waste, and wildlife waste.
3.1.1 Development History of Lake Winnisquam
Lake Winnisquam, meaning "pleasant waters", was once considered part of Lake Winnipesaukee until the late 1800s.
Maps of Lake Winnisquam from the early 1800s label the waterbody as "Great Bay", an extension of Lake Winnipesaukee.
Many Native American tribes resided in the Lakes Region of New Hampshire until the mid-1700s when the European
settlers arrived and established townships throughout the area, bringing in industries such as blacksmith ing, tanneries,
gristmills, and sawmills. By 1795, there were sawmills at Meredith Center, Meredith Bridge, and Lake Village. The Lakeport
Dam was constructed on the Winnipesaukee River in 1851 to provide powerto the mills in the area.
The mostsignificant change thatallowed the Lakes Region of New Hampshire to becomethe bustling recreation destination
that it is today was the introduction of railways in the 1800s. In August 1848, the Boston, Concord, and Montreal Railroad
opened its route between Concord and Meredith Bridge, right along Lake Winnisquam. This route allowed travelers from
other areas to visit New Hampshire's Lakes Region and establish the area as a vacation destination. The railway was extended
overtime to Montreal, and passengers could ride the train to Canada until the 1950s when passenger travel ceased, and the
railroad was used only to transport freight until 1965.
One notable feature of Lake Winnisquam are its islands, including Pot Island, Three Islands, Loon Island, Hog Island, and
Mohawk Island. Mohawk Island was once a peninsula known as Mohawk Point. In 1910, the Lochmere Dam was constructed,
and the water level rose so that the island became permanently separated from the land. Mohawk Island was given its name
because it was the site of a famous battle in 1685 between Mohawk warriors and an alliance of Pennacook and Pequaket
warriors. In this battle, the Mohawk warriors hid behind part of the peninsula and then ambushed their enemy, eventually
leading to their victory.
According to local legend, on the night of Halloween in 1931, a group of local youngsters got their hands on some dynamite
that was being used to create new roads in the area. They rowed out to Pot Island and set the dynamite to blow up the island.
The culprits made it out alive, but only one fourth of the original Pot Island remains because of this explosion.
The Winnisquam Bridge, commonly known as Mosquito Bridge, was built between 1840 and 1844 and eventually replaced in
1916 and again in 1974. This bridge is known as Mosquito Bridge not because it was infested with mosquitos but because the
old bridge's humped shape resembled the back of a mosquito.
What is now known as Waldron Bay, a lakeside community in Meredith, was once Camp Waldron, a boy's camp on the shore
of the lake. The camp was run by the Boston Missionary School Society, which owned an extensive amount of land along Lake
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LAKE WINNISQUAM WATERSHED-BASED PLAN
Winriisquam and also operated a girl's camp (Camp Andover) on the other side of the cove, These camps were created to
provide outdoor opportunities to impoverished children from the Boston area. Camp Waldron was operational from the early
1900s until the 1970s,
Many of the residences along the shores of Lake Winnisquam were once primitive camps with no electricity or running water.
In the 1950s and 1960s, many of these homes were converted to larger, year-round cottages with plumbing and running water.
In the early 1980s, motorboats became increasingly popular, and lakefront properties were in high demand. Since then,
development along the shoreline of the lake has continued to increase as people purchase their second homes in the area.
Winnisquam Bridge.
The Mills at Meredith Center in 1913,
Pot Island, Lake Winnisquam, Laconia
Mosquito Bridge, Laconia
Development along LakeOpechee in 1963,
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LAKE WINNISQUAM WATERSHED-BASED PLAN
3.1.2 Watershed Assessments
Several watershed assessments to identify and document sources of NPS pollution have been completed in the Lake
Winnisquam watershed. As part of the development of this plan, information was obtained through interviews with local
partners, review of municipal documents and property records, desktop analysis of aerial imagery, record searches through
online databases, review of publicly available GIS data, review of prior studies and reports, and field survey investigations.
3.1.2.1 Hueber Brook Investigation (2021)
In 2007, NHDES measured elevated turbidity in Hueber Brook, a small tributary that flows into Lake Winnisquam in Belmont.
This turbidity was initially attributed to construction along Route 3/11. NHDES resampled Hueber Brook in 2015 after
construction had been completed, yet turbidity remained elevated above acceptable water quality standards and the lake
remains listed as impaired for ALI due to excessive turbidity. FBE performed a special investigation of the Hueber Brook
watershed in 2021 to help prioritize next steps for remediation to remove the lake's ALI impairment listing. The investigation
identified four potential sources of high turbidity to the brook. Problems identified included stormwater runoff, erosion, lack
of filtration, degraded culverts, and lack of vegetated riparian buffer.
Stormwater runoff from within the Hueber Brook watershed in Belmont (Figure 11) is diverted into the brook through a series
of roadside ditches, drains, and catch basins and appears to be the main source of flow for the brook. The flow path of Hueber
Brook has been altered greatly by the installation of stormwater infrastructure such as culverts and catch basins. The brook
also flows into a constructed wetland system along Sun Lake Drive in Belmont. Hueber Brook outlets into a retention pond,
which discharges to Lake Winnisquam. The color of water flowing into and from Hueber Brook is orange. This may be due to
naturally occurring iron and iron-oxidizing bacteria or due to degraded and rusting stormwater infrastructure, specifically
metal culvert pipes, which were observed throughout the watershed. It should be noted that this rusty color was also
observed in another small watercourse that flows parallel to Sun Lake Drive, into a catch basin, and then into the retention
pond.
(TOP) Outflow from retention pond into Lake Winnisquam following a rain event. (BOTTOM LEFT) Rusty color and oil
sheen flowing in Hueber Brook. (BOTTOM RIGHT) Rusty colored flow from small watercourse parallel to Sun Lake Drive.
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LAKE WINNISQUAM WATERSHED-BASED PLAN
(1) STORMWATER RUNOFF FROM LOTS ALONG ROUTE 3/11
Observations: Most of the land use in the portion of the
Hueber Brook drainage area that is along Route 3/11 is
industrial and/or commercial with impervious cover that
carries stormwater runoff with any sediment and/or other
particles (oils, etc.) directly into Hueber Brook.
Recommendations: Improve stormwater controls through
the construction and implementation of stormwater runoff
treatment measures, such as bioretention cells.
(2) SEDIMENT/GRAVEL DUMP SITE ON OLD STATE ROAD
Observations: There is a large sediment/gravel dump site
along Old State Road, This site is situated atop a steep
slope, with Old State Rd at the bottom of the slope. The
bank of the elevated dump site is eroding into the road and
is potentially washing down the road and into Hueber
Brook during a storm event.
Recommendations: Remove sand and sediment from the
site. Install erosion control measures along bank, such as
an increased buffer and silt fences.
(3) OLD STATE ROAD
Observations: Old State Rd is a dirt road that runs parallel
to Route 3/11 on the Lake Winnisquam side. This road is
steeply sloped on both sides, with commercial and
industrial land uses occurring atop both banks. Stormwater
runs off impervious surfaces and down a ditch along Old
State Road. Orange/rusty colored water was observed
flowing down this ditch.
Recommendations: Enhance buffer and erosion controls on
both sides of road. Improve stormwater runoff treatment.
(4) FAILING CULVERTS THROUGHOUT HUEBER BROOK
DRAINAGE AREA
Observations: Multiple culverts within the drainage area
were observed to be failing. Failures included rust,
blockages, and algae build up.
Recommendations: Replace culverts.
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LAKE WINNISQUAM WATERSHED-BASED PLAN
£ Potential Source of High Turbidity
Hueber Brook
Retainment Pond
Man-made Wetland Area
I I Hueber Brook Watershed
Road
Hueber Brook Turbidity Investigation
Lake Winnisquam Watershed
Management Plan
Lake Winnisquam
Data Sources: E5R1, NH GRANIT
Map Created By FB Environmental
Date Created: December 2021
Hueber Brook Drainage Area
Figure 11. Map depicting identified sites and features of note during the 2021 investigation of Hueber Brook in Belmont.
3.1.2.2 Black Brook Watershed Surveys (2012. 2020-2022)
Black Brook has been long impacted by excessive sediment
loading from the gravel roads throughout the sub-
watershed, largely in Sanbornton. This sediment load is
transported out into Lake Winnisquam where a visible 300-
ft radius sediment delta has formed over the years
(pictured right). Local groups have prioritized investigation
and remediation of road erosion in the watershed. Large-
scale improvements in erosion and sedimentation in the
Black Brook watershed are needed to improve the water
quality of Black Brook and Lake Winnisquam.
I n 2012, the Black Brook Watershed Management Plan was
created for the Town of Sanbornton by AECOM. The plan
seta water quality goal for reducing the annual phosphorus
load entering Lake Winnisquam from the Black Brook sub-
watershed. A watershed survey was conducted to identify
sites likely contributing disproportionate concentrations of
sediment and phosphorus. BMPs were recommended for
Aerial view of a 300-ft radius sediment delta at the outlet
of Black Brook as it enters Lake Winnisquam.
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LAKE WINNISQUAM WATERSHED-BASED PLAN
each site. The38 identified sites were found in fourgeneral locations within the Black Brook sub-watershed: aiongWoodman
Rd near Black Brook (south branch) (n 5), along Huse Rd {n=12), along Kaulback Rd (near the intersection of Roxbury Road)
(/7=16), and along Black Brook Rd (n= 4), BMP recommendations for sites along these roadways included methods of runoff
diversion, retention, and infiltration. It was recommended that the road shoulders and surfaces be re-graded to discourage
the channelization ofstormwater runoff where it gains velocity and discharges directly into Black Brook. Turnouts and rip rap
lined retention areas were also recommended. Unpaved and steeply sloped roads typical for this area, particularly Huse Rd
and Kaulback Road, are notorious for contributing to sediment and nutrient loads to tributaries and the lake. Routine
maintenance was identified as being critical forthe success of these proposed BMPs due to the highly erodible nature of the
area's gravel roads.
The Sanbornton Roadway Evaluation (Underwood Engineers, Inc., 2020) created a detailed strategy for prioritizing road fixes
in the Town of Sanbornton, which includes the Black Brook watershed. The strategy considered traffic flow, road widths, road
conditions, among other parameters (but not including impact to water quality) forthe 68 miles of the town's Class V roads,
50% of which are unpaved, gravel roads. Fixing all the roads was estimated to cost $26 million or $1.34 million per year over
20 years. Huse, Roxbury, and Woodman roads were among the highest priority roads targeted for immediate remediation,
In 2021, BCCD hired an engineer (G. Lang, P.E.) to review and
assess environmental issues affecting the water quality of
Black Brook with emphasis on assessing the cause of
sedimentation alteringflow conditions at a newly installed box
culvert at the Black Brook Rd crossing. Previous studies
reviewed in preparation for the field assessment included the
2012 Black Brook Watershed Management Plan (AECOM, 2012)
and the 2020 Summary and Final Documentation, Sanbornton
Roadway Evaluation (Underwood Engineers, Inc., 2020). Lang
(2021) found sediment loading issues comingfrom Huse Road,
Kaulback Road, Woodman Road, and Black Brook Road. Lang
(2021) also assessed sedimentation at the new box culvert on
Black Brook Rd, as well as significant trash and organic
material blocking a stop-log structure downstream of the box
culvert, and recommended that the stream be surveyed for
proper channel grade and backwater effects from the
blockage. Lang (2021) recommended that the existing
sediment at the box culvert be removed down to the design
gravel bottom before opening up the stop-log dam to prevent the sediment from washing into Lake Winnisquam with normal
flows restored. A bypass channel may need to be considered to prevent the situation from reoccuring in the future.
In 2022, FBE was hired by BCCD to perform a quantitative evaluation of 11 erosion and sedimentation sites in the Black Brook
watershed, based on review of sites identified in the 2012 Black Brook Watershed Management Plan (AECOM, 2012) and the
2021 Black Brook Watershed Assessment Update Report {Lang, 2021). The evaluation results were used to prioritize the 11
sites for implementation and ultimately to serve as supporting documentation for future grant funding applications (site
locations identified in Figure 12 and pictured on the next page). During the field visits, FBE evaluated the severity of erosion,
collected measurements (length, width, depth) for screening-level erosion volume estimates, noted distance to the nearest
surface water, flow condition, and sediment type (silt, sand, and/or gravel), and took representative photos of the sites. These
observations were input to the Water Erosion Prediction Project (WEPP) model for estimating pollutant loading from each
site. Site prioritization integrated WEPP model results and field observations through a quantitative ranking method (refer to
FBE, 2022 for details). The three highest priority sites occurred along Huse Rd where runoff drains to Black Brook south
branch, followed closely by Kaulback Rd where most runoff drains to Black Brook north branch. Both roads are unpaved
gravel roads on steep slopes, transporting sediment to nearby surface waters.
Sedimentation evident at a new box culvert along Black
Brook at the Black Brook Rd crossing. Photo courtesy of
Lang (2021).
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LAKE WINNISQUAM WATERSHED-BASED PLAN
Site la. Lower Huse Road Site lb. Huse Road crossing Site 2. Upper Huse Road
Site 5. Kaulback Road East
Site 8. Woodman Rd Crossing
Site 4. Kaulback Road West
Site 3. Kaulback-Roxbury Inter
.-V
$£1
Site 6. Kaulback Road Far N
Site 7. Black Bk Rd Crossing
Site 9. Union Cemetery Site 10. Roxbury Road
FB Environmental Associates & Horsley Witten Group
Photos of 11 evaluated
and prioritized
remediation sites in the
Black Brooksub-
watershed in Sanbornton.
See FBE (2022) for more
details. Refer to Figure 12
for site locations.
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LAKE WINNISQUAM WATERSHED-BASED PLAN
LOCUS MAP
Erosion Sites
Black Brook
Sanbornton, NH
Remediation Plan
Waterbody
Stream
Road
Site Location Map
[UUSfe>r»l NHORAIHIT ESS NHD
Coxlmla sruam NAD 1M3 JTV Zco. 14
Map created bj FB ErrriioniRantai on April
12. 2022
Profec!
Locator
Miles
Figure 12. Map of documented and prioritized remediation sites in the Black Brook sub-watershed. Refer to site photos on
the previous page as well as FBE (2022) for more details.
3.1.2.3 Lake Winnisquam Watershed Survey (2021)
A watershed survey of the Lake Winnisquam watershed was
completed by technical staff from HWand FBE. The objective
of the watershed survey was to identify and characterize sites
contributing NPS pollution and/or providing opportunities to
mitigate NPS pollution in the watershed.
Prior to the field work, HW, FBE, and WWN solicited input from
community members and municipal staff about locations
with known NPS pollution, HW and FBE also analyzed aerial
images and GIS data for land use/land cover, roads, municipal
drainage system, public properties, waterbodies, and other
features. This information enabled the team to better plan for
the survey (e.g., to target known or likely high-polluting sites,
such as unpaved roads, beaches, waterfront parks, highly
impervious areas, and public works facilities) and to inform
recommended solutions.
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I
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is
Plume of sediment washing into Lake Winnisquam from
Batchelder Hill Rd in Meredith in the 1990s, The problem
has since been remediated when the Town paved the
road and installed a sediment forebay.
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LAKE WINNISQUAM WATERSHED-BASED PLAN
HW and FBE conducted the watershed survey in April and May
2021. For each location, field staff recorded site data and
photographs on tablets. Information collected included
location description and GPS coordinates; NPS problem
description and measurements (e.g., gully dimensions);
receiving waterbody; discharge type (direct or
indirect/limited); and preliminary recommendations to
mitigate the NPS problem. Field staff accessed sites
throughout the watershed from public roads and waterfront
access points.
HW and FBE identified over 100 problem sites in the
watershed (AppendixB, Map B-5),The main issues found were
unpaved road and ditch erosion; waterfront park and beach
erosion; buffer clearing; and untreated urban stormwater
runoff. For the sites with recommended stormwater
treatment, erosion control, and/or buffer restoration
practices, HW estimated the potential pollutant removal that
could be achieved by implementing recommendations.
Pollutant load reductions were calculated using the MS4 Permit methodology for stormwater treatment systems4, Region 5
model for gully stabilization5, and NH Green Buffer methodology for buffer restoration6. Table 10 summarizes the potential
sediment and total phosphorus reduction by sub-watershed. A list of all identified sites is provided in Appendix C.
Table 10. Estimated pollutant reduction for structural BMPs by sub-watershed. Only those sites with a measurable reduction
in pollutant loading from recommended remediation are included.
Potential Pollutant Reduction
Number of Sites
Average Annual
Average Annual Total
Sub-watershed
with Recommended
Sediment Load
Phosphorus Load
Improvements
(kg/yr)
(kg/yr)
Black Brook
7
15,948
7.3
Chapman Brook
4
10,741
4.8
Collins Brook
1
1,089
0.5
Dolloff Brook
3
239
0,1
Durgin Brook
8
2,559
1.2
Durkee Brook
9
5,764
2.8
Jewett Brook
7
5,293
2.6
Lake Wicwas Direct
6
4,356
1.9
Lake Winnisquam Direct
25
28,541
14.7
Mill Brook
4
1,872
0.9
Lake Opechee
3
1,051
1.0
Swamp Pond
16
26,593
11.5
Unnamed Tributary (North Trib)
5
6,653
2.8
Winnipesaukee River
3
575
1.0
Total
101
111,274
52.9
Example of a road ditch with accumulated sediment and
vegetation scraped outto maintain hydraulic capacity, as
part of the town's maintenance practices.
4 Load reduction for stormwater treatment systems was estimated using the methodology presented in the NH MS4 General Permit Appendix F,
Attachments
5 For bank or gully stabilization, load reduction was estimated using EPA Region 5 Model for Estimating Pollutant Load Reductions.
6 For restored or constructed buffers, load reduction was estimated using the methodology presented in UNH Stormwater Center "Pollutant Removal
Credits for Restored or Constructed Buffers in MS4 Permits", 2019.
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LAKE WINNISQUAM WATERSHED-BASED PLAN
3.1.2.4 Culvert Assessments (2016.2020.2021)
The New Hampshire Geological Survey (NHGS), NHDES, New Hampshire Department of Transportation (DOT), NHFGD, and
Division of Security and Emergency Management (DOS) have been working together to identify the most vulnerable stream
crossings in the State of New Hampshire to allocate resources for replacement. Culvert assessment data collected in the field
by trained personnel are stored on the Statewide Asset Data Exchange System (SADES) database and are used by NHGS,
NHDES, NHDOT, NHFGD, and DOS to rank crossing structures for their risk of overtopping and failure, degree of aquatic
organism passage, and impacts to stream geomorphology.
In 2016, the LRPC and Plymouth State University (PSU) interns conducted an inventory of 101 culverts on Class V roads not
served by storm drains in Laconia. The inventory followed protocols for data collection according to the SADES Data
Collection Specification Guide for Culverts. Most of the culverts inventoried were old, concrete features with evidence of
degradation through spalling or corrosion (in the case of metal culverts), as well as deformation and joint separation (LRPC,
2016).
In October 2020,11 stream crossings along Black Brook were assessed by Trout Unlimited, as funded through the BCCD. Using
the NHDES Stream Crossing Initiative Protocol, culverts were assessed for their risk of failure due to an undersized passage,
degree of aquatic organism passage, and the crossing's impacts to stream geomorphology. A table of Trout Unlimited's
findings can be found in their 2020 Black Brook Stream Crossing Assessment Summary (Trout Unlimited, 2020). Four (4) of
the 11 stream crossings intercepted Woodman Road, with two containing no passage, one with reduced passage, and the
fourth with only adult trout passage. The Steele Hill Rd stream crossing also contained no passage, while Roxbury and Eagle
Ledge Roads contained reduced passages. Four (4) of the 11 stream crossings contained full passage. Five (5) of the stream
crossings received geomorphic compatibility scores of "partially compatible," while three were "mostly compatible" and two
were "fully compatible". The Eagle Ledge Rd reduced passage stream crossing did not receive a geomorphic compatibility
score.
In April 2021, Trout Unlimited conducted 32 stream crossing assessments in the Lake Winnisquam watershed. The NHDES
Wetlands Mitigation Program also committed their seasonal employees to survey the remaining crossing structures in the
watershed (namely the two urban streams in Laconia) in summer 2021. The assessments followed the NHDES Stream Crossing
Initiative protocol. Scoringfor hydraulic vulnerability, geomorphic compatibility, and aquatic organism passage were notyet
available at the time of this publication.
3.1.2.5 Stream Geomorphic & Habitat Assessment (2010)
A stream geomorphic assessment of the Jewett Brook watershed was completed in 2010 by Bear Creek Environmental, LLC
for the New England District of the US Army Corps of Engineers. The assessment was used to identify stressors on the stream's
ecosystem health and recommend restoration projects for the stream. Six miles of stream channel divided into 14 reaches
were assessed following the Vermont Agency of Natural Resources Protocols. The study found that the major issues along
Jewett Brook included " undersized stream crossings, corridor encroachments, increased stormwater runoff from impervious
surfaces, channel straightening associated with the construction of roads and development, lack of riparian buffers, and
degraded water quality' (Bear Creek Environmental, LLC, 2011). Geomorphic conditions along the downstream portion of
Jewett Brook were rated as "fair" due to evidence of adjustment processes, aggradation, widening, and planform migration.
Jewett Brook has been and is currently " undergoing a channel evolution process in response to large scale changes in its
sediment, slope, and/or discharge associated with the human influences on the watershed." Habitat condition throughout
Jewett Brook was generally rated fair to poor, indicating major or severe departures from reference habitat conditions. Thirty
(30) potential restoration projects were identified, including " river corridor protection through conservation easements or
adoption of fluvial erosion hazard zones, replacing undersized structures causing localized channel instability, improving
riparian buffers and water quality through landowner education and outreach, and improved stormwater treatment" [Rear
Creek Environmental, LLC, 2011).
3.1.3 Shoreline Survey
With assistance from FBE, WWN volunteers conducted a shoreline survey of Lake Winnisquam in the summer of 2020. The
shoreline survey uses a simple scoring method to highlight shoreline properties around the lake that exhibit significant
erosion. This method of shoreline survey is a rapid technique to assess the overall condition of properties within theshoreland
zone and prioritize properties for technical assistance or outreach.
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Eight volunteer teams were used for surveying parcels with lake frontage, documenting the condition of the shoreline for
each parcel using a scoring system that evaluates vegetated buffer, presence of bare soil, extent of shoreline erosion, distance
of structures to the lake, and slope. The ratings were evaluated and adjusted by technical staff at FBE to remove potential
biases among the teams. These scores were summed to generate an overall "Shoreline Disturbance Score" and "Shoreline
Vulnerability Score" for each parcel, with high scores indicating poor or vulnerable shoreline conditions. Photos were taken
at each parcel and were cataloged by tax map-lot number. These photos will provide project stakeholders with a valuable
tool for assessing shoreline conditions over time. It is recommended that a shoreline survey be conducted in mid-summer
every five years to evaluate changing conditions.
A total of 725 parcels were evaluated along the shoreline of Lake Winnisquam in Belmont, Laconia, Meredith, Sanbornton,
and Tilton (Appendix B, Map B-6). The average Shoreline Disturbance Score (Buffer, Bare Soil, and Shoreline Erosion) for the
entire lake was 6.2 (Table 11). About 42% of the shoreline (or 302 parcels) scored 7 or greater. A disturbance score of 7 or
above indicates shoreline conditions that may be detrimental to lake water quality. These shoreline properties tended to
have inadequate buffers, evidence of bare soil, and shoreline erosion. The average Shoreline Vulnerability Score (Distance
and Slope) was 3.9 (Table 11). About 82% (or 593 parcels) scored 4 or greater. A vulnerability score of 4 or greater indicates
that the parcel may have a home less than 150 ft. from the shoreline and a moderate or steep slope to the shoreline. Parcels
with a vulnerability score of 4 or greater are more prone to erosion issues whether or not adequate buffers and soil coverage
are present.
Table 11. Average scores for each evaluated condition criterion and the average Shoreline Disturbance Score and average
Shoreline Vulnerability Score for Lake Winnisquam. Lower values indicate shoreline conditions that are effective at reducing
erosion and keeping excess nutrients out of the lake.
Evaluated Condition
Average Score
Buffer (1-5)
3.1
Bare Soil (1-4)
1.8
Shoreline Erosion (1-3)
1.3
Shoreline Disturbance Score (3-12)
6.2
Distance (0-3)
2.5
Slope (1-3)
1.4
Shoreline Vulnerability Score (1-6)
3.9
The pollutant loading estimates are based on the shoreline survey disturbance scores. Twenty (20) parcels with a score of 11
or greater generate approximately 39 kg of phosphorus load to Lake Winnisquam annually7. If shoreline landowners were to
create adequate buffers and install other shoreline BMPs on these properties (at a 50% BMP efficiency rate), the annual
reduction would be 20 kg of phosphorus. The 282 parcels with scores 7-10, are contributing approximately 82 kg of
phosphorus annually8. Remediation efforts on these properties using a 50% BMP efficiency rate could result in the annual
reduction of 41 kg of phosphorus.
Certain site characteristics, such as slope, can cause shorelines to be naturally more vulnerable to erosion. For example,
parcels along the Sanbornton shoreline scored higher for slope, indicating that the western shores of Lake Winnisquam are
more steeply sloped, and thus, more vulnerable to stormwater runoff and erosion. Tilton in the southern portion of Lake
Winnisquam contains Route 3, which diverts near the lake for a portion of the road's length resulting in more impacted
shoreline buffer scores (less natural and more patchy buffers). Other site characteristics such as structure distance to the lake,
are often a direct consequence of the historic development on that parcel and cannot be easily changed. Shoreline buffers
and amount of exposed soil are more easily changed to strengthen the resiliency of the shoreline to disturbance in the
watershed. In summary, the overall average shoreline condition of Lake Winnisquam is good (average disturbance score
below 7) for erosion issues, with 302 properties (42%) needing to address erosion issues that are impacting the lake. Lake
7 Based on Region 5 model bank stabilization estimate for silt loams, using 100 ft (length) by 5 ft (height) and moderate lateral recession rate of 0.2 ft/yr.
8 Based on Region 5 model bank stabilization estimate for silt loams, using 50 ft (length) by 3 ft (height) and moderate lateral recession rate of 0.1 ft/yr.
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LAKE WINNISQUAM WATERSHED-BASED PLAN
Winnisquam is also generally more prone to erosion issues because many homes are located close to shore and on moderate
to steep slopes (average vulnerability score is 3.9).
Scores should be used to prioritize areas of the shoreline for remediation. Recommendations largely include improving
shoreline vegetated buffers. Encouraging landowners to plant and/or maintain vegetated buffers as a BMP along their
shoreline, particularly in areas of bare soil, will help mitigate erosion and reduce sediment and nutrient loading to the lake.
3.1.4 Soil & Shoreline Erosion
Erosion can occur when ground is disturbed by digging, construction, plowing, foot or vehicle traffic, or wildlife. Rain and
associated runoff are the primary pathways by which eroded soil reaches lakes and streams. Once in surface waters, nutrients
are released from the soil particles into the water column, causing excess nutrient loading to surface waters or cultural
eutrophication. Since development demand near lakes is high, construction activities in lake watersheds can be a large
source of nutrients. Unpaved roads and trails used by motorized vehicles near lakes and streams are especially vulnerable to
erosion. Stream bank erosion can also have a rapid and severe effect on lake water quality and can be triggered or worsened
by upstream impervious surfaces like buildings, parking lots, and roads which send large amounts of high velocity runoff to
surface waters. Maintaining natural vegetative buffers around lakes and streams and employing strict erosion and
sedimentation controls for construction can minimize these effects.
3.1.4.1 Surficial Geology
The composition of soils surrounding Lake Winnisquam reflect the dynamic geological processes that have shaped the
landscape of New Hampshire over millions of years. Some 300 to 400 million years ago, much of the northeastern United
States was covered by a shallow sea; layers of mineral deposition compressed to form sedimentary layers of shale, sandstone,
and limestone (Goldthwait, 1951). Over time, the Earth's crust then folded under high heat and pressure to change the
sedimentary rocks into metamorphic rocks (quartzite, schist, and gneiss parent material). This metamorphic parent material
has since been modified by bursts of molten material intrusions to form igneous rock, including the granite for which New
Hampshire is famous (Goldthwait, 1951). Erosion has further modified and shaped this parent material over the last 200
million years.
The current landscape formed 12,000 years ago, at the end of the Great Ice Age, as the mile-thick glacier over half of North
America melted and retreated, scouring bedrock and depositing glacial till to create the deeply scoured basin of the region's
lakes. The retreating action also eroded mountains and left behind remnants of drumlins and eskers from ancient stream
deposits. The glacier deposited a layer of glacial till more than three feet deep. Glacial till is composed of unsorted material,
with particle sizes ranging from loose and sandy to compact and siltyto gravely. This material laid the foundation for invading
vegetation and meandering streams as the depression basins throughout the region began to fill with water (Goldthwait,
1951).
The unique geological formation in this area formed the Winnipesaukee River Basin Stratified Drift Aquifer - one of the
cleanest and most productive aquifers in the region. Seventeen (17) major aquifers comprise the Winnipesauke River Basin
Stratified Drift Aquifer; one of which is within the Lake Winnisquam watershed (Durkee Brook Aquifer) (Ayotte, 1997). The
aquifer's saturated thickness measured between 20 to 40 ft and the aquifer's transmissivity was recorded at less than 1,000
ft2/day. By receiving groundwater from the Durkee Brook Aquifer (along with other smaller aquifers), Lake Winnisquam is a
discharge point for the Winnipesaukee River Basin Stratified Drift Aquifer. Any contamination in the aquifer will move quickly
to surface waters such as Lake Winnisquam due to the high transmissivity of the material. Therefore, protection of the aquifer
is vital to the protection of the lake.
3.1.4.2 Soils and Erosion Hazard
The soils in the Lake Winnisquam watershed (Appendix B, Map B-7) are a direct result of geologic processes. Of the 42 different
soil series present within the Lake Winnisquam watershed (excluding soils beneath waterbodies), the most prevalent soil
group in the watershed isTunbridge-Lymann Becket complex, very stony (7,190 acres, 20%), followed by Millsite-Woodstock-
Henniker complex, very stony (5,978 acres, 17%), Canterbury Fine Sandy Loam, very stony (2,969 acres, 8%), Gilmanton Fine
Sandy Loam, very stony (1,750 acres, 5%), and Pillsbury Sandy Loam, very stony (1,464 acres, 4%). These soils are all classified
with having very stony material and arewelldrained (Tunbridge-Lymann, Millsite, and Canterbury). The remaining45% ofthe
watershed (excluding the lake area) is a combination of 37 additional soil series ranging from 4% to 0.01% ofthe watershed.
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LAKE WINNISQUAM WATERSHED-BASED PLAN
Soil erosion hazard is dependent on a combination of factors, including land contours, climate conditions, soil texture, soil
composition, permeability, and soil structure (O'Geen et al., 2006). Soil erosion hazard should be a primary factor in
determining the rate and placement of development within a watershed. Soils with negligible soil erosion hazard are
primarily low-lying wetland areas near abutting streams. The soil erosion hazard for the Lake Winnisquam watershed was
determined from the associated slope and soil erosion factor Kw9 used in the Universal Soil Loss Equation (USLE). The USLE
predicts the rate of soil loss by sheet or rill erosion in units of tons per acre per year. A rating of "slight" specifies erosion is
unlikely to occur under standard conditions. A rating of "moderate" specifies some erosion is likely and erosion-control
measures may be required. A rating of "severe" specifies erosion is very likely and erosion-control measures and revegetation
efforts are crucial. A rating of "very severe" specifies significant erosion is likely and control measures may be costly. Excluding
the lake area, "severe" and "very severe" erosion hazard areas account for 45% of the Lake Winnisquam watershed (15,897
acres) and are mostly concentrated in the Meredith and New Hampton portions of the watershed (Appendix B, Map B-8).
Moderate erosion hazard areas account for 39% of the watershed land area (13,764 acres). Slight erosion hazard areas
account for 16% (5,592 acres), and 118 acres or 1% are not rated. Development should be restricted in areas with severe and
very severe erosion hazards due to their inherent tendency to erode at a greater rate than what is considered tolerable soil
loss. Since a highly erodible soil can have greater negative impact on water quality, more effort and investment are required
to maintain its stability and function within the landscape, particularly from BMPs that protect steep slopes from
development and/or prevent stormwater runoff from reaching water resources.
3.1.4.3 Shoreline Erosion
Water level fluctuations in lakes and ponds can occur on long- and short-term timescales due to naturally changing
environmental conditions or as a response to human activity. The effect of lake level fluctuation on physical and
environmental conditions depends on several factors including the degree of change in water level, the rate of change,
seasonality, and the size and depth of the waterbody (Leira & Cantonati, 2008; Zohary & Ostrovsky, 2011). Changes in lake
level can impact flora and fauna mainly by altering available habitat, impacting nesting locations, and altering available food
sources. In addition to impacts to the biological communities, lakes can experience physical impacts on water quality from
changes in lake level. Frequent lake level fluctuations can impact the shoreline, leading to erosion and increased
sedimentation in near-shore habitats, inhibiting light penetration and altering water clarity. Exposed shoreline sediment that
is inundated at high water levels can release phosphorus, leading to alterations in nutrient accumulation and algae
populations. High and low water levels can have detrimental effects on water systems, so finding a balance in managing water
level at appropriate times throughout the year is critical to maintaining a healthy waterbody for both recreational enjoyment
and aquatic life use. Management strategies become even more challenging when considering the impact of increased wake
boating and extreme weather events (droughts and storms) on water level.
For about a week in early August 2021, WWN reported that lake water level was very high, about 8 inches above the normal
high water level, causing docks and raised beaches to be flooded and shorelines to be eroded. The record-high rainfall in July
in the Lake Winnisquam area (and across New England) caused severe dirt road erosion, which moved large amounts of
sediment and organic material into the water, causing beach closures and reduced water clarity. Residents were particularly
concerned about the enhanced shoreline erosion caused by boat wakes while the lake was experiencing abnormally high
water level. Since the start of the pandemic, residents have also reported an increase in the number of boaters on the lake
and a corresponding increase in shoreline erosion exposing tree roots.
3.1.5 Wastewater
Untreated discharges of sewage (domestic wastewater) are prohibited regardless of source. An example of an NPS discharge
of untreated wastewater is from insufficient or malfunctioning subsurface sewage treatment and disposal systems,
commonly referred to as septic systems, but which also include holding tanks and cesspools. When properly designed,
installed, operated, and maintained, septic systems can reduce phosphorus concentrations in sewage within a zone close to
the system (depending on the development and maintenance of an effective biomat, the adsorption capacity of the
underlying native soils, and proximity to a restrictive layer or groundwater). Age, overloading, or poor maintenance can result
in system failure and the release of nutrients and other pollutants into surface waters (EPA, 2016). Nutrients from insufficient
septic systems can enter surface waters through surface overflow or breakout, stormwater runoff, or groundwater. Cesspools
9 Kw = the whole soil k factor. This factor includes both fine-earth soil fraction and large rock fragments.
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LAKE WINNISQUAM WATERSHED-BASED PLAN
are buried concrete structures that allow solid sludge to sink to the bottom and surface scum to rise to the top and eventually
leak out into surrounding soils through holes at the top of the structure. Holding tanks are completely enclosed structures
that must be pumped regularly to prevent effluent back-up into the home.
Lake Winnisquam was historically impacted by the dumping of untreated effluent from the City of Laconia's primary
wastewater treatment plant, which was built in 1952 to collect wastewater from homes and businesses in the rapidly
developing area. The excessive nutrients in the untreated effluent spurred severe blooms in the lake throughout the 1950s
and 1960s. In 1959, the Lakes Region Clean Waters Association was formed and through many years of persistent grassroots
efforts from community members, a $1 million dollar grant was secured from the EPA under the CWA Construction Grants
Program to establish the Winnipesaukee River Basin Program (WRBP), a state-owned sewer system with a wastewater
treatment plant in Franklin. The sewer system went online in 1976 and processed sewage from several municipalities in the
area. The plant is located outside the watershed, but there are several pump-out stations and a maintenance facility in the
watershed, along with the connecting sewer lines. The sewer system serves over 14,500 residential connections in 10
communities. WRBP owns and maintains the main sewer line and pump stations that convey the sewage from each
community to the plant. The sewer infrastructure that connects homes and businesses to the main sewer line is owned and
maintained by each respective municipality or by private owners. WRBP is funded by each municipality through the sewer tax
bill collected. Nearly half of the shoreline area of Lake Winnisquam is serviced by sewer systems, which represents a
potential vulnerability if the sewer systems are old or damaged and leaking wastewater into groundwater near the
lake.
In 2021, WWN compiled septic system data for Lake Winnisquam shoreline properties (within 250 ft of Lake Winnisquam),
including date house built, date of most recent septic installation or upgrade, number of bedrooms, and seasonal or year-
round use, if available (otherwise assumed year-round). For the towns of Tilton, Belmont, Meredith, and Sanbornton, WWN
visited town offices and reviewed tax record information to glean relevant septic system information not found through
online records. The City of Laconia provided septic system data to WWN directly. Septic system survey findings are
summarized in Table 12. WWN identified 1,027 parcels within 250 ft of Lake Winnisquam (includes all developed and vacant
parcels), 365 of which were found to be using septic systems for wastewater treatment. An estimated 39% of those septic
systems were over 25 years old. The public survey conducted by WWN (see Section 1.4.3) also found that many systems
were not up to code and were likely cesspools. WWN's online survey noted cesspools on Mohawk Island as concerning for
water quality.
Shoreline septic systems were estimated to contribute 86 kg/yr of total phosphorus loading to Lake Winnisquam, comprising
1% of the total load to the lake (refer to Section 2.3.1 and FBE, 2021a). Despite the relatively minor load estimated for septic
systems around the lake, numerous septic systems, cesspools, or holding tanks are located within a short distance to the
water, leaving little horizontal (and sometimes vertical) space for proper filtration of wastewater effluent. Improper
maintenance or siting of these systems can cause failures, which leach untreated, nutrient-rich wastewater effluent directly
to the lake. This effluent contains not only nutrients and bacteria but also microplastics, pharmaceuticals, and other
pollutants harmful to public health.
Table 12. Summary of septic system data for properties along the shoreline of Lake Winnisquam. Note: The number of
shoreline parcels within 250 ft of Lake Winnisquam (and subsequent percentages) include vacant lots.
Shoreline
Number Of
Percent Of
Number Of
Percent Of
Municipality
Parcels (within
Shoreline
Shoreline
Septic Systems
Septic Systems
250 Ft of Lake
Properties on
Properties on
Older Than 25
Older Than 25
Winnisquam)
Septic
Septic
Years
Years
TILTON
101
0
0%
0
0%
BELMONT
180
8
4%
Unknown
Unknown
MEREDITH
173
157
91%
36
23%
SANBORNTON
182
63
35%
38
60%
LACONIA
391
137
35%
69
50%
TOTAL
1,027
365
36%
143
39%
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LAKE WINNISQUAM WATERSHED-BASED PLAN
3.1.6 Fertilizers
When lawn and garden fertilizers are applied in excessive amounts, in the wrong season, or just before heavy precipitation,
they can be transported by rain or snowmelt runoff to lakes and other surface waters where they can promote cultural
eutrophication and impair the recreational and aquatic life uses of the waterbody. Many states and local communities are
beginning to set restrictions on the use of fertilizers by prohibiting their use altogether or requiring soil tests to demonstrate
a need for any phosphate application to lawns.
WWN's online survey showed that about 42% of respondents used fertilizers on their lawns, with 33% applying 1-2 times per
year, 7% applying 3-4 times per year, and 2% applying five or more times per year. Most respondents (53%) were not using
different application practices near shoreland areas. Tardiff Park along Jewett Brook was identified as a potential source of
nutrients due to observation of grass clippings in the channel and minimal buffer between the stream and park lawn (fertilizer
use unknown), downstream of which was a significant algal bloom in the stream (Bear Creek Environmental, LLC, 2011). The
municipalities of New Hampton, Meredith, Laconia, and Tilton indicated that no fertilizers are used on public land.
Sanbornton hires Swain Landscaping, who likely does not use fertilizer, for maintaining public land in town. Gilford hired
Boucher Landscape Company for mowing and clipping and Belknap Landscape for lawn and garden treatments at the town
hall, fire department, Department of Public Works (DPW) facility, and cemeteries. Treatment at cemeteries is conducted in
May/June and September/October with a broad leaf weed control and slow release fertilizer. Treatment at the town hall is
conducted with Holganixl00% organic bionutritionalfertilizerforturf.
There are also several golf courses within the Lake Winnisquam watershed that use fertilizer: (1) Oak Hill Golf Course uses
Opti-45 fertilizer on the greens; (2) Laconia Country Club & Golf Course uses low or zero phosphorus products of blended
organic and synthetics of historically granular but now liquid form (for direct feeding); and (3) Lakeview Golf Course was
closed and sold in April 2021 to Stone Bluff Property Holdings LLC of Northfield, NH and reopened as a golf course again in
late 2021; they currently use Nature Safe 8-35 Stress Guard fertilizer with 3% available phosphate.
3.1.7 Agriculture
Agriculture in the Lake Winnisquam watershed includes cropland and livestock grazing pasture. Agricultural activities,
including dairy farming, raising livestock and poultry, growing crops, and keeping horses and other animals for pleasure or
profit, involve managing nutrients.
Agricultural activities and facilities with the potential to contribute to nutrient impairment include:
• Plowing and earth moving;
• Fertilizer and manure storage and application;
• Livestock grazing;
• Animal feeding operations and barnyards;
• Paddock and exercise areas for horses and other animals; and
• Leachatefrom haylage/silage storage bunkers.
Diffuse runoff of farm animal waste from land surfaces (whether from manure stockpiles or cropland where manure is spread),
as well as direct deposition of fecal matter from farm animals standing or swimming in surface waters, are significant sources
of agricultural nutrient pollution in surface waters. Farm activities like plowing, livestock grazing, vegetation clearing, and
vehicle traffic can also result in soil erosion which can contribute to nutrient pollution.
Excessive or ill-timed application of fertilizer or poor storage which allows nutrients to wash away with precipitation not only
endangers lakes and other waters, it also means those nutrients are not reaching the intended crop. The key to nutrient
application is to apply the right amount of nutrients at the right time. When appropriately applied to soil, synthetic fertilizers
or animal manure can fertilize crops and restore nutrients to the land. When improperly managed, pollutants in manure can
enter surface waters through several pathways, including surface runoff and erosion, direct discharges to surface water, spills
and other dry-weather discharges, and leaching into soil and groundwater. BCCD was unaware of any active issues with
agricultural practices impacting water quality in the watershed and noted that farmers may not be working with Natural
Resource Conservation Service (NRCS) to review agricultural practices unless they are receiving NRCS funding. A respondent
through WWN's online survey noted that horse waste may be impacting a stream along Oak Hill Rd in Sanbornton. Hunkins
Pond is also very likely impacted by agricultural runoff.
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3.1.8 Pets
In residential areas, fecal matter from pets can be a significant contributor of nutrients to surface waters. Each dog is
estimated to produce 200 grams of feces per day, which contain concentrated amounts of phosphorus (CWP, 1999). If pet
fecesare not properly disposed, these nutrients can be washed off the land and transported to surface waters bystormwater
runoff. Pet feces can also enter surface waters by direct deposition of fecal matter from pets standing or swimming in surface
waters. Dog waste left along Collins Brook Rd in Meredith and along the fire access road between Weed Rd and Waldron Bay
Association was noted in WWN's online survey as a problem area.
3.1.9 Future Development
Understanding population growth, and ultimately development patterns, provides critical insight to watershed
management, particularly as it pertains to lake water quality. After a declining population trend from 1860 to 1900, the
population of the seven watershed municipalities started growing, especially Laconia which grew rapidly from 1870 to 1950
and continued growing steadily over the last 50 years (US Census Bureau, 2022). The other six municipalities started growing
significantly in population from 1970 to 2020 (Figure 13). The Lake Winnisquam watershed area has long been treasured as a
recreational haven for both summer vacationers and year-round residents. The area is among the oldest summer vacation
spots in New Hampshire and offers fishing, hiking, boating, sailing, canoeing, kayaking, and swimming in the summer, and
ice fishing, cross-country skiing, snowshoeing, and snowmobiling in the winter. The desirability of Lake Winnisquam and the
greater Lake Winnipesaukee area as a recreational destination will likely stimulate continued population growth in the future.
Growth figures and estimates suggest that these seven municipalities should continue to consider the effects of current
municipal land-use regulations on local water resources. As the region's watersheds are developed, erosion from disturbed
areas increases the potential for water quality decline.
Belmont Gilford Laconia Meredith New Hampton Sanbornton —Tilton
Figure 13. Historical demographic data for the municipalities of Belmont, Gilford, Laconia, Meredith, New Hampton,
Sanbornton, and Tilton in the Lake Winnisquam watershed. The population of this community has grown dramatically over
the last 50 years. *2020 official census data is only available for municipalities with populations greater than 5,000people, as of the writing of this plan.
3.2 POTENTIAL CONTAMINATION SOURCES
Point source pollution can be traced back to a specific source such as a discharge pipe from an industrial facility, municipal
treatment plant, permitted stormwater outfall, or a regulated animal feeding operation, making this type of pollution
relatively easy to identify. Section 402 of the CWA requires all such discharges to be regulated under the NPDES program to
control the type and quantity of pollutants discharged. NPDES is the national program for regulating point sources through
issuance of permit limitations specifying monitoring, reporting, and other requirements under Sections 307, 318, 402, and
405 of the CWA.
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LAKE WINNISQUAM WATERSHED-BASED PLAN
NHDES operates and maintains the OneStop database and data mapper, which houses data on Potential Contamination
Sources (PCS) within the State of New Hampshire. Identifying the types and locations of PCS within the watershed may help
identify sources of pollution and areas to target for restoration efforts. Downloaded and filtered for the Lake Winnisquam
watershed, these data identify potential sources of pollution to the Lake Winnisquam (Figure 14). On 1/05/2020, FBE
downloaded datasets for aboveground storage tanks, underground storage tanks, automobile salvage yards, solid waste
facilities, hazardous waste sites, local potential contamination sources, NPDES outfalls, and remediation sites.
3.2.1 Above and Underground Storage Tanks
Above and underground storage tanks include permitted containers with oil and hazardous substances such as motor fuels,
heating oils, lubricating oils, and other petroleum and petroleum-contaminated liquids. There are 39 aboveground storage
tanks within the Lake Winnisquam watershed. Two can be found in Belmont, one in Gilford, 30 in Laconia, five in Sanbornton,
and one in Tilton. There are 139 underground storage tanks within the Lake Winnisquam watershed. Eight can be found in
Belmont, eight in Gilford, 109 in Laconia, one in Meredith, five in Sanbornton, and five in Tilton. Ownership of these tanks
range from auto salvage yards, auto dealerships, commercial industries, hospitals, industrial facilities, marinas, petroleum
distributors, utilities, municipal, local, and state governments, and more.
3.2.2 Automobile Salvage Yards
There are two automobile salvage yards within the Lake Winnisquam watershed that either contain at least 12 "end-of-life"
vehicles annually or at least 25 vehicles for more than 60 days at a time. The Reed's Auto Wrecking Co. located in Laconia and
Al's Used Parts in Belmont are currently registered with the NHDES Greenyards Program as active.
3.2.3 Solid Waste Facilities
There are two solid waste facilities within the Lake Winnisquam watershed. One, the Frank Bean Rd Site, is a closed, unlined
landfill no longer under operation, while the other is the Laconia Transfer Station which is currently under operation for
collection, storage, and transfer of waste.
3.2.4 Hazardous Waste Sites
Hazardous waste generating facilities are identified through the EPA's Resource Conservation and Recovery Act (RCRA) and
either require federal or state regulation. Only 41 of the 135 hazardous waste generating facilities within the Lake Winnisquam
watershed are listed as active; the remaining facilities are classified as either inactive (64), declassified (22), classified (7), or
non-notifier (1). Of the 41 active hazardous waste sites, six can be found in Belmont, two in Gilford, 30 in Laconia, two in
Sanbornton, and one in Tilton.
3.2.5 Local Potential Contamination Sources
Local potential contamination sources are sites that may represent a hazard to d rinking water quality supplies due to the use,
handling, or storage of hazardous substances. There may be overlap between local potential contamination sources and
other PCS identified in this section. Of the 26 local potential contamination sources within the Lake Winnisquam watershed,
nine can be found in Belmont, three in Gilford, 10 in Laconia, one in Meredith, and three in Tilton.
3.2.6 NPDES Outfalls
Of the nine NPDES outfalls that discharge pollutants directly to a surface water within the Lake Winnisquam watershed, only
one is actively discharging (General Permit #NH0022730). Located along Durkee Brook, the Scotia Technology facility is
characterized as a facility that processes wastewater, although the water discharging from the outfall is "Non-Contact Cooling
Water" and "no toxic discharge, so no dilution factor" is needed (NHDES Outfalls Metadata).
3.2.7 Remediation Sites
The 295 remediation sites present within the Lake Winnisquam watershed consist of leaking storage facilities that contain
fuel or oil, sites with chlorinated solvents and other non-petroleum products, non-hazardous and non-sanitary holding tanks,
initial spill response sites, historical dump sites, leaking residential or commercial oil tanks for heating or motor oil tanks,
underground injection control of wastewaters not requiring a groundwater discharge permit, unlined wastewater lagoons,
or a flagged groundwater sample for contamination but with no direct connection to a source of contamination. Of the 295
remediation sites, 58 are identified in Belmont, 24 in Gilford, 170 in Laconia, 15 in Meredith, one in New Hampton, 16 in
Sanbornton, and 11 in Tilton.
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LAKE WINNISQUAM WATERSHED-BASED PLAN
FB
environmental
Data Source: NH Granit,
NHD.NWI, ESRI, NHDES
I Coordinate System: NAD 1983
" * ^ State Plane NH FIPS 2800 ft
Map Created By: C. Bunyon
FB Environmental
Date Created: 1/13/2021
Potential Sources
of Contamination
Lake Winnisquam
Watershed Based
Management Plan
Lake Winnisquam Watershed
*£—|
Town Boundary
State Road
— Local Road
Private Road
— Unmaintained Road
Waterbody
Stream/River
Wetland
/S\ Solid Waste Facility
A Flazardous Waste Generator
Q Aboveground Storage Tank
D Underground Storage Tank
• NPDES Outfall
Automobile Salvage Yard
^ Local Potential
Contamination Source
Q Remediation Sites
Tilton
Belmont
Gilmanton
Northfield
ESRI World Imagery 0 0.5 1 2
captured on 3/27/2020 Miles
Center Harbor
New Hampton
Sanbornton
Laconia
Gilford
Figure 14. Potential sources of contamination in the Lake Winnisquam watershed.
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LAKE WINNISQUAM WATERSHED-BASED PLAN
3.3 WILDLIFE
Fecal matter from wildlife such as geese, gulls, other birds, and beaver may be a significant source of nutrients in some
watersheds. This is particularly true when human activities, including the direct and indirect feeding of wildlife and habitat
modification, result in the congregation of wildlife (CWP, 1999). Congregations of geese, gulls, and ducks are of concern
because they often deposit their fecal matter next to or directly into surface waters. Examples include large mowed fields
adjacent to lakes and streams (such asatOpechee Park, Laconia Country Club, or Oak Hill Golf Course) where geese and other
waterfowl gather, as well as the underside of bridges with pipes or joists directly over the water that attract large numbers of
pigeons or other birds. Studies show that geese inhabiting riparian areas increase soil nitrogen availability (Choi et al., 2020)
and gulls along shorelines increase phosphorus concentration in beach sand pore water that then enters surface waters
through groundwater transport and wave action (Staley et al. 2018). When submerged in water, the droppings from geese
and gulls quickly release nitrogen and phosphorus into the water column, contributing to eutrophication in freshwater
ecosystems (Mariash et al., 2019). On a global scale, fluxes of nitrogen and phosphorus from seabird populations have been
estimated at 591 Gg N per year and 99 Gg P per year, respectively (with the highest values derived from arctic and southern
shorelines) (Otero et al., 2018). Additionally, other studies show greater concentrations of nitrogen, ammonia, and dissolved
organic carbon downstream of beaver impoundments when compared to similar streams with no beaver activity in New
England (Bledzki et al., 2010). The model estimated that waterfowl are likely contributing 8.5 kg/yr (4%) of the total
phosphorus load to Lake Winnisquam (FBE, 2021a).
3.4 CLIMATE CHANGE
Climate change will have important implications for water quality that should be considered and incorporated into WBPs. In
the last century, New England has already experienced significant changes in stream flow and air temperature. Out of 28 rural
stream flow stations throughout New England, 25 showed increased flows over the record likely due to the increase in
frequency of extreme precipitation and total annual precipitation in the region. In 79 years of recorded flooding in the Oyster
River in Durham, NH, three of the four highest floods occurred in the past 10 years (Ballestero et al., 2017). Average annual air
temperature in New England has risen by l°Cto2.3 °C since 1895 with greater increases in winter air temperature (IPCC, 2013).
Lake ice-out dates are occurring earlier as warmer winter air temperature melts the snowpack and lake ice; earlier ice-out
allows a longer growing season and increases the duration of anoxia in bottom waters. Increasing storm frequencies will flush
more nutrients to surface waters for algae to feed on and flourish under warmer air temperatures.
These trends will likely continue to impact both water quality and quantity. Climate change models predict a 10-40% increase
in stormwater runoff by 2050, particularly in winter and spring and an increase in both flood and drought periods as seasonal
precipitation patterns shift. Adding to this stress is population growth and corresponding development in New Hampshire.
The build-out analysis for the watershed showed that about 15,027 acres is still developable and up to 6,734 new buildings
could be added to the watershed at full build-out based on current zoning standards. Lake Winnisquam is at risk for water
quality degradation because of new development in the watershed unless climate change resiliency and low impact
development (LID) strategies are incorporated into existing zoning standards.
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LAKE WINNISQUAM WATERSHED-BASED PLAN
4 MANAGEMENT STRATEGIES
The following section details management strategies for achieving the water quality goal and objectives using a combination
of structural and non-structural restoration techniques, as well as outreach and education and an adaptive management
approach. A key component of these strategies is the idea that existing and future development can be remediated or
conducted in a manner that sustains environmental values. All stakeholder groups have the capacity to be responsible
watershed stewards, including citizens, businesses, the government, and others. Specific action items are provided in the
Action Plan (Section 5).
4.1 STRUCTURAL MONPOINT SOURCE (NFS) RESTORATION
Structural NPS restoration techniques are engineered infrastructure designed to intercept stormwater runoff, often allowing
it to soak into the ground, be taken up by plants, harvested for reuse, or released slowly over time to minimize flooding and
downstream erosion. These BMPs often incorporate some mechanism for pollutant removal, such as sediment settling
basins, oil separators, filtration, or microbial breakdown. They can also consist of removing or disconnecting impervious
surfaces, which in turn reduces the volume of polluted runoff generated, minimizing adverse impacts to receiving waters.
4.1.1 Watershed & Shoreline BMPs
Over 100 NPS sites identified during the 2021 watershed survey
and 302 high/medium impact rated shoreline properties from
the 2020 shoreline survey were documented to have some
impact to water quality through the delivery of phosphorus-
laden sediment (refer to Section 3.1.2 and 3.1.3). As such,
structural BMPs to reduce the external watershed phosphorus
load are a necessary and important component for the
protection of water quality in the watershed.
The following series of BMP implementation action items are
recommended for achieving Objectives 1 and 3 (see Action
Plan in Section 5 for more details):
• Remediate stormwater runoff through infrastructure
rehabilitation in the Hueber Brook sub-watershed to
Lake Winnisquam to remove Lake Winnisquam's ALI
impairment listing.
• Address the top 24 high priority sites (and the remaining 84 medium and low priority sites as opportunities arise)
identified during the 2021 watershed survey. The 108 sites were ranked based on phosphorus load reduction and
waterbody proximity. Table 13 presents the recommended improvements and corresponding pollutant load
reductions for the top 24 high priority sites. The full prioritization matrix is provided in Appendix C. Conceptual
designs for three ofthetop24 high priority sites are provided below. Design and implementation for these three sites
are currently underway through a NHDES 319 Watershed Assistance Grant (2022-23) awarded to WWN. These sites
will be used as models for other similar sites in the watershed.
• Address road erosion control measures identified in Lang (2021) and FBE (2022). BCCD and WWN plan to pursue grant
funding for the design and remediation of erosion sites in the Black Brook sub-watershed.
• Provide technical assistance and/or implementation cost sharing to 20 high impact shoreline properties identified
during the 2020 shoreline survey. Encourage landowners to implement stormwater and erosion controls on the 282
medium impact shoreline properties identified during the 2020 shoreline survey. Workshops and tours of
demonstration sites can help encourage landowners to utilize BMPs on their own property. Conduct regular
shoreline surveys to continue prioritizing properties for technical follow-up. WWN will be working with NH Lakes
through the LakeSmart Program to educate homeowners on lake-friendly landscaping and stormwater control
practices.
Example of structural BMPs installed at the Sanbornton
Town Beach.
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LAKE WINNISQUAM WATERSHED-BASED PLAN
For the proper installation of structural BMPs in the watershed, WWN and other stakeholders should work with experienced
professionals on sites that require a high level of technical knowledge (engineering). Whenever possible, pollutant load
reductions should be estimated for each BMP installed. More specific and additional recommendations (including public
outreach) are included in Section 5. For helpful tips on implementing BMPs, see Additional Resources.
Table 13. Top 24 high priority structural BMP sites in the Lake Winnisquam watershed.
Potential Pollutant Reduction
Site
ID
Average Annual
Average
Site Description
Municipality
Recommendations
Sediment Load
Annual TP
(kg/yr)
Load (kg/yr)
1-12
Gale Ave - small
Laconia
Install a bioretention basin within the park to treat
pocket park with
runoff from Gale Ave. Stabilize eroded areas,
2,282
1.6
access to lake
improve buffer.
2-05
Swain Rd at
Gilford
Armor ditch with stone or grass, Install turnout,
Jewett Brook
Reshape ditch, Stabilize banks, Install runoff
1,361
0.8
crossing
diverter, Plant/improve buffer
3-10
Chemung Rd
Meredith
Armor ditch with stone or grass, Reshape ditch,
Reshape or crown road, Reshape/vegetate shoulder
1,633
0.7
3-11
Roxbury Rd
Meredith
Armor ditch with stone or grass, Reshape ditch,
Reshape or crown road, Reshape/vegetate shoulder
2,195
0.9
3-12
Stoney Brook Rd
Meredith
Reshape or crown road, Reshape/vegetate
shoulder, Clean out and stabilize plow pile area
3,024
1.3
3-13
Stoney Brook Rd,
Meredith
Armor ditch with stone or grass, Reshape ditch,
crossing with river
Reshape or crown road, Reshape/vegetate
shoulder, Investigate geomorphic stability of river
1,597
0.7
3-14
Deer Park
Association beach
Meredith
Reshape or crown road, Reshape/vegetate
shoulder, Restore sediment forebay, Install rain
on Weed Rd
garden, tiered landscaping, infiltration steps;
Improve buffer, Install turnouts on south access
road to lake
1,597
0.7
3-16
Weed Rd
Meredith
Armor ditch with stone or grass, Reshape ditch,
Reshape or crown road, Reshape/vegetate
shoulder, Improve buffer
1,814
0.8
3-20
New road
Meredith
Armor ditch with stone or grass, Reshape ditch,
construction off
Reshape or crown road, Reshape/vegetate shoulder
1,996
0.8
Batchelder Hill Rd
3-21
Eagle Ledge Rd
Meredith
Armor ditch with stone or grass, Reshape ditch,
intersection with
Reshape or crown road, Reshape/vegetate shoulder
3,592
1.5
Batchelder Hill Rd
3-22
Eagle Ledge Rd,
Sanbornton
Stabilize inlet and/or outlet, Armor ditch with stone
Black Brook
or grass, Reshape ditch, Reshape or crown road,
2,395
1.0
crossing
Reshape/vegetate shoulder
3-23
Kaulback Rd and
Sanbornton
Stabilize inlet and/or outlet, Replace/enlarge
Roxbury Rd
culvert, Armor ditch with stone or grass, Reshape
ditch, Reshape or crown road, Reshape/vegetate
shoulder
3,393
1.4
3-24
Lower Bay Rd and
Sanbornton
Armor ditch with stone or grass, Reshape ditch,
2,776
1.4
Huse Rd
Reshape or crown road, Reshape/vegetate shoulder
3-25
Woodman Rd
Sanbornton
Stabilize inlet and/or outlet, Armor ditch with stone
2,159
1.1
or grass, Reshape ditch, Reshape/vegetate shoulder
3-26
Woodman Rd
Sanbornton
Armor ditch with stone or grass, Reshape ditch,
Reshape/vegetate shoulder, Divert driveway runoff,
Enhance and stabilize buffer between road and
stream
1,597
0.7
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LAKE WINNISQUAM WATERSHED-BASED PLAN
Potential Pollutant Reduction
Site
ID
Site Description
Municipality
Recommendations
Average Annual
Sediment Load
(kg/yr)
Average
Annual TP
Load (kg/yr)
3-28
Woodman Rd
intersection with
Steele Hill Rd
Sanbornton
Stabilize inlet and/or outlet, Armor ditch/turnouts
with stone or grass with check dams, Reshape ditch,
Reshape or crown road, Reshape/vegetate shoulder
3,629
1.5
3-30
Chapman Rd
Sanbornton
Stabilize inlet and/or outlet, Armor ditch with stone
or grass, Reshape ditch, Reshape or crown road,
Reshape/vegetate shoulder
1,996
0.8
3-31
Philbrook Rd
Sanbornton
Stabilize inlet and/or outlet, Armor ditch with stone
or grass, Reshape ditch/turnouts, Reshape or crown
road, Reshape/vegetate shoulder
2,395
1.0
3-32
Philbrook Rd
Sanbornton
Stabilize inlet and/or outlet, Armor ditch with stone
or grass, Reshape ditch/turnouts, Reshape or crown
road, Reshape/vegetate shoulder
1,361
0.8
3-34
Bay Rd
Sanbornton
Stabilize parking area, pull-off area, and access
ramps
4,990
2.1
3-36
Doctor True Rd
and Maple Circle
Sanbornton
The Town is considering paving Dr True Rd and
Maple Circle to address erosion and travel issues. If
paving moves forward, evaluate BMPs to manage
sand and salt from newly paved roads.
9,273
4.6
4-06
Old Stage Rd
culvert
Meredith
Install turnout, Reshape ditch, Reshape/vegetate
shoulder, Reshape or crown road, Install runoff
diverter
1,814
0.8
4-08
Intersection of Rt
104 and Hatch
Corner Rd
Meredith
Remove wintersand, Install erosion controls (e.g.,
silt fence), Armor ditch with stone or grass
1,814
0.8
4-09
Dow Rd, near
intersection with
Rt 104
Meredith
Armor ditch with stone or grass, Install erosion
controls (e.g., silt fence)
1,814
0.8
4.1.2 Conceptual Designs for Select Priority Structural BMP Sites (2021)
For sites ranked as high priority for structural BMPs, WWN consulted with landowners and municipalities to assess their
willingness to implement the recommended stormwater improvements. The team then selected three high priority sites to
carryforward for conceptual design. In addition to water quality performance and municipal/landowner support, these sites
were selected based on their potential to demonstrate replicable solutions for the key NPS issues observed in the watershed:
urban stormwater runoff, unpaved road and ditch erosion, and private waterfront erosion. The conceptual designs presented
herein represent planning level recommendations for stormwater management improvements at each site, along with
planning level estimates of costs10 and potential phosphorus load reduction11. The overarching goal of proposed
improvements is to reduce phosphorus loading into Lake Winnisquam. These designs seek to accomplish phosphorus
reduction by reducing erosion and by treating stormwater runoff using structural stormwater control measures (SCMs).
Secondarily, these designs aim to demonstrate replicable NPS management practices, maintain existing site uses, preserve
and enhance ecological resources, minimize long-term maintenance requirements, and educate the public about water
quality and stormwater management. Construction-ready design and implementation for these three sites are currently
underway through a NHDES 319 Watershed Assistance Grant (2022-23) awarded to WWN. WWN plans to work with local
partners to complete the designs at each site.
10 Planning-level costs were estimated using EPA Region 1 (2016) Methodology for Developing Cost Estimates for Opti-Tool, NHDOT and MassDOT unit prices,
and best professional judgement. Costs include 25% contingency and are expressed in 2021 dollars.
11 Phosphorus reduction was estimated using NH MS4 Permit Appendix F, EPA Region 5 Erosion Control Model, and UN H Stormwater Center (2019) Pollutant
Removal Credits for Restored or Constructed Buffers in MS4 Permits.
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Gale Ave Park, Laconia, NH
Existing Site Description: Gale Ave Park is a small public park on
Lake Winnisquam at the end of Gale Ave in Laconia. The park is
accessed from Gale Ave by sidewalks that extend into the park to the
south and north. The park features two stone benches and a lawn
area. Along the 80-ft shoreline, there is a concrete block remaining
from a former wharf, a small, vegetated area, and a small beach-like
section that slopes down to the water. The Laconia Department of
Parks and Recreation is developing plans for a shoreline retaining
wall, an accessible paved path, and a kayak launch. Stormwater
runoff from Gale Ave and adjacent residential properties appears to
bypass storm drains along Gale Ave and flow into shallow swales
along the north and south edges of the park. Further investigations
are needed to determine the cause(s) and amount of bypass. The
swales are significantly eroded, particularly at the end of the swale to
the south. A drainage outfall is located to the north of the park. A
sanitary sewer extends from Gale Ave into the park, where there are
two sewer manholes. Soils at the site are categorized as hydrologic
soil group (HSG) C, indicating moderate infiltration capacity.
Proposed Improvements:
• Collect stormwater runoff entering the park with a paved intet flume and route flow into a sediment forebay and
bioretention basin to manage low-flow storm events. The bioretention basin will include an overflow spillway to
route excess flows into a vegetated swale to the north. Plantings for the bioretention basin will include generally
low-growing and tow-maintenance species.
• Convert the eroded swale to the north into a vegetated swale to carry flow from the bioretention basin to the
lake. Plantings for the swale will include low maintenance grasses, sedges, and rushes such as Common Rush
(Juncuseffuses), Prairie Dropseed (Sporobolus heterolepis), and Northern Sea Oats (Chasmanthiumlatifolium).
• Transition the swale to meet a level spreader and stone apron for energy dissipation. Between the stone apron
and the shoreline, plant dense groundcover vegetation.
• Restore the eroded swale to the south with loam and seed to match surrounding lawn.
• Install educational signage about water quality and stormwater management.
• Integrate the bioretention and swale design with park improvements planned by Laconia Parks and Recreation.
Operation and Maintenance: Operation and maintenance (O&M) for the proposed bioretention basin and swale is
anticipated to incur 20 hours annually. Typical O&M includes routine inspections, preventative maintenance, and
corrective actions, such as the following:
1) Clean out trash, debris, and accumulated sediment from inlet, forebay, bioretention basin, spillway, and
swale.
2) Maintain vegetation (weeding, replanting, etc.) and water plants during establishment period.
3) Check for erosion within and downstream of facility; stabilize areas of erosion, if found.
4) Check for standing water (lack of drainage) in the bioretention basin. Investigate and correct clogging if the
basin does not drain within 48 hours following a rain event.
Operation and maintenance for bioretention systems, as provided in EPA Region 1 (2016) Methodology for
Developing Cost Estimates for Opti- Too/
Shoreline of Gale Ave Park.
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LAKE WINNISQUAM WATERSHED-BASED PLAN
SITE SUMMARY
Outlet to swale
Regrade and vegetate
eroded channel
Level spreader and
stone apron for energy
dissipation
Owner: City of Laconia
Receiving Water: Lake Winnisquam
Estimated Phosphorus Load Reduction: 1.6 kg/year
Estimated Costs: Capital costs: $39,000-$47,000
Annual operation and maintenance costs: $2,000
20-year life cycle cost: $83,000
Inicl and
-m sediment
forebay
Rain garden (bioretention
basin) with low-growing,
low-maintenance plants
Suibiiiroc sv/dk-
S-
Dense low-growing S
vegetation
rii ii
® Ii' il
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LAKE WINNISQUAM WATERSHED-BASED PLAN
Deer Park Beach, Meredith, NH
SITE SUMMARY
Owner: Deer Pa rk Association
Receiving Water: Lake Winnisquam
Estimated Phosphorus Load Reduction: 0.7 kg/year
Estimated Costs: Capital costs: $65,000-$79,000
Annual operation and maintenance costs: $3,000
20-year life cycle cost: $132,000
Existing Site Description: Deer Park Beach is a private beach and boat launch on Lake Winnisquam in Meredith.
The beach is accessed via granite steps off Weed Rd, opposite Heritage Rd, and an unpaved driveway to the south.
The beach is owned by Deer Park Association, which consists of 28 member households. The beach is used
primarily for boat launching. The driveway is gated and only members have the lock combination. Daily use rarely
exceeds 10 people on any given day. Some members use golf carts to access the beach, a few use cars, and many
walk to the site. The beach features an unpaved parking area, a permanent canoe/kayak rack, a sandy beach, and a
paved boat ramp. The parking area is located to the north of the driveway. Cars typically park nose-in toward the
post and beam fence. The parking area is not heavily used, and neither the driveway nor parking area are
maintained during the winter. It appears that sediment-laden runoff from Heritage Rd, an unpaved private way,
bypasses catch basins at the intersection with Weed Rd and continues downhill toward the granite steps into Deer
Park Beach. Erosion is evident alongside the steps, likely caused both by runoff and pedestrian traffic. Runoff from
Weed Rd collects in a shallow swale on the east side of Weed Rd and flows south. This runoff was formerly diverted
into a sediment forebay at the top of the slope just north of the access driveway. Due to sediment buildup at the
diversion point on Weed Rd, the runoff now continues along Weed Rd to the beach driveway, where it turns the
corner and flows down the drive. The driveway frequently erodes. Two deep gullies formed along the driveway
during heavy rains in July 2021. Erosion is also evident on the north side of the paved boat ramp and along the
sandy beach. Soils at the site are categorized as HSG A, indicating good infiltration capacity.
Proposed Improvements:
• Improve and formalize the existing footpath opposite Heritage Rd with the addition of infiltrating steps and
vegetation. Revegetate the eroded slope using low-maintenance native plants.
• Create terraced landscaping above eroded beach areas to slow and infiltrate runoff from Weed Rd and the steep
slope above the beach.
• Improve the existing forebay at the top of slope by removing sediment and stone and installing a concrete paver
mat underlain with crushed stone. The concrete paver mat will allow stormwater to pond and infiltrate through
the crushed stone, prevent scour erosion, and will make it easierto remove accumulated sediment.
• On the driveway, install waterbars to divert runoff into a swale to the north. The swale will have a turnout at the
base of the vegetated slope to divert runoff into an infiltrating forebay and bioretention basin. The basin will
include a level-spreader emergency spillway for targe storm events.
• At the end of the swale, install a level spreader and stone apron to slow and spread out flows into a restored
vegetated buffer. The vegetated buffer will be located downhill from the parking area, between the boat ramp
and the tree. It will be planted densely with low-growing plants.
Operation and Maintenance: O&M for the proposed stormwater improvements is anticipated to incur 30 hours
annually. O&M includes routine inspections, preventative maintenance, and corrective actions, such as the
following:
1) Clean out trash, debris, and accumulated sediment from inlets, forebays, bioretention basin, spillway, swale,
and infiltrating steps.
2) Maintain vegetation (weeding, replanting, etc.) and water plants during establishment period.
3) Check for erosion within and downstream of stormwater facilities; stabilize areas of erosion, if found.
4) Check for standing water (lack of drainage) in the bioretention basin and infiltrating steps. Investigate and correct clogging if ponded water does not drain within 48 hours following a
rain event. If the crushed stone in the infiltration steps become filled with sediment overtime, remove the stone, clean out the sediment, and replace.
Operation and maintenance for bioretention systems, as provided in EPA Region 1 (2016) Methodology for Developing Cost Estimates for Opti-Tool
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Kaulback Rd, Sanbornton, NH
Existing Site Description: The focus area is a 1,100 ft segment of
Kaulback Road from the intersection with Roxbury Rd to
approximately 500 ft north of the Black Brook crossing. The road is
unpaved and has eroding shoulders and ditches on both sides, rills,
sediment buildup, and small berms at the road edge caused by road
maintenance with graders (aka grader berms). Soils at the site are
categorized as HSG A (to the south of Black Brook) and HSG C (to the
north).
Proposed Improvements:
• Regrade the road with broad-based dips to break up the drainage area and divert runoff to stabilized ditches and
turnouts into the downgradient forest.
• Create shallow drainage ditches/swales on both sides of the road, with stabilized turnouts. Along the steeper
section to the north (> 5% slope), install stone check dams in the ditches to reduce flow velocity. Remove grader
berms and revegetate shoulders where needed.
• Divert runoff into the forest via turnouts before it reaches the Black Brook crossing. Restore eroded areas at the
stream crossing. Where runoff cannot be diverted before reaching the crossing, install sediment forebay(s) to
settle out sediment and to slow and spread outflows.
Operation and Maintenance:
In addition to typical maintenance for unpaved roads (which typically includes annual or more frequent grading,
removal of sediment from turnouts and periodic correction of eroded areas), O&M for the proposed stormwater
improvements is anticipated to incur 15 hours annually. O&M includes routine inspections, preventative
maintenance, and corrective actions, such as the following:
1) Clean out trash, debris, and accumulated sediment from check dams, ditches, and sediment forebays.
2) Inspection and backfilling of edges of broad-based dips where erosion has occurred. Broad-based dips made
of concrete are most effective and long lasting; other materials typically require more frequent maintenance.
3) In restoration areas, water plants during establishment period.
SITE SUMMARY
Owner: Town of Sanbornton
Receiving Water: Black Brook, tributary to Lake Winnisquam
Estimated Phosphorus Load Reduction: 1.5 kg/year
Estimated Costs: Capital costs: $32,000-$40,000
Annual operation and maintenance costs: $1,500
20-year life cycle cost: $66,000
Erosion along Kaulback Road.
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4.2 NON-STRUCTURAL NONPOINT SOURCE (NPS) RESTORATION
Non-structural NPS restoration techniques refer to a broad range of behavioral practices, activities, and operational
measures that contribute to pollutant prevention and reduction. The following section highlights important restoration
techniques for several key areas, including pollutant reduction best practices, stream restoration, zoning and ordinance
updates, land conservation, septic system regulation, fertilizer use prohibition, proper agricultural practices, pet waste
management, and nuisance wildlife controls.
4.2.1 Pollutant Reduction Best Practices
Pollutant reduction best practices include recommendations and strategies for improving road management and municipal
operations for the protection of water quality. Following standard best practices for road maintenance and drainage
management protects both infrastructure and water quality through the reduction of sediment and other pollutant transport.
Refer to the "Kaulback Rd, Sanbornton, NH" conceptual design (Section 4.1.2) and the New Hampshire Stormwater Manual
(NHDES, 2008) for standard road design and maintenance best practices.
Even though none of the seven watershed municipalities are required to comply with the six minimum control measures
underthe New Hampshire Small MS4 General Permit, each municipality could consider institutingthe permit's key measures,
such as street sweeping, catch basin cleaning, and road/ditch maintenance. The MS4 permit also covers illicit discharge
detection and elimination plans (and ordinance inclusion), source control and pollution/spill prevention protocols, and
education/outreach and/or training for residents, municipal staff, and stormwater operators, all of which are aimed at
minimizing polluted runoff to surface waters.
Each municipality employs the following best practices:
• In New Hampton, the DPW inspects (and cleans, as needed) stormwater outfalls and culverts regularly mostly in the
spring and summer. Street sweeping is conducted once in the spring. No landscaping material is disposed of from
municipal lands except leaves at the transfer station. The Town uses both sand and salt for winter road maintenance
(salt is kept in an enclosed facility). LRPC assisted the Town with a culvert inventory that the Town uses to prioritize
work. The Town maintains, monitors, and regrades as needed 26 miles of gravel roads.
• In Meredith, street sweeping occurs every spring. Catchbasins are inspected and cleaned once per year. The Town
uses an ice control protocol to determine whether sand and/or salt is needed for winter road maintenance. Culverts
are inspected regularly. The Town maintains 36 miles of gravel roads.
• In Laconia, cleaning and inspecting of stormwater infrastructure is completed on an as-needed basis. Street
sweeping is conducted about three times in the summer. Any landscaping material/leaves are brought to Gilford for
composting. The City typically uses sand with some salt on gravel roads and largely salt on paved roads for winter
road maintenance practices, depending on the storm type and severity. There is no City-wide culvert inventory for
prioritized replacement. The City maintains about 5 miles of gravel roads, which are regraded multiple times per
year, especially following heavy rain events. For road maintenance, the City digs out ditches and applies a seed mix.
• In Sanbornton, catchbasins are inspected once per year and cleaned as needed. There is no street sweeping. Sand
is used on gravel roads and salt/sand is used on paved roads in the winter. The Town maintains 40 miles of gravel
roads, which are regraded twice per year. Huse Rd is their most problematic gravel road because it washes out
frequently.
• In Tilton, catch basins and culverts are cleaned 4-5 times per year and inspected twice per year. Street sweeping
occurs once in the spring. Landscaping/leaf/grass clippings are composted at the dump. Salt and sand are both used
for winter road maintenance, and the salt is stored in a covered garage. There is no formal culvert inventory for the
Town. The Town does not maintain any gravel roads.
• In Belmont, an outside engineering firm assists the Town with prioritizing and replacing culverts. The Town uses
both salt and sand on roads for winter road maintenance. Gravel roads are maintained as needed and are usually
regraded in spring each year.
• In Gilford, catch basin cleaning occurs once each year, and culverts are inspected as needed or as part of road
projects. Street sweeping is conducted every spring. Landscaping material is brought to Gilford for composting. Salt
is mainly used for winter maintenance on paved roads. The Town uses a magnesium chloride solution sprayed on
the salt to work faster and better at lower temperatures. DPW drivers have indicated that they are using half the salt
they usually do with this new system. Sand is used for winter maintenance on unpaved roads. Salt is stored inside a
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LAKE WINNISQUAM WATERSHED-BASED PLAN
building. The Town does not currently have a culvert
inventory but plans to complete one in the future.
Culverts were last inspected in 2016. The Town
maintains three gravel roads and plans to pave them
all within the next five years.
4.2.2 Stream Restoration
Ecosystem restoration, such as buffer and wetland
enhancement, stream restoration, and flood plain
reconnection are also management practices that can
provide nutrient and sediment reduction benefits. Large
wood in streams is important for natural function of the
stream and reduces water velocity, traps sediment, and
creates habitat for Eastern brook trout and other aquatic
species. BCCD with Trout Unlimited completed a one mile
stream restoration project (felling large woody material) in
Black Brook in August 2021, This work was funded by a
National Fish and Wildlife Foundation grant and
Demonstration Project funding through the NHACC.
4.2.3 Zoning and Ordinance Updates
Regulations through municipal zoning and ordinances such as LID strategies that prevent polluted runoff from new and re-
development projects in the watershed are equally important as implementing structural BMPs on existing development. In
fact, in most lake watersheds, local land use planning and zoning ordinances can be the most critical components of
watershed protection strategies.
WWN completed a preliminary ordinance review of natural resource protections for the seven municipalities in the Lake
Winnisquam watershed (Table 14). Many of these municipalities have already incorporated into their ordinances important
regulations for shoreland protection, cluster and open space development, LID standards, erosion control, and steep slopes.
A more robust review of these ordinances is encouraged for municipal-specific recommendations for improving ordinances
and regulations related to natural resource protection. Each municipality should also consider its staffing capacity to enforce
existing and proposed regulations.
Local land use planning and zoning ordinances should consider incorporating climate change resiliency strategies for
protecting water quality and im proving stormwater infrastructure based on temperature changes, precipitation, water levels,
wind loads, storm surges, wave heights, soil moisture, and groundwater levels (Ballestero et al., 2017). There are nine
strategies which can aid in minimizing the adverse effects associated with climate change and include the following
(McCormickand Dorworth, 2019).
• Installing Green Infrastructure and Nature-Based Solutions: Planning for greener infrastructure requires that we
think about creating a network of interconnected natural areas and open spaces needed for groundwater recharge,
pollution mitigation, reduced runoff and erosion, and improved airquality. Examples of green infrastructure include
forest, wetlands, natural areas, riparian (banks of a water course) buffers, and floodplains; all of which already exist
to various extents in the watershed and have minimized the damage created by intense storms. As future
development occurs, these natural barriers must be maintained oreven increased to reduce runoff of pollutants into
freshwaters. See also Section 4.2.4: Land Conservation.
• Using LID Strategies: Use of LID strategies requires replacing traditional approaches to stormwater management
using curbs, pipes, storm drains, gutters, and retention ponds with innovative approaches such as bioretention,
vegetated swales, and permeable paving.
• Minimizing Impervious Surfaces: Impervious surfaces such as roads, buildings, and parking lots should be
minimized by creating new ordinances and building construction design requirements which reduce the
imperviousness of new development. Property owners can increase the permeability of their lots by incorporating
permeable driveways and walkways.
The felling of large woody material was completed in a
one mile segment of Black Brook as part of a stream
habitat restoration project in 2021 by the BCCD and Trout
Unlimited.
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LAKE WINNISQUAM WATERSHED-BASED PLAN
• Encouraging Riparian Buffers and Maintaining Floodplains: Municipal ordinances should forbid construction in
flood plains, and in some instances, flood plains should be expanded to increase the land area to accommodate larger
rainfall events. Riparian (vegetated) buffers and filter strips along waterways should be preserved and/or created to
slow runoff and filter pollutants.
• Protecting and Re-establishing Wetlands: Wetlands are increasingly important for preservation because wetlands
hold water, reduce flooding, recharge groundwater, and mitigate water pollution.
• Encouraging Tree Planting: Trees help manage stormwater by reducing runoff and mitigating erosion along surface
waters. Trees also provide critical shading and cooling to streams and land surfaces.
• Promoting Landscaping Using Native Vegetation: Landowners should promote the use of native vegetation in
landscaping, and landscapers should become familiar with techniques which minimize runoff and the discharge of
nutrients into waterbodies (Chase-Rowell et a I., 2012).
• Slowing Down the Flow of Stormwater: To slow and infiltrate stormwater runoff, roadside ditches can be armored
or vegetated and equipped with turnouts, settling basins, check dams, or infiltration catch basins. Rain gardens can
retain stormwater, while waterbars can divert water into vegetated areas for infiltration. Water running off roofs can
be channeled into infiltration fields and drainage trenches.
• Coordinating Infrastructure, Housing, and Transportation Planning: Coordinate planning for infrastructure,
housing, and transportation to minimize impacts on natural resources. Critical resources including groundwater
must be conserved and remain free of pollutants especially as future droughts may deplete groundwater supplies.
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LAKE WINNISQUAM WATERSHED-BASED PLAN
Table 14. Ordinance review summary of regulatory and non-regulatory tools for natural resource protection for the seven watershed municipalities of the Lake
Winnisquam watershed.
STRATEGY
MEREDITH
LACONIA
GILFORD
BELMONT
TILTON
SANBORNTON
NEW HAMPTON
Shoreland Zoning
Zoning Ord, Art.V,D.4,
Zoning Ord. Art. IV, Sec.
Zoning Ord. Art. 2,
Zoning Ord.
Zoning Regs. Art. VII,
Zoning Ord. Art. 14,
Shoreline District -
235-19, Shoreland
2.4, Island and Shore
Art.8.D,
App. C, Dimensional
Shorefront District
setbacks from high water
Protection District
Frontage Dist.
Shorefront
Regs., ref. NH
markonshorefront
Development
Shoreland
properties
Protection Act
Cluster development
Zoning Ord. Art. XXI,
Zoning Ord. Art. VII, Sec.
Zoning Ord. Art. 11,
Zoning Ord. Art.6,
Subdivision Regs.
Zoning Ord. Art.4.T,
Subd. Regs.
and/or open space
Conservation Subdivision
235-40.B, Cluster
4.4.3, Cluster
Open Space
Amendment, Cluster
Cluster
Section VII.C,
provisions for
Design - requires 50% of
Development - 50% of
Development, 4.4,
Residential
Residential
Development
Cluster Dev.,
subdivisions
tractto remain as Open
Space
buildable area required as
Open Space
Planned Unit
Development
Development
Development (pg. 61)
Zoning, 50% of tract
req. as Open Space
tracts >20 AC
Septic Regulations
Zoning Ord. Art. V, D.9,
Zoning Ord. Art.IV, Sec.
Zoning Ord. Art. 6.9,
Zoning Regs. Art.
Zoning Ord. Art. 4.H,
Zoning Ord.
Water Resources
235-17.J., Sec. 235-19.E
Sanitary Regs.
XIV.14.4.1
Art. 14.C.3, Art. 15
Art.V.C, Sewage
Conservation Overlay
Disposal
District, D.10, Lake
Waukewan Watershed
Overlay District - leach field
setbacks
Zoning Districts that
Zoning Ord. Art. V, D.l, D.2,
Zoning Ord. Art. IV, Sec.
Zoning Ord. Art. 2,
Zoning Ord. Art.7,
Zoning Regs., Art.XIV,
Zoning Ord. Art.7,
Zoning Ord.
v>
address
D.4, D.9, D.10, Art. XIV
235-17, Sec. 235-19, Sec.
2.2,2.4, Art. 19,
Aquifer
Wetlands
Forest Conservation
Art.lV.G., Flood
O
H
environmental
235-44, Site Plan Review
Aquifer Protection
Protection,
Conservation Dist.,
Dist., Art. 12, Aquifer
Hazard Dist.,
£"
protection
Regs.
District, Subd. Regs.,
Wetlands
Art. XV, Groundwater
Conservation Dist.,
IV. H.
*->
ro
Site Plan Regs.
Ordinance, Earth
Protection Dis.
Art. 13, Floodplain
Pemigewasset
3
W)
Excavation Regs,
Conservation Dist.,
Overlay Dist.,
a.
Site Plan Regs.,
Subd. Regs
Art. 14, Shorefront
Dist., Art. 15,
Wetlands
Conservation Dist.
IV. 1. Lake
Waukewan
Overlay Dist.
Zoning Districts that
Zoning Ord. Art. V, D.9,
Zoning Ord. Art. IV, Sec.
Zoning Ord. Art. 11,
Wetlands
Zoning Regs. Art. XIV,
Zoning Ord. Art. 15
address wetland
Water Resources
235-17, Wetlands
Wetlands District
Ordinance
Wetlands
Wetlands Cons. Dist.
conservation
Conservation Overlay
District
Conservation and Water
Quality Overlay District
Conservation Dist.
Erosion Control
Zoning Ord., Art.XIV,
Zoning Ord. Art. 1, Sec. 235-
Subd. Regs. Sec.
Site Plan Regs.,
Subd. Regs. Sec.6.E
Zoning Ord. Art.4.M,
Regulations
Erosion and Sediment
44, Erosion and Sediment
VILA, Sedimentation
Subdiv. Regs.
Site Plan Regs.
Control Ordinance
Control, Subdivision Regs.
and Erosion Control
Earth Excavation
Regs.
Sec.V.E.
Zoning Districts that
Zoning Ord., Art. V, D.9,
Zoning Ord. Art.IV, Sec.
Zoning Ord. Art. 19,
Zoning Ord. Art.7,
Zoning Regs. Art.XV,
Zoning Ord. Art.4.H,
Zoning Ord. Art.
protect groundwater
Water Resources
235-17.J, Wetlands
Aquifer Protection
Aquifer
Groundwater
Art. 12, Art. 15.C.3(c),
IV. 1, Lake
Conservation Overlay
Conservation and Water
District
Protection,
Protection Dist.
Waukewan
District
Quality Overlay District,
Sec. 235-22, WaterSupply
Protection Overlay District
Wetlands Ord.,
Earth Excavation
Regs., Site Plan
Regs., Subd. Regs.
Overlay Dist.
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LAKE WINNISQUAM WATERSHED-BASED PLAN
STRATEGY
MEREDITH
LACONIA
GILFORD
BELMONT
TILTON
SANBORNTON
NEW HAMPTON
Protection of steep
Zoning Ord. Art. XXI,
Zoning Ord.Art. VII, Sec.
Zoning Ord. Art.
Zoning Ord. Art. 6,
Subd. Regs. Sec.6.C
Zoning Ord. Art. 16
slopes
Conservation Subdivision
Design - slopes>25%
considered not buildable
235-44.2, Steep Slope
Protection, Site Plan
Review 7.12
5.1.1(e), Sub. Regs
Sec. IX.B.9.d.lO
Site Plan
Regs.,Sec. 9.B
Nutrient loading
Site Plan Regs.
analysis required for
Sec.V.J.
fresh waterbodies
Low impact
Zoning Ord. Art. XXI
Zoning Ord. Art. VII, Sec.
Zoning Ord. Art. 11,
Zoning Ord. Art. 6
Zoning Ord. Art. 4.T
Subd. Regs. Sec.
development
235-40.B, Cluster
4.3,4.4
VII.C
requirements and
Development, Sec. 235-
standards
44.2 Steep Slope
Protection
Fertilizer and
Zoning Ord. Art.IV, Sec.
Zoning Ord. Art.
Zoning Ord. Art.l2.D
pesticides ordinances
235-19.D.2
15.5.1
Storm water
Zoning Ord. Art. XIV, Site
Zoning Ord. Art. VII, Sec.
Zoning Art. 19, Sub.
Site Plan Regs.
Zoning Regs. Art.
Zoning Ord. Art. 4.M,
Site Plan Regs.
Management Plan
Plan Review Regs.,
235-40.B, Cluster
Regs. Sec. VILA, Sec.
Sec.9.E.d, 9.Q,
XV.1.8 Groundwater
Art. 12.E.2.C, Art. 16
Sec. X.J, Subd.
implementation and
Subdivision Regs.
Development, Sec. 235-
IX
Subd. Regs.
Protection
Regs. Sec. VI. C.l,
enforcement
44.2 Steep Slope
Protection, Major Site Plan
Review, Subdivision Regs.
Sec.9.D
performance
standards
VII.C.G
Open Space Plan
Included in Community
2007 Master Plans
2016 Master Plan
2002 Master Plan,
2013 Master Plan
Completed 2019
Plan, 2002
mentions Open Space
mentions Open
Space
Ch.7
mentions Open
Space
Master Plan addresses
Yes
Yes
Master Plan 2016 Ch.
2002 Master Plan,
2013 Master Plan
2012 Master Plan
2021 Master Plan
"o
natural resources and
5
Ch.7
Sec. 3
Sec. III.E
references Open
H
£"
O
environmental
Space Plan
protection
_ra
Municipality-wide
Completed 2005
Completed 2009
Completed 2021
Completed 2007
Completed 2007
M
CI
natural resources
a.
inventory
o
z
Incentive-based
programs for
voluntary low impact
development
implementation
Zoning Ord. Art. XXI
Zoning Ord. Art.IV, Sec.
235-40.B(6)(e)
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4.2.4 Land Conservation
Land conservation is essential to the health of a region, particularly for the protection of water resources, enhancement of
recreation opportunities, vitality of local economies, and preservation of wildlife habitat. Land conservation is one of many
management tools for protecting water quality for future generations. About 2,718 acres (7%) of the Lake Winnisquam
watershed is currently conserved, and major conserved areas (greater than 100 acres) include the Chemung State Forest,
multiple Meredith town forests, the Huston-Morgan State Forest, Ahern State Park, and Prescott State Park (refer to Appendix
B, Map B-9). Local groups should continue to pursue opportunities for land conservation in the Lake Winnisquam watershed.
Areas for land conservation can be prioritized based on the highest valued habitat identified by the NHFGD, which often
includes riparian areas and wetlands critical to water quality protection. NHFGD ranks habitat based on value to the State,
biological region (areas with similar climate, geology, and other factors that influence biology), and supporting landscape.
These habitat rankings are published in the State's 2015 Wildlife Action Plan (with updated statistics and data layers released
in January 2020), which serves as a blueprint for prioritizing conservation actions to protect Species of Greatest Conservation
Need in New Hampshire. The Lake Winnisquam watershed is part of the Sebago-Ossipee Hills and Plains ecoregional
subsection of the biological region (NHFG, 2015). Over 8,031 acres (39%) of the Lake Winnisquam watershed are considered
Highest Ranked Habitat in New Hampshire. This habitat includes Lake Winnisquam and a 200-meter buffer surrounding the
lake. A map of priority habitats for conservation based on the Wildlife Action Plan can be found in Appendix B, Map B-10.
4.2.5 Septic System Regulation
When properly designed, installed, operated, and maintained, septic systems can treat residential wastewater and reduce
the impact of excess pollutants in ground and surface waters. It is important to note, however, that traditional septic systems
are designed for pathogen removal from wastewater and not specifically for other pollutants such as nutrients. The
phosphorus in wastewater is "removed" only by binding with soil particles or recycled in plant growth but is not removed
entirely from the watershed system. Nutrient removal can only be achieved through more expensive, alternative septic
systems. Proper design, installation, operation, maintenance, and replacement considerations include the following:
• Proper design includes adequate evaluation of soil conditions, seasonal high groundwater or impermeable
materials, proximity of sensitive resources (e.g., drinking water wells, surface waters, wetlands, etc.);
• Proper siting and installation mean that the system is installed in conformance with the approved design and siting
requirements (e.g., setbacks from waterways);
• Proper operation includes how the property owner uses the system. While most systems excel at treating normal
domestic sewage, disposing of some materials, such as toxic chemicals, paints, personal hygiene products, oils and
grease in large volumes, and garbage, can adversely affect the function and design life of the system, resulting in
treatment failure and potential health threats; proper operation also includes how the property owner protects the
system; allowing vegetation with extensive roots to grow above the system will clog the system; driving large vehicles
over the system may crush or compact piping or leaching structures;
• Proper maintenance means having the septic tank pumped at regular intervals to eliminate accumulations of solids
and grease in the tank; it may also mean regular cleaning of effluent filters, if installed. The frequency of septic
pumping is dependent on the use and total volume entering the system. A typical 3-bedroom, 1,000 gallon tank
should be pumped every 3-4years;
• Proper replacement of failed systems, which may include programs or regulations to encourage upgrades of
conventional systems (or grandfathered cesspools and holding tanks) to more innovative alternative technologies.
Management strategies for reducing water quality impacts from septic systems (as well as cesspools and holding tanks) start
with education and outreach to property owners so that they are better informed to properly operate and maintain their
systems. Other management strategies include setting local regulations for enforcing proper maintenance and inspection of
septic systems and establishing funding mechanisms to support replacement of failing systems (with priority for cesspools
and holdingtanks).
4.2.6 Sanitary Sewer System Inspections
Because a portion of the watershed also relies on a municipal sewer system, it is important for municipalities with sewer to
develop a program (if not already in place) to inspect and evaluate their sanitary sewer system and reduce identified leaks
and overflows, especially in areas nearwaterbodies.
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4.2.7 Fertilizer Use Prohibition
Management strategies for reducing water quality impacts from residential, commercial, and municipal fertilizer application
start with education and outreach to property owners. New Hampshire law prohibits the use of fertilizers within 25 feet of a
surface water. Outside of 25 feet, property owners can get their soil tested before considering application of fertilizers to their
lawns and gardens to determine whether nutrients are needed and if so in what quantity or ratio. A soil test kit can be obtained
through the UNH Cooperative Extension. Many New England communities are starting to adopt local regulations prohibiting
the use of both fertilizers and pesticides, most especially near critical waterbodies. The seven watershed municipalities could
consider a similar prohibition, at the very least for a watershed zoning overlay of major lakes and ponds, some of which
already have:
• In Meredith, NH Rule 502.04 requires a permit to apply pesticides or fertilizers (including manure or compost) within
250 feet of surface waters in the Lake Waukewan watershed, unless in strict conformance with the Manual of Best
Management Practices for Agriculture in New Hampshire (New Hampshire Department of Agriculture, Markets, and
Food, 2017).
• In Laconia, no phosphorus-based fertilizers or herbicides/pesticides can be applied within 250 feet of any waterbody
in the City.
• In Sanbornton, in the Aquifer Conservation District (areas delineated as having medium-high potential to yield
groundwater by the USGS), spraying or spreading of chemical fertilizers or pesticides may be permitted subject to
approval of the Zoning Board of Adjustment.
• In Tilton, fertilizers (except for lime and wood ash) cannot be applied within the Wetlands Conservation Overlay
District. Fertilizers must be stored within a structure designed to prevent generation and escape of contaminated
runoff or leachate in conformance with the Manual of Best Management Practices for Agriculture in New Hampshire
(New Hampshire Department of Agriculture, Markets, and Food, 2017).
• In Belmont, fertilizers cannot be applied within the Aquifer and Groundwater Protection District. Fertilizers must be
stored within a structure designed to prevent generation and escape of contaminated runoff or leachate in
conformance with the Manual of Best Management Practices for Agriculture in New Hampshire (New Hampshire
Department of Agriculture, Markets, and Food, 2017).
• In Gilford, fertilizers cannot be applied within the Aquifer Protection District. Fertilizers must be stored within a
structure designed to prevent generation and escape of contaminated runoff or leachate in conformance with the
Manual of Best Management Practices for Agriculture in New Hampshire (New Ham pshire Depa rtment of Agricu Itu re,
Markets, and Food, 2017). Fertilizer is listed as a household hazardous waste and must be disposed of properly.
4.2.8 Agricultural Practices
Manure and fertilizer management and planning are the primary tools for controlling nutrient runoff from agricultural areas.
Direct outreach and education should be conducted for both small hobby farms and larger-scale operations in the watershed.
The NRCS is a great resource for such outreach and education to farmers. Larger-scale agricultural operations can work with
the NRCS to complete a Comprehensive Nutrient Management Plan (CNMP). These plans address soil erosion and water
quality concerns of agricultural operations through setting proper nutrient budgets, identifying the types and amount of
nutrients necessary for crop production (by conducting soil tests and determining proper calibration of nutrient application
equipment), and ensuring the proper storage and handling of manure. Manure should be stored or applied to fields properly
to limit runoff of solids containing high concentrations of nutrients. Manure and fertilizer management involve managing the
source, rate, form, timing, and placement of nutrients. Writing a plan is an ongoing process because it is a working document
that changes over time.
4.2.9 Pet Waste Management
Pet waste collection as a pollutant source control involves a combination of educational outreach and enforcement to
encourage residents to clean up after their pets. Public education programs for pet waste management are often
incorporated into a larger message of reducing pollutants to improve water quality. Signs, posters, brochures, and
newsletters describing the proper techniques to dispose of pet waste can be used to educate the public and create a cause-
and-effect link between pet waste and water quality (EPA, 2005). Adopting simple habits, such as carrying a plastic bag on
walks and properly disposing of pet waste in dumpsters or other refuse containers, can make a difference. It is recommended
that pet owners do not put dog and cat feces in a compost pile because it may contain parasites, bacteria, pathogens, and
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viruses that are harmful to humans and mayor may not be destroyed by composting. "Pooper-scooper" ordinances are often
used to regulate pet waste disposal. These ordinances generally require the removal of pet waste from public areas, other
people's properties, and occasionally from personal property, before leaving the area. Fines are typically the enforcement
method used to encourage compliance with these ordinances.
4.2.10 Nuisance Wildlife Controls
Human development has altered the natural habitat of many wildlife species, restricting wildlife access to surface waters in
some areas and promoting access in others. Minimizing the impact of wildlife on water quality generally requires either
reducing the concentration of wild life in an area or reducing their proximity to a waterbody. In areas where wildlife is observed
to be a large source of nutrient contamination, such as large and regular congregations of waterfowl, a program of repelling
wildlife from surface waters (also called harassment programs) may be implemented. These programs often involve the use
of scarecrows, kites, a daily human presence, or modification of habitat to reduce attractiveness of an at-risk area. Providing
closed trash cans nearwaterbodies, as well as discouraging wild life from entering surface waters by installing fences, pruning
trees, or making other changes to landscaping, can reduce impacts to water quality. Public education and outreach on
prohibiting waterfowl or other wildlife feeding is an important step to reducing the impact of nuisance wildlife on the lake.
The Oak Hill Golf Course does not employ any large bird deterrents but will have employees drive down to where the geese
are congregating and scare them off. The Laconia Country Club & Golf Course had a geese problem in the past and used a
herding dog to chase them off. Geese congregation has not been an issue in recent years at the Laconia Country Club & Golf
Course, but the Superintendent indicated that they would use a herding dog again if geese became an issue again.
4.3 OUTREACH & EDUCATION
Awareness through education and outreach is a critical tool for protecting and restoring water quality. Most people want to
be responsible watershed stewards and not cause harm to water quality, but many are unaware of best practices to reduce
or eliminate contaminants from entering surface waters. WWN is the primary entity for education and outreach campaigns in
the watershed and for development and implementation of the plan. WWN and other key watershed protection groups should
continue all aspects of their education and outreach strategies and consider developing new ones or improving existing ones
to reach more watershed residents. Refer to Section 5: Action Plan. Examples include providing educational materials to
existing and new property owners, as well as renters, by distributing them at various locations and through a variety of means,
such as websites, newsletters, social media, community events, or community gathering locations. Additionally, WWN should
continue to engage with local stakeholders such as BCCD, conservation commissions, land trusts, municipalities, businesses,
and landowners. Educational campaigns should include raising awareness of water quality, septic system maintenance,
fertilizer and pesticide use, pet waste disposal, waterfowl feeding, invasive aquatic species, boat pollution, shoreline buffer
improvements, gravel road maintenance, and stormwater runoff controls.
4.4 ADAPTIVE MANAGEMENT APPROACH
An adaptive management approach, to be employed by a committee, is highly recommended for protecting Lake
Winnisquam. Adaptive management enables stakeholders to conduct restoration actions in an iterative manner. Through
this management process, restoration actions are taken based on the best available information. Assessment of the
outcomes following restoration action, through continued watershed and water quality monitoring, allows stakeholders to
evaluate the effectiveness of one set of restoration actions and either adopt or modify them before implementing effective
measures in the next round of restoration actions. This process enables efficient utilization of available resources through the
combination of BMP performance testing and watershed monitoring activities. Adaptive management features establishing
an ongoing program that provides adequate funding, stakeholder guidance, and an efficient coordination of restoration
actions. Implementation of this approach ensures that restoration actions are implemented and that surface waters are
monitored to document restoration over an extended time. The adaptive management components for implementation
efforts should include:
• Maintaining an Organizational Structure for Implementation. Communication and a centralized organizational
structure are imperative to successfully implementing the actions outlined in this plan. A diverse group of
stakeholders through the WWN should be assembled to coordinate watershed management actions. This group can
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include representatives from state and federal agencies or organizations, municipalities, local businesses, and other
interested groups or private landowners. Referto Section 6.1: Plan Oversight.
• Establishing a Funding Mechanism. A long-term funding mechanism should be established to provide financial
resources for management actions. In addition to initial implementation costs, consideration should also be given
to the type and extent of technical assistance needed to inspect and maintain structural BMPs. Funding is a key
element of sustaining the management process, and, once it is established, the plan can be fully vetted and
restoration actions can move forward. A combination of grant funding, private donations, and municipal funding
should be used to ensure implementation of the plan. Referto Section 6.3 for a list of potential funding sources.
• Determining Management Actions. This plan provides a unified watershed management strategy with prioritized
recommendations for restoration using a variety of methods. The proposed actions in this plan should be used as a
starting point for grant proposals. Once a funding mechanism is established, designs for priority restoration actions
on a project-area basis can be completed and their implementation scheduled. Referto Section 5: Action Plan.
• Continuing and Expanding the Community Participation Process. Plan development has included active
involvement of a diversity of watershed stakeholders. Plan implementation will require continued and ongoing
participation of stakeholders, as well as additional outreach efforts to expand the circle of participation. Long-term
community support and engagement is vital to successfully implement this plan. Continued public awareness and
outreach campaigns will aid in securing this engagement. Referto Section 4.3: Outreach & Education.
• Continuing the Long-Term Monitoring Program. A water quality monitoring program is necessary to track the
health of surface waters in the watershed. Information from the monitoring program will provide feedback on the
effectiveness of management practices. Referto Section 6.4: Monitoring Plan.
• Establishing Measurable Milestones. A restoration schedule that includes milestones for measuring restoration
actions and monitoring activities in the watershed is critical to the success of the plan. In addition to monitoring,
several environmental, social, and programmatic indicators have been identified to measure plan progress. Referto
Section 6.5: Indicators to Measure Progress and Section 2.4: Water Quality Goal & Objectives for interim milestones.
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5 ACTION PLAN
5.1 ACTION PLAN
The Action Plan (Table 15) outlines responsible parties, approximate costs12, an implementation schedule, and potential funding sources for each recommendation within
the following major categories: (1) Watershed & Shoreline BMPs; (2) Road Management; (3) Municipal Operations; (4) Municipal Land Use Planning & Zoning; (5) Land
Conservation; (6) Septic System Management; (7) Agricultural Practices; and (8) Education and Outreach. The plan is designed to be implemented from 2022-2031 and is
flexible to allow for new priorities throughout the 10-year implementation period as additional data are acquired.
Table 15. Action Plan for the Lake Winnisquam watershed.
Action Item
Responsible Party
Estimated Cost /
Schedule
Potential Funding
Sources
Watershed & Shoreline BMPs
Further investigate sources of turbidity in Hueber Brook. Recommend and implement
mitigation measures. Cost assumes stormwater retrofit inventory and stormwater
mitigation designs completed along Route 3/11 (no construction costs). Achieves
Objective 1.
WWN, Belmont
$75 K
2022-25
Belmont, CWSRF, Grants
(319)
Complete design and construction of mitigation measures at the top 24 high priority
sites identified in the watershed survey. Three sites will be remediated through a NHDES
319 Watershed Assistance Grant (2022-23) awarded to WWN. Achieves 11% (29 kg/yr P
of 260 kg/yr P) of Objective 3.
WWN, BCCD,
Municipalities, private
landowners
$400K-$800K
2022-27
CWSRF, Grants (319, Moose
Plate, NFWF5-Star, ILFP),
Municipalities, private
landowners
Complete design and construction of mitigation measures at 84 medium and low priority
sites identified in the watershed survey as opportunities arise (refer to Appendix C for
complete list). Achieves 9% (24 kg/yr P of 260 kg/yr P) of Objective 3.
WWN, BCCD,
Municipalities, private
landowners
$100K-$200K
2022-31
CWSRF, Grants (319, Moose
Plate, NFWF5-Star, ILFP),
Municipalities, private
landowners
Within the Black Brook sub-watershed, implement unpaved road erosion control
measures recommended in Lang (2021) and FBE (2022).
WWN, BCCD,
Municipalities
TBD
2022-27
CWSRF, Municipalities,
Grants (Moose Plate, NFWF
5-Star)
Promote the LakeSmart program evaluations and certifications through NH Lakes to
educate property owners about lake-friendly practices such as revegetating shoreline
buffers with native plants, avoiding large grassy areas, and increasing mower blade
heights to 4 inches. Coordinate with NHDES Soak Up the Rain NH program for workshops
and trainings. Cost assumes coordination of and materials for up to 10 workshops.
WWN, BCCD, NH
Lakes, NHDES Soak
Up the Rain NH,
Municipalities
$10K
2022-31
NH Lakes, NHDES Soak Up
the Rain NH, Grants (319,
Moose plate), CWSRF,
Municipalities
12 Cost estimates for each recommendation will need to be adjusted based on further research and site design considerations.
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Action Item
Responsible Party
Estimated Cost /
Schedule
Potential Funding
Sources
Provide technical assistance and/or implementation cost sharing to
watershed/shoreline property owners to install stormwater and/or erosion controls such
as rain gardens and buffer plantings. Prioritize high impact properties identified during
the shoreline survey. Cost assumes technical assistance and implementation cost
sharing provided to the 20 high impact shoreline properties. Achieves 8% (20 kg/yr P of
260 kg/yr P) of Objective 3.
WWN, BCCD,
Municipalities
$200K
2022-25
Grants (319, Moose plate),
CWSRF
Implement stormwater and erosion controls on watershed/shoreline properties.
Prioritize medium impact properties identified during the shoreline survey. Cost
assumes landowner implementation costs (budget: $3Keach) for282 medium impact
shoreline properties. Achieves 16% (41 kg/yr P of 260 kg/yr P) of Objective 3.
Landowners
$850K
2022-31
Landowners
Conduct a shoreline survey for Lake Wicwas and Lake Opechee. Use the results to target
education and technical assistance for high impact sites. Cost assumes hired technical
review and summation of shoreline survey results. Surveys to be performed by
volunteers.
WWN, LWA, LOPA,
Municipalities
$5K
2025
Municipalities, Grants
(Moose plate), CWSRF
Repeat the shoreline surveys in 5-10 years when updating the WBP. Use the results to
target education and technical assistance for high impact sites. Cost assumes hired
technical review and summation of shoreline survey results. Surveys to be performed by
volunteers.
WWN, Municipalities
$8K
2025,2030
Municipalities, Grants
(Moose plate), CWSRF
Road Management
Review practices for road and drainage maintenance currently used for each
municipality and road association and determine areas for improvement.
Municipalities, WWN,
BCCD
$10K
2023
CWSRF, Municipalities,
Grants (Moose Plate, NFWF
5-Star)
Develop and/or update a written protocol for road maintenance best practices.
Municipalities, WWN,
BCCD
$20K
2023
CWSRF, Municipalities,
Grants (Moose Plate, NFWF
5-Star)
Provide education and training to contractors and municipal staff on protocols for road
maintenance best practices. Cost assumes one workshop for all seven municipalities.
Municipalities, WWN,
BCCD
$15 K
2024
CWSRF, Municipalities,
Grants (Moose Plate, NFWF
5-Star)
Incorporate water quality considerations and strategies into roadway evaluations and
action plans (e.g., Sanbornton Roadway Evaluation13).
Municipalities, WWN,
BCCD
N/A
2022-31
Municipalities
Establish inspection and maintenance agreements for private unpaved roads. Cost does
not include the implementation of proper road maintenance by private landowners and
assumes that municipalities can accommodate this additional effort in current budgets.
Municipalities, private
landowners
N/A
2022-31
Municipalities, private
landowners
13 https://www.sanborntonnh.Org/sites/g/fiiesA/yhHf3776/f/upioads/sanbornton roadway evaluation - summary report and final documentation O.pdf
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Action Item
Responsible Party
Estimated Cost /
Schedule
Potential Funding
Sources
Hold informational workshops on proper road management and winter maintenance
and provide educational materials for homeowners about winter maintenance and
sand/salt application for driveways and walkways. Cost assumes up to five workshops.
WWN, BCCD,
Municipalities, private
landowners
$10K
2022-31
CWSRF, Municipalities,
Grants (Moose Plate, NFWF
5-Star), private landowners
Municipal Operations
Review and optimize MS4 compliance for all municipalities (regardless of MS4
designation), including infrastructure mapping, erosion and sediment controls, illicit
discharge programs, and good housekeeping practices. Sweep municipal paved roads
and parking lots two times peryear (spring and fall).
Municipalities (Public
Works/Highway)
TBD
2022-31
Municipalities
Participate in Green SnowPro training. Become Green SnowPro Certified once program
rules for municipalities have been adopted by the Joint Legislative Committee on
Administrative Rules.
Municipalities (Public
Works/Highway)
Est. $150-
$250/person
2022-31
Municipalities
Review and update winter operations procedures to be consistent with Green SnowPro
best management practices for winter road, parking lot, and sidewalk maintenance.
Municipalities (Public
Works/Highway)
N/A
2023
Municipalities
In Sanbornton, Belmont, and Gilford, adopt policies to either eliminate fertilizer
applications on town properties or implement best practices for fertilizer management
(to minimize application and transport of phosphorus). Consider extending these
regulations to private properties as well.
Municipalities (Public
Works/Highway)
N/A
2022-25
Municipalities
For Sanbornton, Belmont, and Tilton, adopt a program to accept residential yard waste
at respective transfer stations for composting. (Other municipalities currently accept
yard waste for no fee.)
Municipalities (Public
Works/Highway)
TBD
2022-25
Municipalities
Develop best practice design standards for stormwater control measures, including deep
sump catch basins.
Municipalities (Public
Works/Highway)
N/A
2023
Municipalities
Municipal Land Use Planning & Zoning
Present WBP recommendations to Select Boards/City Council and Planning Boards in
Meredith, Laconia, Gilford, Belmont, Tilton, Sanbornton, and New Hampton.
WWN
$3K
2022
Grants (319), CWSRF
Meet with municipal staff to review recommendations to improve or develop ordinances
addressing setbacks, buffers, lot coverage, low impact development, and open space.
WWN, Municipalities
$7K
2022-25
Municipalities, Grants
(319), CWSRF
Incorporate WBP recommendations into municipal master plans and encourage regular
review of the WBP action plan.
Municipalities
N/A
2022-25
Municipalities
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Action Item
Responsible Party
Estimated Cost /
Schedule
Potential Funding
Sources
Adopt/strengthen zoning ordinance provisions and enforcement mechanisms:
1) to promote low impact development practices;
2) to require stormwater regulations that align with MS4 Permit requirements;
3) to promote or require vegetative buffers around lake shore and tributary
streams;
4) to require shorefront "tear down and replace" home construction to be no more
non-conforming than existing structures;
5) to require shorefront seasonal to year-round conversions of homes to
Municipalities
N/A
2022-31
Municipalities
demonstrate no additional negative impacts to lake water quality;
6) to establish a lake protection overlay zoning ordinance that prohibits erosion
from sites in sensitive areas (e.g., lake shorefront, along lake tributaries, steep
slopes); and
7) to enhance performance standards for unpaved roads to prevent erosion and
protect lake water quality.
Increase municipal staff capacity for inspections and enforcement of stormwater
regulations on public and private lands.
Municipalities
TBD
2022-31
Municipalities
Update the New Hampton portion of the watershed in the build-out analysis to better
reflect current zoning standards. New Hampton's zoning standards adjust allowable lot
size by slope and drainage conditions that were not fully reflected in the 2021 build-out
WWN, New Hampton
$3K
2022-25
Grants, CWSRF, New
Hampton
analysis.
Land Conservation
Conduct a Natural Resources Inventory (NRI) in Sanbornton. Update the NRIs from 2007
in Belmont and Tilton. (Meredith, Laconia, Gilford, and New Hampton have recent NRIs).
Municipalities,
Conservation
Commissions
$8-16K per
municipality
2022-25
Municipalities, Grants
(NFWFNEFRG), CWSRF
WWN, Municipalities,
Create a priority list of watershed areas that need protection based on NRIs. Refer to
Conservation
Grants (NFWFNEFRG,
NAWCA), CWSRF,
Municipalities
Section 4.2.4 to understand current conservation lands and valuable habitats and
Commissions, Lakes
$4-8K
wildlife in the watershed that can be used to help identify potential areas to target for
conservation.
Region Conservation
Trust or other local
land trusts
2022-25
WWN, Municipalities,
Identify potential conservation buyers and property owners interested in easements
within the watershed. Use available funding mechanisms, such as the Regional
Conservation
Commissions, Lakes
N/A
Grants (Moose Plate,
LCHIP, RCCP, NAWCA,
LWCF, ACEP, CSP, EQIP)
Conservation Partnership Program (RCPP) and the Land and Community Heritage
Region Conservation
2022-25
Investment Program (LCHIP), to provide conservation assistance to landowners.
Trust or other local
land trusts
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Action Item
Responsible Party
Estimated Cost /
Schedule
Potential Funding
Sources
Maximize conservation of intact forest and other ecologically important properties
though education, zoning, and public or private conservation.
WWN, Municipalities,
Conservation
Commissions, Lakes
Region Conservation
Trust or other local
land trusts, private
landowners
TBD
2022-31
Grants (Moose Plate,
LCHIP, RCCP, NAWCA,
LWCF, ACEP, CSP, EQIP,
NFWF NEFRG),
Municipalities, private
landowners
Septic System Management
Distribute educational materials to property owners about septic system function and
maintenance.
Municipalities, WWN
$7K
2022,2027, 2031
Municipalities, Grant (319),
CWSRF
Look into whether any septic pumping companies would give a quantity discount or a
discount to members to incentivize septic system pumping.
WWN
N/A
2022-25
Grants
Evaluate locations of older and/or noncompliant septic systems to identify clusters
where conversion to community septic systems might be desirable.
WWN, Municipalities
TBD
2022-25
Grants, CWSRF,
Municipalities
Require inspection for all home conversions (from seasonal to permanent residences)
and property sales to ensure systems are sized and designed properly. Require upgrades
if needed. Consider modeling an ordinance on Meredith's septic system regulations
pertaining to the Lake Waukewan watershed.
Municipalities
N/A
2022-31
Municipalities
Develop and maintain a septic system database for the watershed to facilitate code
enforcement of any septic system ordinances.
Municipalities
$5-10K per
municipality
2022-25
Municipalities, Grants,
CWSRF
Institute a minimum pump-out/inspection interval for shorefront septic systems (e.g.,
once every 3-5 years). Require cesspools to be pumped every 1-2 years. Pump-outs
(~$250 per system) are the responsibility of the owner.
Municipalities
N/A
2022-25
Municipalities
If not already in place, develop a program to evaluate the sanitary sewer system and
reduce leaks and overflows, especially in the areas near waterbodies. Include periodic
inspections of the sewer line.
Municipalities
N/A
2022-31
Municipalities
Agricultural Practices
Work with NRCS to implement soil conservation practices such as covercrops, no-till
methods, and others which reduce erosion and nutrient pollution to surface waters from
agricultural fields.
NRCS, farm owners
TBD
2022-31
Grants, NRCS
Education & Outreach
Share additional/dynamic information on the WWN website, such as water quality data,
weather conditions, and webcam, to generate more traffic to the website.
WWN
TBD
2022-25
Grants
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Action Item
Responsible Party
Estimated Cost /
Schedule
Potential Funding
Sources
Educate managers of private boat launches about invasive species management, in
addition to the existing lake host program that operates at public boat launches.
WWN
$10K
2022-25
Grants (NHDESAIPC)
Offer workshops for landowners with 10 acres or more for NRCS assistance with land
conservation. Cost assumes up to two workshops.
WWN
$5K
2022-25
Grants (RCCP, ACEP, CSP,
EQIP)
Encourage private property owners to hire Green SnowPro certified commercial salt
applicators.
WWN, BCCD,
Municipalities
N/A
2022-31
Grants, Municipalities
Educate contractors and municipal staff about erosion and sediment control practices
required on plans. Work with municipalities to ensure that there are sufficient resources
to enforce permitting conditions.
Municipalities, WWN,
BCCD
$10K
2022-25
Municipalities, Grants
(319), CWSRF
Create flyers/brochures or other educational materials through printed or online
mediums, regarding topics such as stormwater controls, road maintenance, buffer
improvements, fertilizer and pesticide use, pet waste disposal, boat pollution, invasive
aquatic species, waterfowl feeding, and septic system maintenance. Consider creating a
"watershed homeowner" packet that covers these topics and is distributed (mailed
separately or in tax bills or posted at community gathering locations or events) to
existing and new property owners, as well as renters. Hold 1-2 informational workshops
per year to update the public on restoration progress and ways that individuals can help.
Cost is highly variable.
Municipalities, WWN,
BCCD
$50K-$100K
2022-31
Municipalities, Grants
(319), CWSRF
Collaborate with NH Lakes on legislative or advocacy issues such as cyanobacteria,
septic systems, and wake boat impacts.
WWN, NH Lakes
N/A, 2022-31
Grants
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5.2 POLLUTANT LOAD REDUCTIONS
To meet the water quality goal and state water quality standards for oligotrophic waterbodies, Objective 3 set a target
phosphorus load reduction of 260 kg/yrto achieve an in-lake total phosphorus concentration of 7.2 ppb at Lake Winnisquam
Pot Island Deep Spot [WINPLACD]. The following opportunities for phosphorus load reductions to achieve Objective 3 were
identified in the watershed based on field and desktop analyses:
• Remediating the over 100 watershed survey sites could prevent up to 53 kg/yr of phosphorus load from entering
Lake Winnisquam.
• Treating shoreline sites could reduce the phosphorus load to Lake Winnisquam by 20 kg/yr for the 20 high impact
sites (disturbance score 11+) and by 41 kg/yr for the 282 medium impact sites (disturbance score between 7-10)
identified from the shoreline survey.
• Upgrading the 198 shorefront septic systems older than 25 years is estimated to reduce the phosphorus load to Lake
Winnisquam by 29 kg/yr.
Addressing these field-identified phosphorus load reduction opportunities (i.e., watershed and shoreline sites and shorefront
septic systems) could reduce the phosphorus load to Lake Winnisquam by 143 kg/yr, meeting about half of the estimated 260
kg/yr phosphorus load reductions needed to achieve Objective 3 (Table 16). Because Lake Winnisquam is considered a Tier 2
High Quality Water, additional phosphorus load reductions to fully achieve Objective 3 may not be necessary and should be
re-evaluated after 5-10 years of plan implementation.
Objective 2 (preventing or offsetting additional phosphorus loading from anticipated new development) can be met through
ordinance revisions that implement LID strategies and encourage cluster development with open space protection and/or
through conservation of key parcels of forested and/or open land.
It is important to note that, while the focus of the objectives for this plan is on phosphorus, the treatment of stormwater and
sediment erosion will result in the reduction of many other kinds of pollutants that may impact water quality. These
pollutants would likely include other nutrients (e.g., nitrogen), petroleum products, bacteria, road salt/sand, and heavy
metals (cadmium, nickel, zinc, etc.). Without a monitoring program in place to measure these other pollutants, it will be
difficult to track the success of efforts that reduce these other pollutants. However, there are various spreadsheet models
available that can estimate reductions in these pollutants depending on the types of BMPs installed. These reductions can be
tracked to help assess long-term response.
Table 16. Breakdown of phosphorus load sources to Lake Winnisquam and modeled water quality for current and target
conditions that meet the water quality goal (Objective 3) for Lake Winnisquam and that reflect all field identified reduction
opportunities in the watershed. Reduction percentages are based out of the current condition value for each parameter.
WQ Goal & Estimated
Field Identified Reduction
Reduction Needed
Opportunities
Current
Target
Reduction
Target
Reduction
Parameter
Unit
Condition
Condition
(Unit, %)
Condition
(Unit, %)
Total P Load (All Sources)3
kg/yr
7,455
7,195
-260 (4%)
7,312
-143 (2%)
(A) Background P Load1
kg/yr
1,385
1,385
0 (0%)
1,385
0 (0%)
(B) Disturbed (Human) P Load2
kg/yr
6,070
5,810
-260 (4%)
5,927
-143 (2%)
(C) Developed Land Use P Load
kg/yr
5,871
5,640
-231 (4%)
5,757
-114 (2%)
(D) Septic System P Load
kg/yr
86
57
-29 (34%)
57
-29 (34%)
(E) Internal P Load
kg/yr
113
113
0 (0%)
113
0 (0%)
In-Lake TP*
ppb
7.5
7.2
-0.3 (4%)
7.4
-0.1 (1%)
In-Lake Chl-a*
ppb
1.7
1.6
-0.1 (6%)
1.6
-0.1 (6%)
In-Lake SDT*
meters
7.7
8.0
+0.3 (NA)
7.9
+0.2 (NA)
In-Lake Bloom Probability*
days
0
0
0 (0%)
0
0 (0%)
1 Sum of forested/water/natural land use load, waterfowl load, and atmospheric load (i.e., pre-development load)
2 Sum of developed land use load (including additional atmospheric load), shorefront septic system load, and interna! load (B - C+D+E)
3 TotalP Load (AllSources) - A +B
* Water quality parameters were sourced from the model, but total phosphorus and chlorophyll-a were adjusted to match the Assimilative Capacity analysis
(which uses a slightly different time period for averaging data).
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6 PLAN IMPLEMENTATION & EVALUATION
The following section details the oversight and estimated costs (with funding strategy) needed to implement the action items
recommended in the Action Plan (Section 5), as well as the monitoring plan and indicators to measure progress of plan
implementation overtime.
6.1 PLAN OVERSIGHT
The recommendations of this plan will be carried out largely by WWN with assistance from a diverse stakeholder group,
including representatives from the municipalities (e.g., select boards, planning boards, and conservation commissions), state
and federal agencies or organizations, nonprofits, land trusts, schools and community groups, local business leaders, and
landowners. WWN will need to meet regularly and work hard to coordinate resources across stakeholder groups to fund and
implement the management actions. The Action Plan (Section 5) will need to be updated periodically (typically every 2, 5,
and 10 years) to ensure progress and to incorporate any changes in watershed activities. Measurable milestones (e.g., number
of BMP sites, volunteers, funding received, etc.) should be tracked by WWN.
The Action Plan (Section 5) identifies the stakeholder groups responsible for each action item. Generally, the following
responsibilities are noted for each key stakeholder:
• WWN will be responsible for plan oversight and implementation. WWN will conduct water quality monitoring,
facilitate outreach activities and watershed stewardship, and raise funds for stewardship work.
• Municipalities will work to address NPS problems identified in the watershed, including conducting regular best
practices maintenance on roads, adopting ordinances for water quality protection, and addressing other
recommended actions specified in the Action Plan (Section 5). Each municipality will likely have a unique response
or implementation approach to the recommendations in the Action Plan (Section 5), and thus, the execution of the
actions may take a decentralized path. WWN and other local groups can work with each municipality to provide
support in reviewing and tailoring the recommendations to fit the specific needs of each community.
• Conservation Commissions will work with municipal staff and boards to facilitate the implementation of the
recommended actions specified in the Action Plan (Section 5).
• BCCD will provide administrative capacity and help acquire grant funding for BMP implementation projects and
education/outreach to watershed residents and municipalities.
• NHDES will provide technical assistance, permit approval, and the opportunity for financial assistance through the
319 Watershed Assistance Grant Program and otherfunding programs.
• Private Landowners will seek opportunities for increased awareness of water quality protection issues and
initiatives and conduct activities in a manner that minimizes pollutant impact to surface waters.
The success of this plan is dependent on the continued effort of volunteers and a strong and diverse committee that meets
regularly to coordinate resources for implementation, review progress, and make any necessary adjustments to the plan to
maintain relevant action items and interim milestones. A reduction in nutrient loading is no easy task, and because there are
many diffuse sources of phosphorus reaching the rivers, lakes, and ponds from existing development, roads, septic systems,
and other land uses in the watershed, it will require an integrated and adaptive approach across many different parts of the
watershed community to be successful.
6.2 ESTIMATED COSTS
The strategy for reducing pollutant loading to Lake Winnisquam to meet the water quality goal and objectives set in Section
2.4 will be dependent on available funding and labor resources but will include approaches that address sources of
phosphorus loading, as well as water quality monitoring and education and outreach. Additional significant but difficult to
quantify strategies for reducing phosphorus loading to the lake are revising local ordinances such asserting LID requirements
on new construction, identifying and replacing malfunctioning septic systems, performing proper road maintenance, and
improving agricultural practices (referto Section 5: Action Plan for moredetails). With a dedicated stakeholdergroup in place
and with the help of grant or local funding, it is possible to achieve the target phosphorus reductions and meet the established
water quality goal for Lake Winnisquam in the next 10 years. The cost of successfully implementing the plan is estimated
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at $2.1-$3.2 million over the next 10 or more years (Table 17). However, many costs are still unknown or were roughly
estimated and should be updated as information becomes available. In addition, costs to private landowners (e.g., septic
system upgrades, private road maintenance, etc.) are not reflected in the estimate.
Table 17. Estimated pollutant reduction (TP) in kg/year and estimated total and annual 10-year costs for implementation of
the Action Plan (Section 5) to meet the water quality goal and objectives for Lake Win nisquam. The light gray shaded planning
actions are necessary to achieve the water quality goal. Other planning actions are important but difficult to quantify for TP
reduction and costs, the latter of which were roughly estimated here as general placeholders.
Planning Action
TP Reduction (kg/yr)
Estimated Total Cost
Estimated Annual Cost
Watershed & Shoreline BMPs
114
$1,648,000-$2,148,000
$164,800-$214,800
Road Management
TBD
$55,000
$5,500
Municipal Operations
TBD
TBD
TBD
Municipal Land Use Planning& Zoning
281*
$13,000
$1,300
Land Conservation
$12,000-$24,000
$l,200-$2,400
Septic System Management
29
$42,000-$77,000
$4,200-$7,700
Agricultural Practices
TBD
TBD
TBD
Education & Outreach
TBD
$75,000-$125,000
$7,500-$12,500
Monitoring
NA
$250,0000-$750,000
$25,000-$75,000
Total
424
$2,095,000-$3,192,000
$209,500-$319,200
*Estimated increase in phosphorus toad from new development in the next 10 years.
6.3 FUNDING STRATEGIES
It is important that WWN develop a strategy to collect the funds necessary to implement the recommendations listed in the
Action Plan (Section 5). Funding to cover ordinance revisions and third-party review could be supported by municipalities
through tax collection (as approved by majority vote by residents). Monitoring and assessment funding could come from a
variety of sources, including state and federal grants, municipalities, or donations. Funding to improve septic systems, roads,
and shoreland zone buffers would likely come from property owners. As the plan evolves into the future, the establishment
of a funding subcommittee will be a key part in how funds are raised, tracked, and spent to implement and support the plan.
Listed below are state and federal funding sources that could assist WWN with future water quality and watershed work on
Lake Winnisquam.
Funding Options:
• EPA/NHDES319 Grants (Watershed Assistance Grants) - This NPS grant is designed to support local initiatives to
restore impaired waters (priorities identified in the NPS Management Program Plan, updated 2014) and protect high
quality waters. 319 grants are available for the implementation of watershed-based plans and typically fund $50,000
to $150,000 projects over the course of two years, https://www.des.nh.gov/business-and-community/loans-and-
grants/watershed-assistance
• NH State Conservation Committee (SCC) Grant Program (Moose Plate Grants) - County Conservation Districts,
municipalities (including commissions engaged in conservation programs), and qualified nonprofit organizations
are eligible to apply for the SCC grant program. Projects must qualify in one of the following categories: Water Quality
and Quantity; Wildlife Habitat; Soil Conservation and Flooding; Best Management Practices; Conservation Planning;
and Land Conservation. The total SCC grant request per application cannot exceed $24,000.
https://www.mooseplate.com/grants/
• Land and Community Heritage Investment Program (LCHIP) - This grant provides matching funds to help
municipalities and nonprofits protect the state's natural, historical, and cultural resources.
https://www.lchip.org/index.php/for-applicants/general-overview-scliedule-eligibility-and-application-process
• Aquatic Resource Mitigation Fund (ARM) - This grant provides funds for projects that protect, restore, or enhance
wetlands and streams to compensate for impacted aquatic resources. The fund is managed by the NHDES Wetlands
Bureau that oversees the state In-Lieu Fee (ILF) compensatory mitigation program. A permittee can make a payment
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to NHDES to mitigate or offset losses to natural resources because of a project's impact to the environment.
https://www.des, nh.gov/climate-and-sustainability/conservation-mitigation-and-resto ratio n/wetlands-mitigation
• New England Forest and River Grant (NFWF NEFRG)- This grant awards $50,000 to $200,000 to projects that
restore and sustain healthy forests and rivers through habitat restoration, fish barrier removal, and stream
connectivity such as culvert upgrades. https://www.nfwf.org/newengland/Paees/home.aspx
• Aquatic Invasive Plant Control, Prevention and Research Grants (NHDES AIPC) - Funds are available each year
for projects that prevent new infestations of exotic plants, including outreach, education, Lake Host Programs, and
other activities, https://www.des.nh.gov/business-and-community/loans-and-grants/rivers-and-lakes
• Clean Water State Revolving Fund (NHDES CWSRF) - This fund provides low-interest loans to communities,
nonprofits, and other local government entities to improve and replace wastewater collection systems with the goal
of protecting public health and improving water quality. A portion of the CWSRF program is used to fund NPS
pollution prevention, watershed protection and restoration, and estuary management projects that help improve
and protect water quality in NH. https://www.des.nh.gov/business-and-community/loans-and-grants/clean-water-
state-revo Ivi n g-fund
• Regional Conservation Partnership Program (RCCP) - This NRCS grant provides conservation assistance to
producers and landowners for projects carried out on agricultural land or non-industrial private forest land to
achieve conservation benefits and address natural resource challenges. Eligible activities include land management
restoration practices, entity-held easements, and public works/watershed conservation activities.
https://www.nrcs.usda.gov/wps/portal/nrcs/main/national/programs/financial/rcpp/
• Agricultural Conservation Easement Program (ACEP) - This NRCS grant protects the agricultural viability and
related conservation values of eligible land by limiting nonagricultural uses which negatively affect agricultural uses
and conservation values, protect grazing uses and related conservation values by restoring or conserving eligible
grazing land, and protecting, restoring, and enhancing wetlands on eligible land. Eligible applicants include private
landowners of agricultural land, cropland, rangeland, grassland, pastureland, and non-industrial private forestland.
https://www.nrcs.usda.gov/wps/portal/nrcs/main/national/programs/easements/acep/
• Conservation Stewardship Program (CSP) - This NRCS grant helps agricultural producers maintain and improve
their existing conservation systems and adopt additional conservation activities to address priority resource
concerns. Eligible lands include private agricultural lands, non-industrial private forestland, farmstead, and
associated agricultural lands, and public land that is under control of the applicant.
https://www.nrcs.usda.gov/wps/portal/nrcs/main/national/programs/financial/csp/
• Environmental Quality Incentives Program (EQIP) - This NRCS grant provides financial and technical assistance
to agricultural producers and non-industrial forest managers to address natural resource concerns and deliver
environmental benefits. Eligible applicants include agricultural producers, owners of non-industrial private
forestland, water management entities, etc.
https://www.nrcs.usda.gov/wps/portal/nrcs/main/national/programs/financial/eqip/
• National Fish and Wildlife Federation (NFWF) Five Star and Urban Waters Restoration Grants (NFWF 5-Star) -
Grants seek to address water quality issues in priority watersheds, such as erosion due to unstable streambanks,
pollution from stormwater runoff, and degraded shorelines caused by development. Eligible projects include
wetland, riparian, in-stream and/or coastal habitat restoration; design and construction of green infrastructure
BMPs; water quality monitoring/assessment; outreach and education, https://www.nfwf.org/prograrris/five-star-
and-urban-waters-restoration-grant-program
• North American Wetlands Conservation Act (NAWCA) Grants - The U.S. Standard Grants Program is a competitive,
matching grants program that supports public-private partnerships carrying out projects in the United States that
furtherthe goals of the North American Wetlands Conservation Act (NAWCA). These projects must involve long-term
protection, restoration, and/or enhancement of wetlands and associated uplands habitats for the benefit of all
wetlands-associated migratory birds, https://www.fws.gov/service/north-american-wetlands-conservation-act-
nawca-grants-us-standard
• National Park Service - Land and Water Conservation Fund Grant Program (LWCF) - Eligible projects include
acquisition of parkland or conservation land; creation of new parks; renovations to existing parks; and development
of trails. Municipalities must have an up-to-date Open Space and Recreation Plan. Trails constructed using grant
funds must be ADA-compliant. https://www.nhstateparks.org/about-us/community-recreation/land-water-
conservation-fund-grant
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6.4 MONITORING PLAN
A long-term water quality monitoring plan is critical to evaluate the effectiveness of implementation efforts over time.
WWN, in concert with VLAP and LLMP, has implemented the Lake Winnisquam Tiered Monitoring Plan since 2017 and
should continue the following annual monitoring protocol:
• VLAP monitors three deep spot stations in Lake Winnisquam (Three Island, Pot Island, and Mohawk Island) and LLMP
monitors two nearshore stations in Lake Winnisquam (10 Waldron and 30 Bartlett), three to five times each summer
for total phosphorus (epilimnion, metalimnion, and hypolimnion), chlorophyll-a (composite or epilimnion), Secchi
disktransparency, and dissolved oxygen-temperature-conductivity profiles.
o Ensure that dissolved oxygen-temperature profiles are being collected concurrently with sampling of lake
deep spot stations.
o Work with LOPA to consider monitoring the same parameters at the same frequency at the Lake Opechee
deep spot.
• VLAP also monitors the deep spot, west cove, east cove, and the Route 104 inlet to Lake Wicwas once each year for
total phosphorus, chlorophyll-a, Secchi disk transparency, and/or dissolved oxygen-temperature-conductivity
profiles.
o Work with Lake Wicwas Association to consider increasing the sampling frequency to at least three times
persummer.
• Volunteers collect additional Secchi disk transparency readings at the three deep spot stations in Lake Winnisquam
throughout the summer season (ideally every other week).
o Consider collecting Secchi disktransparency readings every other week in summer at the deep spot stations
for Lake Wicwas and Lake Opechee.
• WWN through VRAP monitors total phosphorus and chloride in nine tributary or outlet stations in the watershed, two
to five times per year each summer. Stations include Black Brook, Win nipesaukee River inlet to the lake, Lake Wicwas
outlet, Durkee Brook, Collins Brook, two branches of Chapman Brook, Durgin Brook, and the outlet of Lake
Winnisquam.
o Consider adding Mill Brook (WINTLACM), Hueber Brook, and Jewett Brook. Measure turbidity at Hueber
Brook and total phosphorus at all three streams. Mill Brook (WINTLACM) is located at its outlet to Lake
Winnisquam and would be helpful for calibration during future model updates,
o Consider monitoring the same parameters at the same frequency at major inflows to Lake Opechee,
especially the inflow from the Winnipesaukee River to Lake Opechee.
o Consider collecting flow measurements or estimates concurrently with grab samples at all tributary stations
for better calculation of nutrient loading.
6.5 INDICATORS TO MEASURE PROGRESS
The following environmental, programmatic, and social indicators and associated numeric targets (milestones) will help to
quantitatively measure the progress of this plan in meeting the established goal and objectives for the Lake Winnisquam
watershed (Table 18). These benchmarks represent short-term (2023), mid-term (2026), and long-term (2031) targets derived
directly from actions identified in the Action Plan (Section 5). Setting milestones allows for periodic updates to the plan,
maintains and sustains the action items, and makes the plan relevant to ongoing activities. WWN should review the
milestones for each indicator on an ongoing basis to determine if progress is being made, and then determine if the plan
needs to be revised because the targets are not being met.
Environmental Indicators are a direct measure of environmental conditions. They are measurable quantities used to evaluate
the relationship between pollutant sources and environmental conditions. They assume that recommendations outlined in
the Action Plan (Section 5) will be implemented accordingly and will result in the improvement of water quality.
Programmatic indicators are indirect measures of watershed protection and restoration activities. Ratherthan indicatingthat
water quality reductions are being met, these programmatic measurements list actions intended to meet the water quality
goal. Social Indicators measure changes in social or cultural practices and behavior that lead to implementation of
management measures and water quality improvement.
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Table 18. Environmental, programmatic, and social indicators for the Lake Winnisquam Watershed-Based Plan.
Environmental indicator milestones determined from Assimilative Capacity Analysis in Section 2.2 and FBE (2021a).
Programmatic and social indicator milestones estimated from best professional judgement.
Indicators
Milestones*
2023
2026
2031
ENVIRONMENTAL INDICATORS
Achieve an in-stream (Hueber Brook) and in-lake (Lake Winnisquam)
turbidity concentration < 10 NTU
10 NTU+
<10 NTU
<10 NTU
Maintain or achieve an average summer deep spot epilimnion total
phosphorus concentration of 7.2 ppb at the deep spot stations in Lake
Winnisquam and Lake Opechee (as well as Lake Wicwas despite being
beholden to only the mesotrophic threshold of 11.6 ppbfortotal
phosphorus)
<7.2 ppb
<7.2 ppb
<7.2 ppb
Maintain an averagesummerdeepspot epilimnion chlorophyll-a
concentration of less than 3.0 ppb at the deep spot stations in Lake
Winnisquam and Lake Opechee
<3.0 ppb
<3.0 ppb
<3.0 ppb
Maintain an average summerdeepspot epilimnion chlorophyll-a
concentration of less than 4.8 ppb at the deep spot station in Lake Wicwas
<4.8 ppb
<4.8 ppb
<4.8 ppb
Eliminate the occurrence of cyanobacteria or algal blooms in Lake
Winnisquam, Lake Opechee, and Lake Wicwas (milestones based on model
resu Its)
0-2 day/yr
0-2 day/yr
0 days/yr
Maintain an average summer water clarity of 7 m or deeper at the deep
spot stations in Lake Winnisquam and Lake Opechee
7 m+
7 m+
7 m+
Achieve an average summer water clarity of 5 m or deeper at the deep spot
station in Lake Wicwas
4.2 m
4.5 m
5.0 m
Prevent and/or control the introduction and/or proliferation of invasive
aquatic species all waterbodies
Absence of
invasives
Absence of
invasives
Absence of
invasives
PROGRAMMATIC INDICATORS
Amount of funding secured from municipal/private work, fundraisers,
donations, and grants
$500,000
$1,500,000
$3,000,000
Number of NPS sites remediated (108 identified)
10
25
75
Linear feet of buffers improved in the shoreland zone
500
1,000
2,000
Percentage of shorefront properties with LakeSmart certification
25%
50%
75%
Number of watershed/shoreline properties receiving technical assistance
for implementation cost sharing
5
25
50
Number of workshops and trainings forstormwater improvements to
residential properties (e.g., NHDES Soak Up the Rain NH program)
2
5
10
Number of updated or new ordinances that target water quality protection
1
5
10
Number of new municipal staff for inspections and enforcement of
regulations
1
3
5
Number of voluntary or required septic system inspections (seasonal
conversion and property transfer)
5
25
50
Number of septic system upgrades
5
25
50
Number of informational workshops and/or trainings for landowners,
municipal staff, and/or developers/landscapers on local ordinances,
watershed goals, and/or best practices for road management and winter
maintenance
2
10
20
Number of parcels with new conservation easements or number of parcels
put into permanent conservation
2
5
15
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Indicators
Milestones*
2023
2026
2031
Number of copies of watershed-based educational materials distributed or
articles published
500
750
1,000
Number of new best practices for road management and winter
maintenance implemented on public and private roads by the
municipalities
5
20
50
Number of best practice design standards for stormwater control
measures created and implemented by the watershed municipalities
5
20
50
Number of municipalities accepting residential yard waste at transfer
stations
4
5
7
Number of municipalities fully implementing key aspects of the MS4
program
2
5
7
Number of meetings and/or presentations to municipal staff and/or
boards related to the WBP
10
50
100
Number of CNMPs completed or NRCS technical assistance provided for
farms in the watershed
1
2
5
SOCIAL INDICATORS
Number of new association members
5
20
50
Number of volunteers participating in educational campaigns
15
25
50
Number of people participating in informational meetings, workshops,
trainings, BMP demonstrations, or group septic system pumping
50
200
500
Number of watershed residents installing conservation practices on their
property and/or participating in LakeSmart
10
100
200
Number of municipal DPW staff receiving Green SnowPro training
5
10
20
Number of groups or individuals contributing funds for plan
implementation
50
100
200
Number of newly trained water quality and invasive species monitors
3
5
10
Percentage of residents making voluntary upgrades or maintenance to
their septic systems (with or without free technical assistance), particularly
those identified as needing upgrades or maintenance
10%
25%
50%
Number of farmers workingwith NRCS or BCCD
1
2
5
Number of daily visitors to the WWN website
20
250
500
*Milestones are cumulative starting at year 1.
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LAKE WINNISQUAM WATERSHED-BASED PLAN
ADDITIONAL RESOURCES
Buffers for wetlands and surface waters: a guidebook for New Hampshire municipalities. Chase, et al. 1997. NH Audubon
Society. Online: https://www.nh.gov/oep/planning/resources/documents/buffers.pdf
Conserving your land: options forNH landowners. Lind, B. 2005. Center for Land Conservation Assistance / Society for the
Protection of N.H. Forests. Online: https://forestsociety.org/sites/default/files/ConservingYourLand color.pdf"
Environmental Fact Sheet: Erosion Control for Construction within the Protected Shoreland. New Hampshire Department of
Environmental Services, SP-1,2020. https://www.des.nh.gOv/sites/g/files/ehbemt341/files/documents/2020-01/sp-l.pdf
Gravel road maintenance manual: a guide for landowners on camp and other gravel roads. Maine Department of
Environmental Protection, Bureau of Land and Water Quality. April 2010. Online:
http://www.maine.gov/dep/land/watershed/camp/road/gravel road manual.pdf"
Gravel roads: maintenance and design manual. U.S. Department of Transportation, Federal Highway Program. November
2000. South Dakota Local Transportation Assistance Program (SD LTAP). Online:
https://www.epa.gOv/sites/production/files/2015-10/documents/2003 07 24 nps gravelroads gravelroads.pdf
Innovative land use techniques handbook. New Hampshire Department of Environmental Services. 2008. Online:
https://www.nh.gov/osi/planning/resources/innovative-land-use-guide.htm
Landscaping at the water's edge: an ecological approach. University of New Hampshire, Cooperative Extension. 2007.
Online: https://extension.unh.edu/resources/files/resource004159 rep5940.pdf
New Hampshire Homeowner's Guide to Stormwater Management: Do-tt-YourselfStormwater Solutions for Your Home. New
Hampshire Department of Environmental Services, Soak Up the Rain NH. Revised November 2019. Online:
https://www.des.nh.gOv/sites/g/files/ehbemt341/files/documents/2020-01/homeowner-guide-stormwater.pdf
Protecting water resources and managing stormwater. University of New Hampshire, Cooperative Extension & Stormwater
Center. March 2010. Online: https://extension.unh.edu/resources/files/Resource002615 Rep3886.pdf
Stormwater Manual, Volumes 1-3. New Hampshire Department of Environmental Services. 2008. Online:
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University ofNew Hampshire Stormwater Center2009 Biannual Report. University of New Hampshire, Stormwater Center.
2009. Online: https://www.unh.edu/unhsc/sites/unh.edu.unhsc/files/pubs specs info/2009 unhsc report,pdf
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Otero, X. L., De La Pena-Lastra, S., Perez-Alberti, A., Osorio Ferreira, T., & Huerta-Diaz, M. A. (2018). Seabird colonies as
important global drivers in the nitrogen and phosphorus cycles. Nature Communications. Retrieved from
https://www.nature.com/articles/s41467-017-02446-8
Paerl, H. W. (2018). Mitigating toxic planktonic cyanobacterial blooms in aquatic ecosystems facing increasing
anthropogenic and climatic pressures. Toxins, 10(2), 76. doi: https://doi.org/10.3390/toxinsl0020076
Przytulska, A., Bartosiewicz, M., & Vincent, W. F. (2017). Increased risk of cyanobacterial blooms in northern high-latitude
lakes through climate warming and phosphorus enrichment. Freshwater biology, 62(12), 1986-1996. doi:
https://doi.org/10.llll/fwb.13043
Staley, Z. R., He, D. D., Shum, P., Vender, R.,& Edge, T. A. (2018). Foreshore beach sand as a reservoir and source of total
phosphorus in Lake Ontario. Aquatic Ecosystem Health & Management, 268-275. Retrieved from
https://www.tandfonline.com/doi/abs/10.1080/14634988.2018.1505353
Trout Unlimited. (2020). Black BrookStream Crossing Assessment Summary, December 2020.
Underwood Engineers, Inc. (2020). Summary Report and Final Documentation: Sanbornton Roadway Evaluation, Town of
Sanbornton, New Hampshire, March 2020.
US Census Bureau (2022). Belknap County, New Hampshire. United States Census Bureau. Available at:
https://www.census.gov/Quickfacts/belknapcountynewhampshire
Zohary, T., & Ostrovsky, I. (2011). Ecological impacts of excessive water level fluctuations in stratified freshwater lakes.
Inland Waters, 1(1), 47-59. doi:https://doi.org/10.5268/IW-1.1.406
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LAKE WINNISQUAM WATERSHED-BASED PLAN
APPENDIX A: PUBLIC WORKSHOP
The following tables (A-l, A-2, A-3) summarize feedback received from participants in break-out sessions during a virtual
public workshop held on May 18,2021. Each break-out session focused on a specific topic related to known or potential NPS
sources to Lake Winnisquam.
Table A-1. Public Workshop: Issues and Challenges
Discussion Topic
Challenges and Issues Identified
Land Conservation
and Municipal
Planning
• Lack of information and knowledge about how landowners can conserve land
• Inconsistent policies/regulations across municipalities in the watershed
• Lack of economic opportunity, need for grant funding for municipalities with smaller budgets
• Issue with land clearing to improve views
Road Erosion
• Lack of established vegetation in ditches leads to erosion
• Small streams contributing contaminants from roads and other NPS sources
• Need for funding to fix roads and other sites
• Specific locations with known erosion:
o Tucker Mountain Rd at/upgradient of Hamlin-Eames conservation land
o Deer Park Association Beach
o Culvert under Collins Brook Rd (at the north end) right where it turns to dirt
Stormwater
Management
• Erosion and sediment control during construction
• Controls are not well maintained and are different from what was on approved plans
• Enforcement is difficult for small communities with limited staff capacity
• Lack of state follow up on approved timber cutting plans
• Clearing within 25' natural buffer on shoreline properties
• Need for homeowner education and support foraddressing stormwater runoff
• Trash and sediment contributions from Winnipesaukee River
Septic Systems
• Need for upgrades to older and failing septic systems
• How to get cooperation of property owners? Need for public outreach and education
• Cost and water quality tradeoffs for septic upgrades versus sewer
• Unknown age of systems, inventories in each municipality
• Question of whether you can put in a viable system on very small lots around Winnisquam
Other water
quality concerns
• Need for better coordination between the state, Planning Commissions, Public Works, and
others
• Many roads dead-end at the lake, conveying stormwater directly into the lake, e.g., Fenton Ave
• DPW grading of road and ditches continues to be source of sediment to lake
• Shoreline erosion issues due to wake from boats and other recreational watercraft
• Messages about "don't do this, don't do that" do not resonate or translate into interest and
action.
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Table A-2. Public Workshop: Potential Solutions
Discussion Topic
Potential Solutions Suggested by Participants
Land Conservation
and Municipal
Planning
• Improve enforcement of regulations at the state and municipal level
• Collaborate with local conservation partners on land conservation initiatives within the
watershed. Assign a liaison to communicate with conservation groups.
Road Erosion and
Maintenance
• Demonstration projects - present DPWs with options and ideas for trial or demonstration site
• Help DPWs pursuegrantfunding
Stormwater
Management
• Work with waterfront property owners to install rain gardens and restore vegetated buffers.
• Access resources through NH Soak up the Rain, NH Lakes - Lake Smart Lake Friendly Living
program, and Belknap County Conservation District.
• Educate homeowners about low-growing plants for shoreline restoration without blocking view
• Encourage soil tests to ensure that fertilizer applications are appropriate and proportional to
site needs.
• Manage trash in Winnipesaukee River - in the past, done by volunteers and BCCD
• Promote/implement BMPs; increase use of permeable pavements, rain gardens
• Engage school kids to do cleanups, learn about runoff going into streams
• Improve inspections and enforcement; focus on increasing staff capacity
• Increase setback requirements for shoreline buffer - e.g., Meredith requires 65' setback to
structure
Septic Systems
• Enforce occupancy limits and have septic system inventories in Master Plans.
• Consider septic system ordinances that require regular pump-outs and inspections to ensure
proper functioning. E.g., Meredith's Health Ordinance and Moultonborough Draft Health
Ordinance Pertainingto Evaluation and Replacement of Certain Subsurface Wastewater
Disposal Systems in Moultonborough
• Work with real estate agents to distribute pamphlet on how to maintain a septic system
• In Mass, septic systems need to be functioning before property sale. Consider a similar
requirement.
Other water
quality concerns
• Install stormwater BMPs, restore shoreline buffers on roads that dead-end at the lake.
• Educate DPW staff about invasive species.
• Share additional/dynamic info on WWN website; e.g., water quality, weather, webcam. See
Kezar Lake Watershed Association website for example. North end of Winnisquam could be
potential location for a webcam.
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LAKE WINNISQUAM WATERSHED-BASED PLAN
Table A-3. Public Workshop: Priority Actions
Discussion Topic
Priority Actions
Land Conservation
and Municipal
Planning
• Create a priority list of watershed areas that need protection based on natural resource
inventories and identify potential conservation buyers and property owners interested in
easements within the watershed.
• Zoning and enforcement
Road Erosion &
Maintenance
• Education and outreach to DPWs.
• Provide guide/written protocol for road installation and maintenance best practices to DPW.
Train public works staff on best practices for unpaved road maintenance.
• Go to DPW with options and ideas for demonstration sites to show them the type of work that
will create win/win to improve water quality and help them save time and money in the long
run. Help to obtain grant funding.
• Review road installation and maintenance practices currently used for each municipality and
determine areas for improvement.
• Establish inspection and maintenance agreements for private unpaved roads.
Stormwater
Management
• Educate contractors and municipal staff about erosion and sediment control practices
• Increase municipal staff capacity for inspections and enforcement
• Educate and provide technical support to waterfront property owners to install rain gardens
and restore vegetated buffers.
Septic systems
• Distribute educational materials about septic system function and maintenance.
• Require inspection for all home conversions (from seasonal to permanent residences), property
sales - make sure systems are sized and designed properly, require upgrades if needed.
• Develop and maintain a septic system database for the watershed to facilitate code
enforcement.
Other water
quality concerns in
the watershed
• Close the gap, improve coordination between planning commissions, public works, and water
quality stakeholders.
• Install stormwater BMPs, restore shoreline buffers on roads that dead-end at the lake.
• Share additional/dynamic info on WWN website; e.g., water quality, weather, webcam.
• Change messaging from "don't do this" to "here's what you can do" and "get involved".
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LAKE WINNISQUAM WATERSHED-BASED PLAN
APPENDIX B: SUPPORTING MAPS
Data Source: NH Granit,
NHD, NWI, ESRI
Coordinate System: NAD 1983
State Plane NH FIPS 2800 ft
Map Created By: C. Bunyon
FB Environmental
Date Created:1/5/2021
Gilmanton
Northfield
ESRI World Imagery 0 0.5 1 2
captured on 3/27/2020 Miles
Land Cover
Lake Winnisquam
Watershed Based
Management Plan
Sanbornton
Outlet
Tilton
Belmont
Urban 1: Low Den Res
Urban 2: Comm/Mid Den Res
| Urban 3: Roads
Urban 5: Mowed Fields
Agric 2: Row Crop
Agric 3: Grazing
Agric 4: Hayfield
Forest 1: Upland
Forest 2: Wetland
I Open 1: Water
Open 2: Meadow
Open 3: Excavation
Other 1: Logging
| Other 2: Unpaved Roads
C3 Lake Winnisquam Watershed
Town Boundary
Waterbody
Stream/River
Wetland
Center Harbor
New Hampton
Meredith
Bay
Lake Winnisquam
Lake Opechee
Gilford
Lake Wicwas
% * ^ Lake
Winnipesaukee
Pickerel Pond
Laconia
Map B-l, Land cover in the direct Lake Winnisquam watershed.
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LAKE WINNISQUAM WATERSHED-BASED PLAN
FB
environmental
Data Source: NH Granit,
NHD, NWI.ESRI
Coord. System: NAD 1983
State Plane NH FIPS 2800ft
Map Created By: K. Ryan
FB Environmental
Date Updated: 11/16/21
Gilford
Janbornton
Development
Constraints
Lake Winnisquam
Direct Watershed
Build-Out Analysis
Meredith
Tilton
C3 Lake Winnisquam Watershed
Road
Existing Building
Conserved Parcel
Waterbody
Stream/River
Wetland
Hydric Soil
Steep Slope
Belmont
New
Hampton
Gilmaaton
najator
Map B-2. Development constraints (including existing buildings) in the direct watershed of Lake Winnisquam in Belmont,
Gilford, Laconia, Meredith, New Hampton, Sanbornton, and Tilton, New Hampshire.
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LAKE WINNISQUAM WATERSHED-BASED PLAN
Buildable Area
by Zone
Lake Winnisquam
Direct Watershed
Build-Out Analysis
C3Lake Winnisquam Watershed
[jTown Boundary
Road
Walerbody
Stream/River
Buildable Area by Zone
Gilford Limited Residential
Meredith Residential District
New Hampton General Residential
Sanbornton General Residence
04 Belmont Residential - Single Family
(fit Gilford Single Family Residential
Laconia Residential Single-Family
District
Tilton Medium Density Residential
District
£4 Belmont Residential - Multi Family
04 Laconia Residential Apartment
04 Meredith Shoreline District
04 Belmont Commercial
04 Gilford Professional Commercial
04 Laconia Commercial
^-Sanbornton Commercial (Lt. Manuf.
Perm.)
Meredith Commercial District -
Meredith Center
04Tilton Resort Commercial
04 Laconia Urban Commercial District
#4 Gilford Industrial
04 Laconia Industrial
04 Meredith Business Industrial District
04 Laconia Industrial Park
Laconia Residential Rural
Belmont Rural
Tilton Rural Agricultural
Sanbornton General Agricultural
Meredith Forestry and Rural District
04 Meredith Forestry and Conservation
04 Sanbornton Forest Conservation
Sanbornton Recreational
Gilford Natural Resource Residential
LTilton Mixed Use District
Map B-3. Buildable area by municipal zone in the direct Lake Winnisquam watershed in Belmont, Gilford, Laconia, Meredith,
New Hampton, Sanbornton, and Tilton, New Hampshire.
New Hampton
Meredi
Gilford
Sanbornton
Tilton
Belmont
Data Source: NH Granit,
NHD, NWI, ESRI
Coordinate System: NAD 1983
State Plane Nil FIPS2800ft
Map Created By: C. Bunyon
FB Environmental
Date Updated: 11/16/2021
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LAKE WINNISQUAM WATERSHED-BASED PLAN
Projected
Buildings
Lake Winnisquam
Direct Watershed
Build-Out Analysis
C3Lake Winnisquam Watershed
£~ Town Boundary
Road
Waterbody
Stream/River
• Projected Building
Existing Building
Map B-4, Projected and existing buildings in the direct Lake Winnisquam watershed in Belmont, Gilford, Laconia, Meredith,
New Hampton, Sanbornton, and Tilton, New Hampshire.
New Hampton
Study Area
Gilford
Sanbornton
Tilton
Data Source: NH Granit,
NHD, NWI, ESRI
Coordinate System: NAD 1983
State Plane NHFIPS 2800 ft
Map Created By: C. Bunyon
FB Environmental
Date Updated: 11/16/2021
FB Environmental Associates & Horsley Witten Group
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LAKE WINNISQUAM WATERSHED-BASED PLAN
FB
environmental
Data Source: NH Granit,
NHD, NWI, ESRI, NHDES
Coordinate System: NAD 1983
State Plane NH FIPS 2800 ft
Map Created By: L. Diemer
FB Environmental
Date Created: 5/17/2022
NPS Sites
Lake Winnisquam
Watershed Based
Management Plan
C3 Lake Winnisquam Wshed
Town Boundary
State Road
- Local Road
- Private Road
— Unmaintained Road
Waterbody
Stream/River
Wetland
O NPS Watershed Sites
Moultonborough
Meredith
Gilmanton
Center Harbor
Sanbornton
Tilton
Northfield
ESRI World Imagery captured on 3/27/2020
Laconia
Gilford
Map B-5. NPS sites identified during the 2021 watershed survey in the direct Lake Winnisquam watershed.
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LAKE WINNISQUAM WATERSHED-BASED PLAN
Shoreline Survey
Lake Winnisquam
Watershed Based
Management Plan
r"r '!
C3 Lake Winnisquam Watershed
Town Boundary
Waterbody
Wetland
Shoreline Disturbance Score
Not Assessed
1-3
4-8
9-12
13-15
Data Source: NH Granit,
NHD, NWI, ESRI, LRPC
||| Coordinate System: NAD 1983
" State Plane NH FIPS 2800 ft
Map Created By: M. Kelly
FB Environmental
Date Created: 4/15/22
Map B-6. Shoreline Disturbance Score for parcels with frontage on Lake Winnisquam, as rated during the 2020 shoreline
survey by WWN volunteers.
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LAKE WINNISQUAM WATERSHED-BASED PLAN
Laconia
Note: Percentages do not account
Center Harbor for soils beneath waterbodies.
New Hampton
Meredith
Gilford
Sanbornton
Northfield
Gilmanton
ESRI World Imagery 0 0.5 1 2
captured on 3/27/2020 Miles
Tilton
Belmont
Soil Series
Lake Winnisquam
Watershed Based
Management Plan
Data Source: NH Granit,
NHD.NWi, ESRI
Coordinate System: NAD 1983
State Plane NH FIPS 2800 ft
Map Created By: C. Bunyon
FB Environmental
Date Created: 1/4/2021
C3 Lake Winnisquam Watershed
n" ! Town Boundary
State Road
Local Road
Private Road
Unmaintained Road
Waterbody
Stream/River
Wetland
Soil Series
Tunbridge-Lyman-Becket
complex, very stony
(20%)
Millsite-Woodstock-
Henniker complex, very
stony (17%)
Canterbury Fine Sandy
Loam, very stony (8%)
Gilmanton Fine Sandy
Loam, very stony (5%)
Pillsbury Sandy Loam,
very stony (4%)
Other
Map B-7. Soil series in the direct Lake Winnisquaim watershed.
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LAKE WINNISQUAM WATERSHED-BASED PLAN
FB
environmental
Data Source: NH Granit,
NHD.NWI, ESRI.WSS
{!& Coordinate System: NAD 1983
State Plane NH FIPS 2800ft
Map Created By: C. Bunyon
FB Environmental
Date Created: 1/5/2021
Soil Erosion Hazard
Lake Winnisquam
Watershed Based
Management Plan
Laconia
Center Harbor
New Hampton
Meredith
Gilford
Sanbornton
Tilton
Northfield
ESRI World Imagery
captured on 3/27/2020
Belmont
Gilmanton
03 Lake Winnisquam Watershed
! Town Boundary
State Road
— Local Road
Private Road
Unmaintained Road
Waterbody
Stream/River
Wetland
Soil Erosion Hazard
Very Severe (3%)
Severe (42%)
Moderate (39%)
Slight (16%)
Not rated (1%)
Note: Percentages do not account
for soils beneath waterbodies.
Map B-8. Soil Erosion Hazard in the direct Lake Winnisquam watershed.
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LAKE WINNISQUAM WATERSHED-BASED PLAN
FB
environmental
Data Source: NH Granit,
NHD, NWI, ESRI
il'fik Coordinate System: NAD 1983
- ~ State Plane NH FIPS 2800 ft
Map Created By: C. Bunyon
FB Environmental
Date Created: 1/4/2021
Laconia
Gilford
Sanbornton
Gilmanton
Northfield
ESRI World Imagery 0 0.5 1 2
captured on 3/27/2020 Miles
Tilton
Belmont
Conservation Land
Lake Winnisquam
Watershed Based
Management Plan
Center Harbor
New Hampton
Meredith
Lake Winnisquam Watershed
Town Boundary
State Road
— Local Road
— Private Road
— Unmaintained Road
Waterbody
Stream/River
Wetland
Conservation Land
Federal
State
Municipal/County
Private
Map B-9. Conservation land within the direct Lake Winnisquam watershed.
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LAKE WINNISQUAM WATERSHED-BASED PLAN
High Value Habitat
Lake Winnisquam
Watershed Based
Management Plan
C3 Lake Winnisquam Watershed
J Town Boundary
State Road
- Local Road
Private Road
- Unmaintained Road
Waterbody
Stream/River
Wetland
Habitat Classification
¦ Highest Ranked Habitat in
New Hampshire
Highest Ranked Habitat in
Biological Region
Supporting Landscapes
Not Classified
Study Area
Data Source: NH Granit,
NHD.NWI, ESRI
Coordinate System: NAD 1983
State Plane NHFIPS2800 ft
Map Created By: C. Bunyon
FB Environmental
Date Created: 1/4/2021
Map B-10, High value habitat according to the 2015 New Hampshire Wildlife Action Plan in the direct Lake Winnisquam
watershed.
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Laconia
Center Harbor
New Hampton
Meredith
Gilford
Sanbornton
Tilton
Northfield
ESRI World Imagery
captured on 3/27/2020
Belmont
Giimanton
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LAKE WINNISQUAM WATERSHED-BASED PLAN
APPENDIX C: BMP MATRIX
Site
ID
Site Descr.
Municipality
Subbasin
Description of Problem
Recommendations
Primary
Recommended
Actions
Total Average
Annual
Sediment
Load
Removed
(kg/yr)
Total
Average
Annual
TP Load
Removed
(kg/yr)
Direct or
Indirect/Limited
Discharge to
Waterbody
Priority
3-36
Doctor True
Rd and Maple
Circle,
Sanbornton
Sanbornton
Lake
Winnisquam
Direct
Identified by Sanbornton
Selectman. Dr. True Rd and
Maple Circle are impassable
during mud season, with ruts
up to a foot deep and large
sections of unpassable mud.
Sediment flows to lake.
Town is considering
paving DrTrue Rd and
Maple Circle to address
erosion and travel
issues. BMPs will be
needed to manage
runoff and pollutants
(including sand, salt)
from newly paved roads.
Stabilization
9,273
4.6
Direct
High
3-34
Bay Rd
Sanbornton
Chapman
Brook
Loose sediment and erosion
observed along unpaved
parking area, access ramp, and
pull-off area atstream crossing
(downstream side), private
property sign posted
Stabilize parking area,
pull-off area, and access
ramps
Stabilization
4,990
2.1
Direct
High
1-12
Gale Ave-
small pocket
park with
access to lake
Laconia
Lake
Winnisquam
Direct
Two gullies directly to water,
reports of trash. Sheet flow
from crowned road goes into
gullies.
Route flow into bio use
existing ditch to north
because it is more stable
Treatment,
Stabilization
2,282
1.6
Direct
High
3-28
Woodman Rd
intersection
with Steele
Hill Rd
Sanbornton
Black Brook
Road shoulder/ditch erosion,
Unstable culvert inlet/outlet,
Concentrated stormwater flow
paths evident, Winter sand,
Steep slope from road to
stream (large boulders and
riprap in place for stabilization)
Stabilize inlet and/or
outlet, Armor
ditch/turnouts with
stone or grass with check
dams, Reshape ditch,
Reshape or crown road,
Reshape/vegetate
shoulder
Stabilization
3,629
1.5
Direct
High
3-21
Eagle Ledge
Rd
intersection
with
Batchelder
Hill Rd
Meredith
Lake
Winnisquam
Direct
Road shoulder/ditch erosion,
Unstable culvert inlet/outlet,
Concentrated stormwater flow
paths evident, Construction site
uphill on Eagle Ledge Rd
without controls in place
Armor ditch with stone
or grass, Reshape ditch,
Reshape or crown road,
Reshape/vegetate
shoulder
Stabilization
3,592
1.5
Direct
High
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LAKE WINNISQUAM WATERSHED-BASED PLAN
Site
ID
Site Descr.
Municipality
Subbasin
Description of Problem
Recommendations
Primary
Recommended
Actions
Total Average
Annual
Sediment
Load
Removed
(kg/yr)
Total
Average
Annual
TP Load
Removed
(kg/yr)
Direct or
Indirect/Limited
Discharge to
Waterbody
Priority
3-23
Kaulback Rd
and Roxbury
Rd, trib to
Black Brook
crossing
Sanbornton
Black Brook
Road shoulder/ditch erosion,
Unstable culvert inlet/outlet,
Concentrated stormwater flow
paths evident, Plow pile area,
Loose sediment, Grader berms
Stabilize inlet and/or
outlet, Replace/enlarge
culvert, Armor ditch with
stone or grass, Reshape
ditch, Reshape or crown
road, Reshape/vegetate
shoulder
Stabilization
3,393
1.4
Direct
High
3-24
Lower Bay Rd
and Huse Rd,
trib to Black
Brook
crossing
Sanbornton
Black Brook
Road shoulder/ditch erosion,
Concentrated stormwater flow
paths evident, Loose sediment
Armor ditch with stone
or grass, Reshape ditch,
Reshape or crown road,
Reshape/vegetate
shoulder
Stabilization
2,776
1.4
Direct
High
3-12
Stoney Brook
Rd
Meredith
Swamp
Pond
Unpaved road with poor crown
and minimal road shoulderto
ditch with direct contact with
water, plow pile area with loose
sediment adjacentto wetland
Reshape or crown road,
Reshape/vegetate
shoulder, Clean outand
stabilize plow pile area
Stabilization
3,024
1.3
Direct
High
3-25
Woodman Rd
Sanbornton
Black Brook
Road shoulder/ditch erosion,
Unstable culvert inlet/outlet, rill
formation from road shoulder
to culvert inlet/outlet
Stabilize inlet and/or
outlet, Armor ditch with
stone or grass, Reshape
ditch, Reshape/vegetate
shoulder
Stabilization
2,159
1.1
Direct
High
3-22
Eagle Ledge
Rd, Black
Brook
crossing
Sanbornton
Black Brook
Road shoulder/ditch erosion,
Unstable culvert inlet/outlet,
Concentrated stormwater flow
paths evident, Minimal road
shoulder at culvert crossing,
Plow pile area, Loose sediment,
Grader berms
Stabilize inlet and/or
outlet, Armor ditch with
stone or grass, Reshape
ditch, Reshape or crown
road, Reshape/vegetate
shoulder
Stabilization
2,395
1.0
Direct
High
3-31
Philbrook Rd
Sanbornton
Chapman
Brook
Road shoulder/ditch erosion,
Unstable culvert inlet/outlet,
Concentrated stormwater flow
paths evident, Loose sediment,
Turnouts lead directly to stream
Stabilize inlet and/or
outlet, Armor ditch with
stone or grass, Reshape
ditch/turnouts, Reshape
or crown road,
Reshape/vegetate
shoulder
Stabilization
2,395
1.0
Direct
High
3-11
Roxbury Rd
Meredith
Swamp
Pond
Road shoulder/ditch erosion
along both sides of road leading
to culvert stream crossing
Armor ditch with stone
or grass, Reshape ditch,
Reshape or crown road,
Reshape/vegetate
shoulder
Stabilization
2,195
0.9
Direct
High
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LAKE WINNISQUAM WATERSHED-BASED PLAN
Site
ID
Site Descr.
Municipality
Subbasin
Description of Problem
Recommendations
Primary
Recommended
Actions
Total Average
Annual
Sediment
Load
Removed
(kg/yr)
Total
Average
Annual
TP Load
Removed
(kg/yr)
Direct or
Indirect/Limited
Discharge to
Waterbody
Priority
3-20
New road
construction
off Batchelder
Hill Rd
Meredith
Lake
Winnisquam
Direct
New road construction up steep
grade, minimal controls in
place to prevent loose gravel
and sediment from eroding,
ponding water on south side,
runoff directed to stream on
north side thatflows under
Batchelder Hill Rd and to the
lake
Armor ditch with stone
or grass, Reshape ditch,
Reshape or crown road,
Reshape/vegetate
shoulder
Stabilization
1,996
0.8
Direct
High
3-30
Chapman Rd
Sanbornton
Chapman
Brook
Road shoulder/ditch erosion,
Unstable culvert inlet/outlet,
Concentrated stormwater flow
paths evident, Loose sediment
Stabilize inlet and/or
outlet, Armor ditch with
stone or grass, Reshape
ditch, Reshape or crown
road, Reshape/vegetate
shoulder
Stabilization
1,996
0.8
Direct
High
2-05
Stream
crossing
Gilford
Jewett
Brook
Road shoulder/ditch erosion,
Unstable culvert inlet/outlet,
Excessive trash, Severe
streambank erosion/failure
Armor ditch with stone
or grass, Install turnout,
Reshape ditch, Stabilize
banks, Install runoff
diverter, Plant/improve
buffer
Stabilization
1,361
0.8
Direct
High
3-32
Philbrook Rd
Sanbornton
Chapman
Brook
Road shoulder/ditch erosion,
Unstable culvert inlet/outlet,
Concentrated stormwater flow
paths evident, Loose sediment,
Turnouts lead directly to stream
Stabilize inlet and/or
outlet, Armor ditch with
stone or grass, Reshape
ditch/turnouts, Reshape
or crown road,
Reshape/vegetate
shoulder
Stabilization
1,361
0.8
Direct
High
3-16
Weed Rd
Meredith
Swamp
Pond
Road shoulder/ditch erosion
along both sides of Weed Rd
leading to wetland, road
shoulder material eroding into
woodline/wetland
Armor ditch with stone
or grass, Reshape ditch,
Reshape or crown road,
Reshape/vegetate
shoulder, Improve buffer
Stabilization
1,814
0.8
Direct
High
4-06
Old stage rd.
culvert
Meredith
Unnamed
Tributary
(North Trib)
Road surface erosion, Road
shoulder/ditch erosion
Install turnout, Reshape
ditch, Reshape/vegetate
shoulder, Reshape or
crown road, Install runoff
diverter
Stabilization
1,814
0.8
Direct
High
FB Environmental Associates & Horsley Witten Group
92
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LAKE WINNISQUAM WATERSHED-BASED PLAN
Site
ID
Site Descr.
Municipality
Subbasin
Description of Problem
Recommendations
Primary
Recommended
Actions
Total Average
Annual
Sediment
Load
Removed
(kg/yr)
Total
Average
Annual
TP Load
Removed
(kg/yr)
Direct or
Indirect/Limited
Discharge to
Waterbody
Priority
4-08
Intersection
of route 104
and Hatch
Corner Road
Meredith
Unnamed
Tributary
(North Trib)
Road shoulder/ditch erosion
with erosion channels leading
to stream.
Remove winter sand,
Install erosion controls
(e.g. siltfence), Armor
ditch with stone or grass
Stabilization
1,814
0.8
Direct
High
4-09
Dow Road,
near
intersection
with Rte.104
Meredith
Unnamed
Tributary
(North Trib)
Road shoulder/ditch erosion
directly to stream/pond
Armor ditch with stone
or grass, Install erosion
controls (e.g. silt fence)
Stabilization
1,814
0.8
Direct
High
3-10
Chemung Rd
Meredith
Swamp
Pond
Road shoulder/ditch erosion
along both sides of road leading
to culvert stream crossing,
groundwater spring at culvert
inlet, multiple turnouts were
noted on the east ditch up road
slope with significant sediment
deposits
Armor ditch with stone
or grass, Reshape ditch,
Reshape or crown road,
Reshape/vegetate
shoulder
Stabilization
1,633
0.7
Direct
High
3-13
Stoney Brook
Rd, crossing
with river
Meredith
Swamp
Pond
Geomorphic instability of river
downstream of road crossing,
large trees uprooted from bank
with fresh soil exposed,
multiple concentrated
stormwater flow paths from
Stoney Brook Rd entering river
Armor ditch with stone
or grass, Reshape ditch,
Reshape or crown road,
Reshape/vegetate
shoulder, Investigate
geomorphic stability of
river
Stabilization
1,597
0.7
Direct
High
3-14
Deer Park
Association
beach on
Weed Rd
Meredith
Lake
Winnisquam
Direct
Road surface erosion, Road
shoulder/ditch erosion from
Heritage Rd and Weed Rd
causing rill formation on road
surface and gully formation on
the beach, beach is positioned
on a steep grade leading to the
lake
Armor ditch with stone
or grass, Reshape ditch,
Reshape or crown road,
Reshape/vegetate
shoulder, Improve
buffer, Consider tiered
landscaping for
infiltration practices,
Install turnouts on south
access road to lake
Stabilization
1,597
0.7
Direct
High
3-26
Woodman Rd
Sanbornton
Black Brook
Road shoulder/ditch erosion,
Concentrated stormwater flow
paths evident from ditch and
residential driveway, Minimal
buffer between road and
stream
Armor ditch with stone
or grass, Reshape ditch,
Reshape/vegetate
shoulder, Divert
driveway runoff,
Enhance and stabilize
buffer between road and
stream
Stabilization
1,597
0.7
Direct
High
FB Environmental Associates & Horsley Witten Group
93
-------
LAKE WINNISQUAM WATERSHED-BASED PLAN
Site
ID
Site Descr.
Municipality
Subbasin
Description of Problem
Recommendations
Primary
Recommended
Actions
Total Average
Annual
Sediment
Load
Removed
(kg/yr)
Total
Average
Annual
TP Load
Removed
(kg/yr)
Direct or
Indirect/Limited
Discharge to
Waterbody
Priority
3-05a
Hamlin Rec
and Cons area
parking lot
Meredith
Swamp
Pond
Parking area surface erosion
leads to road shoulder/ditch
erosion, runoff from Chemung
Rd evident and causing the rill
formation
Build up road/ add
surface material, Install
runoff diverter, Armor
ditch with stone or grass,
Reshape road crown
Stabilization
3,402
1.4
Limited
Medium
4-03
Dirt road with
pot holes on
Eastman
Shore Rd N
Laconia
Lake
Winnisquam
Direct
Road surface erosion, Road
shoulder/ditch erosion,
Unstable culvert inlet/outlet,
Unstable construction site,
Excessive build-up of sediment,
Buried culvert, Surface sheet
erosion from a new
construction lot and unpaved
dirt driveway to an unpaved
road. Culvert under driveway
apron is buried in sediment
from an unpaved steep
driveway with construction at
the top. No sediment control
practices are visible and
sediment is spilling out all over
the private roadway and into
the drainage ditch.
Clean out culvert, Armor
ditch with stone or grass,
Install erosion controls
(e.g. siltfence),
Reshape/vegetate
shoulder, Reshape or
crown road
Stabilization
2,468
1.2
Limited
Medium
2-33
Jefferson Rd
Belmont
Lake
Winnisquam
Direct
Road shoulder/ditch erosion,
Road surface erosion, The full
road is a soft unpaved sandy
material
Build up road/ add
surface material,
Reshape or crown road
Stabilization
1,996
0.8
Limited
Medium
3-07
Chemung Rd
Meredith
Swamp
Pond
Road shoulder/ditch erosion
along both sides of road leading
to culvert crossing, runoff from
east side ditch overtops culvert,
gully formation evident, flowing
water through culvert
Armor ditch with stone
or grass, Reshape ditch,
Reshape or crown road,
Reshape/vegetate
shoulder
Stabilization
1,814
0.8
Limited
Medium
3-19
Camp
Waldron Rd
Meredith
Swamp
Pond
Road shoulder/ditch erosion,
Unstable culvert inlet/outlet, rill
formation from road shoulder
to culvert inlet/outlet
Stabilize inlet and/or
outlet, Armor ditch with
stone or grass, Reshape
ditch, Reshape or crown
road, Reshape/vegetate
shoulder
Stabilization
1,814
0.8
Limited
Medium
FB Environmental Associates & Horsley Witten Group
94
-------
LAKE WINNISQUAM WATERSHED-BASED PLAN
Site
ID
Site Descr.
Municipality
Subbasin
Description of Problem
Recommendations
Primary
Recommended
Actions
Total Average
Annual
Sediment
Load
Removed
(kg/yr)
Total
Average
Annual
TP Load
Removed
(kg/yr)
Direct or
Indirect/Limited
Discharge to
Waterbody
Priority
2-04
Swain Rd
Gilford
Jewett
Brook
Road shoulder/ditch erosion
Reshape/vegetate
shoulder, Armor ditch
with stone or grass
Stabilization
1,542
0.8
Limited
Medium
2-06
Garden Hill
Drive
Gilford
Durkee
Brook
Road shoulder/ditch erosion
Install erosion controls
(e.g. siltfence),
Reshape/vegetate
shoulder, Armor ditch
with stone or grass, The
ditch is armored with
riprap but is getting filled
in from the smaller stone
lining the roadway.
Stabilization
1,542
0.8
Limited
Medium
3-08
Chemung Rd
Meredith
Swamp
Pond
Road shoulder/ditch erosion
along both sides of road leading
to culvert crossing, runoff from
east side ditch overtops culvert,
gully formation evident, flowing
water through culvert, grader
berms evident
Armor ditch with stone
or grass, Reshape ditch,
Reshape or crown road,
Reshape/vegetate
shoulder
Stabilization
1,542
0.8
Limited
Medium
2-01
Savage Rd
Gilford
Jewett
Brook
Road shoulder/ditch erosion
Armor ditch with stone
or grass, Install ditch,
Reshape ditch, Remove
winter sand,
Reshape/vegetate
shoulder, Plant/improve
buffer
Stabilization
1,597
0.7
Limited
Medium
3-15
Weed Rd
Meredith
Swamp
Pond
Road shoulder/ditch erosion
along both sides of Weed Rd
leading to wetland, road
adjacent to wetland with
minimal buffer, ditch scraping
maintenance evident
Armor ditch with stone
or grass, Reshape ditch,
Reshape or crown road,
Reshape/vegetate
shoulder, Improve buffer
Stabilization
1,451
0.6
Direct
Medium
3-09
Chemung Rd
Meredith
Swamp
Pond
Road shoulder/ditch erosion
along both sides of road leading
to culvert stream crossing,
green PVC pipes under road
may be directing water from
west to east side ditch
Armor ditch with stone
or grass, Reshape ditch,
Reshape or crown road,
Reshape/vegetate
shoulder
Stabilization
1,080
0.5
Direct
Medium
FB Environmental Associates & Horsley Witten Group
95
-------
LAKE WINNISQUAM WATERSHED-BASED PLAN
Site
ID
Site Descr.
Municipality
Subbasin
Description of Problem
Recommendations
Primary
Recommended
Actions
Total Average
Annual
Sediment
Load
Removed
(kg/yr)
Total
Average
Annual
TP Load
Removed
(kg/yr)
Direct or
Indirect/Limited
Discharge to
Waterbody
Priority
3-05 b
Chemung Rd
to Hamlin Rec
and Cons area
trail head
Meredith
Swamp
Pond
Road surface runoff down steep
grade concentrates in turnout
at bend in road, turnout leads
down steep slope through the
woods to the trail head and
crossing with a stream,
significant material movement
and soil erosion, severe gully
formation, erosion impacting
trail stability, sediment/soil
depositing directly into stream
Reshape/vegetate
shoulder, Reshape or
crown road, Install runoff
diverter, Armor ditch and
turnout with stone or
grass, Stabilize trail
Stabilization
1,270
0.5
Direct
Medium
2-35
Union Rd
stream
crossing
Belmont
Lake
Winnisquam
Direct
Lack of buffer flowing through
agricultural fields. Horses do
not have access to stream itself
Plant/improve buffer
Buffer
0
0.5
Direct
Medium
3-02
Camp
Waldron Rd
near
intersection
with
Chemung Rd
Meredith
Lake Wicwas
Direct
Significant road shoulder/ditch
erosion along south side of
Chemung Rd and both sides of
Camp Walton Rd; significant
gully formation in west side
ditch leading to culvert
Stabilize inlet and/or
outlet, Armor ditch with
stone or grass, Reshape
ditch, Stabilize banks,
Reshape/vegetate
shoulder
Stabilization
1,197
0.5
Direct
Medium
3-06
Tucker Mtn Rd
Meredith
Swamp
Pond
Road surface erosion, Road
shoulder/ditch erosion to
culvert crossing under Tucker
Mtn Rd, culvert conveys small
flowing stream
Armor ditch with stone
or grass, Reshape ditch,
Reshape or crown road,
Reshape/vegetate
shoulder
Stabilization
1,179
0.5
Direct
Medium
2-24
Across from
drinking
water
protection
area
Belmont
Lake
Winnisquam
Direct
Road shoulder/ditch erosion,
Trash
Armor ditch with stone
or grass, Install check
dams
Stabilization
925
0.5
Direct
Medium
2-10
Province Rd
Laconia
Durkee
Brook
Stockpiled soil, Road surface
erosion, Source of sand is a
private driveway
Install erosion controls
(e.g. siltfence),Install
runoff diverter, The sand
that spills out onto the
state road shoulder isn't
leading to anywhere just
piling up on itself. This
could be a residential fix
if it becomes connected
to a waterbody or catch
basin
Maintenance
1,331
0.6
Limited
Low
FB Environmental Associates & Horsley Witten Group
96
-------
LAKE WINNISQUAM WATERSHED-BASED PLAN
Site
ID
Site Descr.
Municipality
Subbasin
Description of Problem
Recommendations
Primary
Recommended
Actions
Total Average
Annual
Sediment
Load
Removed
(kg/yr)
Total
Average
Annual
TP Load
Removed
(kg/yr)
Direct or
Indirect/Limited
Discharge to
Waterbody
Priority
4-07
Hatch Corner
Rd north of
Old Stage Rd
Meredith
Unnamed
Tributary
(North Trib)
Road surface erosion, Road
shoulder/ditch erosion
Armor ditch with stone
or grass
Stabilization
1,210
0.5
Limited
Low
4-04
Livingston Rd
Meredith
Mill Brook
Road surface erosion, Road
shoulder/ditch erosion,
Unstable culvert inlet/outlet.
Road shoulder eroding down to
the drainage ditch with gullies.
Clean out culvert, Armor
ditch with stone or grass,
Stabilize inlet and/or
outlet, Reshape ditch,
Reshape/vegetate
shoulder
Stabilization
1,028
0.5
Limited
Low
3-04
Chemung Rd,
across from
Hamlin Rec
and Cons
parking area
Meredith
Swamp
Pond
Road shoulder/ditch erosion
down steep grade with flowing
water along south side of
Chemung Rd, driveway culvert
small
Reshape/vegetate
shoulder, Reshape ditch,
Armor ditch with stone
or grass, Replace culvert
Stabilization
1,179
0.5
Limited
Low
2-30
Mile Hill Rd
Belmont
Durkee
Brook
Road shoulder/ditch erosion,
Unstable culvert inlet/outlet
Clean out culvert, Install
plunge pool, Stabilize
inlet and/or outlet,
Armor ditch with stone
or grass, Install ditch,
Reshape ditch
Stabilization
925
0.5
Limited
Low
4-13
Corner of
Collins Brook
Rd and
Meredith
Center Rd
Meredith
Collins
Brook
Road shoulder/ditch erosion
Armor ditch with stone
or grass, Reshape ditch
Stabilization
1,089
0.5
Limited
Low
4-20
Wicwas
Shores Rd
culvert
Meredith
Lake Wicwas
Direct
Road surface erosion, Road
shoulder/ditch erosion
Armor ditch with stone
or grass, Install erosion
controls (e.g. silt fence),
Check dams
Stabilization
1,089
0.5
Limited
Low
1-10
City hall
parking lot-
north
Laconia
Winnipesauk
ee River
Depression filled with sediment
Retrofit basin into
attractive bio with
Forebay. Check property
lines. Only upper basin is
city owned. Might be
able to include private.
Do not remove parking.
Treatment
0
0.4
Direct
Low
2-23
Near
Hurricane Rd,
Union Rd
intersection
Belmont
Lake
Winnisquam
Direct
Road shoulder/ditch erosion,
Buried culvert partially
Reshape ditch, Armor
ditch with stone or grass
Stabilization
998
0.4
Direct
Low
FB Environmental Associates & Horsley Witten Group
97
-------
LAKE WINNISQUAM WATERSHED-BASED PLAN
Site
ID
Site Descr.
Municipality
Subbasin
Description of Problem
Recommendations
Primary
Recommended
Actions
Total Average
Annual
Sediment
Load
Removed
(kg/yr)
Total
Average
Annual
TP Load
Removed
(kg/yr)
Direct or
Indirect/Limited
Discharge to
Waterbody
Priority
1-01
Opechee Park
parking lot,
picnic/play
area, and
beach
Laconia
Lake
Opechee
Goose habitat, parking lot
runoff erosion. Existing
vegetated swale.
Buffer planting, enhance
veg swale along beach,
swale along parking
edge conveying to
terrace with infiltration
under picnic tables with
timber ties. Slide tables
away from oak.
Treatment,
Stabilization
0
0.4
Direct
Low
3-17
Camp
Waldron Rd
Meredith
Swamp
Pond
Road shoulder/ditch erosion,
Unstable culvert inlet/outlet,
gully and rill formation from
road shoulder to culvert
inlet/outlet, Stormwaterflow
path noted entering stream at
inlet end
Stabilize inlet and/or
outlet, Armor ditch with
stone or grass, Reshape
ditch, Reshape or crown
road, Reshape/vegetate
shoulder
Stabilization
798
0.3
Direct
Low
3-18
Camp
Waldron Rd
Meredith
Swamp
Pond
Road shoulder/ditch erosion,
Unstable culvert inlet/outlet, rill
formation from road shoulder
to culvert inlet/outlet
Stabilize inlet and/or
outlet, Armor ditch with
stone or grass, Reshape
ditch, Reshape or crown
road, Reshape/vegetate
shoulder
Stabilization
798
0.3
Direct
Low
4-10
Meredith
Center Rd by
house 27
(Lake Wicwas
outflow?)
Meredith
Lake Wicwas
Direct
Road shoulder/ditch erosion,
Severe streambank
erosion/failure, lack of stable
buffer, no buffer.
Stabilize banks,
Plant/improve buffer,
Reshape/vegetate
shoulder
Stabilization
798
0.3
Direct
Low
1-04
Opechee Park
and N Main
St/Rt 106-
Overland flow
and outfall
from road
Laconia
Lake
Opechee
Large outfall. Road runoff (N.
Main St) overtops at CB, flows
overland through park toward
Opechee, causing erosion.
To treat road runoff: Cap
CB, curb cut and divert
ru noff i nto vegetated
infiltration swale. For
outfall, evaluate if it
would be possible to add
DMH with perforated
laterals to divert first
flush into subsurface
sand filters. Would likely
encounter issues with
high groundwater.
Treatment,
Stabilization
370
0.3
Direct
Low
FB Environmental Associates & Horsley Witten Group
98
-------
LAKE WINNISQUAM WATERSHED-BASED PLAN
Site
ID
Site Descr.
Municipality
Subbasin
Description of Problem
Recommendations
Primary
Recommended
Actions
Total Average
Annual
Sediment
Load
Removed
(kg/yr)
Total
Average
Annual
TP Load
Removed
(kg/yr)
Direct or
Indirect/Limited
Discharge to
Waterbody
Priority
1-08
Highway
garage,
equipment
storage, salt
sheds
Laconia
Winnipesauk
ee River
Sand buildup. Degraded
stream.Snow storage nextto
stream. Erosion and dead grass
where runoff flows overland
from north parking lot entrance
into stream. Erosion and
sediment-laden runoff from
parking area along stream.
Sediment forebay and
level spreader at north
entrance where runoff
flows overland into
stream. Cap CB.
Treatment,
Stabilization
575
0.3
Direct
Low
3-03
Camp
Waldron Rd
Meredith
Lake Wicwas
Direct
Road shoulder/ditch erosion,
gully formation on sloping road
shoulder; road shoulder
material slumping evident; lack
of proper road crown
Reshape/vegetate
shoulder, Reshape or
crown road
Stabilization
748
0.3
Direct
Low
1-11
Ahern State
Park beach
Laconia
Lake
Winnisquam
Direct
Eroding road and parking lot
Swale/stabilized channel
of drivable grass across
fire road to redirect run-
on from above lot, into
bio. Bio in area of
standing water to south
of lot. Water bar across
lot to direct flow to it.
Stabilization
679
0.3
Direct
Low
1-09
City Hall
parking lot-
south
Laconia
Winnipesauk
ee River
Existing small biobasin for large
parking lot, not well maintained
Enlarge bio, add
grasspave forebay,
plants that are easier to
maintain
Treatment
0
0.3
Direct
Low
2-02
Salt marsh
pond NHFGD
boat ramp
Gilford
Jewett
Brook
Road surface erosion, lack of
vegetated buffer
Reshape or crown road,
Install erosion controls
(e.g. siltfence), Install
runoff diverter, Install
water bars over
driveway, and before
boat ramp,
Plant/improve buffer
Stabilization
514
0.3
Direct
Low
2-21
Jefferson Rd
Belmont
Lake
Winnisquam
Direct
Road shoulder/ditch erosion,
Excessive build-up of sediment,
Severe streambank
erosion/failure, Buffer not wide
enough, Poor/degraded buffer
Plant/improve buffer,
Reshape/vegetate
shoulder
Stabilization
599
0.3
Direct
Low
3-29
Lower Bay Rd
Sanbornton
Lake
Winnisquam
Direct
Minimal buffer between road
and lake, Unstable bank in
some areas
Stabilize bank with living
shoreline techniques
Buffer
0
0.2
Direct
Low
FB Environmental Associates & Horsley Witten Group
99
-------
LAKE WINNISQUAM WATERSHED-BASED PLAN
Site
ID
Site Descr.
Municipality
Subbasin
Description of Problem
Recommendations
Primary
Recommended
Actions
Total Average
Annual
Sediment
Load
Removed
(kg/yr)
Total
Average
Annual
TP Load
Removed
(kg/yr)
Direct or
Indirect/Limited
Discharge to
Waterbody
Priority
3-01
Chemung Rd
at
intersection
with Camp
Waldron Rd,
across from
white house
with blue roof
#157
Meredith
Lake Wicwas
Direct
Significant road shoulder/ditch
erosion along Chemung Rd;
drainage from Chemung Rd
feeds into collapsed undersized
culvert; significant rill and gully
formation off road shoulder
around culvert outlet
Replace and enlarge
culvert, Stabilize inlet
and/or outlet, Armor
ditch with stone or grass,
Reshape ditch, Stabilize
banks,
Reshape/vegetate
shoulder
Stabilization
499
0.2
Direct
Low
2-22
Jefferson Rd
at Union Rd
stream
crossing
Belmont
Lake
Winnisquam
Direct
very slight road shoulder
erosion. Culvert looks great.
Regrade and stabilize
road shoulder
Stabilization
366
0.2
Direct
Low
3-27
Woodman Rd,
open field
Sanbornton
Black Brook
Minimal stream buffer through
open field, landowners mow
grass rightto stream bank
edges.
Enhance buffer with
shrubs, Establish a
minimum 50 ft no-mow
zone around stream
Buffer
0
0.1
Direct
Low
4-18
Chase Rd
stream
crossing
Meredith
Dolloff
Brook
Road shoulder/ditch erosion,
Lack of stream shading, Buffer
not wide enough, unstable road
shoulder.
Stabilize inlet and/or
outlet, Stabilize banks,
Reshape/vegetate
shoulder, Bank
stabilization
Stabilization
239
0.1
Direct
Low
2-26
Hurricane Rd
stream
crossing
Belmont
Lake
Winnisquam
Direct
Lack of stream buffer. Buffer
not wide enough/or present.
Culvert itself and stabilization
rip rap look great.
Improve stream buffer
near the slope to the
roadway and
downstream on private
property with the large
lawn.
Buffer
0
0.1
Direct
Low
2-20
Union Rd
stream
crossing
Belmont
Durgin
Brook
Bank/channel
downcutting/incision, Severe
streambank erosion/failure
Bank stabilization
Stabilization
160
0.1
Direct
Low
2-07
Country Club
Rd stream
crossing
Gilford
Jewett
Brook
Road shoulder/ditch erosion,
Only slight road shoulder
erosion leading to stream
crossing, Excessive trash, Buffer
not wide enough,
Poor/degraded buffer
Reshape/vegetate
shoulder, Plant/improve
buffer
Stabilization
120
0.1
Direct
Low
4-19
Chemung Rd
near a
wetland
crossing
Meredith
Lake Wicwas
Direct
Road shoulder/ditch erosion,
Buffer not wide enough
Armor ditch with stone
or grass, Plant/improve
buffer
Stabilization
24
0.0
Direct
Low
FB Environmental Associates & Horsley Witten Group
100
-------
LAKE WINNISQUAM WATERSHED-BASED PLAN
Site
ID
Site Descr.
Municipality
Subbasin
Description of Problem
Recommendations
Primary
Recommended
Actions
Total Average
Annual
Sediment
Load
Removed
(kg/yr)
Total
Average
Annual
TP Load
Removed
(kg/yr)
Direct or
Indirect/Limited
Discharge to
Waterbody
Priority
1-13
End of Water
St, town land
and outfall
Laconia
Lake
Winnisquam
Direct
Tons of trash, partially buried
outfall. Some trash blows in
and some from homeless
camps.
Trash cansand regular
cleanups. Remove
pavement and restore
buffer, with plantings to
discourage water access
and keep trash from
blowing/washing into
water. Evaluate
feasibility of constructed
wetland; potential soil
contamination.
Buffer,
Maintenance
0
0.0
Direct
Low
2-19
Hubble Rd
Belmont
Durgin
Brook
Road shoulder/ditch erosion,
Excessive build-up of sediment
Armor ditch with stone
or grass, Install turnout,
Reshape ditch,
Reshape/vegetate
shoulder, Install runoff
diverter, Install erosion
controls (e.g. silt fence)
Stabilization
907
0.4
Limited
Low
2-15
Logan Dr
Belmont
Durkee
Brook
Road shoulder/ditch erosion
Armor ditch with stone
or grass, Install check
dams
Stabilization
771
0.4
Limited
Low
2-31
Mile Hill Rd
Laconia
Durkee
Brook
Road surface erosion, Road
shoulder/ditch erosion,
Unstable culvert inlet/outlet,
Bare soil/fields, 2 catch basins
are like this
Clean out culvert, Install
plunge pool, Remove
wintersand, Build up
road/ add surface
material, Clean out ditch
Stabilization
771
0.4
Limited
Low
4-01
On State
Route 106 just
north of the
Meredith
Center Rd
intersection
Laconia
Lake
Opechee
Road shoulder/ditch erosion
leading to a catch basin
Armor ditch with stone
or grass, Reshape ditch
Stabilization
681
0.3
Limited
Low
2-13
Plummer Hill
Rd
Belmont
Durgin
Brook
Road shoulder/ditch erosion,
Stockpiled soil, This entire road
has really sandy shoulders
which may be from winter sand
not being swept up
Armor ditch with stone
or grass, Reshape ditch,
Remove berms created
by road grader, Remove
wintersand
Stabilization
463
0.2
Limited
Low
2-27
Union Rd
Belmont
Lake
Winnisquam
Direct
Road shoulder/ditch erosion,
About2' deep, Poor/degraded
buffer
Armor ditch with stone
or grass, Plant/improve
buffer
Stabilization
463
0.2
Limited
Low
FB Environmental Associates & Horsley Witten Group
101
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LAKE WINNISQUAM WATERSHED-BASED PLAN
Site
ID
Site Descr.
Municipality
Subbasin
Description of Problem
Recommendations
Primary
Recommended
Actions
Total Average
Annual
Sediment
Load
Removed
(kg/yr)
Total
Average
Annual
TP Load
Removed
(kg/yr)
Direct or
Indirect/Limited
Discharge to
Waterbody
Priority
4-14
Leighton Ave
N
Laconia
Lake
Winnisquam
Direct
Road shoulder/ditch erosion,
Stream ditch channel has check
dams. Leaves need to be
cleaned out
Armor ditch with stone
or grass, Stabilize banks
Stabilization
544
0.2
Limited
Low
4-02
Eastman Rd
Laconia
Lake
Winnisquam
Direct
Road surface erosion, Road
shoulder/ditch erosion leading
to an unpaved driveway toward
the lake
Install ditch, Install
turnout, Reshape ditch,
Remove winter sand,
Reshape/vegetate
shoulder, Install runoff
diverter, Plant/improve
buffer
Stabilization
411
0.2
Limited
Low
4-21
Intersection
of Chemung
and Meredith
Center Road
Meredith
Mill Brook
Road shoulder/ditch erosion
Armor ditch with stone
or grass
Stabilization
435
0.2
Limited
Low
2-17
Dutile Rd
Belmont
Durgin
Brook
Road shoulder/ditch erosion
Armor ditch with stone
or grass, Install check
dams
Stabilization
399
0.2
Limited
Low
4-11
Meredith
Center Rd
between
Meredith
Center Coop
MHP and
Baywoods Rd
Meredith
Mill Brook
Road shoulder/ditch erosion
Reshape/vegetate
shoulder, Reshape ditch,
Armor ditch with stone
or grass
Stabilization
363
0.2
Limited
Low
2-08
Frank Bean
Rd
Laconia
Durkee
Brook
Road shoulder/ditch erosion,
Bare soil/fields
Armor ditch with stone
or grass, Install turnout
Stabilization
308
0.2
Limited
Low
2-12
Plummer Hill
Rd
Belmont
Durgin
Brook
Road shoulder/ditch erosion,
Unstable culvert inlet/outlet, To
house 141
Armor ditch with stone
or grass, Clean out
culvert,
Reshape/vegetate
shoulder, Reshape ditch
Stabilization
308
0.2
Limited
Low
2-18
Hubble Rd
Belmont
Durgin
Brook
Road shoulder/ditch erosion,
Until house 39
Remove berms created
by road grader, Install
ditch, Reshape ditch,
Armor ditch with stone
or grass
Stabilization
154
0.1
Limited
Low
2-28
Hurricane Rd
Belmont
Lake
Winnisquam
Direct
Road shoulder/ditch erosion
Reshape ditch, Armor
ditch with stone or grass
Stabilization
154
0.1
Limited
Low
FB Environmental Associates & Horsley Witten Group
102
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LAKE WINNISQUAM WATERSHED-BASED PLAN
Site
ID
Site Descr.
Municipality
Subbasin
Description of Problem
Recommendations
Primary
Recommended
Actions
Total Average
Annual
Sediment
Load
Removed
(kg/yr)
Total
Average
Annual
TP Load
Removed
(kg/yr)
Direct or
Indirect/Limited
Discharge to
Waterbody
Priority
2-03
Sawmill Rd
and Country
Club Rd
intersection
on Bank of NH
corner
Gilford
Jewett
Brook
Road shoulder/ditch erosion
Reshape ditch, Armor
ditch with stone or grass
Stabilization
160
0.1
Limited
Low
2-29
Mile Hill Rd
Belmont
Durkee
Brook
Road shoulder/ditch erosion
Install ditch, Armor ditch
with stone or grass,
Install turnout, Reshape
ditch, Install plunge pool
Stabilization
116
0.1
Limited
Low
4-15
Leighton Ave
N and Collins
Brook Rd
Laconia
Lake
Winnisquam
Direct
Road surface erosion, Road
shoulder/ditch erosion
Install ditch, Armor ditch
with stone or grass,
Reshape ditch,
Reshape/vegetate
shoulder, Reshape or
crown road, Check dams
Stabilization
121
0.1
Limited
Low
2-14
Plummer Hill
Rd
Belmont
Durgin
Brook
Road shoulder/ditch erosion,
Road shoulder sediment sliding
down hill perpendicular to road
with flow channels
Install erosion controls
(e.g. siltfence), Armor
ditch with stone or grass,
Reshape/vegetate
shoulder
Stabilization
91
0.0
Limited
Low
2-16
Dutile Rd
Belmont
Durgin
Brook
Road shoulder/ditch erosion
Armor ditch with stone
or grass,
Reshape/vegetate
shoulder
Stabilization
77
0.0
Limited
Low
2-32
Lakeside of
Lakeshore
Drive
Sanbornton
Lake
Winnisquam
Direct
Road shoulder/ditch erosion,
Road surface erosion. The road
is a soft unpaved sandy
material.
Build up road, add
surface material,
reshape or recrown road.
Stabilization
77
0.0
Limited
Low
4-12
Near Meredith
town park
playground
on Meredith
Center Rd
Meredith
Mill Brook
Road surface erosion, Road
shoulder/ditch erosion
Remove winter sand,
Reshape ditch, Armor
ditch with stone or grass
Stabilization
45
0.0
Limited
Low
FB Environmental Associates & Horsley Witten Group
103
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LAKE WINNISQUAM WATERSHED-BASED PLAN
Site
ID
Site Descr.
Municipality
Subbasin
Description of Problem
Recommendations
Primary
Recommended
Actions
Total Average
Annual
Sediment
Load
Removed
(kg/yr)
Total
Average
Annual
TP Load
Removed
(kg/yr)
Direct or
Indirect/Limited
Discharge to
Waterbody
Priority
1-02
Opechee
Park- Point
where parking
lot runoff
could be
diverted to
infiltration
under picnic
area
Laconia
Lake
Opechee
Goose habitat, parking lot
runoff erosion. Existing
vegetated swale.
Propose swale to
infiltration under picnic
table terrace
NA
0
0.0
Direct
Low
1-03
Opechee Park
- Swale along
beach
Laconia
Lake
Opechee
Goose habitat, parking lot
runoff erosion. Existing
vegetated swale.
Swale could be
expanded/enhanced to
provide additional
treatment
NA
0
0.0
Direct
Low
1-05
MesserSt
boat ramp
Laconia
Lake
Opechee
Contaminated site, capped.
Gravel drive, two paved spaces
near ramp. Owned by
Eversource.
Buffer plantings but
probably not a feasible
site due to ownership
and contamination.
NA
0
0.0
Direct
Low
1-14
Bartlett Beach
Laconia
Lake
Winnisquam
Direct
Gravel/sand parking lot. Graded
away from lake into what looks
like was meantto be a swale.
Wetland at back of lot.
No recommendations
except perhaps to ensure
maintenance of swale
along back of lot.
Maintenance
0
0.0
Direct
Low
1-15
Leslie Beach,
Belmont
Belmont
Lake
Winnisquam
Direct
No issues - stormwater and
erosion appearwell managed
NA
0
0.0
Direct
Low
2-09 b
Province Rd
Laconia
Durkee
Brook
Road shoulder/ditch erosion,
Unstable culvert inlet/outlet,
Bare soil/fields
Stabilize inlet and/or
outlet, Install plunge
pool, Clean out culvert,
Reshape/vegetate
shoulder, Armor ditch
with stone or grass
Stabilization
0
0.0
Direct
Low
2-34
Linda Drive
Belmont
Lake
Winnisquam
Direct
Lots of private large and very
green lawns with little to no
buffers.
Target this
neighborhood for
sustainable lawn
maintenance and buffer
practices.
Buffer,
Education
0
0.0
Direct
Low
FB Environmental Associates & Horsley Witten Group
104
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LAKE WINNISQUAM WATERSHED-BASED PLAN
Site
ID
Site Descr.
Municipality
Subbasin
Description of Problem
Recommendations
Primary
Recommended
Actions
Total Average
Annual
Sediment
Load
Removed
(kg/yr)
Total
Average
Annual
TP Load
Removed
(kg/yr)
Direct or
Indirect/Limited
Discharge to
Waterbody
Priority
3-33
Philbrook Rd
Sanbornton
Lake
Winnisquam
Direct
Green algae observed in
ponded water area, water is
conveyed through a culvert
under the road, small stream
flowing into ponded area,
drains residential and
agricultural land, residential
home nearby, may be lawn
fertilizer, faulty septic, or
manured fields
Investigate source of
nutrients in drainage
area
Other
0
0.0
Direct
Low
3-35
Lower Bay Rd
Bay Rd
intersection
Sanbornton
Chapman
Brook
No noticeable channelization
from the roadway. There is a rip
rapped drainage/slope
stabilization perpendicular to
the stream but the stream
banks themselves are natural.
Did not walk on private
property.
No major problems
observed so no
recommendations.
NA
0
0.0
Direct
Low
4-05
Stream
crossing from
an unnamed
pond under
Hatch Corner
Rd
Meredith
Unnamed
Tributary
(North Trib)
Downstream of a beaver
wetland, Hanging culvert (no
fish passage), Icky smell,
undetermined if its sewage or
just a high organic content.
Trash around stream.
Pedestrian said it sometimes
has a strong sulfur smell.
Re-align, repair, or
upgrade culvert
Other
0
0.0
Direct
Low
1-06
Sanborn Park
Laconia
Lake
Opechee
Urban runoff to closed drainage
Green space. Potential to
divert from drainage
structure on Clinton St
but at top of catchment
area, not great
opportunity.
NA
0
0.0
Limited
Low
1-07
Tributary to
Jewett Brook
at Gilford Ave
Laconia
Jewett
Brook
Mowed to edge of stream on
one side, stockpile on other
side. Minor erosion.
Generally, encourage
stream buffers
Buffer,
Education
0
0.0
Limited
Low
2-09a
Province Rd
Laconia
Durkee
Brook
Road shoulder/ditch erosion,
Unstable culvert inlet/outlet,
Bare soil/fields
Stabilize inlet and/or
outlet, Install plunge
pool, Clean out culvert,
Reshape/vegetate
shoulder, Armor ditch
with stone or grass
Stabilization
0
0.0
Limited
Low
FB Environmental Associates & Horsley Witten Group
105
-------
LAKE WINNISQUAM WATERSHED-BASED PLAN
Site
ID
Site Descr.
Municipality
Subbasin
Description of Problem
Recommendations
Primary
Recommended
Actions
Total Average
Annual
Sediment
Load
Removed
(kg/yr)
Total
Average
Annual
TP Load
Removed
(kg/yr)
Direct or
Indirect/Limited
Discharge to
Waterbody
Priority
2-36
Belmont Mall
Belmont
Lake
Winnisquam
Direct
Large paved parking area with
stores. Increases stormwater
runoff temperature
Install parking lot
stormwater controls and
infiltration areas (need
more investigation, info
on existing BMPs)
NA
0
0.0
Limited
Low
4-16
Straits Rd
New
Hampton
Dolloff
Brook
Winter sand lining the road
Remove winter sand
Maintenance
0
0.0
Limited
Low
4-17
Forest Pond
Rd
New
Hampton
Dolloff
Brook
So much winter sand still on the
road
Remove winter sand
Maintenance
0
0.0
Limited
Low
FB Environmental Associates & Horsley Witten Group
106
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