Lake Winnipesaukee Watershed Management Plan

Lake Winnipesaukee
Watershed Management Plan
Project Update: August 2010
A Phased Approach to a Comprehensive Plan
People in Partnership with Lake Winnipesaukee
Partners
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Lake Winnipesaukee Watershed Association
Lakes Region
g
Planning
g Commission
North Country Resource Conservation &
Development Area Council
B lk
Belknap
C
County
t C
Conservation
ti Di
District
ti t
University of New Hampshire Center for Freshwater
Biology & Cooperative Extension
Plymouth State University – Center for the
Environment
NH Dept. of Environmental Services
Municipalities
Other Organizations
Funding
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NH DES – 319 Program
NOAA – Watershed Planning
Water Quality Monitoring
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Town of Meredith
City of Laconia
Town of Gilford
Plymouth State University – Center for the
Environment
The Subwatershed Approach
Phase I:
Meredith, Laconia, Gilford:
Meredith, Paugus, and Saunders Bays
Subwatersheds
Phase II:
Center Harbor, Moultonborough, Sandwich,
Tuftonboro
Center Harbor, Moultonborough Bay
Subwatersheds
Phase III:
Alton, Brookfield, New Durham, Tuftonboro,
Wolfeboro
Broads, Wolfeboro Bay Subwatershed
Phase IV:
Alton,, Brookfield,, Gilford,, New Durham
Why
y develop
p a Lake Winni WMP?
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Balance land uses with water quality
Protect the lake and livelihood
Generate new opportunities to protect and
conserve Lake Winnipesaukee as a state and
national resource
Ed
Education
ti and
d stewardship
t
d hi
Establish water quality baseline for
phosphorus
ID areas to restore/protect from ‘P’
Why develop a Lake Winni WMP?
What are the goals?
g
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Protect the natural resources and water
quality health of the Lake Winnipesaukee
watershed for the long term.
Protect the economic vitality of the Lakes
Region
Protect and preserve the natural beauty of
the watershed and quality of life for all.
What are the key components of a watershed
management plan?
Physical Features
Chemical Features
Lake Biology
Lake
Wi i
Winnipesaukee
k
Watershed
Management
Plan
W t
Watershed
h d Management
M
t
Primary concern is watershed phosphorus loading and its
i
impact
t on lake
l k water
t quality.
lit
C+N
Lake 226
Phosphorus:
Important
Limiting
Nutrient
From: Schindler
ELA, Ontario CA
1973
C+N+P
Why Phosphorus?
Lake 226
Algal blooms (including cyanobacteria)
C+N+P
Milfoil
f
Increased levels of P may result in
• Decline in swimming, fishing and
boating use
• Public health risk
• Decline in property values
• Increase in public expenditures
to address water quality impairment
The economic impact of deteriorating water
quality is real.
Lakes Region
Lost Sales: $25 M
Lost Income: $8.8 M
Lost jobs: 396
Full report can be downloaded at www.nhlakes.org
What are sources of P?
Source: lake.access project
What are
sources of P?
Nitrates are the main
pollutant of concern
with failing septic
systems
What are sources of P?
What are sources of P?
How do we
meet the goal
of protecting
th water
the
t
quality health
of the lake?
What
information do
we need to
make informed
decisions?
What do we need to know to make
informed decisions?
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What is the current water quality?
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How much do we P now?
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Water quality data analysis
Estimation of pollutant loads based on
land use
How can we limit our P in the future?
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Pollutant load reductions from
implementation of best management
practices
Restoration of impaired sites
An opportunity and a challenge
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State Standard for Phosphorus
TP and Chl a Criteria for Aquatic
Aq atic Life Designated Use
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Trophic State
TP (ug/L)
Chl a (ug/L)
Oligotrophic
<8.0
<3.3
Mesotrophic
<= 12.0
<= 5.0
Eutrophic
<= 28
<= 11
Local Water Quality Goals
Meredith, Laconia, and Gilford have the opportunity to set a local water
quality goal for phosphorus for each of the three assessment units
-
set the local goal for P at the State Standard of 8 ug/L
Set a goal to maintain P at the current level in each bay
Set a goal to improve the level of P
What are the implications if P goes
above the State Standard of 8 ug/L?
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A waterbody will be considered “impaired”
impaired if it’s
it s
water quality does not meet the criteria
established by the state. ($$$)
Impairment means that no additional
phosphorus loading will be allowed, i.e. no new
sources of P. ($$$)
Impairment means the State will mandate
actions
i
to correct the
h iimpairment.
i
($$$)
What do we need to know to make
informed decisions?
Lake Winnipesaukee Median Total Phosphorus Trend
Lake Winnipesaukee Median Total Phosphorus Trend
8 ppb NH DES Standard
To
otal Phosph
horus (ppb)
8
6
7
6
4.9
5
4
3
2
1
Pre‐1998 Historical TP Median
1998‐2008 Summer TP Median
2008‐2018 Possible Future Median
What is the current water quality?
The water quality data and assimilative
capacity analysis support Lake
Winnipesaukee’s
Winnipesaukee
s designation as a high
quality water and oligotrophic
classification.
Existing Water Quality
Total P
(ug/L)
Chl a
(ug/L)
Waukewan
Meredith
Bay
Paugus
Bay
Saunders
Bay
7.1
6.3
5
5.4
2.5
1.9
2.1
1.5
Above data represent the median P
values for all sites combined in each
bay for the last 10 years.
years
.
2009 Water Quality Monitoring Summary
Summary of Sampling Results
Parameter
Total Phosphorus (ug/L)
Meredith
Paugus Bay
Saunders Bay
Bay
Deep
Shallow Deep Lake Shallow
Deep Lake
Lake
Sites
Sites
67
6.7
56
5.6
61
6.1
51
5.1
56
5.6
Chlorophyll a (ug/L)
2.1
Secchi Disk depths (m)
7.1
Dissolved Color (CPU)
9.8
Notes:
Total Phosphorus values represent the median of
all values
Chlorophyll a, Secchi Disk, and Dissolved Color
are the average of all data points.
2.0
2.0
1.8
9.0
10.4
7.6
1.9
9.6
8.3
7.8
How much do we P now?
Lake Sustainability
Its the LOAD that
that’ss important!
P LOAD (Mass of P) =
P concentration in tribs & runoff x volume of water from tribs & runoff
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MORE LOAD = FASTER EUTROPHICATION
Landscape change causes more load*
Human activityy causes more load*
*Unless Best Management Practices are put in place and maintained
Sustainability is obtained when human activity in the lake
watershed is managed so that eutrophication occurs at a no
greater rate than natural eutrophication.
Estimated Phosphorus Loading
2009 Estimated Total P Load by Land Use
in the MPSB Subwatersheds (including Waukewan)
217 lbs
17%
25%
5600 lbs
3%
Urban
268 lbs
Agriculture
Forest
55%
Water
*Estimate of P loading generated using STEPL Model
Phosphorus Load per acre
0.80
lbs p
per acre
0.70
0.60
0.50
0.40
0.30
0.20
0.10
0.00
Urban
Agriculture
Forest
Developed Land: Agricultural Land:
Forested Land: Urban areas, roads, residential Includes Pasture land and crops Areas covered primarily with trees
How can we limit or reduce P in the
future?
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Implement
p
best
management practices
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No phosphorus fertilizers
Use Low Impact Development
practices
Vegetated Buffers along
streams, shoreland, and
roads
Identify and mitigate sites in
need of restoration
Vegetative Buffers are a very effective and low
cost best management practice to reduce
pollutant loading to surface waters
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40 ft buffer has a 19% TP
removal efficiency
50 ft b
buffer
ff – 26% TP
removal efficiency
80 ft buffer – 45 % TP
removal efficiency
Continued water quality monitoring
is important.
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Limited data currently available – both
spatially
p
y and temporally
p
y
Need data to compare with post BMP
implementation
Determine long term trends
Many thanks to the sponsors and
volunteers for their involvement!

2010 Water Qualityy Monitors
Bruce Bond
Angela LaBrecque
Ji MacBride
Jim
M B id
Alan and Janis Sherwood
David Beardsley
Jim Boselli
Cathy Hunt
Chuck Coons
Rick Holder
Pat Tarpey
Dean Anson
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2010 WQ Sponsors
p
Town of Meredith
Laconia Conservation
Commission
Gilford Rotary
Winnipesaukee Yacht Club
Governor’s
Go
e o s Island
s a d Assoc.
ssoc
Town of Gilford Conservation
Commission
Fay’s
y Boat Yard
Contacts
www.lakesrpc.org/lwwmp/
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Pat Tarpey, Project Planner, LRPC
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603-279-8171
[email protected]
Steve Kahl, President
Lake Winnipesaukee Watershed Assn
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[email protected]
Questions?
www.lakesrpc.org/lwwmp/