Lake Management for
Conservation Commissions
and Lake Associations
Ken Wagner, PhD, CLM, Water Resource Services
Part I – Lake Management
and the Wetlands Protection Act
Reasons for lake management
Algae control
Rooted plant control
Sedimentation mitigation
Fishing enhancement
Other interests
Nuisance animals
Rare species
Part I – Lake Management
and the Wetlands Protection Act
Algae control
– Most algae grow in proportion to
available nutrients and light
– Focus on nutrient control, esp P,
for best results
• Watershed management
• Internal load reduction
 Dredging
 Inactivation
 Oxygenation
 Drawdown
Part I – Lake Management
and the Wetlands Protection Act
Total Phosphorus vs. Chlorophyll a
Chl (ug/l)
0 10 20 30 40 50 60 70 80 90 100110120130140150160170180190200
TP (ug/l)
From Watson et al. 1997
L&O 42(3): 487-495
(10 ug/L)
(100 ug/L)
Relationships of TP to
Chl to cyanobacteria:
More P leads to more
algae and more algae
leads to more
cyanobacteria. Other
algae can bloom too, but
probability of cyano
blooms rises with P.
Part I – Lake Management
and the Wetlands Protection Act
Algae control
– Where nutrient control is not feasible, control should
focus on prevention of blooms, not removal of existing
• Algaecides
• Circulation
• Flushing
• Sonication
• Dyes
• Biomanipulation
• Bacterial additives
• Mechanical removal?
Part I – Lake Management
and the Wetlands Protection Act
Rooted plant control
– Choice of method highly dependent upon:
• Species of plants to be controlled
• Areal coverage
• Density of coverage
• Potential non-target impacts
Part I – Lake Management
and the Wetlands Protection Act
Rooted plant control
– Watershed management will not solve the problem
– Water quality management unlikely to solve the problem
– Often need a combination of techniques
– Often need repeat application
– Quick action upon discovery of an invasion is essential if
there is to be any chance of eradication
Part I – Lake Management
and the Wetlands Protection Act
Rooted plant control
– Physical: drawdown, harvesting, dredging, benthic
– Chemical: herbicides, dyes
– Biological: herbivores, pathogens, competitors
– Each has pros and cons, each has optimal conditions for
application (see Lake Management in MA)
Part I – Lake Management
and the Wetlands Protection Act
Sediment mitigation
– Four choices: live with it, dredge it, decompose organic
matter, raise water level
– Dredging is the most restorative choice, but is very
expensive and requires considerable information to plan
and permit; sediment quality and quantity must be
thoroughly evaluated
– Decomposing organic sediments is possible with
adequate oxygen and appropriate microbes; an industry
has arisen around this approach, but little scientific
evidence of successes
– Raising the water level is not practical in many cases
Part I – Lake Management
and the Wetlands Protection Act
Fishing enhancement
– Boils down to habitat and stocking; both have a role
– Habitat will determine long term fishery conditions;
temperature, oxygen, pH and trophic status all matter
– Stocking provides short term enhancement and may
provide longer term benefits if habitat is suitable
– Regulation may also be important; overfishing can be a
real force
– State agencies have interest and expertise in habitat,
but focus mainly on stocking and regulation
Part I – Lake Management
and the Wetlands Protection Act
Other interests
– Nuisance animals – beavers, geese, leeches, swimmer’s itch –
need to view control in context of habitat and ecosystem function
– Rare species – protected by law, promoting them is desirable, but
requires a plan and permission
– Birding – popular passtime, many water dependent species, not
always compatible with other uses – need to consider habitat
needs, spatial and temporal separation from potentially conflicting
– Access – public vs. private lakes pose major issues with regard to
responsibility, funding, downstream impacts, individual vs. societal
rights – room for a lot of debate, a very sensitive area with many
Part I – Lake Management
and the Wetlands Protection Act
– How the Wetlands Protection Act (WPA) relates to lakes
• History of WPA
 Act and subsequent regulations (1983) and
revisions (1987, 1997) to protect wetlands, an
imperiled set of habitats
 BVW, LSF, Bank, VP, LUW: lakes as wetlands
 Lakes as embodiment of range of wetland habitats
 Conundrum of active management of lakes
– Limited projects10.53 (4)
– Land Under Water 10.56
– Performance standards 10.60
Part I – Lake Management
and the Wetlands Protection Act
– How the Wetlands Protection Act (WPA) relates to lakes
Seven original “interests” of the WPA
 Protection of public and private water supply
 Protection of ground water supply
 Flood control
 Storm damage prevention
 Prevention of pollution
 Protection of land containing shellfish
 Protection of fisheries
Part I – Lake Management
and the Wetlands Protection Act
– How the Wetlands Protection Act (WPA) relates to lakes
• Regulatory adjustments
 Addition of 8th “interest”: habitat – problem issue
for any management program
 Policies and guidance over the years to address
specific issues
 GEIR for Eutrophication and Aquatic Plant
Management in Massachusetts
– Not the last word; meant to be updated
– Provides guidance, not regulation or rules
– Problem situations accumulating
– No regulatory provision for revision
Part I – Lake Management
and the Wetlands Protection Act
– Related legislation and regulation
• MA Endangered Species Act and NHESP
• Riverways Act – streams and rivers, not lakes
• MA DEP Storm Water Policy
• Chapter 91: Waterways License re: Great Ponds
• Federal Clean Water Act, Sec 401 and 404
• Federal Clean Water Act, Sec 305b and 303d
• Federal Clean Water Act, Sec 314 and 319
• Federal Insecticide Rodenticide and Fungicide Act
• National Pollutant Discharge Elimination System
• Invasive species transport bans
• Instream flow initiatives
Part I – Lake Management
and the Wetlands Protection Act
– Related issues
• Double jeopardy from overlapping regulation
• Lack of a mandate to control invasive species
• Focus on endangered species instead of communities
• Little inclusion of safety, economic limits or recreation
in WPA – but there is some, and room to interpret
• Lack of process for rapid response planning and
• Ability to monitor to predict problems and be proactive
Part I – Lake Management
and the Wetlands Protection Act
– Bottom Line:
• There is a lot for a Conservation Commissioner or a
Lake Association to know when dealing with lakes
• Lake projects have potentially more environmental
regulation than development projects
• Like buildings, lakes require maintenance to remain in
acceptable condition; no action is not preservation
• Prevention is much preferred over rehabilitation, but
can’t always be arranged
• The WPA and related regulations provide a framework
for lake management, but also have gaps,
contradictions and confusing aspects that make the job
of a Commissioner more difficult
Part I – Lake Management
and the Wetlands Protection Act
Reasonable expectations from applicants
 Properly characterize the resources involved
 Clearly identify the problem(s)
 Demonstrate consideration of options
 Provide an evaluation of non-target impacts
 Show how the interests of the WPA are affected
 Provide an appropriate monitoring program
 List follow up and contingency actions
 Explain how other permitting processes apply
 Identify who will be responsible for what actions
Part I – Lake Management
and the Wetlands Protection Act
Reasonable expectations from conservation commissioners
 Be familiar with available guidance on lake management (GEIR,
other resources)
 Do not base feasibility or applicability conclusions on any one
example; consider range of possible outcomes, avoid secondary
sources, personal opinions, and unsubstantiated claims
 Keep an open mind; do not limit options due to personal
prejudices for or against any technique
 Know where you can compromise and where you have to hold
the line on WPA provisions – not easy to do, but work at it
 Help craft reasonable monitoring programs, not extorted
research projects
 Do not overstep jurisdictional bounds; avoid requiring actions not
related to the problem
 Seek to be part of a solution to any problem; commissioners
should be more than umpires
Lessons from Experience
• There is no one size fits all solution; the specific
conditions in each case dictate the most viable course
of action
• There are likely multiple possible solutions, and
multiple techniques are likely to be involved over time
• Comparisons between lake projects must be tempered
by lake-specific situations; because something did or
did not work at Lake A is not grounds for a strong
conclusion at Lake B without careful analysis
• Questions from conservation commissions should
help shape the project within the context of the WPA;
foster adaptive management over time
I’m gonna
need another
one of these
Part II – Common Western Massachusetts
Plant Management Approaches
Water quality tends to be acceptable; more problems with
rooted plants, partly due to higher water clarity
• Drawdown practiced where outlet control over water level exists
and permits can be obtained
• Herbicides tend to be applied where problem is serious enough to
warrant major biomass reduction
• Mechanical harvesting was popular when county operated
machines, still a viable method of maintaining selected areas for
• Manual harvesting difficult on very big scale, but proven useful for
limited area lakes; sometimes aided by suction harvesting
• Benthic barriers useful for localized near-complete control
• Dredging very desirable in many cases, but too expensive and
extra depth not essential
• Limited biomanipulation; more experimental, grass carp not
– Potential for control of
nuisance aquatic
plants by drawdown
– Key attributes of
success: water level
control, dewatering,
weather, physical
– Primary impediments:
impacts to non-target
species, flooding and
refill issues
Drawdown Targets
– Vegetative propagators
vs. seed producers
– Possible control of
milfoil, fanwort, coontail,
water lilies, watershield
– No adverse effect on
naiad, most
pondweeds, water
chestnut, Chara and
Nitella, except by longterm sediment changes
Drawdown Issues
Importance of physical
disruption of
overwintering plant
30 days of dryness
and/or freezing temp.
Ripping plants up with
early refill possible
Variability in response,
need for planning for
annual drawdown
Drawdown Issues
Impacts on wells
Impacts to other
aquatic plants
Impacts to contiguous
Impacts to
Impacts to reptiles and
Impacts to fish
Impacts to birds
Impacts to furbearers
Drawdown Experience
Weather dependent technique; have to consider
longer term conditions and expect year to year
variation – evaluation should span 3-5 years!
Can be very effective against milfoil, fanwort, any
submergent perennial if killing conditions achieved
Not directly effective against emergents (tend to be
dormant) or annual species (come back from seed)
Makes substrate more coarse (more rock, gravel,
coarse sand) over time with enough slope; provides
indirect control through substrate limitation
Rare to be able to draw down to level that prevents
any nuisances by target species
Deeper drawdowns present spring refill issues,
possible ecological impacts
9 active ingredients available:
• Copper- mostly for algae, limited vascular plant applications
• Diquat – contact herbicide, spot treatments
• Endothall – contact herbicide, spot treatments
• 2,4-D – older systemic; limits on use, but potentially
effective on some species where other herbicides are not
• Glyphosate – systemic, mainly for emergent growths
• Imazopyr/Imazomox – systemic, mainly for emergent plants
• Fluridone – systemic, slow acting, mostly whole lake or
sequestered applications, species targeting by dose
• Triclopyr – systemic, fast acting, spot treatments possible,
effective on milfoil but not pondweed species
• Flumioxazin – contact herbicide, spot treatments possible,
effective on wide range of invasive and nuisance species
• With very different active ingredients, labels, and
application conditions, blanket statements about
herbicides are inappropriate
• Herbicide costs vary substantially; cost per treatment and
number of treatments needed over 20 years should be
• It is reasonable to be concerned over possible non-target
impacts, including human health, but direct impacts are
very, very rare; experience shows that risks are small
• Very few techniques can get a plant infestation under
control quickly and at reasonable cost the way herbicides
can, when properly chosen and applied
Herbicide Treatments
– Contact herbicides
kill only the part of
the plant with which
they come in
contact, but tend to
act fast
– Systemic herbicides
are taken up and kill
whole plant at
sufficient dose, but
tend to act more
Herbicide Treatments
– Effectiveness varies
with target species
and ambient
– Selectivity can be
achieved by timing of
treatment, location of
treatment, and dose
for some herbicides
– Longevity limited for
ideal growing
situations, but can be
enhanced by
encouraging desired
Herbicide Treatments
– Direct impacts to
non-target fauna
are very limited
when label
restrictions are
– Indirect impacts
are possible as
habitat is altered
by change in plant
density or relative
Herbicide Treatment
Long-term control
Low dose “success/risk”
Water supply restrictions
Minimal issues for fish,
No issues for flood or
storm control
Legal debate over
pollution applicability
Certainly changes
Herbicide Experience
– Diquat is most popular contact herbicide; used to clear
swimming areas, control regrowth after some whole lake
systemic treatments
– Glyphosate and Imazopyr/Imazomox most often used on
floating or emergent plants, such as water lilies, cattails,
– Fluridone used most on Eurasian milfoil and fanwort, often
whole lake treatment, but advanced in pellet formulas aids
spot treatment
– Triclopyr newer, gaining acceptance, works on certain
plants (including milfoil) relatively quickly and thoroughly
– Flumioxazin also newer, gaining acceptance, works fast in
smaller areas, affects wide range of nuisance species
– 1-4 years of control is to be expected; more only with follow
up actions – for best results, let professionals guide
herbicide use planning
• Hand pulling
• Rakes and cutters
• Mechanical harvesting
• Rotovation
• Hydroraking
Harvesting- Hand Pulling
– Effective for limited
area infestations
– Can be very selective
– Best with sparse
growth of invasive
– Need to control
– Possible high labor
cost, repetition
– Suction systems may
help with denser areas
Harvesting- Rakes and
– Can clear small areas
– Moderately selective
– Fragments collection
necessary for some
– Effective for seed
producers if timed
– Labor cost usually
moderate, repetition
Harvesting - Mechanical
– Can clear larger areas
– Best results if biomass
collected and removed
– Analogous to mowing
the lawn for many
– Limited but possible
selectivity over time
– Some evidence of carryover effect
– Capital or contract cost
high, repetition
Harvesting – Rotovation
– Can clear moderate
sized areas
– Disrupts plants at
roots, but rarely
includes collection of
– Non-selective
– Highly variable
– “Messy” operation
– Capital or contract
costs high, repetition
not as likely as for
other techniques
Harvesting –
– Can clear moderate
– Removes plants at
roots with some
– Non-selective
– Variable longevity, but
successful for certain
– High capital or
contract cost,
repetition not as likely
as for other options
Harvesting Experience
– Rotivation not applied much in New England
– Hydroraking mostly used to control water lilies,
remove floating islands and debris, less common in
– Mechanical harvesting less common now (less
convenient, higher cost), but works well as a
maintenance technique with adequate equipment –
WPA issues limited by affected area
– Manual methods gaining momentum; both
professional and volunteer efforts have
demonstrated success – longer term success
remains to be documented, but trends are
encouraging – few WPA issues
One more
and this will
all make
Part III: Keys to
Successful Lake
Ken Wagner, Ph.D., CLM
Water Resources Manager
Water Resource Services, Inc.
[email protected]
Key Elements:
Set realistic goals
Involve all relevant parties
Apply sound science
Prevention with any rehabilitation
Organize, prepare, anticipate
Focus and persevere
Adequately fund actions
Publicize and recognize
Monitor and follow up
…true, but boring…
So hang on and we’ll do it differently!
Summary in One Word: Openness
– Open process – inclusive, fair, comprehensive
– Open minds – evaluate without prejudice
– Open lake – private property vs. public
– Open checkbook – you get what you pay for
– Open ended management – no clear endpoint,
follow-up needed
Open Process
• Solicit input from all
interested parties:
lake users, potential
lake users, property
owners, those with
political or regulatory
jurisdiction, those
holding the purse
Open Process
• Try to accommodate reasonable uses
Ballroom catfish dancing –
one esoteric pursuit
Incredible fishing?
Recognize potential
Open Process
• Set realistic goals, arrived at as a group
Most lakes can support multiple uses, but recognize the limits
Open Process
• Seek true conflict resolution, not to win
a power struggle
One ring to rule them all…
I’ll show you how we resolve
conflicts in Chicago
Open Process
• Think about how the other guy feels…
Open Process
• Let the process run its course – don’t
rush or force decisions on others!
• Provide one or two of the three forms of
satisfaction to all parties
Get your ducks in a row
OK, we’ll do it your way…
Open Process
• Revisit goals and progress periodically
Look at the big picture first
…then ask specific
questions, like “Is the
fishing better now?” and
“Has boating safety
Open Minds
• Spin is revered in law, accepted in
politics, tolerated in the media, but
should be avoided in science
In the race to the moon, the US
finished next to last, while the USSR
was second
…making lemonade
from lemons?
Open Minds
• Recognize that there are multiple
sides to every issue (and
management technique)
• There is usually more than one
possible effective approach to
• No one technique is likely to be the
whole answer
• Science, economics and politics form
the 3-legged stool of management
Open Minds
Open Minds
• Evaluate options in a balanced way;
do not be blinded by prejudice or
spin (yours or that of others!)
Two extreme and inappropriate
views on herbicide use
Open Minds
• Refine goals and management methods
as necessary; don’t blindly follow an
approach that is not working, but give
the plan a fair trial
Open Lake
• Private property, private rights and
private responsibility: reality and
Sharing the resource
is unappealing to
Open Lake
• Who owns the water in a private lake?
The water upstream? Downstream?
Does water respect boundaries?
• If lake water quality in a private lake
declines, should shoreline owners get a
reduced tax rate? If so, who suffers?
• If a nuisance species invades a private
lake, who is threatened? Who should pay
for control?
Open Lake
• Shared resources, shared
responsibility: avoiding the Tragedy
of the Commons
A "commons" is any resource used as though it
belongs to all. In other words, when anyone can use a
shared resource simply because one wants or needs to
use it, then one is using a commons. A commons is
destroyed by uncontrolled use—neither intent of the
user nor ownership are important.
- Jay Hansen, 1997, explaining the concept
attributed to Garrett Harding, 1968
Open Lake
• The European model for ownership
and access
Balancing personal and public rights
Ownership of shoreline
does not convey a right
to exclude in many
Open Lake
• Public access facilitates public
funding in most states in the USA
Open Checkbook
• Invest in reliable data for decision
Open Checkbook
• Paraphrase of old proverb: A dollar of
prevention is worth thousands of
dollars of cure
EWM - from fragment to
dominance in under 5 years
in many lakes
Open Checkbook
• Evaluated over a human lifetime,
costs of alternative rehabilitation
methods will be more similar than a
simple comparison of initial costs
Open Checkbook
• You get what you pay for…or less
“We couldn’t
afford barley
straw, so we
tried stale
wheat bread”
“Will build to suit”
“If it seems too good to be
true, it probably is”
Open Ended
• Just like gardening, landscaping, and
home maintenance, lake management
does not have a clear end
Open Ended
• Recommend 5-year plan and 20-year
plan as minimum timeframes for
• Vigilance is the price of
freedom…from costly rehabilitation Prevention of problems is a never
ending task
• Follow-up to rehabilitation is critical
to minimizing long-term costs and
protecting the investment
Open Bar
Sometimes it makes more sense
after a drink
Open Season (on the presenter)
Questions and comments?

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