Download Notes - International Upper Great Lakes Study

Notes
Coastal Experts Workshop
Port Huron, Michigan October 14-16, 2008
The Coastal Zone Technical Working Group (CZTWG) of the International Upper Great
Lakes Study (IUGLS) held an Experts Workshop to help develop a strategy to evaluate
the impacts of fluctuating water levels due to lake level regulation at Sault Ste. Marie on
the coastal riparian interest. Primary issues of concern to the coastal riparian interest
include (but are not limited to) flooding, erosion of property, integrity of shore protection,
and property value decrease during times of low water conditions. As lake level
regulation at Sault Ste. Marie has only a small influence on water levels and the IUGLS
covers an extensive geographical area, the CZTWG is challenged with ensuring
assessment tools are sensitive to minor differences between regulation plans while
being applicable to a large geographic area. The CZTWG is particularly interested in
defining features and characteristics that are critical to the evaluation process and
providing a general estimate of uncertainty.
1. Welcome and Introductions: The meeting began at 1:20 pm with round table
introductions. Those in attendance were:
TWG Members:
 Scott Thieme, US Coastal TWG Lead
 Mike Shantz, Canadian Coastal TWG Lead
 Robin Davidson-Arnott, University of Guelph
 Matt Warner, Michigan Department of Environmental Quality
 Gene Clark, University of Michigan
 Ian Cameron, Ontario Ministry of Natural Resources
 Nick Zager, LRE Associate
Coastal Experts:
 Don Forbes, Natural Resources Canada
 Phil Keiller, Coastal Expert, University of Wisconsin
 Dave Hart, Coastal Expert, University of Wisconsin – GIS,
WisconsinCoastalGuide.org
 Ralph Moulton, Canadian, Com. Nav. TWG – Coastal Expert
 Bill Kamphuis, Coastal Expert, Queens University
 Brian Greenwood, University of Toronto-Scarborough
 Heather Stirratt, NOAA-Minnesota
 Joe Gailani, ERDC-Vicksburg
Other International Upper Great Lakes Study Participants:
 Wendy Leger, Canadian PEG Lead
 Bill Werick, US PEG Lead
 David Fay, Canadian Lake Superior Regulation Task Team Lead
 Tony Eberhardt, US Lake Superior Regulation Task Team Lead
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Jim Bredin, US Study Board Member
Greg Mayne, Acting for Sandie George, Canadian Ecosystem TWG
Roger Smithe, US PIAG Member
Jim Anderson, Canadian PIAG Member
2. Review of Outline and Objectives for the Workshop in the Context of Upper
Lakes Study Objectives: Mike Shantz began with a general overview to set the tone
for the workshop as noted in the attached presentation. Key elements to keep in mind
throughout the workshop were:
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Context – sensitivity to water level changes as a result of regulation
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The need to utilize Impact Analysis Tools to compare regulation plan impacts
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The TWG budget is limited and will influence some decisions of the TWG
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Future Projections – consider future hydrologies (climate change,
stochastics), but not future economies
Welcome and
Introduction - Oct 14 2008.pdf
3. Background on Regulation at Sault Ste. Marie: David Fay discussed the history
of the regulation of Lake Superior as noted in the attached presentation. Key things
noted were:

The original orders were issued by the IJC in 1914 with first regulation plan
developed and applied in 1916
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Supplementary orders were issued in 1979. The important change was the
introduction of “systemic” regulation with the intent of trying to balance levels
of Lake Superior and Lakes Michigan-Huron (relative to their long term
average)
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Plan 1977-A has been in use since 1990. It incorporates a lower limit for
Lake Superior (182.76 m), an upper limit (183.86 m), with chart datum being
183.2 m
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He noted that you may not be able to differentiate one alternative regulation
plan from another, particularly for Lakes Michigan-Huron, since the impacts
due to new plans are expected to be small.
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A question was asked about seasonality of future plans. It was noted that the
current regulation plan and the fencepost plans don’t really impact this at all.
Fay Presentation
4. Current and Past Water Level Impacts: Scott Thieme provided some background
on past water level associated coastal zone impacts and what areas of the upper Great
Lakes have been impacted (see attached presentation). Key impacts noted were:
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Flooding of property and structures, seen mostly heavily in the past around
Lakes St. Clair and Erie.
Erosion of property and loss of structures. While erosion has been more of a
problem on Lakes Michigan, Erie, and parts of Lake Huron, it has been light
along large sections of Canadian shoreline of Georgian Bay and Lake
Superior.
Low water impacts include a variety of things such as aesthetics,
environmental quality and ownership issues. There have been complaints
related to such issues on Georgian Bay, the eastern shore of Lake Michigan,
Saginaw Bay, and Lake St. Clair.
Current and Past
water level impacts - Oct 14 2008.pdf
5. Performance Indicators: Mike Shantz led a discussion about the use of
Performance Indicators (PIs) in the study and things we should be thinking about. Two
presentations were used (see attached presentations). For the IJC’s Lake Ontario St.
Lawrence River Study, there were three primary PIs used for the coastal impact
evaluation including: first floor flooding, erosion to unprotected shoreline property, and
damage to existing shore protection.
Potential PIs - Oct 14
2008.pdf
Following the introductory presentations, the workshop participants brainstormed
potential coastal PIs for IUGLS recognizing the need to go offshore to breaking wave
depth and the need to consider glacial isostatic adjustment (for example, Georgian
Bay is emerging). A variety of suggested PIs were listed, grouped into 4 general
categories.
Flooding
 wave set up,
 structural failure – type of structure, etc.
 permits and the difficulty acquiring,
 property claims,
 insurance premiums.
 need for monitoring stations.
 related issues: habitat migration studies,
 ramps out of service,
 habitat loss,
 safe navigation,
 impact on tribal cultures,
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Erosion
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infrastructure concerns - differences between storm and design
elevations,
number of plants impacted,
impacts in creeks,
recreational value
land value,
tourism,
deposition of material (low water),
the number of boundary disputes,
property values (change on municipal tax base) (also relates to
flooding),
changes in water quality,
near-shore erosion,
tourism perspectives on public lands,
encroachment when levels are low
Shore protection
 assessment of design. Consider updated forecasts of water levels
including, possible climate change impacts,
 adaptation and design decisions and criteria,
 structural modifications,
 freeze-thawing cycles (can also effect erosion),
 movement of sediment resulting in failure (sediment budget),
 storm surge
Low Water Issues
 exposed sediment
 development pressure
 property values
 inconvenience
 Georgian Bay wetlands
 Sediment budget (deposition)
 Aesthetics – view (vegetation growth, levels too far down to too far
away)
 Tourism (e.g. access to beaches and recreational value) – note that
some areas see benefits from low water and other areas see negative
impacts
 Costs to move water level gauges or other infrastructure
 Safe navigation
 Change in water velocities/currents as it relates to pathogens and nonpoint source pollution
 Habitat change (e.g. wild rice beds, changes to hunting areas)
 Management of contaminated sediment
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Boat ramps out of service
Change in property value – reflected in tax base
Drainage in local creeks
Following the brainstorming on Day 1, the items were entered into an Excel
spreadsheet and an attempt was made to categorize them relative to their
importance in relation to water level regulation (low, moderate, or high), whether
they could (or needed to be) modelled vs. whether they could be considered in a
qualitative sense, and whether they could be used to select new regulation plans or
whether they were better used in relation to a potential Adaptive Management
program. The excel file is attached for reference. Highlights are included below:
Rating Potential PIs Oct 15 2008.xls
Flooding
 Flooding damages to residential/ commercial/ industrial property – high
(expert agreement = EA) – related to regulation plan (RP) and adaptive
management (AM)
 Changes in flood hazard management zones (change in return period,
1:100 and linked to climate change) – high (EA), AM
 Flooding of municipal infrastructure – moderate (expert disagreement =
ED – high when considering larger cities like Milwaukee), RP
 Blowout of barrier beaches – low (EA, need to determine how many
exist).
 Infrastructure flooding – impaired operation – moderate (related to 3
above)
 Infrastructure flooding – damages to infrastructure – moderate (related
to 3 above)
 Decreased municipal tax base (also erosion) – low (could be done with
data and tools now)
 Loss of beach access due to flooding – moderate (ED – low when
compared to residential flooding and infrastructural concerns)
Shore Protection
 Structure failure – high (EA, RP, AM)
 Deterioration of exposed timbers – moderate (don’t model, more
related to climate change)
 Changes in design standards – high (EA, AM)
 Permits to protect property – low (EA – describe in contextual
narrative, AM)
 Percent of shoreline protected –high
 Number of permits requested – low
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Erosion
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Distinguished between well engineered and ad hoc – high (EA – link
with design standards, AM)
Structure modification – low
Changes to damage from freeze-thaw – low
Loss of land - high
Decrease in property values - high
Sediment budget - high
Nearshore erosion - high
Remobilization of contaminated sediments – low
Increase in shore protection on unprotected shoreline – moderate (ED
– more important, not sure how many sites. Related to climate change)
Sediment deposition – high
Freeze thaw bluffs – low
High vs. low water erosion rates – high
Deposition of sediments at creek/ lake interface – moderate
Low Water
 Alga - moderate
 Exposed sediment - high
 Development pressure - high
 Property values – high
 Inconvenience - low
 Georgian Bay wetlands - ETWG
 Sediment budget and deposition - high
 Aesthetics – view impacts due to vegetation growth - low
 Aesthetics – view –levels too far down to far away - low
 Costs to move gauges or other infrastructure impairment – M&I TWG
 Safe navigation (# of ships groundings or dredging requests) –
CNTWG
 Change in water velocities/ currents - low
 Habitat change – wild rice beds and people dependent on hunting ETWG
 Management of contaminated sediments - Moderate
 Boat ramps out of service - RBTWG
 Development pressure - high
 Drainage in local creeks – low
Other
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Tourism – access to beaches – high
Tourism – recreational value – high
Safe navigation – CNTWG
Habitat – ETWG
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Drowned river mouths – low
Water levels as it impacts water quality – low
Impact of water levels on tribal lands - ETWG
Wild rice – ETWG
6. Uncertainty in Predicting the Future: Robin Davidson-Arnott discussed the
concept of uncertainty and the need to consider it in our work (presentation attached).
How do we characterize uncertainty and be defensible? There is uncertainty about
future climate change and variability, uncertainty about the data we use, uncertainty in
the modeling exercises and our ability to distinguish between water level scenarios
generated by alternative regulation plans. We need to work with the combinations of
lake levels and storms to ensure the range of surge and wave conditions are
considered. Likely our primary consideration for uncertainty is how to translate our
information from specific sites to broader sections of the study area shoreline. There
was general agreement from invited experts on the importance of considering
uncertainty in the work of the Coastal Zone TWG. However, recommendations on
specific methodologies were not identified in the discussion.
Uncertainty Experts Workshop 101508.pdf
7. Flooding of Shoreline Property: Nick Zager presented information to set the
context for discussion by identifying locations of past flooding impacts and outlining
some key considerations for potential assessment methodologies. The draft guidelines
for the FEMA Great Lakes Runup Methodology were presented as an example of a
possible option.
Potential U.S. sites of interest include:
 Duluth (Lake Superior)
 Green Bay (Lake Michigan)
 Saginaw Bay (Lake Huron)
 Southeastern Lake Michigan (Lake Michigan)
 Western Lake Erie (Lake Erie)
 Buffalo (Lake Erie)
 Lake St. Clair
Potential Canadian sites of interest include:
 Goulais Bay (Lake Superior)
 Thunder Bay (Lake Superior)
 Collingwood (Georgian Bay)
 Essex (Lake Erie)
 Lake St. Clair
 There is a need to define a site on Lake Huron
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Methodology was discussed:
 Should be physically-based
 Should not be too costly
 Site specific (represent site conditions)
 A suggestion was to add possible wave surge to the water levels resulting
from regulation options at specific sites. Since we have instantaneous
gauge data, regression analyses can be run and added to water levels.
 We can consider the draft guidelines for FEMA Great Lakes Run-up
Methodology, using the one percent exceedence:
 Determine maximum monthly water level
 Use WIS data to find maximum monthly wave height associated with
the maximum water level
 Use best topography and bathymetry at specific site
 A distribution can be plotted and a specific return period wave setup
elevation can be gathered.
 Wave data would be required. Circulation modeling may be available from
NOAA/GLERL or the NOAA GNOME model. Check with ERDC to see
about the timing of WIS updates.
 LIDAR data may be available but is likely very limited (need to follow up
with COE, Mobile and ERDC, Vicksburg)
 It was strongly recommended that the methodology needs to be verified
using field data due to the potential differences between theoretical wave
runup and actual conditions along complex shorelines. As well, need to
prove that model assumptions are valid through the verification process.
However, it was also noted that field verification may be difficult.
 Given the potential difficulty in differentiating regulation plans that result in
fairly similar water levels (especially on Lakes Michigan-Huron and
downstream), it was suggested that first efforts should be related to
focusing on methods to get the water levels correct and then move to
including economic impacts if differences between plans are evident.
 A suggested process was to start with monthly water levels from available
gauge records and determine monthly probability distributions. Next move
to add storm surge based on statistical analysis of within month variability
at recorded time sequence from water level gauges, then move towards
adding local wave and wave transformation impacts and associated
runup. These values can then be added to the new water level scenarios
generated by alternative regulation plans.
 Another suggestion is to look at past stage-damage curves generated by
other studies, specifically the 1993 IJC Reference Study although there
was some concern that these would no longer be useful.
 It was noted that the State of Wisconsin has good parcel data available
and the Office of Coast Survey may have bathymetry data we can use.
Coastal TWG
Flooding - Oct 15 2008.pdf
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8. Erosion to Unprotected Land: Robin Davidson-Arnott provided the background for
discussion on erosion (see attached presentation). Key points were:
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Is changing the timing and magnitude of Lake Superior regulation likely to
produce significant changes in erosion for either shoreline type (sandy and
cohesive shores)?
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Long term erosion is driven by sediment budget. Problem is if sediment
moves out of littoral system.
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Bay mouth bars could be breached (Wisconsin Point)
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Low lake levels might cause more bypassing
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It is difficult to assess catastrophic bluff failure, which is typical on many
shorelines in the Great Lakes. Is there a connection between offshore
downcutting and deep seated bluff failure? Is it possible to predict such
failures?
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Are there existing models we can use?
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What are the data requirements?
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What are the state-of-the-art models that can be used to predict longshore
sediment transport gradients within a littorial cell? COSMOS seems to be
the most effective for quantitatively evaluating cohesive shorelines, but it
would require very site specific data
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Discussion (based on a report by Baird): the “Superior for Michigan-Huron
Plan” increases erosion (cohesive shoreline) at a site on Lake Michigan,
about 10 meters more than 77A, Pre-project and “Superior for Superior
Plan” over 100 years.
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Educating Public: the public needs to be educated on various aspects of
erosion such as downcutting because it is an issue that can not be visibly
seen. The public also needs to be educated on how sandy shorelines
erode
Some conclusions to move forward with:
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Dynamic sandy beach
 Not concerned with dynamic beaches as there was general
consensus from the experts that the water levels considered within
the fencepost plans were not likely to cause large changes in such
systems – only caution would be if sediment were actually being
lost from the closed systems – it was noted however, that these
types of beaches are inherently dynamic and transient so the
question really isn’t whether water levels would impact the
processes but would they be to the extent that the normal dynamic
nature of the beach would change (e.g. loss of sediment)
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Erosional sandy beach
 models can be fairly expensive and also require considerable data
information to calibrate properly so they may not be appropriate for
trying to compare regulation plans
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experts thought significant impact were not expected from
regulation plan based on the fencepost plan options
wave and wave impacts are primary forces influencing longshore
transport
climate change could be important because of the potential
changes in wind and wave conditions. Therefore may want to
consider climate change implications
Cohesive shoreline
 Experts thought COSMOS model may be most detailed available
given its use on the Lake Michigan Potential Damages Study and
other situations. However, the model was also considered fairly
data intensive
 Further sensitivity analysis with COSMOS may be needed using
Lake Superior levels as they are likely to be more variable under
different regulation plan options (as evidenced by examples
presented by David Fay on Day 1 of workshop)
 There was some concern regarding the challenge of predicting
large slump erosion using such a model – it isn’t clear how this
could be included
erosion cohesive and
sandy - Oct 15 2008.pdf
9. Damage to Shore Protection: Gene Clark led this discussion about data,
information, and modeling strategies to address damages to shore protection (see
attached presentation).
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One option could be to develop standard failure conditions based on water
levels for existing shore protection classes
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Another option could be a FEPS style analysis
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Looking at comparison of Baird results on Lake Michigan-Huron (based on
a Chicago District project): down-cutting failures vary from $80M (Plan
77A) to $96M (Superior for Michigan-Huron); overtopping failures vary
from $17.2M (77A) to $18.7M (Superior for Michigan-Huron); total
maintenance relative to 77A, max +14%.
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What is the shore protection protecting? Some protection is more
important than other.
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We need to address the issue of structure design. Well designed
structures should last until old age and not be affected by small changes
in water levels.
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We will need the water level information plus surge for this analysis too, as
well as wave run-up.
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May need more detail on structures currently in place. We could use
Google Earth to look for areas with structures. We could use the 1993
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Levels Reference Study shoreline classification database to inventory
structures. We could use the Corps and other agency permit databases to
find out information on structure details. Other high resolution imagery
may be available in specific locations for use in classifying the shoreline.
Some conclusions to move forward with:
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We could start with hypothetical structures to model with new water level
scenarios generated by alternative regulation plans to see what their
response is. We should do a sensitivity analysis to take into account the
various design parameters.
We may need to conduct field surveys of existing structures to evaluate
our process. We would need top elevations, notes about the structure,
etc.
We need to see what modeling packages are available to use. Examples
include Baird model (FEPS) or models from ERDC.
Still need to consider how sites would be chosen?
Also need to consider how many areas would be sampled?
IJC Workshop
Structures Issues (Clark 10-15-08).pdf
10. Low Water Impacts to Riparians: Mike Shantz led this discussion with a short
presentation (attached). Key points of the discussion are summarized below.
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Lower water levels can be viewed as positive or negative by property
owners based on location and perspective.
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There may be concern with the water intake at Superior Wisconsin. M&I
TWG should know about this.
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There are questions of land ownership as more offshore becomes
exposed.
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Current climate change is increasing bluff recession because bluff faces
are not freezing and instead they are failing
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Should downcutting be examined with Low Water effects? Downcutting
during low water is big concern and when water levels rise, catastrophic
failures occur. This should be covered directly in erosion and shore
protection analysis
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Do we have to deal with longshore transport and deposition? Is it
impacted by low water levels? General expert consensus that fencepost
regulation plans weren’t likely to cause major changes in longshore
transport and deposition. However, extremely low levels resulting from
climate change may be more sensitive. Could deal with as part of erosion
assessment
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Natural inlets are getting blocked with sediment during low water. The
inconvenience to fix this is high while the cost to fix it is relatively low. It is
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relatively easy to fix with equipment available, but can occur several times
a year with low water. Not clear as to the geographic extent of such
problems and may need to examine further.
We need to be able to convey all this information to the public. Need to
consider options for clearly explaining processes to the public.
A general note was brought up that perhaps if likely regulation plan levels
show no change in impacts then it may be advisable to examine extreme
levels
We may want to look at past studies such as “Design Water Levels” to see
how things have changed over the years due to changing water level
regimes.
We also need to address the benefits of low water levels. One example
cited was the restoration of the Cat Island Chain in Green Bay.
Low Water Impacts Oct 15 2008.pdf
11. Linking Coastal Processes and Non-Economic Impacts: Robin DavidsonArnott presented information on barriers and dunes (see attached).
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Modifications of regulated lake levels will effect dynamics and influence
biology.
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If future regulation options are within the natural range, they should not
drastically alter processes. If regulation gets beyond historic range, then
may be more of a problem to consider.
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Low terrace or relic beaches have not been mentioned and may want to
be considered because there is significant development in these areas.
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Should work with the ecosystem group to consider impacts for that
interest.
dunes and barriers Oct 15 2008.pdf
12. Adaptive Management: Scott Thieme lead an open discussion about things the
CZTWG should consider recommending to the Study Board as items that would be
important to an Adaptive Management Plan.
 Triggers for when we are outside a defined water level range
 What about how long we are above or below the range?
 Need to consider response time – it takes some lead time to implement
any changes
 Need dynamic/ rapid information – better forecasts
 Need to prepare for extremes – Great Lakes regional climate model Information on the internet
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It was suggested that the term ‘lake level regulation’ isn’t really accurate
on Lake Superior given the relatively limited control regulation has on the
water levels. This fact needs to be better conveyed to the public.
There was also a sense that adaptive response does not occur until after
the situation has reached an extreme. Need to consider adaptive
management vs. reactive management.
Models are not always accurate especially since evaporation is so difficult
to estimate and predicting climate change could bring on more liability
Key things to keep track of and consider
 Wind information
 Historic ice and coverage
 Off-shore bathymetry – but one or two sites won’t tell you much.
 Shore management
13. Final Discussion:
 Brian Greenwood: Doesn’t see extreme problems with the plans that will
be developed. People should be made aware of natural variability.
 Bill Kamphuis: Nothing more to add.
 Ralph Moulton: Not much benefit in using old stage-damage/ erosiondamage curves from Levels Reference Study. Consider specific sites.
 David Hart: Hope to help from a regional urban planner perspective and
with GIS.
 Phil Keillor: Nothing to add.
 Don Forbes: Consider varying interests around the lake and glacial
isostatic rebound.
 Joe Gailani: Need to consider various coastal models (COSMOS) and
their sensitivity to small changes; but many are data intensive.
 Jim Anderson: Extremely important to have technical commentary
regarding what public is experiencing. Understand public concerns and
have anticipatory framework.
 Roger Smithe: No Great Lake water diversions. Opinions regarding
changing the GL Charter – don’t push for high lake levels since coastal
opinion could change and want to eliminate water.
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