HomeMy Public PortalAbout160405_BCAG_MeetingSlidesBrewster Coastal Risks
Yesterday, Today, and Tomorrow
BCAG
–
Mee)ng
3
For
Committee
consideration
Local
Tides
Historic
storm
surge
measurements
for
Nor’Easters
Sea
Level
Rise
(SLR)
and
storm
surges
in
the
context
of
high
tides
Coastal
Change
–
a
historic
perspective
Updated
GIS
visualizations
Preliminary
parking
impacts
2016
NOAA
)dal
predic)ons
Sesuit
Harbor,
East
Dennis,
MA
Tidal
range
(consecutive
Low/High
Tides):
Average:
10.3
feet
Ranging
from
6.8
to
15.2
feet
Relative
to
the
shoreline
(Mean
High
Water
or
MHW)
Most
(58%)
high
tides
are
above
MHW
~
1
in
17
high
tides
(5.8%)
are
≥2
ft
above
MHW:
that’s
41
high
tides
3
greatest
high
tides
are
2.8
feet
above
MHW
Measured
Historic
Storm
Surges
Historic
Storm
Surges
from
NOAA’s
Boston
Gauge
4.21'
on
February
9,
2013
(Winter
Storm
Nemo)
4.57'
on
October
29,
2012
(Hurricane
Sandy)
4.88'
on
October
30,
1991
("Perfect
Storm"
Halloween
Nor'easter)
4.34'
on
February
6,
1978
(Blizzard
of
1978)
3.69'
on
February
14,
1940
(Valentine's
Day
Nor'easter
)
For
visualizations
purposes,
assume
4
ft
surge
SLR
Scenarios
–
Boston
Gauge
Source:
U.S.
Army
Corps
of
Engineers
(USACE)
Sea
Level
Change
Curve
Calculator,
Version
2015.46
1
ft
@2038
(in
~20
years)
2
ft
@2054
(in
~40
years)
4
ft
@2078
(in
~60
years)
Scenarios
Presented
at
BCAG
Meeting
2
SLR:
2
ft
and
4
ft
above
MHW
Storm
surges:
6
and
10
ft
(SLOSH
model)
Requested
after
Meeting
2,
presented
here
SLR:
2
ft
and
4
ft
above
MHW
Storm
surge:
4
ft
(a
“Nor-‐Easter”)
To
put
things
into
perspective
2
ft
above
MHW
already
occurs
40
times
a
year
4
ft
SLR
is
a
daily
equivalent
to
a
Nor-‐Easter
surge
Coastal Change
A Historic Perspective at the Landings
Breakwater
and
Little
Breakwater
Paine’s
Creek
Crosby
Breakwater and Little Breakwater Landings
Town and State Owned Property
Breakwater and Little Breakwater Landings
1994 Color Aerial and MA CZM Shoreline
Breakwater and Little Breakwater Landings
2009 Color Aerial and MA CZM Shorelines
Breakwater and Little Breakwater Landings
2014 Color Aerial and MA CZM Historic Shorelines
Breakwater and Little Breakwater Landings
Historic Shorelines, Erosion Rates and Variability
Short Term: 3.05 ft/year (accretion)
Long Term: -0.26 ft/year (erosion)
Short Term: -1.41 ft/year (erosion)
Long Term: -0.56 ft/year (erosion)
1951
1994
2009
1934
Paine’s Creek
2014 Color Aerial and MA CZM Historic Shorelines
Crosby Landing
2014 Color Aerial and MA CZM Historic Shorelines
Challenging
Predic)ons
Large
variability
Spatially
Temporally
Limited
data
(shorelines)
Built
environment
has
changed
Updated
GIS
Flood
Visualiza)ons
Paine’s
Creek,
Mant’s
Landing,
and
Wing
Island
Linnell
and
Crosby
Landings
Little
Breakwater
and
Breakwater
Ellis
Landing
Paine’s Creek, Mant’s Landing, and Wing Island
Salt & Fresh Water Wetlands, and Town Owned Land
Paine’s Creek, Mant’s Landing, and Wing Island
Mean High Water
Paine’s Creek, Mant’s Landing, and Wing Island
MHW + 2 feet Sea Level Rise
Paine’s Creek, Mant’s Landing, and Wing Island
MHW + 4 feet Sea Level Rise
(or MHW + 4 foot Storm Surge – possible today)
Paine’s Creek, Mant’s Landing, and Wing Island
MHW + 4 ft SLR + 4 ft Storm Surge
Paine’s Creek, Mant’s Landing, and Wing Island
Flooding at Various SLR and Surge Levels
Linnell and Crosby Landings
Salt & Fresh Water Wetlands, and Town/State Owned Land
Linnell and Crosby Landings
Mean High Water
Linnell and Crosby Landings
MHW + 2 feet Sea Level Rise
Linnell and Crosby Landings
MHW + 4 feet Sea Level Rise
(or MHW + 4 foot Storm Surge - possible today)
Linnell and Crosby Landings
MHW + 4 ft SLR + 4 ft Storm Surge
Linnell and Crosby Landings
Flooding at Various SLR and Surge Levels
Little Breakwater and Breakwater Landings
Salt & Fresh Water Wetlands, and Town Owned Land
Little Breakwater and Breakwater Landings
Mean High Water
Little Breakwater and Breakwater Landings
MHW + 2 feet Sea Level Rise
Little Breakwater and Breakwater Landings
MHW + 4 feet Sea Level Rise
(or MHW + 4 foot Storm Surge - possible today)
Little Breakwater and Breakwater Landings
MHW + 4 ft SLR + 4 ft Storm Surge
Little Breakwater and Breakwater Landings
Flooding at Various SLR and Surge Levels
Ellis Landing
Salt & Fresh Water Wetlands, and Town Owned Land
Ellis Landing
Mean High Water
Ellis Landing
MHW + 2 feet Sea Level Rise
Ellis Landing
MHW + 4 feet Sea Level Rise
(or MHW + 4 foot Storm Surge - possible today)
Ellis Landing
MHW + 4 ft SLR + 4 ft Storm Surge
Ellis Landing
Flooding at Various SLR and Surge Levels
Paine’s
Creek
–
Access
Impacts
Paine’s
Creek
–
Access
Impacts
Preliminary
Impacts
to
Parking
and
Access
Coastal
Landing Parking
Spaces Scenarios
with
Impacts
Parking
Access
to
Parking
Paines
Creek 19 4
ft
SLR 4
ft
SLR
+
4
ft
surge
Mants 44 4
ft
SLR/surge 4
ft
SLR/surge
Saints 38 N/A N/A
Little
Breakwater 6 N/A 4
ft
SLR
Breakwater 62 4
ft
SLR
+
4
ft
surge 4
ft
SLR
+
4
ft
surge
Point
of
Rocks 3+8 N/A N/A
Ellis 19 4
ft
SLR
+
4
ft
surge N/A
Linnell 25 4
ft
SLR
+
4
ft
surge N/A
Crosby 60 4
ft
SLR/surge 4
ft
SLR/surge
Questions?
Paine’s Creek
Town and State Owned Property
Paine’s Creek
1994 Color Aerial and MA CZM Shoreline
Paine’s Creek
2009 Color Aerial and MA CZM Shorelines
Paine’s Creek
2014 Color Aerial and MA CZM Shorelines
Crosby Landing
Town and State Owned Property
Crosby Landing
1994 Color Aerial and MA CZM Shoreline
Crosby Landing
2009 Color Aerial and MA CZM Shorelines
Crosby Landing
2014 Color Aerial and MA CZM Historic Shorelines