1. Adapting to Climate Change
with Low Impact Development (LID):
Scott Horsley
Horsley Witten Group, Inc.
Sandwich
Boston
Providence
Newburyport
2.
3. Image
Credit:
New
England
Integrated
Sciences
and
Assessment,
h8p://inhale.unh.edu/Climate/
index.html
4. Image
credit:
U.S.
Global
Change
Research
Program
(www.globalchange.gov).
5.
6. Future
Design
Storms?
• Kirshen
et
al.
(2008)
project
sea-‐level
rise
onto
Pme-‐series
of
past
surge
events
in
the
U.S.
Northeast
to
esPmate
that
the
2005
100-‐year-‐event
will
become
the
30-‐70
year
event
by
2050.
• By
2050,
Boston
could
experience
the
current
100-‐year
riverine
flood
every
two
to
three
years
on
average
and,
by
2100,
the
current
100-‐year
riverine
flood
is
expected
to
occur
every
one
to
two
years
under
both
the
low-‐
and
high-‐
emissions
scenarios
(MA
Climate
Change
AdaptaPon
Report)
7. 100-‐Year
Design
Storms
(inches)
Springfield
Worcester
Boston
TP40
Design
Storm
(1930
–
1960)
6.5
6.5
6.6
Cornell
Design
Storm
(1936
-‐
2008)
8.8
8.8
8.8
Hydrology
Handbook
for
Conserva2on
Commissions:
Appendix
F.
Rainfall
Data
for
MassachuseBs
from
Rainfall
Frequency
Atlas
of
the
United
States
(TP-‐40).
Users
of
this
Handbook
should
note
that
current
MA
DEP
wriFen
guidance
(see
DEP
Waterlines
newsleFer
-‐-‐
Fall
2000)
requires
the
use
of
TP-‐40
Rainfall
Data
for
calculaJons
under
the
Wetlands
ProtecJon
RegulaJons
and
the
Stormwater
Management
Policy.
More
stringent
design
storms
may
be
used
under
a
local
bylaw
or
ordinance.
8. 100-‐Year
Design
Storms
(inches)
Springfield
Worcester
Boston
TP40
Design
Storm
(1930
–
1960)
6.5
6.5
6.6
Cornell
Design
Storm
(1936
-‐
2008)
8.8
8.8
8.8
Hydrology
Handbook
for
Conserva2on
Commissions:
Appendix
F.
Rainfall
Data
for
MassachuseBs
from
Rainfall
Frequency
Atlas
of
the
United
States
(TP-‐40).
Users
of
this
Handbook
should
note
that
current
MA
DEP
wriFen
guidance
(see
DEP
Waterlines
newsleFer
-‐-‐
Fall
2000)
requires
the
use
of
TP-‐40
Rainfall
Data
for
calculaJons
under
the
Wetlands
ProtecJon
RegulaJons
and
the
Stormwater
Management
Policy.
More
stringent
design
storms
may
be
used
under
a
local
bylaw
or
ordinance.
9. Future
Design
Storms
with
ConPnued
Climate
Change
Source:
University
of
New
Hampshire
13. FEMA
100-‐year
flood,
depth
>
1
foot,
at
2me
building
constructed
FEMA
100-‐year
flood,
depth
<
1
foot,
at
2me
building
constructed
Building
constructed
between
2005
and
2008,
in
loca2on
not
designated
as
FEMA
floodplain
14. Prior
100-‐year
flood,
depth
>
1
foot
100-‐year
flood,
depth
>1
foot,
from
2010
FEMA
study
Building
constructed
between
2005
and
2008,
now
in
regulated
floodplain
aQer
2010
FEMA
re-‐study
22. Rain
Barrels
and
Cisterns
Runoff
ReducPon
&
Water
ConservaPon
• Downspouts
directed
to
tanks
or
barrels
• 50
–10,000
gallons
• Excess
diverted
to
drywell
or
rain
garden
• Landscaping,
car
washing,
other
non-‐
potable
uses
23. Dry
Well
Infiltra2on
of
Roof
Runoff
Source:
CWP
DisconnecPon
of
Roogop
Runoff
to
Vegetated
Swale
Source:
Horsley
Wi8en
Group
28. Vegetated
Swales
Conveyance,
Treatment,
Infiltra2on
• Roadside
swales
(“country
drainage”)
for
lower
density
and
small-‐scale
projects
• For
small
parking
lots
• Mild
side
slopes
and
flat
longitudinal
slopes
• Provides
area
for
snow
storage
&
snowmelt
treatment
36. Green
Roofs
• Stormwater
Runoff
absorpPon/collecPon
• Reduced
flooding
of
and
damage
to
urban
streets
• Interior
heaPng
and
cooling
benefits
of
10
degrees
or
more
• Air
purificaPon
• RecreaPonal
amenity
• Improved
aesthePcs
World
Trade
Center,
Boston
• Extended
roof
life,
esPmated
at
40
years
37.
38.
39.
40.
41. Stormwater
Planters
• VegetaPve
uptake
of
stormwater
pollutants
• Pretreatment
for
suspended
solids
before
they
reach
water-‐
treatment
faciliPes
• AesthePcally
pleasing
• ReducPon
of
peak
discharge
rate
42. Dry
Well
Infiltra2on
of
Roof
Runoff
Source:
CWP
DisconnecPon
of
Roogop
Runoff
to
Vegetated
Swale
Source:
Horsley
Wi8en
Group
43. Natural Conservation Area
Lawn
IrrigaPon
50-‐100
gals/day
Roogop/Driveway
Runoff
36-‐94
gals/day
Dry
Well
InfiltraPon
Swale
Open
SecPon
Road
45. LID
Principles
at
The
Pinehills
•
•
•
•
•
•
Cluster
Development
Reduce
Impervious
Areas
AlternaPve
Landscaping
Stormwater
Management
Wastewater
Re-‐use
Nutrient
Management