essex climatechangeflooding_scotthursley
DESCRIPTION
From 2013 Great Marsh CoalitionTRANSCRIPT
Adapting to Climate Change with Low Impact Development (LID):
Scott Horsley
Horsley Witten Group, Inc.
Sandwich Boston Providence Newburyport
Image Credit: New England Integrated Sciences and Assessment, h8p://inhale.unh.edu/Climate/index.html
Image credit: U.S. Global Change Research Program (www.globalchange.gov).
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)
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.
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.
Future Design Storms with ConPnued Climate Change
Source: University of New Hampshire
No building present on lot, 2005 photo
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
Building constructed between 2005 and 2008, now in regulated floodplain aQer 2010 FEMA re-‐study
100-‐year flood, depth >1 foot, from 2010 FEMA study
Prior 100-‐year flood, depth > 1 foot
Same building, March 2010 flood (approximately 40-‐year flood)
Key Stormwater RegulaPons
Federal Clean Water Act, NaPonal Pollutant Discharge EliminaPon System (NPDES): • EPA 2003 MS4 Permits • EPA General Stormwater Permit (MA) (expected 2013??)
Key Stormwater RegulaPons
Federal Clean Water Act, NaPonal Pollutant Discharge EliminaPon System (NPDES): • EPA 2003 MS4 Permits • EPA General Stormwater Permit (MA) (expected 2013??) Massachuse8s IniPaPves: • MA Stormwater Standards (jurisdicPon under Wetlands ProtecPon RegulaPons)
• MA Water Management Act (Sustainable Water Management IniPaPve, SWMI)
• MA Climate Change AdaptaPon Report/Regulatory Changes
Key Stormwater RegulaPons
Federal Clean Water Act, NaPonal Pollutant Discharge EliminaPon System (NPDES): • EPA 2003 MS4 Permits • EPA General Stormwater Permit (MA) (expected 2013??) Massachuse8s IniPaPves: • MA Stormwater Standards (jurisdicPon under Wetlands ProtecPon RegulaPons)
• MA Water Management Act (Sustainable Water Management IniPaPve, SWMI)
• MA Climate Change AdaptaPon Report/Regulatory Changes Local Ordinance/Bylaw/RegulaPons (required MS4)
LID Stormwater Management Techniques
• Rain Barrels and Cisterns / Water Re-‐use • Stormwater Planters, Tree PlanPng • Permeable Paving • Open Channels • BioretenPon • Stormwater Wetlands • Green Roogop Systems • VegetaPve Buffers • InfiltraPon
Permeable Pavement
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
Dry Well Infiltra2on of Roof Runoff
DisconnecPon of Roogop Runoff to Vegetated Swale
Source: CWP
Source: Horsley Wi8en Group
Permeable Pavement
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
Source: Larry Gavin
BioretenPon ApplicaPons
• Parking lot islands • Median strips • ResidenPal lots • Office parks
Source: LID Center
BioretenPon Cell Water Street, Plymouth Center, MA
NYC GI Design Criteria
New York City – Bioreten2on Retrofit
Rain Garden
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
• Extended roof life, esPmated at 40 years
World Trade Center, Boston
Stormwater Planters
• VegetaPve uptake of stormwater pollutants
• Pretreatment for suspended solids before they reach water-‐treatment faciliPes
• AesthePcally pleasing • ReducPon of peak
discharge rate
Dry Well Infiltra2on of Roof Runoff
DisconnecPon of Roogop Runoff to Vegetated Swale
Source: CWP
Source: Horsley Wi8en Group
Natural Conservation Area
Lawn IrrigaPon 50-‐100 gals/day
Dry Well
Open SecPon Road
InfiltraPon Swale
Roogop/Driveway Runoff 36-‐94 gals/day
Horsley Witten
LID Principles at The Pinehills
• Cluster Development • Reduce Impervious Areas • AlternaPve Landscaping • Stormwater Management • Wastewater Re-‐use • Nutrient Management
Preserved Historic Sandwich Road
Horsley Witten
Stormwater Management
Integrated Water Management
Water Table Map With Groundwater Flow Arrows
Horsley Witten
Zone II
WWTP
Zone II
WWTP
Zone II
Interceptor/Irrigation Wells
MWRA Water
Water to Cafe Irrigation & Water Fountain
Floor Washing
Over!ow toSewer
Groundwater Pumping
StorageTank
THANK YOU!
QUESTIONS?