Presenting the
Great Marsh Coastal Adaptation (Resiliency)
Plan
Wayne Castonguay, Ipswich River Watershed Association
www.greatmarshresiliency.org
Project area: the Great Marsh and its coastal communities in MA
Photo credit: David Stone
The Great Marsh: an ecosystem that provides a host of benefits to our communities, including critical coastal protection
WHY? Weather-related hazards are enhanced by
climate change
Warming temperatures bring…
More powerful storms and sea level rise.
Climate Changes: What are the Impacts?
Ocean
Water
Changes
Number of
hot days
Precipitation
Changes
Drought
Sea level
rise
Precipitation
Changes –
Flooding
Seasonal
Changes
• Coastal erosion
• Flooding
• Salt water intrusion
• Changing habitats
• Invasive species
• Changes in crops
• Snow pack • Flooding
• Changes in crops
• Health risks
• Energy use
• Fires
• Water supply
• Stream flow
All blue slides provided by and credited to MAPC
For the Northeast United States: temperature increased by almost 2 degrees, between 1895 and 2011 (US National Climate Assessment 2014)
Blue Hill Observatory Annual Temperature, 1831-2008 Source: Michael J. Iacono (from MA Climate Change Adaptation Report 2011)
Temperature change: observed
www.mass.gov/service-details/climate-change-in-massachusetts-and-its-impacts
Projected Temperatures North Coastal Watershed (including Essex)
Temperature F°
Observed
Baseline
1971-2000
Predicted
2050s
Predicted
2090s
Annual temperature 49.69°F 52.4- 55.88°F 53.2-60.47°F
Days over 90 °
(days/year) 7.69 days 14.56-33.98 17.68-70.13
Days over 100 °
(days/year) 0.04 days .2-3.14 .28-12.57
Temperature change: predicted Temperatures are predicted to increase by 3.78° to 5.22°F by mid-century, and by 2.9° to 9.54°F by the end of the century, with greater increases in winter compared to summer. The frequency with which heat waves (three or more consecutive 90°F days) occur are expected to increase.
Source: Sea Level Rise: Understanding and Applying Trends and Future Scenarios for Analysis
and Planning, Massachusetts Office of Coastal Zone Management, December 2013.
Precipitation change: observed
For the Northeast United States: 71% increase in the amount of heavy rain events that fell from 1958 – 2012. Source: US National Climate Assessment 2014
For Boston area: 10% increase over the past 50 years
Precipitation change: projected North Coastal Watershed (includes Salisbury)
Parameter
Current
Conditions
(1971-2000)
Predicted
Change by 2050
Predicted
Change by 2100
Low High Low High
Annual Precipitation 45.31 inches 45.34 50.83 46.07 52.48
Annual Consecutive
Dry Days 17.01 17.16 19.58 17.21 19.75
www.mass.gov/service-details/climate-change-in-massachusetts-and-its-impacts
Sea level rise: observed
• Boston tide station
• Records from 1921-2016
• Equivalent to 11 inches in 100 years
Sea level rise: projected (Greater Boston Harbor)
Source: Sea Level Rise: Understanding and Applying Trends and Future Scenarios for Analysis
and Planning, Massachusetts Office of Coastal Zone Management, December 2013.
In summary, changes to our region include….
The goal of the Great Marsh Resiliency Planning Project is to help communities to: Develop adaptation strategies to address climate
impacts so that critical human and natural systems can continue to function effectively and be resilient in the face of climate-driven threats
Great Marsh Resiliency Planning Process
Year 1 Task forces formed Vulnerable community assets & concerns identified Community climate-vulnerability assessments & public workshops Year 2 Review all adaptation strategies Identify community asset-specific strategies Regional adaptation workshops Write coastal adaptation plan Year 3 Regional implementation workshops
with Municipal Task Forces and Community Meetings
Great Marsh Resiliency Planning
SALISBURY
Salisbury
• Northernmost coastal community in MA
• 15.4 sq. miles land area, 27% of which is Great Marsh
• 8,283 year-round residents
• Majority of the town’s infrastructure is located in two sections:
o Salisbury Beach
o Salisbury Square
Salisbury Beach at Broadway
Probability of Coastal Inundation in 2030 and 2070
(includes projected storm surge)
2030 2070
GIS-Based Vulnerability Assessments
Assessment of Barriers to Flow
High-Priority Assets Identified by the
Salisbury Resiliency Task Force Priority Asset Location Hazard Type
Salisbury Beach at Broadway East of Broadway, stretching 200ft
north and south
Erosion,
flooding
Route 1A (Beach Road) West of Broadway, stretching over 0.5
miles Flooding
Salisbury Barrier Beach 3.8 mile long beach from NH Border to
Merrimack River Jetty
Erosion,
flooding
Coastal Dunes
- East of southern end of Atlantic Ave
- East of Ocean Front South
- North of the Beach Center, east of
Central Ave
Erosion,
flooding
Low-lying residential areas
bordering the Blackwater River
salt marsh
9th Street south to Lewis Ave Flooding
North End Boulevard from Old Town Way to 18th street Flooding
Sewage Pumping Station 228 Beach Rd Flooding
Seawall @ First Street 32 1st Street Erosion,
flooding
Highest-Priority Assets Identified By The
Salisbury Resiliency Task Force
A1 Salisbury Beach @ Broadway
A2 Route 1A (Beach Road)
A3 Salisbury Barrier Beach
A4 Coastal Dune south of Broadway
Salisbury Beach
at Broadway
VULNERABILITIES:
• Erosion – chronic and storm-related
• Storm surge flooding
Photo Credit: Gregg Moore
Climate Adaptation Strategies: actions taken to build resilience and to adjust to climate impacts on society and the environment
Climate Adaptation &
Resilience Policy
Natural Solutions
Nature-Based & Hybrid
Gray Infrastructure
Great Marsh Regional Adaptation Strategies
#1 Adaptation Strategy:
Increase Natural Security
• Protect natural habitats
• Restore degraded natural habitats
• Replicate natural systems & cycles
in developed areas
Wetlands Reduce Flooding!
Coastal wetlands are estimated to have saved $625 million in flood damages during Hurricane Sandy.
- COASTAL WETLANDS AND FLOOD
DAMAGE REDUCTION Using Risk Industry-based Models to Assess Natural Defenses in the Northeastern USA
Natural and Nature-Based Strategies
Restore connectivity of river and coastal systems
Use living shorelines to stabilize shoreline edges
Protect and enhance shellfish reefs and beds
Protect and restore barrier beaches and dunes
Beneficially reuse dredged material
Restore submerged-aquatic vegetation
Protect and restore salt marshes
Facilitate marsh migration
Enhance land conservation efforts
Protect & enhance biodiversity
Natural Defenses
BEACHES & DUNES SALT MARSHES
RIVERS & FLOODPLAINS BIODIVERSITY
Land-use Planning and Policy
Update municipal policies
Prioritize low-impact development (LID) practices
Revise local wetlands protection bylaws and regulations
Move development away from the coast and wetlands
Create “freeboard incentive” for buildings
Use incentives (e.g. TDCs) to reduce risky development
Institute comprehensive water resources management
Natural Strategies
DUNE RESTORATION INVASIVE SPECIES
REMOVAL
SALT MARSH
RESTORATION RESTORE CONNECTIVITY
Landcons MAST here
Great Marsh Land Conservation
Policy Strategies
LAND-USE REGS
CLIMATE-SMART
DEVELOPMENT
WATER RESOURCES MGT.
POLLUTION CONTROL
Low-Impact/Climate-Smart Development & Retrofits
Revise Local Bylaws and Regulations
Outreach included:
Symposiums, posters…
brochures, maps…
… E-newsletters, local cable videos, press, websites, & social media
Need to incorporate climate projections into everyday discussions, decisions and planning, including economic
development
Great Marsh Restoration Partners
“Let’s face it, folks, this is just one more statement about the fact that it’s really important for us to put time,
money, and resources into resiliency and adaptability.”
On January 7, 2018, on WGBH radio, Governor Baker said it’s important to learn from storms like this, and make adjustments.*
*https://news.wgbh.org/2018/01/07/local-news/storm-flooding-raises-issue-coastal-resiliency
Photo credit: Abigail Manzi uploaded to MyCoast
Thank you. Questions?
www.greatmarshresiliency.org
Wayne Castonguay Ipswich River Watershed
Association [email protected]