6/1/2016

1

Assessing the Risk and Vulnerability of NH Coastal Communities to

Sea Level Rise and Storm Surge

FROM TIDES TO STORMS:

PREPARING FOR NEW

HAMPSHIRE’S FUTURE COASTSeabrook - Hampton Falls – Hampton - North Hampton – Rye - New Castle - Portsmouth

This project is funded by New Hampshire HomelandSecurity and Emergency Management (HSEM)through a Pre-Disaster Mitigation Grant from theFederal Emergency Management Agency (FEMA). Julie LaBrancheSenior Planner

NH Office of Energy and Planning

Spring 2016 Planning and Zoning ConferenceJune 4, 2016

FROM TIDES TO STORMS: PREPARING FOR

NEW HAMPSHIRE’S FUTURE COAST

Portsmouth

New Castle

Rye

North Hampton

Hampton

Hampton Falls

Seabrook

Project Deliverables

• Maps and Data

• Regional and Municipal

Vulnerability Assessment

reports

Project Overview

• Evaluate impacts from sea-

level rise and storm surge

flooding

• Roadways, Critical

Infrastructure, Natural

Resources

FROM TIDES TO STORMS: PREPARING FOR

NEW HAMPSHIRE’S FUTURE COAST

� Best-available science

� Maps and Data

� Municipal Coordination

� Implementation Guidance

� Vehicles for Informed Planning

� Applicability

Tools and Applications

6/1/2016

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FROM TIDES TO STORMS: PREPARING FOR

NEW HAMPSHIRE’S FUTURE COAST

+6.3 feet sea level

+4.0 feet sea level

+1.7 feet sea level

Source: Wake CP, Kirshen P, Huber

M, Knuuti K, and Stampone M

(2014) Sea-level Rise, Storm Surges,

and Extreme Precipitation in

Coastal New Hampshire: Analysis of

Past and Projected Future Trends.

Best Available Science- SLR Scenarios/Projections

FROM TIDES TO STORMS: PREPARING FOR

NEW HAMPSHIRE’S FUTURE COAST

Sea-level rise Sea-level rise + Storm surge

High-

Resolution

Mapping

Flood Extents

Impacts to

assets and

resources

FROM TIDES TO STORMS: PREPARING FOR

NEW HAMPSHIRE’S FUTURE COAST

High-

Resolution

Mapping

Flood Extents

Impacts to

assets and

resources

Example: Rye Harbor

6/1/2016

3

FROM TIDES TO STORMS: PREPARING FOR

NEW HAMPSHIRE’S FUTURE COAST

0

10

20

30

40

50

60

MHHW+ 1.7

feet SLR

MHHW+ 4.0

feet SLR

MHHW+ 6.3

feet SLR

storm surge +

1.7 feet SLR

storm surge +

4.0 feet SLR

storm surge +

6.3 feet SLR

State and Local Roadways (miles)

Local State

Impacts by

Asset type

FROM TIDES TO STORMS: PREPARING FOR

NEW HAMPSHIRE’S FUTURE COAST

0

5

10

15

20

25

Hampton Hampton

Falls

New

Castle

North

Hampton Portsmouth

Rye Seabrook

Miles of Roadway by Municipality

SLR + 1.7 feet SLR + 4.0 feet SLR +6.3 feet

FROM TIDES TO STORMS: PREPARING FOR

NEW HAMPSHIRE’S FUTURE COAST

0

200

400

600

800

1,000

1,200

1,400

Upland - acres above mean higher high water

SLR + 1.7 feet SLR + 4.0 feet SLR +6.3 feet

6/1/2016

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FROM TIDES TO STORMS: PREPARING FOR

NEW HAMPSHIRE’S FUTURE COAST

0

200

400

600

800

1,000

1,200

1,400

1,600

Municipal Zoning Districts (acres)

SLR + 1.7 feet SLR + 4.0 feet SLR +6.3 feet

FROM TIDES TO STORMS: PREPARING FOR

NEW HAMPSHIRE’S FUTURE COAST

Implementation Guidance

• Designing for resiliency in the current 100-year floodplain

will protect against long term sea-level rise

• Adaptation strategies need to be customized to address

variable conditions

• Iterative actions, not a one-size-fits-all problem

• No-regrets policies and investments

• Periodic review and evaluation of climate science findings,

adjust strategies accordingly

FROM TIDES TO STORMS: PREPARING FOR

NEW HAMPSHIRE’S FUTURE COAST

Municipal Coordination

Administration

Public Works

Planning

Building/Code Enforcement

Conservation

Public Outreach &

Participation

Community Support

For Actions

Regional & State

Coordination

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• Critical Infrastructure

• State and Local Roads

• Utilities and Infrastructure

• Natural Resources - Environment

• Policy and Planning Recommendations

• Regulatory Strategies

• Non-Regulatory Approaches

Local

Hazard Mitigation

Plans

State Agency

Plans

Regional

Master Plan

Natural Resource

Conservation

Vulnerability Assessment

Regional Planning Recommendations

FROM TIDES TO STORMS: PREPARING FOR

NEW HAMPSHIRE’S FUTURE COAST

Vehicles for Informed Planning

FROM TIDES TO STORMS: PREPARING FOR

NEW HAMPSHIRE’S FUTURE COAST

How can the project results be useful?

o Inform recommendations in the CRHC Final Report

o Assist regional practitioners with technical assistance

and outreach to municipalities

o Guide policy changes by state agencies

o Provide a solid rationale for grant proposals to fund

infrastructure improvements, planning and community

outreach

Project Applicability

FROM TIDES TO STORMS: PREPARING FOR

NEW HAMPSHIRE’S FUTURE COAST

• Regional Assessment and Maps

• Municipal Assessment and Maps

http://www.rpc-nh.org/regional-community-planning/climate-change/resources

For information contact:

Julie LaBrancheSenior Planner

Rockingham Planning Commission

156 Water Street, Exeter, NH 03833

Phone: (603) 778-0885

Email: jlabranche@rpc-nh.org

Project Materials