State of New Hampshire, Natural Hazards Mitigation Plan, Executive Summary: October 2000 Edition
State of New Hampshire
Natural Hazards Mitigation Plan
October 2000 Edition
Ice Storm – January 1998, FEMA DR-1199-NH
Rt. 175A Holderness – Plymouth October 1995
Prepared by the New Hampshire
Office of Emergency Management 107 Pleasant Street Concord, New Hampshire 03301 (603) 271-2231
1 State of New Hampshire, Natural Hazards Mitigation Plan, Executive Summary: October 2000 Edition
Table of Contents
Table of Tables 4 Table of Maps 4 Table of Graphs 4 Table of Figures 4 Introduction 5 Authority 6
Definition of Hazard Mitigation 6
Purpose 6
Scope of the Plan 6
Overall Goals and Objectives of the State of New Hampshire 7
Disaster Declarations: An Overview 8
Presidential Disaster Declarations January 1, 1965 to December 31, 1998 9 State of N.H. Major Disasters and Emergency Declarations 1/1/82 to 10/21/98 10
Plan Sections: (Including Hazard Definitions and Vulnerability Assessments)
I. Flood, Drought, Extreme Heat and Wildfire
A. Flooding 12 1. Riverine Flooding: Heavy Rains and/or; 13 a. Debris Impacted Infrastructure 12 b. Rapid Snowpack Melt 15 c. River Ice 16 d. Dam Failure 17 NH Dam Safety Strategic Hazard Mitigation Overview 19
2. Coastal a. Excessive Stormwater Runoff 20 b. Storm Surge 20 c. Tsunami 22
3. New Hampshire Flood History 23 4. New Hampshire Strategic Flood Hazard Mitigation Plan Overview 29
B. Drought 30 New Hampshire Strategic Drought Mitigation Plan Overview 31
C. Extreme Heat 32 New Hampshire Strategic Extreme Heat Hazard Mitigation Plan Overview
D. Wildfire 34 NH DRED Strategic Wildfire Hazard Mitigation Initiatives 34 Phragmites Australis 35 NH Strategic Phragmites Australis Wildfire Hazard Mitigation Plan Overview 36 2 State of New Hampshire, Natural Hazards Mitigation Plan, Executive Summary: October 2000 Edition
II. Geologic Hazards
A. Earthquake 37 B. Landslide 45 C. Subsidence 47 D. Tsunami 48 E. Volcanism 49 F. Geomagnetism 50 G. Radon 51
New Hampshire Strategic Geologic Hazards Mitigation Plan Overview 53
III. Severe Wind
A. Tornado 54 B. Hurricane 56 C. Nor’easter 58 D. Thunderstorm Related 1. Downburst 59 2. Lightning and Thunder 62 3. Hailstorms 67
New Hampshire Strategic Severe Wind Hazard Mitigation Plan Overview 68
IV. Winter Weather
A. Heavy Snow Storms and Nor’easters 69 B. Blizzard 71 C. Ice Storm 80 D. Snow Avalanche 81
New Hampshire Strategic Winter Weather Hazards Mitigation Plan Overview 83
Risk Analysis 84
Data Assessment 103
Capability Assessment 104
Plan Implementation and Maintenance 130
Table of Plan Section Appendices 132 List of Acronyms and Abbreviations 134 Plan Contributors 135 Index of Useful Websites 138
Hazard Mitigation Goals and Objectives of the State of N. H. 139 (See last Tab following page 139 of this document)
(Including Sections I. – IV. and IAHMTR Recommendations from DRs: 876 - Flood, 923 - Flood, 917- Severe Wind, 1077 - Flood, 1144 - Flood, 1199 – Ice Storm, 1231 - Flood and 1305 - Flood)
Plan Annexes: Resource Profile Annex and Earthquake Historical Reference Papers Annex
3 Table of Maps State of New Hampshire, Natural Hazards Mitigation Plan, Page Executive Summary: October 2000 Edition Introduction Region I. Presidential Disaster Declarations 8 Table of Tables Presidential Disaster Declarations by State/County 9 Page Presidential Disaster Declarations 1975-95 by State 11 Introduction State of NH Major Disaster and 10 Section I Flood etc. Emergency Declarations NH Climate / Rainfall origins 12 Costliest U.S. Hurricanes: 1990-94 11 Major River Basin Watersheds in New Hampshire 12 New Hampshire Coastal Zone 20 Section I Flood etc. Survey of Great Tsunamis 22 NHDES-WRD Dam Classification Schedule 18 June 1998 Rainfall Map 28 NH Flood History 23 Palmer Drought Forecast, July 24,1999 30 Recent New Hampshire Drought History 31 Palmer Drought Severity Index - 1965 31 Extreme Heat Data: Concord NH, 1960-94 33 Drought Plans in Effect by State - 1992 31 Summary of State Wildfire Burns 34 Severity &Areal Extent of Extreme Summer Heat in U.S. 32
Section II Geologic Section II Geologic Seismic Risk Map of the U.S. 37 NE Earthquake w/magnitude 4.2 or > 1924-1989 37 Seismic Events in the Northeast U.S., 1638 – 1995 38 New England States Historical Earthquakes 37 Epicenters:4.0/+ Earthquake Events Since 1975 39 Earthquakes Adjacent to New Hampshire with 37 New England Seismic Network Station Locations 39 Magnitude 4.5 or greater - 1924-1989 Maximum Experienced Intensities in the Northeast 42 4.0 > Earthquake Events Since 1975 in the NE 39 Historic Earthquake Locations, Eastern U.S. 42 The Relationship Between Richter 41 Landslide and Debris Flow Potential 46 and Modified Mercalli Intensity Landslide Incidence and Susceptibility 46 New England Seismic Hazard 43 NH Radon Data by Community 52
NH Indoor Radon Test Results 52 Section III Severe Wind Total Number of Tornadic Events per 55 Section III Severe Wind one degree of latitude and longitude 1954-83 Tornadic Events by County – F2 or Greater 54 Wind Zones in the United States 55 Fujita Scale 54 Tornado Activity in the United States 55 Hurricanes Impacting on NH – 1635–1991 56 1938 Hurricane Path 57 Saffir/Simpson Hurricane Scale 56 Landfalling Hurricanes for Coastal Counties 57 U.S. Hurricane Landfalls 57 NOAA Weather Radio Signal Coverage in NH 59 (Categories 1-5) 1900–1994 Areal Extent and Severity of Lightning Hazard 62 Dolan-Davis Nor’easter 58 based on mean annual lightning strike density 1948-97 NH Downburst Activity 59 & 61 Annual Frequency of Hailstorms in the United States 67 Classification Scale Section IV Winter Weather Section IV Winter Weather Northeast Snowstorm Events >25cm by Month 69 History of Snowstorms in the NE U.S. 72 Northeast Mean Seasonal Snowfall 71 Return Periods for Large Ice Storms 80 1998 Ice Storm (Forest) Damage in NH 79 Recent History of Significant 80 Areas Exposed to High Snow Avalanche Risk 82 New Hampshire Ice Storms Risk Analysis Risk Analysis NH Major River Basin Watersheds 87 NH Population by County 85 State of New Hampshire Electric Utility Franchise Areas 88
NH Essential Facility Numbers by County 88 Capability Assessment NH Natural Hazards Vulnerability Overview 89 Number of Households in the Floodplain 110
Capability Assessment Open HMGP Accounts 107 Total HMGP Funds Available to NH 107 Table of Graphs Flood Mitigation Assistance Grants to NH 111 CDBG / Unmet Needs Funding 1997-1999 115 Introduction Page Resource Profile Annex Index 118 FEMA Region I Disasters by Type 8 U.S. Disasters by Type 9 Total Insured Losses from Disasters 1989-95 11
Section I Flood etc., Table of Figures NH Ice Events by River (CRREL Database*) 16 NH Ice Events by Community (CRREL*) 16 Page Timing of NH Ice Events by Month (CRREL*) 16 Section II Geologic Heatwaves per Year 33 Epicenter – Wave Front: directions of vibrations 40 # of Days 90 Degrees of Above 33 Section III. Severe Wind # of Days 95 Degrees or Above 33
(Hail) Supercell Inflow Winds 67
Section II Geologic Northeaster United States Modified Mercalli 44 Section IV. Winter Weather Intensity Attenuation Curves Factors Contributing to Heavy Snowfall 70 U.S. Hurricane Landfalls, 1900-1994 57 Along the Northeast Coast Airflow Through a Northeast Storm 70 Risk Analysis NH Population Change 1960-97 by County #1 85 Risk Analysis NH Population Change 1960-97 by County #2 86 Vulnerability and Risk 84 4 NH Population Change 1960-97 (Overall) 86 State of New Hampshire, Natural Hazards Mitigation Plan, Executive Summary: October 2000 Edition
“The Plan is nothing, planning is everything” (General Dwight David Eisenhower)
The Editor would like to take this opportunity to offer his sincere gratitude to all those who contributed to this planning process. (Pleas e see Contributors List, pages 135 through 137)
Introduction
In July, 1998, upon the Declaration of DR-1231-NH (a Flood event), FEMA Region I Mitigation Division staff and the New Hampshire State Hazard Mitigation Officer (SHMO) conducted an assessment of New Hampshire’s existing Hazard Mitigation planning tools and determined that there was not a viable plan in place which would satisfy the requirements of Section 409 of the Robert T. Stafford Disaster Relief Act.
An eight-month planning effort was undertaken and a Plan was produced.
The State’s Plan exists in four bound volumes appended with seven Inter-Agency Hazard Mitigation Team Reports and copious technical papers (i.e., as to the Region’s flood, seismic, hurricane etc. vulnerability and associated risk), and two Annexes, including an Annex of Hazard Mitigation Resource Profiles, each outlining the capacity of various Federal, State and private agencies that support the State’s Hazard Mitigation initiatives (See pages 132 – 133 for Tables of Plan Appendices and page 118 for an index of Resource Profiles).
This document is intended to make the concepts and data contained in the Plan more accessible (and portable) in addition to satisfying the essential requirements of 44 CFR, Section 206.405.
The initial edition of this Plan was presented to FEMA on April 1, 1999. As per CFR 206:405, and subsequent to DR 1305-NH, the State submitted this updated edition on October 22, 1999. This submission is filed with FEMA Region I as an update to the State Plan as prescribed by 44 CFR Subpart M, Section 206.405 (a) (4).
The Planning effort of the State is an ongoing process and the Plan is considered to be a “living document.” The appendices of the expanded Plan will continue to be refined, upgraded and amended as pertinent material is forthcoming.
Any Hazard Mitigation Planner is encouraged to contact John Shaughnessy, Plan Editor, at NHOEM for a copy of the expanded Plan and access to the appendices and Resource Profiles.
John J. Shaughnessy, State Hazard Mitigation Officer, Editor NHOEM, 107 Pleasant Street, Concord, NH 03301 Voice: (603) 223-3637 or 271-2231 or (800) 852-3792 Fax: (603) 225-7341 TDD: (603) 271-2254 [email protected]
This document is available on the NHOEM website: www.nhoem.state.nh.us/mitigation
This Publication will be made available in alternative formats upon request. Please contact the New Hampshire Office of Emergency Management ADA Coordinator at (603) 271-2231, 1- (800) 852-3792 or TDD Access, Relay NH, 1- (800) 735-2964 with your request 5 State of New Hampshire, Natural Hazards Mitigation Plan, Executive Summary: October 2000 Edition
Authority
This Summary of the All Hazards Mitigation Plan for the State of New Hampshire was prepared pursuant to, and in accordance with Section 409 of Public Law 93-288 as amended by Public Law 100-707, the Robert T. Stafford Disaster Relief and Emergency Assistance Act of 1988, hereinafter referred to as the “Stafford Act.” Accordingly, this Plan will hereinafter be referred to as the “409 Plan.”
Authority for the development of this Plan by the Office of Emergency Management of the State of New Hampshire is contained in the New Hampshire Revised Statutes Annotated (RSA), Chapter 107-C, as amended, the State Emergency Management Act.
Definition of Hazard Mitigation
According to the Stafford Act: “Hazard Mitigation means any action taken to reduce or eliminate the long-term risk to human life and property from natural hazards” (44 CFR 206.401).
Purpose
Pursuant to the Presidential Disaster Declaration DR 1305-NH Declared on October 18, 1999 the SHMO conducted an assessment of the condition of the State’s existing Hazard Mitigation Plan and determined that this update was indicated. The purpose of this Executive Summary is to provide an overview of the Natural Hazards that impact upon the State and to outline the State’s Plan for the mitigation of damages as may be associated with these events.
Scope of the Plan
The concept of an “All Hazards Mitigation Plan” for the entire State is a broad one indeed. Therefore, the Plan has been prepared and bound in Sections I. – IV. As catalogued below: (additional Sections addressing Technological Hazards i.e., Hazardous Materials, Radiological Materials, etc. and Societal Hazards i.e., Civil Unrest and Terrorism, are under construction).
I. Flood (Riverine and Coastal), Drought, Extreme Heat and Wildfire.
II. Geological Hazards (Earthquake, Landslide, Subsidence, Tsunami, Volcanism Geomagnetism, and Radon).
III. Severe Wind (Tornado, Hurricane, Nor’easter and Thunderstorm Related: Downburst, Lightning and Hailstorms
IV. Winter Weather (Heavy Snow, Nor’easter, Blizzard, Ice Storm and Snow Avalanche. River Ice related flooding will be addressed in the Flood Section).
6 State of New Hampshire, Natural Hazards Mitigation Plan, Executive Summary: October 2000 Edition
Overall Hazard Mitigation Goals of the State of New Hampshire
Although Strategic Goals are stipulated to in the related Sections of this Executive Summary and, this document is appended with a list of the State’s specific Goals, Objectives and anticipated Mitigation Measures, the overall Goals of the State with respect to Hazard Mitigation are stipulated to here in the following order:
1. To improve upon the protection of the general population, the citizens of the State and guests, from all natural and man-made hazards.
2. To reduce the potential impact of natural and man-made disasters on the State’s Critical Support Services.
3. To reduce the potential impact of natural and man-made disasters on Critical Facilities in the State.
4. To reduce the potential impact of natural and man-made disasters on the State’s infrastructure.
5. To improve Emergency Preparedness.
6. Improve the State’s Disaster Response and Recovery Capability.
7. To reduce the potential impact of natural and man-made disasters on private property.
8. To reduce the potential impact of natural and man-made disasters on the State’s economy.
9. To reduce the potential impact of natural and man-made disasters on the State’s natural environment.
10. To reduce the State’s liability with respect to natural and man-made hazards generally.
11. To reduce the potential impact of natural and man-made disasters on the State’s specific historic treasures and interests as well as other tangible and intangible characteristics which add to the quality of life of the citizens and guests of the State.
12. To identify, introduce and implement cost effective Hazard Mitigation measures so as to accomplish the State’s Goals and Objectives and to raise the awareness of, and acceptance of Hazard Mitigation opportunities generally.
7 State of New Hampshire, Natural Hazards Mitigation Plan, Executive Summary: October 2000 Edition
Disaster Declarations
An Overview
Upon the Declaration of a State of Emergency, the Governor may request of the Federal Emergency Management Agency (FEMA) to perform a Preliminary Damage Assessment (PDA) of the effected area. If the estimate of damage exceeds an amount that can be reasonably borne by the State, the Governor may request a Presidential Declaration of Disaster and Federal assistance.
The most common Presidential Disaster Declaration type in the nation is Flood related. The same holds true for the Northeast Region of the United States and the State of New Hampshire.
Although New Hampshire is exposed to a wide variety of types of Natural Hazards, it may be surmised from the maps on the following pages of this chapter, that New Hampshire enjoys a relatively moderate overall exposure to most Natural Hazards with respect to frequency.
An analysis of the dimensions of New Hampshire’s exposure to various Natural Hazards i.e., the “vulnerability” of the diverse regions of the State to these event types will be addressed below. The study of the “frequency” and “magnitude” of such events experienced in various locations throughout the State forms the basis of the planning for Preparedness, Mitigation, Response and Recovery with respect to those effects.
It is the intent of this undertaking to provide the reader with a basic understanding of those Natural Hazards, which impact the various regions throughout the State, and, to offer a systematic approach for the mitigation of the effects of such hazards.
It is hoped that officials in each NH community will take the opportunity to familiarize themselves with this Plan. Furthermore, it is hoped that each may be inspired to conduct a systematic analysis of their own unique exposure to Natural Hazards and begin the process of Hazard Mitigation Planning as well as the implementation of any cost effective Hazard Mitigation measures as may be indicated.
8 State of New Hampshire, Natural Hazards Mitigation Plan, Executive Summary: October 2000 Edition
9 State of New Hampshire, Natural Hazards Mitigation Plan, Executive Summary: October 2000 Edition
STATE OF NEW HAMPSHIRE MAJOR Disasters (DR) & Emergency Declarations (EM) January 1, 1982 to October 21, 1998
Date Declared Event Type FEMA Disaster Program(s) Dollar Amount Counties Declared Declaration #
August 27, 1986 Severe Storms/Flooding FEMA-771-DR PA 1,005,000 Cheshire & Hillsborough
April 16, 1987 Severe Storms/Flooding FEMA-789-DR PA/IA 4,888,889 Cheshire, Carroll, Grafton, Hillsborough Merrimack, Rockingham & Sullivan
August 29, 1990 Severe Storms/Winds FEMA-876-DR PA 2,297,777 Belknap, Carroll, Cheshire, Coos, Grafton, Hillsborough, Merrimack & Sullivan
September 9, 1991 Hurricane FEMA-917-DR PA 2,293,449 Rockingham & Strafford
November 13, 1991 Coastal Storm/Flooding FEMA-923-DR PA/IA 1,500,000 Rockingham
March 16, 1993 Heavy Snow FEMA-3101-EM PA 832,396 Statewide
January 3, 1996 Storms/Floods FEMA-1077-DR PA 2,220,384 Carroll, Cheshire, Coos, Grafton, Merrimack & Sullivan
October 29, 1996 Severe Storms/Flooding FEMA-1144-DR PA 2,341,273 Grafton, Hillsborough, Merrimack, Rockingham, Strafford & Sullivan, Belknap, Carroll, Cheshire, Coos, January 15, 1998 Ice Storm FEMA-1199-DR PA/IA 12,446,202 Grafton, Hillsborough, Merrimack, Strafford, Sullivan
July 2, 1998 Severe Storms FEMA-1231-DR PA/IA 3,420,120 Belknap, Carroll, Grafton, Merrimack, Rockingham & Sullivan October 18, 1999 Hurricane/Tropical Storm FEMA-1305-DR PA 750,133 Grafton, Belknap and Cheshire Floyd (as of 10/31/00)
10 Declarations Totaling $33,995,623 (as of 10/31/00)
10 State of New Hampshire, Natural Hazards Mitigation Plan, Executive Summary: October 2000 Edition Presidential Disaster Declarations by State Frequency of Declarations For the period of 1975 – 1995 FEMA Publication, Multi Hazard Identification and Risk Assessment As is indicated by the Map to the left, New Hampshire, and all of the New England states are recipients of Presidential Disaster Declarations less frequently than several other regions in the nation. The specific New Hampshire Emergencies, as Declared by the Governor and, Presidential Disaster Declarations (since 1986) are itemized on the preceding page. NOTE: Although flooding is by far the most common Declared Disaster type experienced in the State, the most costly by far was the Ice Storm of 1998 (See also, Hurricane of 1938 data below).
Total Insured Losses from Major Disasters Devastating Events
1989 – 1995 Of the three most devastating Presidential Source: Property Claim Services and Insurance Research Council, 1997 Disaster Declarations in the nation’s history, two Billions of Dollars were hurricanes.
The Hurricane of 1938 impacted certain 89 Hurricane Hugo areas in New Hampshire with devastating 4.2 consequences, initiating both floods and a massive 89 Earthquake Loma Prieta CA 0.96 conflagration in downtown Peterborough (600 lives were lost in the Northeast U.S.). 90 Wind Hail Tornados Denver CO 0.625
91 Fire Oakland CA 1.7 Costliest U.S. Hurricanes: 1900-1994
92 Hurricane Andrew
15.5
Hurricane Year Cat Damage (Est)
(1990 dollars)
92 Hurricane Iniki
1.6 Andrew (SE FL, SE LA) 1992 4 $25,000,000,000
Hugo (SC) 1989 4 $ 7,155,120,000
93 Winter Storm 1.75
Betsy (SE FL, SE LA) 1965 3 $ 6,461,303,000
93 Midwest Floods 0.6
Agnes (FL, NE U.S.) 1972 1 $ 6,418,143,000
Camille (MS, SE LA/VA) 1969 5 $ 5,242,380,000
93 Fires So CA 0.725
Diane (NE U.S.) 1955 1 $ 4,199,645,000
12.5 94 Northridge CA New England 1938 3 $ 3,593,853.00
1.6 Frederic (AL, MS) 1979 3 $ 3,502,942,000
94 Winter Storm
Alicia (N TX) 1983 3 $ 2,391,854,000
1.35
95 Hail TX & NM Carol (NE U.S.) 1954 3 $ 2,370,215
2.1 95 Hurricane Opal Source: Based on Hebert and others 1995 11 State of New Hampshire, Natural Hazards Mitigation Plan, Executive Summary: October 2000 Edition
Section I. Flood, Drought, Wildfire and Extreme Heat
Flood New Hampshire’s rivers and streams are of great benefit to the people of this state. However, during flooding events, they can be devastating and can do great damage. Flood safety is a significant concern along these watercourses.
New Hampshire has more than 16,000 miles of rivers and streams and the State’s settlement pattern is confluent with these locations. Communities developed along the waterways that provided
mills with power and transportation. As a result of this development pattern, the floodplains of the State were rapidly settled. The shift to
industrialization during the mid-nineteenth century compounded the problem, residents moved to the floodplains of the cities and larger
villages. Such encroachment has lead to problems, as the floodplains are extensions of the watercourses and evolved to carry excessive
runoffs naturally.
(From USGS Water Supply Paper 2375)
Riverine Flooding
New Hampshire has a climate of
abundant precipitation. Weather ranges from
moderate coastal to severe continental, with
annual precipitation ranging from about 35
inches in the Connecticut and Merrimack
River valleys, to about 90 inches on top of
Mount Washington. Localized street flooding
occasionally results from severe
thundershowers, or over larger areas, from
more general rain such as tropical cyclones
and coastal “northeasters.” More general and
disastrous floods are rare but some occur in
the spring from large rainfall quantities
combined with warm, humid winds that
rapidly release water from the snowpack.
(Flood Introduction text reprinted from the Pemigewasset Flood Mitigation Project HMGP Proposal with permission of Ray Wenninger, P.E., Project Engineer)
12 (For larger scale representation see page 87) State of New Hampshire, Natural Hazards Mitigation Plan, Executive Summary: October 2000 Edition
Riverine Flooding (cont’d)
General flooding is also caused by major hurricanes that closely follow major rainstorms. Significant flooding occurs periodically along the watercourses with resultant loss of lives and property. As a result, New Hampshire has a high flood risk. There are no plans to make any major additions to the State Dam system to control flooding. There is considerable resistance to any building of major dams and it appears that there will be few, if any, significant structural readjustments to the physical water flow picture.
Flood safety is a great concern along these watercourses and can be greatly enhanced by Flood Hazard Mitigation Planning. Flood Hazard Mitigation in New Hampshire is a management strategy in which current action and costs to reduce the occurrence and severity of potential flood disasters are balanced against potential losses from future floods. The goal of Flood Hazard Mitigation Planning is to eliminate or reduce the long-term risks to human life and property from flooding by:
• Reducing the cause of the hazard or • Reducing the effects through preparedness, response and recovery measures.
Hazard Mitigation is the only phase of emergency management that can break the cycle of damage, reconstruction and repeated damage.
Riverine Flooding is the most common disaster event in the State of New Hampshire (aside from frequent inconveniences from rather predictable moderate Winter Storms).
Significant riverine flooding impacts upon some area in the State in less than ten year intervals. (See the Table of Major Disasters on page 10 and NH Flood History; page 23).
Photo from DR-1077-NH IAHMTR Debris Impacted Infrastructure
As can be seen from the photo to the right, debris carried by floodwaters can significantly compromise the effectiveness of otherwise adequately designed bridges, dams, culverts, diverting structures etc. Storm debris, and structures such as poorly designed snowmobile bridges, carried by floodwaters, may exacerbate a given flooding hazard by becoming obstructions to normal stormwater flow.
As per the Inter-Agency Hazard Mitigation Team Meeting going to the Flood Disaster Declared as FEMA DR-1077-NH, a project was born, designed to educate the public as to the dimensions of this problem.
The Pemigewasset River Corridor Stewardship Program: In cooperation with NHDES Wetlands Bureau, NHOEM is also engaged in activities to develop Best Management Practices to facilitate river corridor stewardship (i.e., stream bank maintenance and the development of stream maintenance plans. See page 116). 13 State of New Hampshire, Natural Hazards Mitigation Plan, Executive Summary: October 2000 Edition Steam Bank Erosion and Scouring
Scouring is a significant problem, in New Hampshire, especially along the State’s watercourses in the higher elevations that tend to be “flashy” in terms of the flooding experienced.
Pictured here, is a location beside the Moose River in Gorham. As can be seen from the photos, the railway bridge, railway and rail bed are threatened and, stormwater drainage pipes have been uncovered by the scouring.
What is not apparent from these photos, is the threat to the community’s only Fire Station, which is also its Emergency Operations Center. The Fire Station lies just downstream of the rail bed in the floodplain.
Typically in New Hampshire, the land along such rivers is relatively heavily developed and this site is no exception. State Routes 2 and 16 parallel the railway at this location, only a few hundred yards downstream of this site.
(all photos on these three pages were provided courtesy of Roger Guilmette, DPW Director, Gorham, NH)
Short Term Mitigation Measures
Riprap has been installed at this site but, given the threat to the Fire Station/EOC, the State Highway and residents nearby, other measures may be indicated.
Additionally, a mobile home park lies just 14 beyond the bend of the river at this location State of New Hampshire, Natural Hazards Mitigation Plan, Executive Summary: October 2000 Edition
Rapid Snowpack Melt
The State’s climate, mountainous terrain and riverine watersheds are susceptible to flooding which may be accelerated by the seasonal rapid melting of the snowpack coupled
with moderating temperatures and moderate to heavy rains. The upland areas may be exposed to flash- flood incidents with associated erosion and deposition issues in, or near streambeds.
The lower lying areas of the State may experience either flash flooding or inundation
events accelerated by the rapid melting of the snowpack.
Photos courtesy of Roger Guilmette EMD and DPW Director, Gorham, NH
15 State of New Hampshire, Natural Hazards Mitigation Plan, Executive Summary: October 2000 Edition
River Ice
Ice forming in riverbeds and against structures often presents significant hazardous conditions for many communities in the State. Meltwater and/or stormwaters may then encounter these ice formations, a situation which may tend to apply lateral and/or vertical force upon structures. Moving ice may scour abutments and riverbanks. Ice may also create temporary dams. These dams may create flood hazard conditions where none previously existed.
Mitigation Measures Gorham, NH
Photo: Roger Guilmette The State's exposure to this hazard type has prompted several interventions in NH by the U.S. Army Corps of Engineers, Cold Regions Research and Engineering Laboratory (CRREL). The Corps has constructed dams and ice diversion structures to arrest the flow of large, potentially damaging ice formations in order to reduce flooding potential and the possible impact by ice on bridges and other structures. Gorham, NH Photo: CRREL Mitigation measures include, excavation, mechanical breaking, ice blasting, overspraying an area with ash or leaf mulch to accelerate melting, planned releases of relatively warmer water from impoundments and the installation of electronic devices to signal ice movement which might aid in evacuations and other response measures.
In April of 1999 NHOEM and CRREL (with FEMA Project Impact funding) conducted a workshop for ice affected communities and State agencies. Ice Hazards identification, and strategies for mitigating River Ice Hazards were the subject of the workshop. A workshop to train a cadre of ice observer / reporters will be held on December 6, 2000. In cooperation with CRREL and the NWS, Ice Observers will be given the opportunity to report ice conditions in real-time to CRREL, the NWS and the NHOEM via the Internet.
Distribution of Ice Events NH River Ice Statistics Timing of Ice Events in NH
CRREL’s Ice Jam Data-base contains information on 520 ice events in New Hampshire between 1835 and 1999. These ice events were located on 72 rivers and streams and one lake. The events impacted 96 communities and were implicated in at least one death. (Graphic data courtesy of Kate White at CRREL)
16 State of New Hampshire, Natural Hazards Mitigation Plan, Executive Summary: October 2000 Edition
Dam Failure
The Department of Environmental Services Effects of Dam Failure (DES), through its Dam Bureau, is charged with the responsibility of ensuring the public safety as it relates to Meadow Pond Dam, Alton, N.H. the regulation of dams. Specifically, authority is granted Event Date: March13, 1996 in the Revised Statutes Annotated, Chapter 482 “Dams, Dam Classification: B (Now C) Mills and Flowage”. These laws enable DES to regulate 1 Fatality the construction and reconstruction of dams, as well as to $8 million +/- in Property damage periodically inspect existing dams to ensure that design, construction, maintenance and operation meet accepted NH Department of Environmental engineering standards. Services–Water DES also owns and operates 110 dams throughout Resources Division Prior Hazard the state and, is responsible for completing major repair and reconstruction activities for dozens of others. These Mitigation Involvement dams function to serve the needs of flood control, recreation, wildlife enhancement and water resources Owing to the nature of DES’s charter, the management. majority of the activities carried out by the Dam Bureau are aimed at risk reduction or Hazard Mitigation. Routine functions such as periodic inspections, ownership and operation of stream gages and completing and updating emergency action plans are examples of NHDES-WRD’s ongoing Hazard Mitigation initiatives. These activities apply to both the dams that DES regulates and the dams that it owns. Some other examples of past projects include:
• Flood Forecasting/Warning. DES, in cooperation with private, Federal, municipal and other State entities, has been involved in the funding, installation, maintenance and operation of several streamflow and rain measuring gages for many years.
• Safety Planning/Emergency Response Coordination: DES oversees a program of ensuring that the owners of private and municipal “significant hazard” (Class B) and “high hazard” (Class C) dams complete emergency action plans (See definitions of dam classes on the following page). DES must create such Plans itself for many State owned dams. Within the past few years, 12 such plans were completed with assistance from the NH Office of Emergency Management and funding from FEMA.
• Outreach and Dam Safety Program Enhancement
(Material in this section was provided courtesy of Steve Doyon of the NHDES – Water Resources Division and is reprinted from the Hazard Mitigation Resource Profile Submitted by the Dam Bureau) 17 State of New Hampshire, Natural Hazards Mitigation Plan, Executive Summary: October 2000 Edition
DES maintains an array of guidance material, in the form of Fact Sheets, booklets, permit application worksheets, etc. to assist dam owners in understanding the many New Hampshire Dams aspects of dams and dam ownership. are classified In addition, several workshops were held within the past in the following manner: few years with assistance from the NH Office of (From: NH DES WRD Code of Emergency Management via DPIG funding, and geared Administrative Rules; Env-Wr 101) toward operation and maintenance issues or, toward emergency action planning. Class AA Structure Experience has shown that education builds awareness, and awareness increases If failed, would not threaten life or property, is compliance with DES’s directives, which are not: a) greater than 6 feet in height and stores less than 50 acre-feet and b) greater than 25 feet aimed at making dams safer. in height with a storage capacity of 15 acre-feet.
Hazard Mitigation Goals and Objectives Class A Structure
DES intends to continue to execute its dam safety Low hazard potential where there is potentially; program focusing on the same goals and objectives as it a) no possible loss of life, b) only minimal has for the last several decades. The function of the Dam economic loss, c) no major damage to town and Bureau will remain one of initiating, overseeing, city roads, d) only minor damage to Class I and II enhancing and regulating those activities associated with State Highways and e) no release of liquid keeping dams, and the inhabitants living downstream of industrial , agricultural or commercial wastes or them safe. Recent initiatives, some of which are municipal sewage if the storage capacity is less described above, have served to enhance DES’s ability to than 2 acre-feet and is located more than 300 reach its goals and will likely be built upon. Continuing feet from a water body or watercourse. objectives include: Class B Structure ¾ Operational Safety of Dams – NHDES-WRD performs regular inspections and compliance follow- A dam with significant hazard potential, the up visits. Included is the monitoring, repair and failure of which would result in any of the reconstruction of those dams owned and following: a) Possible loss of life, b) Significant economic loss, c) Major damage to Class I and operated by the State; DES and other state agencies. Class II State Highways, e) Loss of municipal ¾ Flood Forecasting/Warning - cooperating with water supply reservoir which constitutes more other Federal, State, private and municipal entities than 50% of a community’s source or, who’s loss in maintaining and expanding the network of could endanger public health, or, f) The release of streamflow and rainfall measuring gages throughout liquid industrial, agricultural or commercial wastes the State. or municipal sewage from dams which do not ¾ Safety Planning/Emergency Response Planning – meet the criteria in Env-Wr 101.04(e). oversight for ensuring that all significant and high hazard dams that pose a threat to downstream life Class C Structure or property have coordinated and viable emergency action plans in place. A dam with high hazard potential, the failure of which would result in any of the following: A significant part of what DES does to try to meet its •Probable loss of life or, public safety goals is done cooperatively with other State and Federal agencies. The NH Office of Emergency •Major damage to interstate highways. Management, the NH Association of Conservation Districts, the NH Department of Transportation, the United States Geological Survey and the Natural Resources Conservation Service (and its many County Districts) are all entities that DES has partnered with over the last several years to perfect its Hazard Mitigation objectives.
18 State of New Hampshire, Natural Hazards Mitigation Plan, Executive Summary: October 2000 Edition
NH DES-WRD Dam Safety / Hazard Mitigation Overview
Potential Projects and Planning Activities:
Although DES has been involved with several Hazard Mitigation projects in recent years, the subject matter and level of detail associated with each is just a small sampling of the types of activities that could occur. Other potential projects and planning activities are briefly identified below:
Dam Owner Assistance Projects:
1. A series of workshops focusing on dam-related issues such as: repair alternatives / techniques, routine operation and maintenance - including the formulation of operational procedure plans, emergency action planning, storm event response planning and operation, etc.
2. Establishment of a fund (either grants or low interest loans) to assist dam owners with complying with current safety standards - including planning activities. (Seminars are planned in cooperation with NHOEM to avail dam owners of relevant grants and other resources with respect to Hazard Mitigation).
3. Updating and enhancement of currently available printed guidance materials, such as Fact Sheets, guidebooks, booklets and permit application worksheets.
Flood Forecasting/Warning Projects:
1. Assessment and enhancement of the current network of streamflow and rainfall measuring gages throughout the State. A project to analyze the current network and, to upgrade certain assets within it, will be underway soon. However, it is envisioned that this analysis will identify additional areas in which the network may be supplemented. Possibilities include; developing real-time Internet access and inter-agency cooperation/data transfer - both of which could speed flood warning and response activities.
2. Augmentation and reconfiguring of the DES’s current dam information database to allow additional data such as electronic flood inundation areas and digital photographs to be included in a form easily accessed by response staff. Portions of this project have been initiated with funding provided through FEMA and the National Dam Safety Program Act of 1996.
Construction Related Projects:
1. Repair, reconstruction or removal of dams identified to be structurally or hydraulically deficient as to withstand the stresses induced by routine or storm-related conditions.
2. Remove flow restrictions or rechannel sections of rivers and streams identified as areas that increase local flooding or restrict the passage of flood waters.
3. Install floating barriers or other safety devices at dams to reduce the risk of injury to transient users. Hazard Mitigation - Design Standards In addition to the initiatives outlined above, All dams constructed in the State must conform to the standards contained in U.S. Department of Interior, Bureau of Reclamation publication, Design of Small Dams (inclusive of seismic safety standards).
19 State of New Hampshire, Natural Hazards Mitigation Plan, Executive Summary: October 2000 Edition
COASTAL STORMS AND EROSION
The State’s Atlantic seacoast and estuaries are vulnerable to extremes in stormwater runoff and storm surge from coastal storms and hurricanes. Storm surge from these events, especially when coupled with astronomical high tides, presents a threat to all land areas adjacent to the marine environment.
The State’s erosion threat is moderate as compared to some neighboring coastal states. The conditions with respect to this hazard and all natural coastal related hazards are monitored by the NH Office of State Planning, Coastal Program.
Little River Salt Marsh, Hampton, NH New Hampshire Office of State Planning, Coastal Program
75% of New Hampshire’s Atlantic Coast is publicly owned. The NH Office of State Planning’s Coastal Program assumes the responsibility for planning and management of the Coastal Management Programs for the
State, including Section 309 of the Coastal Zone Management Act. Projects such as dune restoration and restoration of tidal saltmarsh habitat are consistent with the State’s Hazard Mitigation Goals and Objectives.
Description and Mission The New Hampshire Coastal Program (NHCP), located within the Office of State Planning, is funded by NOAA and charged with coordinating the management of coastal zone resources. The NHCP’s boundaries include all coastal waters seaward 3 miles and, all lands along the State’s Atlantic Ocean shoreline from Seabrook to the Portsmouth/Newington town line, extending inland 1,000 feet. The boundaries in the Great Bay area extend 1,000 feet back around Great and Little Bays and to the tidal limits of estuarine rivers. The legal authority of the NHCP comes from State law and from the Federal Coastal Zone Management Act (CZMA).
Hazard Mitigation Involvement The NHCP has been involved on the periphery of Hazard Mitigation for many years. Below are examples of projects that the NHCP has funded over the last 20 years that pertain to Hazard Mitigation: • Assessment of the effects of the Blizzard of ‘78 with recommendations for improvements • 1984 report on low-cost design for shore stabilization • Erosion and deposition study of the coast - 1986 • 1991 report on the potential impacts of sea level rise • Numerous wetland and floodplain delineations in coastal towns • Funding of the Regional Planning Commissions to help towns draft floodplain protection ordinances • Direct funding to towns to improve and stabilize their shorelines (e.g. Exeter, Portsmouth and Dover) • Sand dune restoration in Seabrook to provide wildlife habitat and protection
20 State of New Hampshire, Natural Hazards Mitigation Plan, Executive Summary: October 2000 Edition
Hazard Mitigation Goals and Objectives Although the mitigation of coastal hazards is not one of the NHCP’s highest priorities, NHCP does help to educate other parties. For example, the NHCP is currently taking steps to insure that dredging and shoreline stabilization work in Hampton Harbor does not create unintended susceptibility to erosion in off-site areas. Also, the NHCP is dedicated to salt marsh restoration. As part of this work, it is important to assure that the restoration effort will alleviate, and not cause flooding problems. Finally, in the longer term, the NHCP is dedicated to better planning and protecting infrastructure in New Hampshire’s coastal communities. To this end, the Program will assist communities with stabilizing shores, assessing resources and writing regulations.
Planning Projects Desired The NHCP would like to have better information as to the risk to both infrastructure and the natural environment from episodic events. The primary events that put the coast at risk are hurricanes and nor’easters. Damages associated with these events result from flooding, storm surges, high winds and the combination of all three. Furthermore, sea level is expected to rise between 1 and 3 feet over the next one hundred years. This will not only directly impact low lying areas but, may increase the impacts of flooding, storm surge and wind to those areas which are not presently impacted.
NHCP Resources with respect to Hazard Mitigation
Funding NHCP’s Competitive Grant Program has provided funding for hundreds of coastal projects over the past 20 years. Each year approximately $250,000 is awarded to projects proposed by communities, nonprofit organizations and universities. The maximum grant amount is $50,000, which must be matched on a 1:1 basis with non-federal funds. The grant applications are due in mid-January each year and funding is available by the following July. Technical assistance grants are also awarded each year to the regional planning commissions to work with communities on a variety of planning activities, including, rewriting regulations, conducting natural resource inventories and other small projects.
Coordination One of the primary roles of the NHCP is the dissemination of information. From time to time, the NHCP hosts workshops on varied issues of interest. Workshops are usually targeted to a specific audience rather than to the general public, although they are also open for anyone to attend. Secondly, the NHCP’s newsletter “Tidelines” is widely distributed throughout State government and the coastal communities. Finally, a web page contains information about the NHCP and its partners.
Another coordinating role is served by NHCP through Coastal Consistency Review. By law, the NHCP must assure that any federally funded or permitted project in the Coastal Zone is consistent with state laws and policies. Therefore, the NHCP is in a unique position to identify those projects that could address Hazard Mitigation or, conversely, those projects that may create additional hazards.
Finally, NHCP staff are available to assist communities by facilitating projects, writing grants, convening meetings and workshops, and generally being resources for coastal stakeholders.
The Editor would direct the reader to the information contained in publications provided by the NH Office of State Planning’s Coastal Program for all Coastal related inquiry. See “Coastal Hazards,” on page 9, of New Hampshire Coastal Program: Enhancement Grants Program Assessment and Strategy (February 20, 1997). See also, A Vision for the New Hampshire Coast, September 1996).
(Visit the NH Coastal Program website at www.state.nh.us/coastal) (NH Coastal information in this Pl an has been provided courtesy of Ted Diers, of the NHOSP - Coastal Program and is reprinted from the NHCP Hazard Mitigation Resource Profile)
21 State of New Hampshire, Natural Hazards Mitigation Plan, Executive Summary: October 2000 Edition
TSUNAMI
**For Definition and additional information See Geologic Hazards, Section II., page 48, of this Summary.
Although little information was available to the SHMO (or to the NHOEM/NHP Officer) as of the pre paration of this Summary of the Plan with respect to this hazard type, it is understood that the Tsunami refe rred to as the “1929 Grand Banks Canada” event (Richter Scale magnitude 7.2) impacted upon the Maine shoreline (See Plan: Geological Hazards Section II., Appendix C. page 16 and Appendices K., and L. of that Section. For additional information regarding Tsunamis).
Tsunami Hazard Mitigation
The Hazard Mitigation indicated for this hazard type is primarily twofold:
¾ Public education - as to the potential probability, magnitude and scope of such events
- as to any evacuation routes and procedures as may be expeditious - as to prudent preparation for the consequences from these events (i.e., consequences of flooding in normally unaffected areas etc.)
¾ Developing and employing Tsunami Warning Systems
The SHMO shall endeavor to ascertain the specific vulnerability of the State to this hazard type and assess the relative Risk which appears to be significant, given the seismicity of areas directly offshore e.g., the “Cape Ann” earthquake event of 1755 (with an estimated intensity VIII. on the Modified Mercalli Scale. See Plan: Geological Hazards Section II, Appendix C. page 10.) and the seismicity of areas on, and offshore of Canada, as well as those associated with Iceland, and submarine events elsewhere in, or near the North Atlantic.
Survey of Great Tsunamis Reprinted from http://www.geophys.washington.edu/tsunami/general/historic/historic.html
22 State of New Hampshire, Natural Hazards Mitigation Plan, Executive Summary: October 2000 Edition
New Hampshire’s Flood History
Date Area Effected Recurrence Remarks (River Basins or Region) interval (in years) December 1740 Merrimack Unknown First recorded flood in New Hampshire
October 23, 1785 Cocheco, Baker, Unknown Greatest discharge at Merrimack and at Lowell, Pemigewasset, Contoocook Mass. Through 1902 and Merrimack March 24-30, Pemigewasset, Merrimack, Unknown and at Lowell, Mass. Through 1902 and at Lowell, 1826 Contoocook, Blackwater and Mass. Through 1902 Ashuelot April 21-24, 1852 Pemigewasset, Unknown Merrimack River at Concord; highest stream stage Winnespaukee, Contoocook, for 70 years. Merrimack River at Nashua,; 2 feet Blackwater, and Ashuelot lower than 1785 April 19-22, 1862 Contoocook, Merrimack, Unknown Highest stream stages to date on the Connecticut Piscataquog, and Connecticut River; due solely to snowmelt October 3-5, 1869 Androscoggin, Pemigewasset, Unknown Tropical storm lasting 36 hours. Rainfall, 6-12 Baker, Contoocook, inches Merrimack, Piscataquog, Soughegan, Ammonoosuc, Mascoma, and Connecticut November 3-4, Pemigewasset, Baker, 25 to > 50 Upper Pemigewasset River and Baker River; 1927 Merrimack, Ammonoosuc exceeded the 1936 Flood. Down stream at and Connecticut Plymouth; less severe than 1936 flood March 11-21, Statewide 25 to > 50 Double flood; first due to rains and snowmelt; 1936 second, due to large rainfall September 21, Statewide Unknown Hurricane. Stream stages similar to those of March 1938 1936 and exceeded 1936 stages in the Upper Contoocook River June 1942 Merrimack River Basin Unknown This was the fourth flood in the lower Merrimack River basin at Manchester, NH June 15-16,1943 Upper Connecticut, Diamond 25 to >50 Intense rain exceeding 4 inches; highest stream and Androscoggin stages of record in parts of the effected area June 1944 Merrimack River Unknown This was one of the five highest known floods at Manchester on the Merrimack November 1950 Contoocook River and Unknown Localized storm resulted in flooding of this area. Nubanusit Brook March 27, 1953 Lower Androscoggin, Saco, 25 to > 50 Peak of record for the Saco and Ossipee Rivers. Ossipee, Upper Ammonoosuc Little damage Israel, and Ammonoosuc
23 State of New Hampshire, Natural Hazards Mitigation Plan, Executive Summary: October 2000 Edition
New Hampshire’s Flood History (continued)
Date Area Effected Recurrence Remarks (River Basins or Region) interval (in years) August 1955 Connecticut River Basin Unknown Heavy rains caused extensive damage throughout the basin area October 25, 1959 White Mountain Area; Saco, 25 to > 50 Largest of record on Ammonoosuc at Bethlehem Upper Pemigewasset and Junctions; third largest of record on the Ammonoosuc Rivers Pemigewasset and Saco Rivers December 1959 Piscataquog - Portsmouth Unknown A Northeaster brought tides exceeding maximum tidal flood levels in Portsmouth. Damage was heavy along the coast April 1960 Merrimack and Piscataquog Unknown Flooding resulted from rapid melting of deep snow covering and the moderate to heavy rainfall. This was the third highest flood of record on the rivers April 1969 Merrimack River Basin Unknown A record depth of snow cover in the Merrimack River Basin and elsewhere resulted in excessive snowmelt and runoff when combined with sporadic rainfall February 1972 Coastal Area Unknown The Coastal Area was declared a National Disaster Area as a result of the devastating effects of a severe coastal storm, damage was extensive June 1972 Pemigewasset River Unknown Five days of heavy rain caused some of the worst flooding since 1927 along streams in the upper part of the State, damage was extensive along the Pemigewasset River and smaller streams in northern areas June 30, 1973 Ammonoosuc River 25 to > 50 Northwestern White Mountains
April 1976 Connecticut River Unknown Rain and snowmelt brought the river to 1972 levels, flooding roads and croplands. March 14, 1977 South-central and Coastal 25 to 50 Peak of record for Soucook River New Hampshire February 1978 Coastal New Hampshire Unknown A Nor’easter brought strong winds and precipitation to the entire state. Hardest hit area was the (“The Blizzard coastline, with wave action and floodwaters of ’78) destroying homes. Roads all along the coast were breached by waves flooding over to meet the rising tidal waters in the marshes July 1986 – Statewide Unknown Severe summer storms with heavy rains, tornadoes; August 10, 1986 flash flood and severe winds. FEMA DR-771-NH
24 State of New Hampshire, Natural Hazards Mitigation Plan, Executive Summary: October 2000 Edition
New Hampshire’s Flood History (continued)
Date Area Effected Recurrence Remarks (River Basins or Region) interval (in years) March 31 to Androscoggin, Diamond, 25 to > 50 Caused by snowmelt and intense rain
April 2, 1987 Saco, Ossipee, Piscataquog, Precursor to a significant, following event Pemigewasset, Merrimack, and Contoocook Rivers. April 6-7, 1987 Lamprey River and Beaver 25 to > 50 Large rainfall quantities following the March 31- Brook April 2 storm. FEMA DR-789-NH August 7-11, 1990 Statewide Unknown A series of storm events from August 7-11, 1990 with moderate to heavy rains during this period produced widespread flooding in New Hampshire. FEMA DR-876-NH August 19, 1991 Statewide Unknown Hurricane Bob struck New Hampshire causing extensive damage in Rockingham and Stafford counties, but the effects were felt statewide. FEMA DR-917-NH October 1996 Northern and Western Unknown Counties Declared: Carroll, Cheshire, Coos, Regions Grafton, Merrimack, and Sullivan (See page 26). FEMA DR-1077-NH October – Northern and Western Unknown Counties Declared: Grafton, Hillsborough, November 1995 Regions Merrimack, Rockingham, Strafford and Sullivan(See page 27). FEMA DR-1144-NH June – July 1998 Central and Southern Regions Unknown Series of rainfall events. Counties Declared: Belknap, Grafton, Carroll, Merrimack, Rockingham and Sullivan. (1 fatality) (See page 27 - 28) (Several weeks earlier, significant flooding, due to rain and rapid snowpack melting, occurred in Coos county, undeclared in this event. Heavy damage to secondary roads occurred) FEMA DR-1231-NH September 18 - Central and Southwest Unknown FEMA DR-1305-NH: Heavy rains associated with 19, 1999 Regions Tropical Storm/Hurricane Floyd. Counties Designated: Belknap, Cheshire and Grafton.
25 State of New Hampshire, Natural Hazards Mitigation Plan, Executive Summary: October 2000 Edition
Description of Three Recent Flooding Events in the State
FEMA DR-1077-NH October 21 – November 15, 1995
Counties Declared: Carroll, Cheshire, Coos, Grafton, Merrimack, and Sullivan
Executive Summary:
Severe storms brought rain totaling as much as 23 inches in the mountain areas and other sections of New Hampshire from October 20 to November 15, 1995. The heavy rainfall caused increased runoff from the mountains, resulting in flash flooding, mudslides, stream and river erosion, damages to bridges, culverts, dikes, railroad beds, and recreational facilities. In addition, a large number of gravel roads were eroded. The high winds and precipitation produced downed trees, numerous power outages and resulted in the evacuation of a mobile home park and an elderly housing complex. Two sewage treatment facilities sustained damages to their protective dikes that resulted form erosion caused by high velocity floodwaters.
Roads were closed in the towns of Gorham, Lincoln, Woodstock, Wentworth and Waterville Village Estates as rivers rose above the flood stage. In Lincoln, the main bridge over the Pemigewasset River to Loon Mountain Ski area sustained heavy damage and was temporarily closed.
Severe flooding occurred in the town of Campton, where the Mad River rose 14 feet above normal and forced the temporary evacuation of 500 residents. In the White Mountain National Forest, extensive damage occurred to several roads and bridges.
Description of the Event:
Total precipitation amounts for the October 20 – November 15 period over New Hampshire ranged from 6.5 inches along the northern Connecticut River Valley to more than 26 inches on Mount Washington. Pinkham Notch reported in excess of 20 inches of precipitation. Reported precipitation in Grafton County ranged from about 6.5 inches in the Connecticut River Valley to slightly more than 12 inches in the southeast. The higher terrain of southern Coos and northern Carroll counties likely received more than 20 inches of precipitation.
The US Geological Survey (USGS) determined that the precipitation events of October and November generally produced runoff events with a frequency of less than two years. The area of the White Mountains that form the headwaters of the Ammonoosuc River and East Branch Pemigewasset River are the exception to the general pattern. Both the Ammonoosuc River and the East Branch Pemigewasset River experienced runoff peak flows that exceeded previous peaks of record. The Ammonoosuc River peak at Bethlehem was 10% higher than the previous peak of record and in the 50 to 100 year frequency range. East Branch Pemigewasset River peak flows at Lincoln exceed that previous peak by 80%, which falls in the 250 to 500 year frequency range.
26 State of New Hampshire, Natural Hazards Mitigation Plan, Executive Summary: October 2000 Edition
FEMA DR-1144-NH
Event: October 20-26, 1996
Counties Declared: Grafton, Hllsborough, Merrimack, Rockingham, Strafford and Sullivan
Executive Summary
Starting during the early morning hours of October 20, 1996, and ending during the evening of October 21, rainfall in excess of 12 inches occurred in portions of Southeast New Hampshire. Precipitation fell at the rate of 1 to 2 inches per hour causing road closings, flooded residences, damage to low lying public facilities and general erosion problems throughout the affected area. On October 20,1996 the Governor declared a statewide State of Emergency which included Grafton, Hillsborough, Merrimack, Rockingham, Strafford and Sullivan counties. Forty-one communities in eight counties were impacted.
Meteorological Description of the Disaster Event
In excess of one foot of rain fell in portions of Rockingham County during this period; several meteorological factors combined to produce this major event.
On Sunday, October 20, a strong Nor’easter was located near Washington, DC. At the same time, Hurricane Lili was located about 900 miles Southeast of Portsmouth, with a strong high- pressure system centered over Labrador. The high pressure system acted as a block, preventing other systems from moving. The Nor’easter remained nearly stationary for about 36 hours while moisture from Hurricane Lili became entrained into the large circulation created by the Nor’easter. This “conveyor belt” of moisture from Hurricane Lili combined with the slow movement of the Nor’easter resulted in the tremendous rainfall totals for New Hampshire.
Precipitation fell at the rate of 1 to 2 inches per hour in portions of Southeast New Hampshire. These rainfall rates occurred during the evening hours of the 20th through the early morning hours of the 21st.
FEMA DR-1231-NH
Event: June 12 – June 27, 1998
Counties Declared: Belknap, Carroll, Grafton, Hllsborough, Merrimack, Rockingham, and Sullivan
Executive Summary
During the period between June 12 through June 27, 1998, persistent rainfall caused widespread stream, river and lake flooding. The combination of moist air and low-pressure centers caused very heavy rain to persist across much of east central and southeastern New Hampshire.
Most sections of the State experienced heavy rain, with the heaviest accumulations in the eastern part of the State. Precipitation amounts for this event were well over 10 inches and caused major streams, rivers and lakes to overflow their banks.
27 State of New Hampshire, Natural Hazards Mitigation Plan, Executive Summary: October 2000 Edition
The total monthly rainfall for June ranged from 5 inches in the upper Connecticut River Valley to approximately 20 inches on Mt. Washington.
At the request of Governor Jeanne Shaheen, President Clinton declared a major disaster on July 2, 1998, as a result of flooding caused by these heavy rains. The counties of Belknap, Carroll, Grafton, Merrimack, Rockingham, and Sullivan were declared eligible for Individual and Public Assistance. The County of Hillsborough was added to the declaration on July 28, 1998.
Description of the Storm
A series of low pressure centers moving eastward from the Midwest, with a persistent flow of very moist air, caused heavy rains across much of east central and southeastern New Hampshire from June 12 to June 21, 1998. Widespread heavy showers and thunderstorms occurred on June 26 and 27, persisting on and off through July 1, 1998.
This persistent rainfall caused lakes, rivers, and streams to spill their banks. Although most sections of the State had heavy rain at times, the greatest accumulations were in the eastern part of the state where precipitation amounts exceeded 10 inches.
Mount Washington, in southern Coos County, reported more than 16 inches during this 9 day period. Rainfall amounts statewide were mostly in the 4 to 11 inch range. Several dams in the State were threatened by the high runoff. The heavy rain also caused major rivers in the State to rise above normal, and caused flooding along the Saco River. The observed flow on the Saco River downstream of West Buxton, Maine reached its fourth highest record flow since measurements were initially recorded in 1917. The heaviest rainfall occurred between June 13 and June 14 when rainfall amounts in most of eastern and southeastern New Hampshire generally ranged from 4 to 8 inches. Portsmouth reported more than 8.5 inches of rainfall during this period.
Another area hard hit during the period of June 27-28, was in central New Hampshire from Grafton County through Belknap County. A slow moving line of showers and thunderstorms dropped about 2 inches of rain in several hours causing the Baker River and many of its tributaries to quickly overflow their banks. This heavy rainfall also caused the Connecticut River at West Lebanon to flood. Image courtesy of the NWS, Gray, ME
For the month of June, rainfall amounts ranged about 5 Note: the continuity of this rainfall inches in the upper Connecticut River Valley in northern pattern with the Map of Historic Region New Hampshire, to almost 20 inches on Mt. Washington. I. Declarations by County on page 8 and the relative number of Declarations in the contiguous areas of Western Maine.
28 State of New Hampshire, Natural Hazards Mitigation Plan, Executive Summary: October 2000 Edition NH Strategic Flood Mitigation Plan Overview (See Appendix of specific Goals, Objectives and Mitigation Measures)
¾ Develop the State’s Flood Forecasting and Warning systems to their fullest potential (interface all with the National Weather Service in real time as practical) ¾ Support the enhancement of the NHOEM Communications Capability ¾ Support the EAS and NOAA Weather Radio Signal expansion including SAME signals ¾ Continued support of the position of Hazard Mitigation Officer/Protection Planner with DPIG and MAP funding ¾ Continued support of the position of Natural Hazards Program Officer with MAP funding ¾ Support the NFIP and endeavor to expand NFIP participation (including CRS) ¾ Continued (and expanded, where indicated) support of the NHDES Dam Safety Program ¾ Identify and assess the State’s Critical Facilities as may be subject to Flooding ¾ Identify and assess the State’s Critical Infrastructure as may be subject to Flooding ¾ Support cost effective Hazard Mitigation measures to harden the State’s Critical Facilities, roads and other infrastructure with funding from HMGP, FMAP Project Impact, CDBG and other sources as may be identified ¾ Support Project Impact ¾ Support the Pemi River Project ¾ Extend lessons learned and milestones achieved with the Pemi River Project and Project Impact to all NH communities as indicated ¾ Support the development of local Flood Mitigation Planning vis a vis: - Flood Mitigation Assistance Program - Project Impact Hazard Mitigation Planning - Development of a Planning Guide for NH Communities - NFIP CAVs - Distribution of Planning Guides ¾ Support All Hazards Mitigation Planning including Flood Mitigation Planning and Programs with funding from FMAP, DPIG, MAP, Project Impact, HMGP, and CDBG. ¾ Support the New Hampshire Coastal Program in Flood Mitigation activities and in the preservation of the State’s marine and adjacent environments ¾ Support Comprehensive Emergency Management Planning for Schools with MAP funding ¾ Support State and local officials with Emergency Planning, Preparedness, Response and Recovery training ¾ Orient State and local officials as to cost effective Flood Mitigation measures. ¾ Support and/or Provide Communities with Technical Assistance ¾ Continued support of Non-Commercial Service Announcements ¾ Produce and/or distribute informational materials going to cost effective Flood Hazard Mitigation ¾ Support the production of workshops to educate State and local officials as to cost effective Flood Mitigation Strategies and Measures ¾ Investigate the feasibility and desirability of enhancing State and/or local building codes and land use regulations as pertain to Flood Hazard Mitigation ¾ Support research as may be useful in Flood Hazard Mitigation Planning in the areas of climate, meteorology, demographics, economics, forestry, agriculture, fish and wildlife etc., going to the impact upon New Hampshire from Flood events. ¾ Support the State of New Hampshire Division of Historical Resources in protecting the State’s Historical and Archaeological treasures
29 State of New Hampshire, Natural Hazards Mitigation Plan, Executive Summary: October 2000 Edition
Drought
Hydrological drought is evidenced by extended periods of negative departures from normal rainfall.
In the summer of 1999 New Hampshire experienced relatively dry conditions. The map to the right is reprinted from a NOAA website and represents the July 1999 Palmer Drought Survey Index conditions for the nation and indicates “Moderate Drought” conditions for most of the State. http://enso.unl.edu/monitor/forecast.html
A Drought " Warning" was issued on 6/29/99 by the Governor's Office, as recommended by the State's Drought Management Team. There are 4 action levels associated with drought in the State Drought Plan: Alert, Warning, Severe and Emergency.
Droughts are rare in New Hampshire. They generally are not as damaging and disruptive as floods and are more difficult to define. The effect of droughts or decreased precipitation is indicated through measurements of soil moisture, groundwater levels, and streamflow; however, not necessarily all of these indicators will be minimal during a particular drought. For example, frequent minor rainstorms can replenish the soil moisture without raising ground-water levels or increasing streamflow.
Low streamflow also correlates with low ground-water levels, because it is ground-water discharge to streams and rivers that maintains streamflow during extended dry periods. Low streamflow and low ground-water levels commonly cause diminished water supply.
Hydrological drought is evidenced by extended periods of negative departures. Four droughts of significant extent and duration are evident in this century: 1929-36, 1939-44, 1947-50, and 1960-69. All of these droughts were statewide in extent and had recurrence intervals ranging from 10 to more than 25 years.
The drought of 1929-36 has a recurrence interval of greater than 25 years. The drought in New Hampshire coincided with severe drought conditions in large areas of the central and eastern United States.
Two, moderate to severe droughts in the 1940’s affected the entire State. Statewide, the recurrence intervals were between 10 and 25 years during both droughts, with the exception of the coastal area, where the recurrence interval was greater than 25 years for the 1939-44 drought.
The most severe drought recorded in New Hampshire occurred from 1960 to 1969. The drought affected the entire State and had a recurrence interval of greater than 25 years. This drought was regional in scope, encompassing most of the northeastern United States (U.S. Army Corps of Engineers, 1965, p.1.; Barksdale and others, 1966. (See: Palmer Drought Survey Index Map on the following page).
Historically, droughts in New Hampshire have had limited effect because of plentiful water resources and the sparse population. The major effects have been decreased crop yields, decreased water supplies, dry wells, and decreased hydropower production. Since 1960, the population has more than doubled; this growth has increased demand for the State’s water resources. Further droughts, equal to or greater than the four discussed in this report, may have considerable effect on the State’s densely populated areas along the seacoast and in the south-central area.
(Drought information represented here is taken from: New Hampshire Floods and Droughts, USGS Water-Supply Paper 2375)
30 State of New Hampshire, Natural Hazards Mitigation Plan, Executive Summary: October 2000 Edition
Significant Drought conditions were experienced in the Northeast during the 1960s, peaking in 1965. The Palmer Dro ught Survey Index maps in Appendix H of Section I. of the Plan offer a perspective on the Region’s exposure to Drought and the relative frequency of occurrences that su pports the findings outlined in the USGS analysis above.
http://enso.unl.edu/ndmc/climate/palmer/pdsihist.htm
Recent New Hampshire Drought History NH Strategic
Area Recurrence Remarks Drought Mitigation Date Effected Interval (Years) 1929-36 Statewide 10 to >25 Regional Plan Overview 1939-44 Statewide 10 to > 25 Severe in southeast and moderate elsewhere 1947-50 Statewide 10 to 25 Moderate ¾ Support NHDES-WRD in the 1960-69 Statewide >25 Regional Longest recorded administration of the State’s continuous spell of less than Drought Plan as warranted normal precipitation. Source: USGS Water-Supply Paper 2375 ¾ Support Project Impact and encourage Project Impact communities to include Status of Drought Planning in the United States, 1992 Drought Hazard Mitigation Source: Wilhite 1993 planning in their All Hazards Mitigation Plan ¾ Support cost effective Drought Hazard Mitigation measures with funding from HMGP, FMAP, DPIG, Project Impact, and CDBG as indicated ¾ Produce and/or distribute informational materials going to cost effective Drought Hazard Mitigation as necessary ¾ Orient State and local officials as to cost effective Drought Hazard Mitigation measures. ¾ Support NHDES-WRD and/or Provide Communities with Drought related Technical
FEMA Publication, Multi Hazard Identification and Risk Assessment Assistance ¾ Support the production of workshops to educate State The State of New Hampshire’s Hazard Mitigation initiatives and programs may be and local officials and NH accessed in The New Hampshire Drought Management Plan (circa, 1990). citizens as to cost effective
The Plan was produced, and is maintained by NH Department of Environmental Drought Hazard Mitigation Services – Water Resources Division. Strategies and Measures as the need arises 31 State of New Hampshire, Natural Hazards Mitigation Plan, Executive Summary: October 2000 Edition Severity and Areal Extent of Extreme Summer Heat in the United States Based on the NWS Heat Index EXTREME HEAT (Source: U.S. Dept. of Commerce and others, 1993)
The summer of 1999 was one of the hottest summers on record. As of 7/27/99, there had been 13 days with temperatures recorded above 90 degree s, 5 days above 95 degrees and 2 above 97 degrees.
Normally, the State enjoys variably moderate temperatures throughout the summer months with occasional peaks of high temperature and humidity. As observed in the panel to the right, the State, is positioned to receive occasional extreme heat events, particularly in the Southern areas. These event conditions may impact on the health of both humans and livestock.
Roads, bridges, railroads etc. may be FEMA Publication, Multi Hazard Identification and Risk Assessment damaged in these events. Utilities are also vulnerable as the demand for artificial cooling rises. Prolonged high temperature has also been associated with civil unrest and the SHMO is Extreme Heat Facts: pursuin g such New Hampshire specific data as may shed light on this and other phenomena related to ¾ New England has recorded temperatures of up to 107 extreme heat. degrees Fahrenheit. The recorded New England high is hotter than the all-time high temperature ever recorded in Miami, Florida or Atlanta, Georgia.* At the time of the presentation of this Plan Summary, sufficient information was not available (NOTE: The recorded New England low of 50 degrees to the SHMO with respect to this hazard type to below zero Fahrenheit is colder than the record low formulate a meaningful Risk Analysis. temperature in Anchorage, Alaska or International Falls, Minnesota).* The SHMO is working with the NHP Officer and representatives from NOAA/ NWS, the ¾ The major threat from extreme heat is heatstroke.** Univ ersity of New Hampshire Complex Systems ¾ Approximately 200 deaths per year are attributable to Department, Earth Oceans and Space Institute, the heatstroke.** Mete orology Department at Plymouth State College, the State’s Climatologist, the Mount Washington ¾ In 1980, when summertime temperatures reached all time Observ atory and the USDA/USGS to continue to high levels in most Central and Southern States, more than develop such data as may become useful in future 1700 deaths were diagnosed as heat related.**
Hazard Mitigation planning initiatives with respect ¾ A July 1995 heat wave caused 670 deaths, 375 in the to all areas of meteorological phenomena and Chicago area alone.** climate. This data, when available, will reflect the best data available to these agencies. ¾ Roads, bridges and railroads are susceptible to the effects of extreme heat.**
As additional data becomes available it will ¾ In the Summer of 1988, a drought/heatwave in the Central be a ppended to this Plan. A systematic compilation and Southern states resulted in 40 billion in damages as of da ta regarding the impact upon the State by well as many fatalities** Extrem e Heat related Hazards will be commissioned as funding and/or other resources are identified.
(See page 12. Of New England’s Changing Climate, Hazard Mitigation Weather and Air Quality* or in the pocket of Plan Section I or,. .http://www.neci.sr.unh.edu/neccwaq.html See also, The SHMO has requested information of the State’s FEMA publication; Multi Hazard Identification and Risk Climatologist who has agreed to commission students at UNH to
Assessment).** organize data with respect to this condition. As meaningful data becomes available, the SHMO and the State’s Hazard Mitigation Team will evaluate same with respect to any and all Hazard 32 Mitigation initiatives indicated (See below for preliminary data). State of New Hampshire, Natural Hazards Mitigation Plan, Executive Summary: October 2000 Edition
The data below and to the right has HHeeatatwwaavesves perper yearyear been provided by the State’s Climatologist and reflects data for the Concord area. Additional research is ongoing. 66
As data becomes available on a county- 44 by-county basis, analysis of that data will be 2 conducted and the State’s Hazard Mitigation 2 Team shall review any and all specific Hazard 00 Mitigation strategies indicated. 22 55 88 11 44 77 00 33 66 99 22 yryr 6 8 88 88 9696 969 9 11 11 196196 197197 197197 197197 1981 1919 1919 198198 199199 Extreme Heat Data: Concord, NH (Source, Barry Keim, Ph.D.)
yr #Heatwaves >95f >90f #Days#Days 9090 degreesdegrees oror aboveabove 1960 0 0 5 1961 1 0 12 3030 1962 0 1 5 1963 3 9 16 2020 1964 1 3 13 1010 1965 0 2 7 1966 3 5 24 00 1967 0 0 1 33 6 22 11 7 3 6 6 7 8 878 939 1968 1 1 5 9 9 969969 9 975975 978978 9 984984 196019601961 19661 11 1971 11 11 1981 11 1919 199019901919 1969 0 0 3 1970 2 2 17 1971 0 1 5 1972 0 0 3 ##DDaayyss 9955 dedegrgreeeess oror aabovbovee 1973 3 4 16 1974 0 0 11 10 1975 2 4 19 10 1976 1 1 14 88 1977 2 5 17 66 1978 4 6 27 44 1979 1 1 10 22 1980 1 3 11 00 1981 0 0 4 00 33 66 99 22 55 88 11 44 77 00 33 1982 1 2 6 66 99 9696 9696 9696 9797 9797 9797 9898 9898 9898 9999 9999 1983 0 2 21 11 11 11 11 11 11 11 11 11 11 11 11 1984 0 1 8 1985 0 0 2 1986 0 0 2 1987 2 1 12 Heatwave 1988 5 4 25 1989 1 1 7 A “Heatwave” is defined as a period of three 1990 1 0 9 consecutive days during which the air temperature 1991 1 5 17 reaches 90 degrees Fahrenheit or higher on each day. 1992 0 0 6 1993 2 5 17 1994 2 3 9 33 State of New Hampshire, Natural Hazards Mitigation Plan, Executive Summary: October 2000 Edition
Wildfire
New Hampshire is heavily forested and is therefore exposed to this hazard, particularly during periods of Drought. The proximity of many populated areas to the State’s forested lands exposes these areas and their populations to the potential impact of Wildfire.
The NH Department of Resources and Economic and Development (NHDRED), Division of Forests and Lands, manages all forest and Wildfire related issues within the State. The Department has its own planning staff and programs to address the threat of Wildfire. DRED enjoys compacts with the Forest Service of the USDA as well as neighboring states and the adjacent and nearby Canadian Provinces of Quebec, New Brunswick and Nova Scotia. The reader is referred to the State’s 2000 Forest Fire Plan, The 1999 Northeastern State and Private Forestry Annual Operating Plan and RSA 227-L for further information with respect to the State’s Capability with respect to this hazard type.
NH DRED Wildfire Mitigation Initiatives
(In association with the State Fire Marshall’s Office Summary of State Wildfire Burns and NH Fire Standards and Training)
¾ Aids, directs and trains municipal Fire Departments (50/50 cost NH averages 500 fires per year and averages ½ acre share) in prevention, pre-suppression and suppression of or less per fire due to the excellent coordination between Fire Towers and local Fire Departments Wildland Fire ¾ Maintains Forest Fire Protection Agreements with the ACRES YEAR AREA OF STATE Northeastern states and the Federal Government BURNED ¾ Maintains a cache of pumps, hose and tools for Forest Fire 1885 Wild River Area East 3,000 suppression assistance 1886 Zealand Valley 12,000 ¾ Maintains 15 Fire Towers (Mar.- Nov. as needed) and 1888 Zealand Valley 12,000 ¾ Aerial detection systems (3 routes ) as fire conditions necessitate 1903 Kilkenney (Berlin) 25,000 ¾ Coordinates the activities of Federal, State and local agencies at 1903 Wild River (West) 3,000 Wildland Fires on State property 1903 Zealand Valley 12,000 ¾ Cost share 50/50 in the cost of suppression when no known 1907 Swift River 10,000 person/cause exists 1908 Pemi Valley Mt. Liberty 4,800 NHDRED, Division of F&L appoints a Fire Warden in every ¾ 1912 Swift River (Conway) 1,000 NH community. The Wardens then nominate Deputies 1914 Rock Branch (Conway) 10,052 1923 Waterville Valley 3,500 1947 Newbury-Goshen 2,125 Historically, large NH Wildland Fires run in roughly 50-year cycles. The 1947 Farmington 7,333 increased incidence of large Wildland Fir e activity in the late 1940s and 1947 Freedom 1,225 early 1950s is thought to be associated, in part, with debris from the 1947 Salem 1,518 Hurricane of 1938. Significant woody “fuel” was deposited in the forests 1953 Tuftonboro 1,794 during that event. Present concerns of NHDRED Div. of F&L are that the 1953 Enfield 1,595 Ice Storm of 1998 has left a significant amount of woody debris in the 1984 Table Mountain (Bartlett) 100 forests of the region as may fuel future Wildfires (See Map, page 79) (Other data being compiled by NHDRED) 34 State of New Hampshire, Natural Hazards Mitigation Plan, Executive Summary: October 2000 Edition
Phragmites Australis: (Common reed)
A very tall grass that proliferates in brackish water near the coast. This plant is a recognized fire danger. The National Fire Danger Rating System has designated this type of marsh grass as a fire hazard described as “Marsh situations where the fuel is coarse and reed-like. One-third of the areal portion of the plants is dead. Fast-spreading, intense fires can occur even over standing water.” (Bradshaw, et al. 1983. The National Fire-danger Rating System: technical documentation. Gen. Tech. Rep. INT-169).
According to that report, the amount of live fuel in reed marshes averages 2.0 tons/acre while dead fuel average 3.0 tons/acre. This can be compared to Western perennial grasslands that have live fuel and dead fuel averages of 0.5 tons/acre and 0.25 tons/acre, respectively. Phragmites is a prolific species that spreads by its root system and can grow to be over 12 feet in height. The amount of above ground biomass and biologic productivity rivals that of a midwestern cornfield.
Fires in Phragmites are well known for being particulatly hot and fast moving. The towns of Seabrook and Hampton have recently experienced Phragmites fires as well as neighboring Salisbury, MA. A Seabrook fire in 1996 was started as a controlled burn. However, due to the density of the Phragmites, the fire burned so hot, it melted the vinyl siding off a nearby house. That fire was the impetus for a current Phragmites elimination project at that site funded by the NH Coastal Program. A fire in Salisbury, MA on April 8, 1999 is indicative of the danger that Phragmites poses. This fire began in the Phragmites and within 20 minutes had consumed 7 acres of the marsh. The fire then jumped a road, burned down a vacant home and threatened three other occupied dwellings. Fire fighters responding from 4 communities saved these dwellings. Seabrook was one of the the fire departments to respond and the firefighters spent 6 hours bringing the blaze completely under control. Although the three houses were saved, one of them lost the vinyl siding on one side of the house and at least one outbuilding was lost. Although, this type of fire has not occurred often in the past, it is becoming more prevalent as Phragmites spreads. Twenty years ago Phragmites Note: the proximity of the was located in a few isolated pockets, today it covers hundred of acres in New growth of this dry plant material with respect to the structures Hampshire's salt marshes. adjacent to the marsh.
Hazard Mitigation
Public Education
One Hazard Mitigation strategy, which will be aggressively pursued by the State, will be the education of the public to the dimensions of this hazard type.
Note: the barbecue grille in the far corner of this yard.
35 State of New Hampshire, Natural Hazards Mitigation Plan, Executive Summary: October 2000 Edition
Phragmites is known as an invasive species because it tends to move into areas that are inhabited by other types of vegetation and proceeds to out-compete other species. .Phragmites stands tend toward monocultures, that is, all other types of vegetation are excluded. This circumstance reduces native habitat that normally sustains a variety of native flora and fauna.
The high productivity and the tendency for the previous year’s growth to remain as dead standing plants interspersed among the current year’s growth, make it a wildfire danger. Additionally, the areas where Phragmites is spreading are near houses and community infrastructure.
This proliferation is due to the drainage of freshwater from paved surfaces and rooftops that decrease the salinity of nearby marshes allowing the Phragmites to invade. This drop in salinity is seen as the primary reason for Phragmites expansion in New Hampshire. The other primary reasons for decreasing salinities is the reduction of tide elevation due to marsh ditching and undersized culverts and bridges. The invasion of Phragmites also causes problems other than increased wildfire danger, including structural damage to structures from the invasive root systems.
High winds are customary in these coastal locations which contribute to the rapid spread of Phragmites related Wildland Fires and frustrate their suppression. Often it is the case that the firefighters have little choice but to allow the fire to burn itself out while attempting to prevent harm to the adjacent structures.
Structures adjacent to these tidal marshes tend to be relatively high in dollar value. This, coupled with the significant resources required to be dispatched to suppress these events, creates a significant financial risk associated with such events.
Phragmites Wildland Fire Hazard Mitigation Overview
¾ Support Research with respect to environmentally sound and cost effective Phragmites Wildland Fire Hazard Mitigation techniques ¾ Support Public Education regarding Phragmites Wildland Fire Hazards and cost effective, environmentally sound Hazard Mitigation techniques ¾ Support the NH OSP - Coastal Program's saltmarsh restoration initiatives including Phragmites related Wildland Fire Hazard Mitigation initiatives (i.e., increasing tidal flushing, ditching etc.).
36 State of New Hampshire, Natural Hazards Mitigation Plan, Executive Summary: October 2000 Edition
Section II. Geologic Hazards
Seismic Hazards:
Earthquake
(See Geologic Hazards Section, Ap pendices A. through I.).
A series of vibrations induced in
the Earth’s crust by the abrupt rupture and rebound of rocks in which elastic
strain has been slowly accumulating.
Tabular information below is taken from a NESEC publication (to 1989)
New En gland Location Date Magnitude Ossipee, NH December 20, 1940 5.5 New Hampshire Earthquake Activity
Ossipee, NH December 24, 1940 5.5 One of the earliest written accounts of Dover-Foxcroft, ME December 28, 1947 4.5 Kingston , RI June 10, 1951 4.6 Earthquake activity in North American extant (from 1638), describes an event Portlan d, ME April 26, 1957 4.7 Middl ebury, VT April 10, 1962 4.2 which most probably had its epicenter Near NH Quebec Border, NH June 15, 1973 4.8 in, or near the Ossipee Range of Central
West of Laconia, NH Jan. 19, 1982 4.5 New Hampshire (See Plan: Geologic Hazards Section II., Appendix G. page
56 col. 2 ppg 2. See also, pages 58 and
State Years of Record # of Earthquakes 59, Figures 5 and 6 respectively). Co nnecticut 1568 – 1989 137 Maine 1766 – 1989 391 For an overview of the historical Massachusetts 1627 – 1989 316 frequency, magnitude and damages New Hampshire 1728 – 1989 270 associated with New Hampshire’s Rh ode Island 1766 – 1989 32 seismic activity to date, the reader is Verm ont 1843 – 1989 69 referred to the historical data contained Total Number of Earthquakes within New England 1215 in the synopsis of earthquake events as Total Number of Earthquakes in the Northeast, 1538-1989 = 4498 compiled thus far by the NHOEM/NHP Office. This material is contained in Plan Section II, Appendix A. of the Plan.
Additional material may be found in Northea st Location Date Magnitude
Appendices B. - I. of the Geologic Hazards La Malb aie, PQ September 30, 1924 5.5 Section of the Plan. Also, click on La M albaie, PQ March 1, 1925 6.6 “Earthquakes in NH” on the NHOEM La Malbaie, PQ December 25, 1930 4.6 website: www.nhoem.state.nh.us
Lake George, NY April 20, 1931 5.0
La Malb aie, PQ January 8, 1931 5.4 The State is considered to lie in an area Dann emora, NY April 15, 1934 4.5 of “Moderate” seismic activity with NW of La Malbaie, PQ June 24, 1939 4.8 respect to other areas of the United La Malbaie, PQ October 19, 1939 5.8 States and is bordered to the North and La Malbaie, PQ October 27, 1939 5.2 NW of La Malbaie, PQ October 13, 1940 4.7 Southeast by areas of “Major” activity (See Plan: Geologic Hazards Section, Appendix I.). 37 State of New Hampshire, Natural Hazards Mitigation Plan, Executive Summary: October 2000 Edition
Of particular interest to Risk Analysis in New Hampshire is the crescent shape of events originating in the Ossipee Range and including the cities of Laconia, Concord, Manchester, Merrimack, Nashua through to Boston MA.
Approximate epicenter of all seismic events in or near the Northeast U.S. from 1638 to 1995
38 State of New Hampshire, Natural Hazards Mitigation Plan, New England Seismic Network Executive Summary: October 2000 Edition Station Map
Events of 4.0 or greater since 1975
WES WESTON NESN Stations (operated by Weston Observatory, Boston College) MIT NESN Stations (operated by the MIT Earth Resources Lab) Event Information USNSN (United States National Seismic Network) Stations (operated by the USGS)
(Time is UCT = GMT)
1: 1975NOV03 at 20:54: magnitude=4.1: The New England Seismic Network NY, RAQUETTE LAKE
2: 1979APR18 at 02:34: magnitude=4.0: NESN is cooperatively operated by the Weston ME, BATH Observatory of Boston College and the Earth Resources 3: 1982JAN19 at 00:14: magnitude=4.7: Laboratory of MIT with funding from the U.S. Geological Survey NH, W OF LACONIA under the National Earthquake Hazards Reduction Program.
4: 1983OCT07 at 10:18: magnitude=5.1: The purpose of the NESN is to monitor all earthquake activity in NY, GOODNOW the vicinity of New England and to use the data from this seismic
5: 1983OCT07 at 10:39: magnitude=4.1: monitoring to better understand the seismic hazard of the region. NY, GOODNOW (AFTERSHOCK) Analysis of the earthquake data recorded by the NESN will help improve the understanding of the possible locations, magnitudes 6: 1985OCT19 at 10:07: magnitude=4.0: NY, WHITE PLAINS and probabilities of future strong and damaging earthquakes in our region, as well as enable accurate predictions of where, and 7: 1988OCT20 at 13:09: magnitude=4.0: NH, 5 KM NE OF BERLIN how strong, damaging earthquake shaking can be expected. This information can, in turn, be used by public and private 8: 1988DEC28 at 06:28: magnitude=4.0: ME, 3 KM NE OF ALBION officials to take Earthquake Hazard Mitigation steps to minimize the damage from future earthquakes in the region. 9: 1989APR06 at 02:35: magnitude=4.1: (Courtesy, John E. Ebel Ph.D.) NH, NEAR BERLIN
10: 1991JUN17 at 08:53: magnitude=4.5: NY, SUMMIT
11: 1992MAR10 at 23:50: magnitude=4.1: NY, EAST HAMPTON 39 State of New Hampshire, Natural Hazards Mitigation Plan, Executive Summary: October 2000 Edition
Event Epicenter
In the Western and Central Regions of North America, the earthquake activity is understood to be associated with “faults” in the Earth’s crust. Seismologists have described the various types of ground movement and identified and catalogued such phenomena as waves of force releasing the stored energy in different directions with respect to the “epicenter” (the location on the Earth’s surface directly above the “focus,” or event center), from where the energy has been released. Wave Fronts; Direction of Vibration
Casual Factors in the Northeast The probability of occurrence of seismic activity is a guess at best. When asked when the next earthquake could Earthquakes in Northeast U.S. be expected, Charles F. Richter, creator of the scale which and environs cannot be associated with bears his name, would reply, “Tomorrow!” specific known faults (See Plan: Geo- logic Hazards Section II, Appendix B. Richter vs. Modified (MM) Mercalli Scales page 4. and 8.). As opposed to the typical seismic activity evident in Rich·ter scale (mb Scale) California which occurs at, or near the Prononciation: 'rik-t&r- conjunction of two of the Earth’s major Charles F. Richter Date: 1938 tectonic plates (or “interplate” events), : an open-ended logarithmic scale for earthquakes with epicenters in the expressing the magnitude of a seismic environs of New Hampshire are instead, disturbance, as an earthquake, in terms of the energy dissipated in it referred to as “intraplate” activity. with 1.5 indicating the smallest earthquake that can be felt, 4.5 an Casual factors of this seismicity earthquake causing slight damage, and are, as yet, speculative. Theories which 8.5 a very devastating earthquake. credit North American tectonic plate stresses, coupled with the elastic response of some areas of this plate to the Mer·cal·li scale (MM Scale) retreating glacier of some 10,000 years Prononciation: mer-'kä-lE Etymology: Giuseppe Mercalli died 1914 ago, are supported by the most recent Italian priest and geologist studies and data as potentially causal Date: 1921 (See Plan: Geologic Hazards Section : a scale of earthquake intensity ranging II, Appendix F., page 93 – 96). from I, for an earthquake detected only For additional information on by seismographs to XII, for one causing New England’s Regional Seismicity visit: total destruction of all buildings http://www-erl.mit.edu/NESN/homepage.html
40 The Relationship Between Richter Magnitude and Modified Mercalli Intensity Richter - Mercalli Not felt or rarely felt under favorable circumstances. Richter- Mercalli All people are frightened and run outdoors; general alarm. Sometimes, under certain conditions, • Many people find it difficult to stand; - • trees, structures, liquids, and bodies of water sway; - • water is stirred and muddied; • dizziness or nausea may be experienced; • some sand and gravel stream banks cave in; - • doors swing very slowly; - • chimneys crack considerably and walls crack I • birds and animals are uneasy or disturbed. VII somewhat; 2- - • plaster and stucco fall in considerable amounts;
- - • loosened bricks and tiles fall.
- -
- Felt indoors by a few persons, especially on upper floors, or - People are generally frightened, with alarm approaching by sensitive or nervous persons. panic. - • hanging objects swing 6- • Persons driving vehicles are disturbed; • trees, structures, liquids and bodies of water sway; • trees shake strongly and branches break off; - • dizziness or nausea may be experienced; - • sand and mud are ejected from earth in small amount; II • doors swing very slowly. VIII • temporary and permanent changes occur in springs - - and wells; • ground becomes wet to some extent, even on steep - - slopes; • chimneys, columns, monuments, and towers fall. - - Felt indoors by a number of people. Motion is usually a General panic - rapid vibration, and sometimes, - • Ground cracks conspicuously;
• vibrations are not at first recognized as an earthquake, • Masonry structures are thrown out of plumb; 3- - • movement is significant on upper levels of tall • large parts of well-built masonry buildings collapse; buildings; • some buildings shift off of foundations, and frames - III - IX • standing vehicles rock slightly; crack; - • hanging objects swing. - • reservoirs are seriously damaged; • some underground pipes break. - -
- 7- Felt indoors by many and outdoors by a few. Ground cracks at widths up to several inches. Parallel to - • A few people awaken, especially light sleepers; - canals and stream banks, fissures open to a yard wide. • Vibrations feel like those of a heavy truck passing by; • Numerous landslides occur on river banks and on steep - • dishes, windows, and doors rattle; - coastal formations;
• walls and frames of structures creak; • dams, dikes, and embankments are seriously - IV - X damaged; • liquids in open vessels are slightly disturbed; • most masonry and frame structures are destroyed; • standing vehicles rock noticeably. - - • buried pipelines are torn apart or crushed;
• cracks and broad, wavy folds open in concrete - - pavement and asphalt road surfaces.
4- - Felt indoors and outdoors by most people. outdoors, the Disturbances in the ground are many and widespread,
direction of the earthquake could be estimated. varying with ground materials. - - • Buildings tremble • Broad fissures, landslides, and liquefaction; - • dishes and glassware break; - • water, sand, and mud are ejected from earth in large • small or unstable objects overturn and may fall; amounts; - V • doors and shutters open or close abruptly; - XI • dams, dikes, and embankments are greatly damaged; • small objects move and furnishings move slightly; • few masonry structures remain standing; - • liquids in well-filled open containers spill slightly. 8- • large, well-built bridges are destroyed; • Plaster may fall and chimneys may be damaged. • railroad rails are greatly bent and thrust endwise. - -
- Felt by all people indoors and outdoors. - Damage is total, and nearly all works of construction are • people move unsteadily; greatly damaged or destroyed. - - • dishes, glassware, and windows break; • Landslides; numerous shearing cracks appear;
knick-knacks, books, and pictures fall; • large rock masses are wrenched loose and torn off; - • - • lakes are dammed, waterfalls form and rivers are • some furniture overturns; VI XII deflected; - • moderately heavy furniture moves; - • waves are seen on ground surfaces; 5- - • lines of sight and level are distorted; • objects are thrown upward into the air. - -
How are Earthquakes Measured?
Earthquakes are commonly measured by their magnitude and intensity. Magnitude is a measure of the total energy released during an earthquake. It is determined from a seismogram, which plots the ground motion produced by seismic waves. On the Richter scale, each whole-number step represents an approximate thirty-two-fold increase in released energy. For example, a 6.0 earthquake would equal 32 times the energy of a 5.0 quake, 1000 times the energy of a 4.0 quake and 32,000 times the energy released by a 3.0 earthquake. Scientists also gauge earthquakes by intensity, which is the degree of damage from an earthquake at a particular location. The intensity scale, the Modified Mercalli Scale, is divided into 12 degrees, each identified by a Roman numeral.
41 State of New Hampshire, Natural Hazards Mitigation Plan, Maximum Historic Modified Mercalli Intensity Executive Summary: October 2000 Edition Experienced in the Northeast United States
Historical Event Epicenters in the Northeastern United States and Southeastern Quebec, Canada
As can be seen by the map to the right, the areas of the most significant historical seismicity in New Hampshire lie in the Southeast corner of the State and in, and near, the Ossipee Range.
Depending on the type of soils (specific- ally, loosely consolidated layers or fill) underlying a given structure, the degree of MM Scale intensity felt at a given site may rise by as much as a factor of II.
On the map below, open circles indicate events with mb (Ricther) values of between 3.0 and 4.9 since 1929. The filled circles represent events greater than, or equal to 5.0 mb since 1700.
(From: Seismological Research Letters, vol 66, Number 4, July/August, 1995. “Mapping the Seismic Hazard in Courtesy of John E Ebel, Ph.D., Director, the Central and Eastern United States.”) Weston (Seismic) Observatory
42 State of New Hampshire, Natural Hazards Mitigation Plan, Executive Summary: October 2000 Edition
(Reprinted from NESEC paper, NEW ENGLAND EARTHQUAKES, 4/28/92, by Louis Klotz, Ph.D., P.E., Director. See Plan: Geologic Hazards Section, Appendix B.)
As to the probability of an earthquake, the New England Seismic Hazard calculated odds of an earthquake of the Richter Time in Years magnitude of the Magnitude 1 10 50 100 200
1755 Cape Ann (6.0) 4.6 .10 .64 .99 1.00 1.00 quake are 1/300 per 5.0 .05 .38 .91 .99 1.00 year. The odds of a 5.5 .01 .17 .60 .84 .97 potentially 6.0 .01 .07 .29 .50 .75 damaging 6.5 .003 .03 .12 .23 .41 earthquake of 7.0 .001 .01 .05 .10 .18 magnitude 5 or greater are 1/20 per year.
The “return times” are estimated to be 10 years for magnitude 4.6 and 1000 years for magnitude 7. Weston (Massachusetts) Observatory detects about 20 earthquakes a year that have a magnitude greater than 2; about ½ dozen of these may be felt by the inhabitants of New England. It is important to recall what Richter said when he was asked when the next earthquake would occur. His answer was “Tomorrow.” He then explained that tomorrow was as good as any other time because no one knows where we are on the probability curve. Some values of probability of an earthquake of particular magnitude in a specific time period within New England are given in the table above.
New England is particularly vulnerable to the injury of its inhabitants and structural damage because of our built environment. Few New England States currently include seismic design in their building codes. Massachusetts introduced earthquake design requirements into their building code in 1975 and Connecticut very recently did so. However, these specifications are for new buildings, or very significantly modified existing buildings only. Existing buildings, bridges, water supply lines, electrical power lines and facilities, etc. have rarely been designed for earthquake forces (New Hampshire has no such code specifications).
In general, New England is considered to have a moderate seismic vulnerability but a high seismic risk because of our built environment.
New England Earthquake Related Facts
¾ New England has a population density 10 times greater than that of California ¾ Most major cities in New England have a greater population density than the major cities in California ¾ The area impacted by an earthquake in New England will be from 4 to 40 times greater than that of
California ¾ Much of New England’s Built Environment is very old, non-seismically designed and brittle ¾ Predominant structures are built of unreinforced masonry which may be as much as 8 stories in height
¾ Gravity is too often relied upon for structural stability ¾ The current model Building Codes, such as BOCA, do not include provisions for the vertical effects of
earthquakes: i.e., Vertical Acceleration, Velocity or Displacement
43 State of New Hampshire, Natural Hazards Mitigation Plan, Executive Summary: October 2000 Edition
Attenuation : means to lessen in force or magnitude or, weaken. An earthquake attenuates over distance. The rate of atten uation is subject to several things, including the make up of the material through which the waves travel. In New Eng land, these intensities may travel from 4, to as much as 40 times the distance of quakes in other regions of the country.
New Hampshire’s Seismic Hazard Mitigation Initiatives
The State’s principle Hazard Mitigation initiatives with respect to seismic hazards have been undertaken in three forms:
¾ NHDO T - Designs infrastructure (i.e., bridges etc) to current American Association of State Highway and Transportation Officials (AASHO) standards -- inclusive of seismic and, ¾ NHDES -WRD - All dams constructed in the State must conform to the standards contained in U.S. Department of Interior, Bureau of Reclamation publication, Design of Small Dams (inclusive of seismic safety standards). ¾ NHOE M - Public information initiatives such as; - Non-Commercial Service Announcements (paid spots, aired in prime time) - Supporting the CEMPS Program
Comprehensive Emergency Management Planning for Schools (CEMPS)
CEMPS is an intensive two-day workshop, which brings together school, emergency management, fire and police personnel as well as members of the community, to discuss methods of preparing schools, school personnel and the community for any emergency. Instructor s for the CEMPS workshops include representatives from the private sector as well as State and local government, and cover varied fields of expertise. By utilizing the strengths and knowledge of these individuals, the workshop is able to tailor itself to the needs of the participants. CEMPS relies on the all-hazards approach to emergency management. All four phases of emergency management (i.e., Preparedness, Mitigation Response and Recovery) are included and discussed in detail . Emphasis is placed on the importance of including all four phases in school emergency planning. procedur es, which are based on the Incident Command System, are demonstrated through tabletop exercises that emphasize the team approach. The multiple hazards faced by New Hampshire communities make it necessary to demonstrate actions and techniques that can be used for a variety of situations. For example, photographs of a New Hampshire school that was impacted by a tornado are shown, demonstrating how the 'Drop, Cover and Hold' drill, which can also be utilized for an earthquake or an intruder, would protect staff and students. Techniques such as placing tinted plastic sheeting over windows are discussed. This may mitigate the potential of shards of glass injuring students during a severe wind event, an application which also inhibits intruders from looking through windows. The importance of communications and advanced warning are also emphasized. The NHP is in the early stages of a program to facilitate the placement of Weather Warning Radios into all Superintendent’s offices throughout the State. This mitigation will work in conjunction with NHOEM efforts to improve the coverage area of weather warning. One of the basic understandings of the CEMPS program is that planning is a process not an event. With this in mind, follow-up is another important element of CEMPS. After the initial workshop, CEMPS personnel are available for a variety of activities. These have included two-hour staff develop ment presentations, review of plans, resource distribution and acting as advisors during school planning meetings. 44 State of New Hampshire, Natural Hazards Mitigation Plan, Executive Summary: October 2000 Edition
Landslide Webster: “The sliding of a mass of soil, detritus or rock on, or from a steep slope.”
Jacksonville, VT, 1999
Photos courtesy of Richard N. Downer, Ph.D., P.E. of the University of Vermont and the HMGP Coordinator for the State of Vermont Emergency Management Agency.
More specifically, a Landslide is the downward or outward movement of slope
forming materials reacting under the force of gravity including: mudflows, mudslides,
debris flows, rockslides, debris avalanches, debris slides and earth flows.
Landslides may be formed when a layer of soil atop a slope becomes saturated by significant precipitation and slides along a more cohesive layer of soil or rock. Seismicity may play a role in the mass movement of landforms, such as was reported in Newcastle, NH and Berlin, MA during the Cape Ann event of 1755.
Landslides are characterized by the type of movement and the type of material. The types of
materials are soils and bedrock. The types of movement are slides, flows, lateral flows, falls and topples.
The action that appears to be indicated, given the level of risk, may be being conducted at this time. The State, through the Office of State Planning enforces planning and zoning regulatory activity statewide that may serve to regulate the construction of buildings in harm’s way. Rangers and other recreational facility monitors have posted vulnerable recreational areas. The SHMO will continue to investigate the State’s risk with respect to this hazard type and will submit any and all meaningful findings for inclusion into the Plan at the annual review. For a full explanation of these terms, the reader is referred to FEMA Publication: Multi Hazard, Identification and Risk Assessment from whence come the following facts: Landslide facts:
¾ According to a 1985 study, roughly 40% of the U.S. population is exposed to landslide activity.
¾ Landslides have damaged or destroyed roads, railroads, pipelines, electrical and telephone lines, mines, oil wells buildings, canals, sewers, bridges, dams, seaports, airports, forests, parks and farms.
¾ The best estimates of annual losses form Landslides in the U.S. are from 25 to 50 lives and from $1 to $2 billion in property damage.
¾ As of 1997, landslides have accounted for 38 Presidential Disaster Declarations, 15 of which were in California.
¾ The incidence of loss from landslide is often unreported or mis-reported, being ascribed instead to a precipitating event such as an earthquake, volcanism, hurricane or flood.
45 State of New Hampshire, Natural Hazards Mitigation Plan, Landslide Potential Based Executive Summary: October 2000 Edition on Adverse Formations
New Hampshire, although mountainous, consists largely of relatively “old” geologic formations that had been worn by the forces of nature for eons prior to the arrival of the Europeans. Consequently, much of the landscape is relatively stable and the exposure to this hazard type is generally limited to recreational and sparsely populated areas in the North and North Central portion of the State. Formations of sedimentary deposits and along the Connecticut and Merrimack Rivers also create potential landslide conditions. (See Maps to the right).
Although the Vulnerability to Landslide activity statewide is generally modest, the reader should be aware that the State has considerable terrain that is susceptible to Landslide action. Along the roadside in the area known as Crawford Notch on Route 302 in the White Mountain National Forest, appears an historical maker documenting a farm family who perished in a landslide event.
Anyone visiting the site of the “Old Man of the FEMA Publication, Multi Hazard Identification and Risk Assessment Mountain” or many other of New Hampshire’s mountainous landscapes, will likely encounter the debris accumulation deposited at the base of these slopes. The continuous action upon the seemingly solid rock of the freezing and thawing of the moisture which invades the rock’s fissures causes the rock to split and separate as the formed ice expands. As this action occurs repetitively on the steeply sloped areas of the State, eventually this detritus (referred to by geologists as “colluvium”) succumbs to the force of gravity. An accumulation of this relatively loose debris may eventually become unstable en mass and form a landslide (See Photo to the right. Note the recent activity - the lighter colored area).
Given the proximity of these landslide vulnerable areas to the areas of relatively high seismicity originating form nearly due north in the St. Lawrence River Basin, as Scene from Franconia Notch, NH - Photo by JJS well as those events originating in the Ossipee Mountain Range and elsewhere (See pages 37 and 38), coupled with Landslide Incidence the relatively high incidence of flooding in these areas with associated saturated soil conditions, consideration must be and Susceptibility given to the vulnerability of man-made structures in these areas to seismicity and/or soils saturation induced landslide activity.
Losses going to this hazard type are often attributed to other related events. During a recent Flood event (FEMA DR-1231-NH) a death occurred when a mass of saturated soil collapsed taking a man’s life. The death was attributed to the declared Flood event.
On the Maps to the right, note the areas of high incidence in Coos and Carroll counties and the areas with “adverse formations” in the regions of southeast Coos county and northern Carroll county.
Also note the indication of adverse formations all along the Connetticutt River and along some portions of the Merrimack River.
46 FEMA Publication, Multi Hazard Identification and Risk Assessment State of New Hampshire, Natural Hazards Mitigation Plan, Executive Summary: October 2000 Edition
Photo: FEMA Pub: Multi Hazard Identification and Risk Assessment Subsidence
The collapse of the Earth’s
surface elevation due to the
removal of subsurface support.
Events range from broad regional
lowering of the land surface that occurs over long periods of time, to
sudden localized collapse.
Peterborou gh, the State’s first Project Impact Community is currently faced with a
Subsidence hazard issue. A canal, which is runnin g through the center of the downtown area, poses a potential threat to life and property . The exact location of the canal is unknown to the local officials. The community has presented the State’s Hazard Mitigation Team with a proposal pursuant to the Hazard Mitigation Grant Program to assist in the engineering costs associated with deter mining the exact location of the canal, the creation of specifications for remedial action and funds for project implem entation.
This condition is not unique to Peterborough, as many of the older light/heavy industrial communities in the Region have canals that were constructed to facilitate hydro-mechanical power to local factories. These canals may not only no longer be in use, their location or, very existence, may be unknown to residents today.
Subsidence Hazard Mitigation
The Hazard Mitigation which is appropriate for Subsidence issues in the State include: ¾ Identification of local potentially hazardous sites by communities or others
¾ Mapping such sites as may be indicated ¾ Public awareness as to the potential hazard(s) ¾ Adjusting local Zoning ordinances to account for the potentially hazardous conditions
Subsidence Facts: (See FEMA Publication; Multi Hazard, Identification and Risk Assessment)
¾ Subsidence may be caused by a wide variety of man-made and natural causes including mining, withdrawal of groundwater, petroleum and geothermal fluids, de-watering of organic soils, wetting of dry, low-density deposits know as hydrocompaction as well as natural sediment compaction, melting of permafrost, liquifaction, and crustal deformation.
¾ The majority of these events result from human activity.
¾ Generally, Subsidence poses a greater risk to property than to life.
¾ The average annual damage from all types of Subsidence events is conservatively estimated to be at least $125,000,000.
¾ Damage consists of direct structural damage, property loss and depreciation of land values, but also includes business and personal losses that accrue during periods of repair.
¾ This hazard type affects parts of at least 45 states.
47 State of New Hampshire, Natural Hazards Mitigation Plan, Executive Summary: October 2000 Edition
Tsunami
(See also, Plan, Geologic Hazards, Section II., Appendices K. and L.).
**Tsunamis are also addressed in Section I. of this Summary; see page 22.
The Japanese characters that form the word “Tsunami” (pronounced tsoo-nah-mee) mean literally, “harbor wave.” The term is often mistakenly used interchangeably with
“Tidal Wave” but tsunamis exist independent of the Earth’s tidal activity.
“A tsunami is a wave train or series of waves generated in a body of water by an
impulsive disturbance that vertically displaces the water column. Earthquake, landslides (surface to ocean and/or submarine), volcanic eruptions, explosions and even
the impact of cosmic bodies such as meteorites can generate tsunamis.” (See Plan: Geologic Hazards, Section II., Appendix K.).
Although little information was available to the SHMO (or to the NHOEM/NHP Officer) as of the preparation of this Summary of the Plan with respect to this hazard type, it is understood that the Tsunami referred to as the “1929 Grand Banks Canada” event (Richter Scale magnitude 7.2) impacted upon the Maine shoreline (See Survey of Great Tsunamis graphic on page 22).
Normally these events are associated with earthquake activity along the Earth’s subduction zones with an upward thrust displacing a large volume of water vertically. Since there is thought to be no such feature near the Grand Banks (off the East coast of Canada), there is uncertianity as to the origin of the 1929 tsunami event. John Ebel, Ph.D., Director or the Weston (seismic) Observatory of Boston College advised the SHMO that the current theory leans toward a submarine landslide associated with the earthquake as the causal factor precipitating the wave event.
Tsunami Facts:
¾ Tsunamis are capable of wrecking devastation to both the natural and man-made environment at, or near the coastline and along estuaries.
¾ The most deadly tsunami in recorded history followed the eruption of Indonesia’s Krakatoa volcano in 1883 when an estimated 36,000 people were killed.
¾ The most frequent cause of tsunamis is the buckling of the seafloor, caused by an undersea earthquake that generally happens in subduction zones. Generally undetectable in the deep ocean, they deliver their force as they make landfall.
¾ The energy of tsunami waves may approach speeds of up to 500 mph, traveling great distances with little loss of energy.
¾ An earthquake off the cost of Chile in 1960, traveled some 10,000 miles in 22 hours and, had sufficient force when it arrived in Japan, to cause destruction of property and the deaths of some 150 people.
¾ During the 1993 event in Okushiri, Japan, the wave “runup” at the coast averaged about 30 – 65 feet. In one area where the terrain created a V shaped valley, the water ran up some 90 feet above sea level.
¾ The Great Alaska Quake in Prince William Sound of 1964, generated a tsunami, took the lives of more than 122 people and caused over $106,000,000.00 in damage.
48 State of New Hampshire, Natural Hazards Mitigation Plan, Executive Summary: October 2000 Edition
Volcanism
(See Plan: Geologic Hazards Section II., Appendix J. Definition below from www.pbs.org).
“All volcanoes are born when hot magma rises to the surface, infiltrates a weak spot in the Earth’s outer crust, and breaks through. Most of the 600-plus active volcanoes on Earth are associated with the boundaries of the tectonic plates, the seven great plates that carry the oceans and the continents. They are especially common in subduction zones, which occur when one plate dips beneath another. As the plate dives into the mantle – the layer of hot flexible rock on which the plates glide – is gradually is heated. That releases fluids, which heat the overlying rock, producing blobs of molten rock that rise to the surface. The molten rock – or magma – collects in weak patches of crust, in structures called magma chambers. If the pressure of the magma chambers builds high enough, the magma will erupt; a volcano is born.” * (Photo: Cover; Seismological Research Letters, Vol. 69 No..3)
Given the relative antiquity of the geologic formations in New Hampshire, the editor was surprised to find any evidence of volcanic activity in the written history of New England, let alone in that of New Hampshire. One reference was uncovered however, in a publication entitled Historical Notes on the Earthquakes of New England, 1638 – 1869 by William T. Brigham, A.M., AAS. That account was from the Memiors of the Boston Society of Natural History, vol. 2, page 1. ***
It would appear that some level of volcanic activity has manifested in the State at the Earth’s surface within the past 250 years. Although this event presents grounds for some curiosity and further investigation, significant vulnerability to volcanic activity does not appear to be indicated as presenting any risk to the citizens of the State (See Plan: Geologic Hazards Section II, Appendix H.)
***1 Stillman’s Journal (2), vol. 1 p.434.
2 Memoirs American Academy, vol. 1 (1), p. 312. In Dr. Dwight’s Travels, is the following: - “ At Hinsdale, on the Connecticut River, in the State of New Hampshire, was an eruption of fire in 1752, from a volcanic mountain, called West River Mountain. This miniature eruption was accompanied by a loud noise, resembling the sound of a cannon. A hole was found about six inches in diameter: a pine tree which stood near it, was partially covered by a black mineral substance forced out of the passage, consisting chiefly of melted and calcined iron ore, and strongly resembling the scoria from a blacksmith’s forge.” ______Editor’s Note: Interestingly, significant Earthquakes are recorded in: 1727 - Off the N.H., Mass. Coast; the shock was felt from the Kennebec to the Delaware Rivers and, 1755 – The Cape Ann Earthquake; estimated Magnitude of Richter, 6.0
49 State of New Hampshire, Natural Hazards Mitigation Plan, Executive Summary: October 2000 Edition
Geomagnetism (See Geologic Hazards Section II., Appendix M. Also, search the Internet for “Solar Wind Coupling”)
Of, or pertaining to the Earth’s magnetic field and related phenomena. “Large geomagnetic disturbances commonly known as magnetic storms, if global in scale, or as magnetic substorms if localized in scale and limited to night-time high altitude auroral regions, are of particular significance for electric power utilities, pipeline operations, radio communications, navigation,
satellite operations, geophysical exploration and GPS (global positioning system) use.”
Solar Wind Coupling and Geomagnetic Activity
(Reprinted from: The Solar Wind Coupling and Geomagnetic Activity Coupling Group website)
Solar Wind Coupling Magnetic Storms
Solar wind coupling is the name Magnetic storms occur when the applied to empirical studies of the radiation belts become filled with energetic relation between phenomena on the Sun and ions and electrons. The drift of these in the solar wind to various measures of particles produces a doughnut shaped ring of geomagnetic activity. This field of electrical current around the Earth. The research often treats the earth's magnetic perturbations of this current are magnetosphere as a black box whose measured on the ground as a decrease in the properties can be ascertained from magnitude of the horizontal component of the records of its past behavior. These earth's magnetic field. Magnetic storms are properties are then used in conjunction often initiated by the sudden arrival of a with measurements of the Sun and solar high-speed stream of solar wind, carrying wind, to predict future geomagnetic high particle density and high magnetic activity. field. Such predictions are frequently If the solar wind field is southward, used in empirical methods of space prior to the arrival of the high-pressure weather forecasting. Measures of solar wind, the earth's magnetotail may be geomagnetic activity are called magnetic loaded with magnetic energy and a violent indices. The most popular indices magnetospheric substorm is immediately include; the planetary range index, Kp, triggered. Such substorms often trigger the polar cap index, PC, the auroral transients on electrical power lines, electrojet index, AE, and the ring telephone lines and north-south pipelines, current index, Dst. and cause failures in these systems.
Geomagnetic Hazard Mitigation
“The energy connects into the rocks in the ground and into electrical power grids, long-distance phone lines, petroleum pipelines, and other manmade objects. A modest substorm can disrupt communications and make utility operators a little grayer. A major pipeline fire in the USSR in the 1990s may have been caused by galvanic erosion from solar storms. A major storm blacked out the Canadian and American Northeast in 1989. Nothing can be done to shield the Earth itself from space storms. But a better understandi ng of how the energy is funneled our way will help in alerting operators on the ground to protect equipment.” (Reprinted from the NASA website)
Little information was available to the SHMO or to the NHOEM/NHP Officer as to the local impact of such events on communications and other infrastructure as of the preparation of this Summary of the Plan.
The SHMO shall endeavor to ascertain the State’s vulnerability and Risk with respect to this hazard type within the year and shall recommend any appropriate amendments to the Plan at the annual review.
50 State of New Hampshire, Natural Hazards Mitigation Plan, Executive Summary: October 2000 Edition
Radon A naturally occurring radioactive gas with carcinogenic properties
is a common problem in many states; New Hampshire is one of them.
Spatial Extent of the Problem
Data collected by the NH Office of Community and Public Health’s Bureau of Radiological Health indicate that one third of the houses in New Hampshire have indoor radon levels that exceed the US Environmental Protection Agency’ s “action level” of four picocuries per liter for at least some portion of the year. Measured values exceeding 100 pCi/l have been recorded in at least eight of New Hampshire’s ten counties. The highest indoor radon reading in New Hampshire of which Bureau staff is aware is greater than 900 pCi/l, higher values probably exist (See Map on the following page).
In New Hampshire, homes with high levels of airborne radon are most prevalent in the North, East and Southeast portions of the State.
Radon may also enter homes dissolved in drinking water from drilled wells. High levels of radon in water from individual drilled wells is a common occurrence in New Hampshire.
Resources Response and Hazard Mitigation Information concerning radon in New
- Services offered by the NH Bureau of Hampshire may be obtained by calling the Radiological Health include: Bureau of Radiological Health at, (603) 271-4674 / 4764. ¾ responding to radon-related telephone inquiries, ¾ distribution of written material and, Radiation has traditionally been measured in units called “Curies” (Ci ). The prefix “p” stands for “pico” ¾ conducting an annual survey of radon levels in (pronounced, “pea-co”) and refers to a tiny fraction of homes through distribution of fixed numbers of a whole amount (1 trillionth part of some quantity). radon test devices. The “/l” is the abbreviation for “per liter.” So, the whole phrase is “picocuries per liter.” The term is a measure of the concentration of radon in the air or in The Origins of Radon water.
Outdoors, the national average radon concentration Radon is one of the transient radioactive isotopes is estimated to be 0.4 pCi/l. EPA recommends taking created during the decay of uranium-238. Whether or steps to reduce radon in indoor air when the average not a particular type of granite emanates radon is indoor concentration exceeds 4.0 pCi/l that is, ten dependent on the geochemistry of that particular granite, times the average outdoor concentration. some are a problem and some are not. Radon can also It is important to understand that EPA’s recommended be associated with some of the metamorphic rock in action level of 4.0 pCi/l is a technology driven standard that originated in the mid-1980s and not a health southeastern New Hampshire. In other parts of the country, radon is associated with certain black shales, dependent standard.
sandstones and even limestones. There is not a “safe” level of radon per se. It is simply a matter of the less you are exposed to, the smaller your risk. At some point the risk becomes too The map on the following page and related data depict small to be concerned with but, at what point (concentration) this might be is an individual decision. the distribution of indoor radon concentrations around the State as indicated by approximately 14,000 short- In any event, it is impossible to reduce indoor radon
term radon tests conducted by homeowners. For the concentrations to zero because the ambient outdoor air, which continually infiltrates homes, is estimated to most part, tests were conducted between November and contain some small amount of radon that varies from April in the lowest level of the home suitable for place-to-place and time-to-time but is usually occupancy... often the basement. (Data through May 1999). considerably less than 1.0 pCi/l.
51 State of New Hampshire, Natural Hazards Mitigation Plan,
Executive Summary: October 2000 Edition EPA has estimated that radon in indoor air is responsible for about 13,600 lung cancer deaths in this country each year (EPA document, EPA 811-R-94-001, 1994).
In February of 1998, the National Academy of Sciences released a summary of the findings of a four-year investigation by their committee on the Biological Effects of Ionizing Radiation (BEIR) on the health risks associated with radon in indoor air, BEIR VI. The Executive Summary and, a Public Summary, are available on the web at: http://www.epa.gov/iaq/radon/beirvi1.html
The committee concluded that radon was a significant health risk and that, depending on which of two separate models they used, their best estimates of the extent of the risk posed by residential radon in the United States were 15,400 or 21,800 radon- related lung cancers deaths each year. These numbers represent increases of 13% and 60%, respectively, over EPA’s earlier risk estimate, and 10% - 15% of all lung cancer deaths in the United States each year. Smokers, and former smokers, are at substantially more risk of developing a radon related lung cancer than those who have never smoked.
(All radon related nformation presented in this Plan has been provided courtesy of David S. Chase of the NH Office of Community and Public Health’s Bureau of Radiological Health)
Summary Table of Short-term Indoor Radon Test Results in NH’s Radon Database (5/7/99) COUNTY # of Tests †G. Mean ‡Maximum % > 4.0 pCi/l %>12.0 pCi/l Belknap 522 1.4 22.3 12.6 1.1 Carroll 1,082 3.5 478.9 45.4 18.3 Cheshire 889 1.3 131.2 14.5 1.8 Coos 1,034 3.4 261.5 40.5 17.4 Grafton 1,536 2.0 174.3 23.7 5.6 Hillsborough 1,724 2.2 119.7 29.6 7.7 Merrrimack 1,761 1.9 143.8 22.3 4.9 Rockingham 3,513 2.8 108.7 37.4 8.8 Strafford 1,316 3.3 122.8 41.9 12.3 Sullivan 430 1.4 29.4 13.5 1.9 STATEWIDE 13,807 2.4 478.9 31.1 8.6
† In a radon sampling of radon levels in homes, readings are known to be lognormally distributed. Therefore, the geometric mean, rather than the arithmetic mean, is a more appropriate measure of central tendency. ‡ This table reflects only data collected as part of State-run surveys and, in no way should be considered to represent the full range of values found in the respective counties.
52 State of New Hampshire, Natural Hazards Mitigation Plan, Executive Summary: October 2000 Edition
NH Strategic Geologic Hazards Mitigation Goals (See specific Goals, Objectives and Mitigation Measures Appendix)
¾ Develop the State’s Seismic Forecasting and Warning systems to their fullest potential ¾ Support a Statewide and/or Regional network analysis of Seismic sensing and warning (and/or early damage assessment and location estimation) systems to promote efficient an effective dispatch of resources in an event as indicated ¾ Support prudent and cost effective upgrades to the Seismic sensing network as indicated ¾ Support the enhancement of the NHOEM Communications Capability ¾ Support the EAS ¾ Continued support of the position of Natural Hazards Program Officer with MAP funding ¾ Support the CEMPS Program with MAP funding ¾ Continued support of the position of Hazard Mitigation Officer/Protection Planner with DPIG and MAP funding ¾ Continued (and expanded, where indicated) support of the NHDES Dam Safety Program ¾ Identify and assess the State’s Critical Facilities as may be subject to Seismic Events ¾ Identify and assess the State’s Critical Infrastructure subject to Seismic loads ¾ Support cost effective Hazard Mitigation measures to harden the State’s Critical Facilities and infrastructure with HMGP, FMAP Project Impact, and CDBG funding ¾ Support Geologic Hazards Mitigation Planning and programs with funding from FMAP, DPIG, MAP, Project Impact, HMGP, and CDBG. ¾ Support the development of local Geologic Hazards Mitigation planning vis a vis: - Flood Mitigation Assistance Program - Project Impact Hazard Mitigation Planning - Development of a Planning Guide for NH Communities - NFIP CAVs - Distribution of Planning Guides ¾ Support All Hazards Mitigation Planning including Geologic Hazards Mitigation Planning and Programs with funding from FMAP, DPIG, MAP, Project Impact, HMGP, and CDBG. ¾ Support State and local officials with Emergency Preparedness, Response and Recovery training ¾ Support Non-Commercial Service Announcements ¾ Orient State and local officials as to cost effective Seismic and other Geologic Hazards related Hazards Mitigation measures. ¾ Support and/or provide NH communities with related Technical Assistance ¾ Produce and/or distribute informational materials going to cost effective Geologic Hazards Mitigation Measures ¾ Support the production of workshops to educate State and local officials as to cost effective Geologic Hazards Mitigation Strategies and Measures ¾ Investigate the feasibility and desirability of enhancing State and/or local building codes and land use codes as pertain to Geologic Hazards Mitigation ¾ Support research as may be useful in Geologic Hazards Mitigation Planning in the areas of seismology, geology, construction practices and standards, demographics, economics, etc., going to the impact upon New Hampshire from Geologic Hazards ¾ Support the State of New Hampshire Division of Historical Resources in protecting the State’s Historical and Archaeological treasures
53 State of New Hampshire, Natural Hazards Mitigation Plan, Executive Summary: October 2000 Edition
Section III. Severe Wind
Tornado
A tornado is a violent windstorm characterized by a twisting, funnel shaped cloud. These events are spawned by
thunderstorms and, occasionally by hurricanes, and may occur singularly or in
multiples. They develop when cool air overrides a layer of warm air, causing the warm air to rise rapidly. Most vortices
remain suspended in the atmosphere. Should they touch down, they become a force of destruction.
Tornado damage: Fufita Scale; F 2
Great Brook School, Antrim, N.H.
Event Date: May 23, 1998 NH Tornado History (Only F2 and greater events are presented here) Tornados are measured on the Fujita Scale, developed in COUN TY DATE F SCALE the late 1960’s by University of Chicago professor Theodore
Belknap July 3, 1972 F2 Fujita. The Table below lists the scales, wind speeds, and Carroll July 18, 1963 F2 average national occurrence rates from 1953 to 1989. Information Cheshire June, 1793 Cheshire July 19, 1807 for the Table to the left was gleaned in part from: Cheshire August 4, 1822 www.tornadoproject.com Cheshire September 15, 1922 F2 Only F2 and greater events are presented here. Cheshire September 13, 1928 F2 Cheshire August 13, 1963 F2 Cheshire June 6, 1969 F2 Coos May 5, 1929 F2 Scale Wind Speed Impact Average per year Grafton August 20, 1816 F0 40-72 mph Light damage 218 or 29% Grafton September 9, 1821 Grafton July 16, 1880 F2 F1 73-112 mph Moderate damage 301 or 40% Grafton August 11, 1966 F2 F2 113-157 mph Considerable damage 175 or 23% Grafton May 11, 1973 F2 F3 158-206 mph Severe damage 43 or 6% Hillsborough July 28, 1748 F4 207-260 mph Devastating damage 10 or 1% Hillsborough May 21, 1814 Hillsborough September 15, 1922 F2 F5 261-318 mph Catastrophic damage 1 or .002% Hillsborough July 2, 1961 F2 Hillsborough June 9, 1963 F2 Hillsborough July 19, 1966 F2 Tornado Facts: (See Severe Wind Section III., Appendix H.) Hillsborough July 17, 1968 F2 Hillsborough August 20, 1968 F3 ¾ On average, the United States experiences 100,000 thunderstorms Merrimack July 14, 1791 Merrimack September 5, 1792 each year and approximately 1,000 tornadoes develop from these Merrimack July, 1793 storms. Merrimack September 9, 1821 ¾ Damage from tornadoes is caused as a result of high wind velocity Merrimack July 24, 1911 F2 and wind blowm debris. Rockingham May 21, 1814 Rockingham May 16, 1890 F2 ¾ Over 80% of tornadoes strike between Noon and Midnight. Rockingham August 21, 1951 F2 ¾ “Tornado season” is marked from March through August Rockingham June 9, 1953 F3 (although tornadoes may occur at any time of the year). Rockingham June 19, 1957 F2 ¾ Normally, a tornado will stay on the ground for no more than 20 Rockingham July 2, 1961 F2 Rockingham June 9, 1963 F2 minutes. Strafford May 17, 1773 ¾ Injuries and deaths most often occur when buildings collapse. Strafford August 15, 1787 ¾ Although tornadoes occur throughout the world, the United States Strafford May 14, 1963 F2 experiences the most intense and devastating tornadoes. Strafford May 3, 1976 F2 Strafford June 22, 1981 F2 ¾ In 1974 148 tornados in 13 states killed 300 and injured 6,000 Sullivan May 23, 1782 causing $600 million in damages ALL IN THE SAME DAY! Sullivan September 9, 1821 Sullivan July 1, 1831 54 State of New Hampshire, Natural Hazards Mitigation Plan, Executive Summary: October 2000 Edition
Number of Tornadic Events per One Degree Latitude, 1954 – 1983
The highest winds ever recorded in the world (by fixed equipment)
231 Mph - were recorded on
FEMA Publication, Multi Hazard Identification and Risk Assessment Mt. Washington in New Hampshire
on April 12, 1934. Note: on the Map to the lower left, the area
designated as a “Special Wind Region” along the Connecticut River Valley.
FEMA-TTU Publication: Taking Shelter from the Storm FEMA-TTU Publication: Taking Shelter from the Storm 55 State of New Hampshire, Natural Hazards Mitigation Plan, Executive Summary: October 2000 Edition
Hurricane Facts:
Hurricane ¾ The clear, calm, “eye” of the hurricane is bordered in the (See Severe Wind Plan, Appendices C., D., E., and H.). “eyewall” by a ring of thunderstorms where winds are the
strongest and rains are torrential A hurricane is a heat engine that ¾ Of the 126 tropical storms or hurricanes that struck the derives its energy from ocean water. These United States’ Atlantic and Gulf coasts between 1949 and storms develop from tropical depressions 1990, 25 (19.9%), were classified as “Major,” rating “3” which form off the coast of Africa in the or higher on the S/S Scale warm Atlantic waters. ¾ The hurricane induced winds can give a coconut the force of a cannonball When water vapor evaporates, it absorbs ¾ Storm surge accounts for about 9 out of 10 hurricane energy in the form of heat. As the vapor associated deaths. More than 6000 people lost their lives rises, it cools within the tropical depression, in an estimated “Category 4” hurricane in Galveston, and then condenses, releasing heat, which Texas on September 9, 1900 when a 20 foot storm surge sustains the system. hit shore accompanied by winds estimated at 120 mph
The name “hurricane,” is derived from the
aboriginal Caribes’ (indigenous peoples of the SAFFIR/SIMPSON SCALE West Indies at the time of the arrival of Christopher Columbus) expression for “evil Scale No Winds Storm Surge Potential spirit.” (Category) (mph/km) (ft/m) Damage
A tropical depression becomes a hurricane 1 74-95 / 119-153 4-5 / 1-2 MINIMAL
when its sustained recorded winds reach 74 mph. 2 6-110 / 154-177 6-8 / 2-2.5 MODERATE Although hurricane forecasting has improved over the years tremendously, the path of these 3 111-130 / 178-209 9-12/ 3-4 EXTENSIVE
storm s may only be approximated. 4 131-155 / 210-249 13-18 / 4-6 EXTREME
5 > 155 / 250 18 / 6 CATASTROPHIC
Hurricanes Impacting on New Hampshire SCALE NO. (Category) KEY 1635 - 1991 1) No real damage to building structures. Damage primarily to Name Event Wind unanchored mobile homes, shrubs, and trees. Some coastal Date Speed flooding and minor pier damage.
Hurricane of 1635 August, 1635 2) Some roofing material, door and window damage. Considerable damage to vegetation, mobile homes, piers. Hurricane of 1778 October 18-19, 1778 40 – 75mph Coastal and low lying escape routes flood two to four hours Hurricane of 1804 October 9, 1804 before landfall. Small craft in unprotected anchorage’s break Gale of 1815 September 23, 1815 >50 mph moorings. Hurricane of 1869 September 8, 1869 3) Some structural damage to small residences with minor Hurricane of 1938 September 21, 1938 186 mph (max) curtainwall failures. Mobile homes destroyed. Flooding near Hurricane Carol September, 1954 the coast destroys small structures. Larger structures Hurricane Donna September, 1960 damaged by floating debris. Flooding may extend inland eight Hurricane Gloria September 28,1985 >70 mph miles over terrain lower than five feet above mean sea level (MSL). Hurricane Bob August, 1991 >60 mph 4) Extensive wall failures with some roof structure failure on small residences. Major beach erosion. Major damage to lower floors of structures near shore. Flooding of terrain lower than ten feet causes massive evacuation of These systems are rated from 1 – 5 residential areas up to six miles from shore. on the Saffir-Simpson Scale (“S/S Scale”) 5) Complete roof failure of many residences and industrial developed in the early 1970s by Herbert Saffir, buildings. Some complete building failures. Major damage to Consulting Engineer, and Robert Simpson, then lower floors located less than 15 feet above MSL, and within 500 yards of shore. Massive evacuation of residential areas directo r of the National Hurricane Center. may be required on low ground within five to ten miles of the shore. (Courtesy of National Weather Service)
56 State of New Hampshire, Natural Hazards Mitigation Plan, Executive Summary: October 2000 Edition
NH Hurricane Exposure Landfalling Hurricanes For Coastal Counties As can be seen from the Map to the right and the Graph below, New Hampshire’s exposure to direct and indirect impacts from hurricanes is real, but modest, as compared to other states in the region.
The most devastating recorded hurricane impact on New Hampshire occurred in September, 1938.
FEMA Publication, Multi Hazard Identification and Risk Assessment
The Map above indicates the path of the “38 hurricane.” The storm drove U.S. Hurricane Landfalls through the heart of southern New (Catagories 1-5): 1900-1994 England after devastating Providence Rhode Island and leaving some 600 dead in the Northeast.
As for the State of New Hampshire, the Southwest corner of the State experienced the brunt of that event but, according to most hurricane track paths, damage is more likely to occur on, or near the seacoast, and in the Southeast portion of the State (See Map to the upper right for “landfalling” hurricane statistics). (See Plan, Section III., Appendices C. and D. for a New Hampshire specific hurricane damage history narrative). FEMA Publication, Multi Hazard Identification and Risk Assessment (Source: Modified from Hebert, Jarrel and Mayfield, 1995)
57 State of New Hampshire, Natural Hazards Mitigation Plan, Executive Summary: October 2000 Edition
“Nor’easters” (1840-50) Northeaster (See page 70):
A large weather system traveling from South to North passing along or near the seacoast. As the storm approaches New England and its intensity becomes increasingly apparent, the
resulting counterclockwise cyclonic winds impact the coast and inland areas form a Northeasterly direction. The sustained winds may meet or exceed hurricane force, with larger bursts, and may exceed hurricane events by many hours in terms of duration.
Unlike the relatively infrequent hurricane, New Hampshire generally experiences at least 1 or 2 “significant” (see below) events each year on average with varying degrees of severity. These storms have the potential to inflict more damage than many hurricanes because the high storm surge and high winds can last from 12 hours to 3 days, while the duration of hurricanes ranges from 6 to 12 hours.
Because of the coincidence of the storm surge with the high winds from such an event, the coastline is particularly vulnerable. The coincidence of an event with high tides adds an additional layer of vulnerability and associated risk. New Hampshire’s coastline, although modest in size as compared with other coastal states, is highly developed and consequently, is at significant risk from coastal storms.
Infrastructure, including critical facilities, may be impacted by these events, and power outages and transportation disruptions (i.e. snow and/or debris impacted roads, as well as hazards to navigation and aviation) are often associated with the event.
In the winter months, the State may experience the additional coincidence of blizzard conditions with many of these events as well as the added impact of the masses of snow and/or ice upon infrastructure, impacting upon transportation and the delivery of goods and services for extended periods of time and various related impacts upon the economy.
The Dolan-Davis Scale is used to rate these systems with respect to their impact on coastal areas. Little New Hampshire specific information as to the impact of these class types upon the NH economy was available to the SHMO at the time of the submission of this Plan. The SHMO shall continue research for this information and report his findings to the State’s Hazard Mitigation Team.
DOLAN-DAVIS NOR’EASTER CLASSIFICAITON SCALE
AVE. RETURN AVE. PEAK AVE. DURATION STORM CLASS PERCENT OF INTERVAL WAVE (IN HOURS) IMPACT NOR’EASTERS HEIGHT (FT)
1 - WEAK 49.7 3 DAYS 4.6 8 MINOR BEACH EROSION
2 - MODERATE 25.2 1 MONTH 6.2 18 MODEST PROPERTY DAMAGE; LOWER - BEACH EROSION
3 - SIGNIFICANT 22.1 9 MONTHS 10.8 34 LOCAL-SCALE DAMAGE; EROSION ACROSS BEACH, PLUS SIGNIFICANT DUNE EROSION
4 - SEVERE 2.4 11 YEARS 16.4 63 COMMUNITY-SCALE DAMAGE; LOW BEACHES WASHED OVER; SEVERE BEACH RECESSION, DUNE DESTRUCTION
5 - EXTREME 0.1 100 YEARS 23.0 95 REGIONAL-SCALE DAMAGE; MASSIVE OVERWASHING; EXTENSIVE DUNE DESTRUCTION
58 State of New Hampshire, Natural Hazards Mitigation Plan, Executive Summary: October 2000 Edition NOAA Weather Radio Signal in New England
Emergency Warning Systems
With respect to Severe Wind Hazards, and aside from Planning and Prepared- ness, the National Oceanic and Atmospheric Administration’s (NOAA) National Weather Service (NWS), by way of their Severe Weather Alert Signals, provide the best Hazard Mitigation available.
The Graphic overlays on the Map to the right indicate the optimal reception coverage of the existing NOAA/NWS Weather Radio signal associated with the transmitter locations and frequencies indicated. Given the State’s varied topo- graphy, the signal is often unavailable in the areas indicated. Only one transmitter is currently broadcasting the NOAA signal from the State of New Hampshire. As can be seen by the Map, the northern half of the State is poorly covered or, not covered at all. Since these signals also carry the NOAA Specific Area Message Encode (SAME) severe weather alerts, these vital early warning signals as to impending tornadic, downburst, and other Severe Wind events are available in specific areas of the State only.
Downburst Recent Downburst Activity in NH (See Severe Wind Section III., Appendices F., page 2 and E., page 2.).
Event Type Microburst A downburst is a severe localized wind blasting FEMA DR-917-NH down from a thunderstorm. These “straight line” winds are distinguishable from tornadic activity by County Rockingham the pattern of destruction and debris. Location Town of Stratham Depending on the size and location of these events, the destruction to property may be Event Date August 18, 1991 devastating. Injuries 11 Downbursts fall into two categories: Fatalities 5 Cumulative Damages $ 2,498,974
Microburst: (The SHMO did not have access to systematically organized Covers an area less than 2.5 miles in diameter data with respect to this hazard type. Macroburst: As funding allows, research will be commissioned as to the State’s Vulnerability and Risk with respect to such events. Covers and area at least 2.5 miles in diameter (See page 60 and 61 for additional data).
Due to the historical and potential impact upon aviation by these phenomena, significant effort has been expended to devise a method of forecasting or anticipating these events. Doppler Radar is now capable of recognizing the signs of impending events to some degree and NOAA/NWS provides Alerts when such conditions are recognized. 59 State of New Hampshire, Natural Hazards Mitigation Plan, Executive Summary: October 2000 Edition
Tornadic verses Downburst Activity
The two photos above capture images of a debris path that is indicative of Downburst activity (left) and Tornadic activity (right). Note: in the photo on the left, the debris is lying in line with the path of the event, while in the photo to the right, the debris is lying perpendicular to the path of the event. (Photos courtesy of the National Weather Service, Gray, ME)
Downburst:
Infrastructure Damage
Downbursts can be very destructive. In 1979 a “mighty windstorm” des- troyed the newly renovated
Bedell covered bridge in Haverhill, NH. Compare this 396-foot span with the Cornish, NH - Windsor, VT
460-foot span below. Life- line losses such as a bridge may have devastating economic and emergency
services access con- Bedell Bridge Span Photo: JJS sequences for a community.
Photo Credit: John J. Shaughnessy
The Stone Marker At This Site Reads: Bedell Bridge: 1866 – 1979
Destroyed in a mighty windstorm on September 14, 1979. This had been the longest Two-Span Arch Truss left in America. Closed to traffic by damage in 1958 and due to be demolished n 1973, it was restored during a six-year program by Bedell Covered Bridge Inc. and reopened on July 22, 1979. 60 Cornish, NH-Windsor, VT - 460 Ft Photo: JJS Longest two-span covered bridge in the world This was the second time a bridge at this State of New Hampshire, Natural Hazards Mitigation Plan, location had been destroyed by wind! Executive Summary: October 2000 Edition
Bedell Bridge, Haverhill, NH, September 1979 Restored Bedell Bridge, Haverhill, NH, July 1979 Photo courtesy of Glen English Photo courtsey of Glen English
Location Moultonborough Location Central NH
County CarrollCounties Merrimack, Grafton, Hillsborough Event Date July 26, 1994 Event Date July 6, 1999
Event Type Microburst Event Type Macroburst Scope of Event ½ mile wide Fatalities 2
4-6 miles in length Damages 2 Roofs blown off Structures Damages Downed trees, utility poles and wires Widespread power outages (some lasting days)
1800 homes without power Downed trees, utility poles, and wires Approximately 50 – 60 houses damaged
(All photos below are of the Moultonborough event,
courtesy of Nancy Wurtz, NHOEM Field Representative)
Many of New Hampshire’s 61 neighborhoods support heavy forest growth State of New Hampshire, Natural Hazards Mitigation Plan, Executive Summary: October 2000 Edition Lightning and Thunder
By definition, all thunderstorms contain lightning. Lightning is a giant spark of electricity that occurs within the atmosphere or between the atmosphere and the ground. As lightning passes through the air, it heats the air to a temperature of about 50,000 degrees Fahrenheit, considerably hotter than the surface of the Sun. During a lightning discharge, the sudden heating of the air causes it to expand rapidly. After the discharge, the air contracts quickly as it cools back to ambient temperatures. This rapid expansion and contraction of the air causes a shock wave that we hear as thunder, a shock wave that can damage building walls and break glass. Photo: Dave Gammon, Lake Winnisquam, Laconia, NH, July, 1999
Areal Extent and Severity of Lightning Hazard in the U.S. Based on Mean Annual Lightning Strike Density: 1948 – 1997 (Source: Data from MacGorman and others, 1984)
FEMA Publication, Multi Hazard Identification and Risk Assessment 62 State of New Hampshire, Natural Hazards Mitigation Plan, Executive Summary: October 2000 Edition
D uring the development of a thunderstorm, the rapidly rising air within the cloud, combined with the movement of the preci pitation within the cloud, causes electrical charges to build up within the cloud. Generally, positive charges build up near the top of the cloud, while negative charges build up near the bottom. Normally, the Earth’s surface has a slight negative charge. However, as the negative charges build up near the base of the cloud, the ground beneath the cloud and the area surrounding the cloud becomes positively charged. As the cloud moves, these induced positive charges on the ground follow the cloud like a shadow. Main types of lightning:
Ligh tning is a giant spark of electricity that occurs between the positive and negative ¾ In cloud charg es within the atmosphere or between the atmosphere and the ground. In the initial ¾ Cloud to cloud stages of development, air acts as and insulator between the positive and negative charges. ¾ Cloud to ground Howev er, when the potential between the positive and negative charges becomes too great, (Ball lightning is rare there is a discharge of electricity that we know as lightning. and is not discussed here)
In -cloud lightning occurs between the positive charges near the top of the cloud and the negative charges near the bottom. Cloud to cloud lightning occurs between the positive charges near the top of the cloud and the negative charges near the bottom of a second cloud. Cloud to ground lightning is of course, the most dangerous, and occurs between the cloud and the ground.
In summertime, most cloud to ground lightning occurs between the negative charges near the bottom of the cloud and positive charg es on the ground (Negative stroke). However, in some cases, lightning occurs between the positive charges near the top of the cloud and negatively charged ground (Positive stroke). The rare wintertime thunderstorms in Northern New England gen erally have a higher percentage number of positive strokes. In the usual summertime cloud to ground stroke, an invisible, negatively charged, channel of air forms near the cloud base and surges downward toward the ground. As this “Step Leader” appro aches the ground, “Streamers” of positive charge reach upward from trees, buildings and other objects on the ground. (Continued on the following page). (All information contained in this chapter is provided courtesy of the National Weather Service)
Deaths from Lightning in the United States
Lightning kills an average of 87 people per year in the United States with many other people injured by lightning. This is more than the average of 82 deaths per year caused by tornadoes and an average of 27 deaths per year caused by hurricanes. Because lightning generally kills only one or two victims at a time, it generally receives much less attention than some more destructive weather-related phenomena.
Lightning Facts
¾ Lightning kills an average of 87 people per year in the United States ¾ Most lightning deaths and injuries occur outdoors ¾ There are an average of 300 documented lightning injuries per year in the U.S.
¾ Some estimate from 750 to 5000 lightning injuries per year nationally ¾ (Where known) About 45% of lightning casualties in the U.S. occur in open fields, ballparks etc., 23% were under trees, 14% involved water activities, golfing (either in the open or under trees) accounted for 8%. Those operating farm equipment accounted for 5% of the causalities. ¾ New Hampshire has the 16th highest casualty rate in the nation (Maine is 8th) ¾ Lightning can strike as much as 10 miles from the side of a thunderstorm ¾ A thunderstorm moving at 30 miles per hour will travel 5 miles in 10 minutes ¾ If you can hear the thunder, you are in striking distance of the storm ¾ Most lightning deaths occur in the summer months - in the late afternoon or evening, when lightning is most likely to occur and people are apt to be outdoors ¾ Moderate summer temperatures in the Northeast allow people to enjoy outdoor activities which accounts for the relatively high casualty rate in New England
¾ Lightning awareness and proper action (or the lack of proper action) can influence your personal chances of being struck by lightning significantly ¾ Many lightning victims are struck after the worst part of the storm has passed ¾ Pets chained to outside "runs" attached to tall trees are vulnerable to strikes 63 State of New Hampshire, Natural Hazards Mitigation Plan, Executive Summary: October 2000 Edition
Once a connection is made, and the channel is complete, a surge of electrical current moves from the ground to the cloud causing the visible “Return Stroke” that we call “Lightning.” The entire process takes only a fraction of a second. Immediately after the initial stroke has ended, the charges return, and another step leader forms, positive charges surge upward and the connection is made, another return stroke can follow the first in the same channel. On average, a typical flash of lightning will have 2 to 4 return strokes and will last less than a second.
While both negative and positive strokes can be deadly, the positive strokes generally contain more current and are more apt to catch more people by surprise. In the usual summertime thunderstorm, the ground is shielded from the positive charges of the thunderstorm cloud by the negative charges near the bottom of the cloud. In storms that are vertically tilted, positively charged air near the top of the cloud may be leading the negatively charged cloud base. In this case, a few scattered positive strokes of lightning may precede the lower part of the storm where the precipitation is falling. These storms are particularly dangerous since many people have not sought, or reached, a safe shelter when these positive strokes occur.
In other instances, storms with little, if any, precipitation falling from the cloud base may not have a sufficient negative charge in the lower part of the cloud to shield the ground from the upper level positive charges. The lack of precipitation from these relatively weak, or weakening thunderstorms may lead people to believe that there is little, if any, threat of lightning and again, may catch many by surprise.
Finally, in another instance, positive charges may linger in the middle and upper atmosphere, even though the lower clouds and negative charges associated with the main part of the thunderstorm may have moved away from the area. In these cases, the sky may not appear to be at all threatening and, portions of the sky may be clear and blue! In these instances, people tend to return to their outdoor activities before the lightning threat is actually gone.
Because of these lingering positive strokes, people should wait at least 30 minutes after the last lightning is seen or thunder is heard before going back outside.
Lightning and Buildings: The Facts Lightning Safety Inside Buildings
¾ ¾ Most lightning property damage occurs inside Stay away from windows, outside homes and businesses doorways, porches and good conductors of ¾ Small wooden buildings with metal roofs electricity provide little or no protection and should ¾ Basements should generally be avoided not be used for shelter during thunderstorms ¾ ¾ Lightning enters a building through: Small metal buildings should be used as a 1. A direct strike last resort for shelter (stay in the center and
2. Conductors that extend through the avoid contact with the walls and floor as structure much as possible) ¾ 3. The ground Avoid all contact with phones that are ¾ Once in a building, lightning can travel connected to outside wires ¾ through the electrical, plumbing, phone, radio Avoid all contact with appliance cords and television reception systems and connected to the electrical system ¾ reinforcement wires in concrete walls or floors Avoid all contact with the plumbing system ¾ The majority of injuries from lightning including washing hands, showering, indoors are through the hand or head and bathing and doing laundry are phone related ¾ Do not stand next to a concrete wall and do ¾ Except for contact with the cradle, and the not lie flat on a concrete floor antenna presenting an increased hazard ¾ Unplug electronic, motorized and other outdoors, near windows and outside doors, a such devices long before the storm arrives cordless phone is safer than others if possible
64 State of New Hampshire, Natural Hazards Mitigation Plan, Executive Summary: October 2000 Edition
When lightning strikes, the electricity not only travels through the air but, also travels through the ground. Although we generally can’t see lightning as it travels through the ground, there is about as much electrical energy traveling through the ground as we observe in the air.
Contrary to what some people may think, most of the electrical energy does not flow deep in the ground, but rather, flows near the surface of the ground. If you are near where the electricity is flowing through the ground, even if you are some distance from the visible lightning strike, you could be killed by the lightning.
The point of contact where the lightning enters the ground is not necessarily the highest object in the area. While the height of an object increases the risk of being struck, its ability to collect the positive charges from near the ground surface, and its ability to produce streamers of positive charges as the step leader approaches the ground, all contribute to the likelihood that the object could be struck by lightning.
In northern New England, tall pine trees seem to be a favorite target for lightning. The long shallow roots can collect positive charge from a relatively large area, while the tree’s conductivity and height, seem to make it a vulnerable target.
As lightning travels through the air and ground, it travels along the path of least resistance. That is, it follows the path of the best conductivity. The human body is a very good conductor of electricity. As such, if given the chance, lightning will often choose to flow through a human body rather than through the air, the ground or other objects. To be safe, you must not only protect yourself from the lightning as it enters the ground, but you must also protect yourself from the lightning as it travels through the ground.
Certain objects and substances in, on, or just above the ground, are also good conductors of electricity. If given the chance, lightning will follow these conductors for long distances from the original lightning strike. These objects include; wires, metal pipes or rods, water, tree roots and moist soils. All of these should be avoided during thunderstorms.
WHERE (IN RELATIONSHIP TO THE STORM) ARE MOST PEOPLE STRUCK BY LIGHTNING?
Most cloud to ground lightning strokes occur directly under the thunderstorm cloud, usually near the location where the heaviest rain is falling. Therefore, this area is the most dangerous part of the storm. However, cloud to ground lightning can strike the ground as much as 10 miles from a thunderstorm. While most people take shelter when a storm is overhead, they often leave themselves vulnerable to being struck by lightning when the main part of the storm is several miles away.
Studies of lightning casualties in Florida over an 8-year period showed that there were more people stuck by lightning before (35%), and after (47%), the peak lightning activity than during peak lightning activity (18%). In the same study, more causalities were associated with storms with infrequent flashes and light precipitation than with storms with very frequent flashes and heavy precipitation.
We are fortunate in Northern New England to have less lightning than most other areas of the country. On average, much of New Hampshire and Maine have less than 2 cloud to ground lightning strokes per square mile per year. Only several states in the Western U.S. have lightning flash density rates as low. In comparison, many states in the Midwest and South have flash density rates of 10 flashes per square mile per year, and, parts of Florida experience flash rates of 30 flashes per square mile per year!!
Despite the relatively low incidence of lightning in New Hampshire and Maine, these states have relatively high casualty rates (combined injury/death rate) due to lightning. New Hampshire ranks 16th in the nation, while Maine ranks 8th!
While there are several factors contributing to this high rate, residents and visitors to Northern New England are likely to be more vulnerable to being struck by lightning because of the activities with which they are involved, particularly on those warm summer days when lightning is most likely to occur. Often, many people are outside enjoying the variety of recreational activities that attract people to Northern New England during the summer when the vulnerability to lightning strike is highest.
What is often referred to as “Heat Lightning” is simply the result of distant thunderstorms that are too far away for the resultant thunder to be heard. In most cases, the light you observe is being reflected off distant clouds near the horizon.
65 State of New Hampshire, Natural Hazards Mitigation Plan, Executive Summary: October 2000 Edition
Personal Lightning Strike Hazard Mitigation Signs that a Lightning Planning for Outdoor Safety Lightning Strike is Imminent ¾ Become educated on the dangers of lightning ¾ Learn to recognize the early signs of a developing thunderstorm ¾ Your hair stands on end ¾ Know when the lightning threat begins and when it is over (as the positive charge ¾ The key to lightning safety outdoors is planning ahead. Outdoor activity officials should develop a Lightning Safety Plan from the ground surges to ¾ The plan should stipulate to specific actions upon specific indices the top of your head) ¾ You hear a distinctive ¾ Plan alternate dates for your event if practical ¾ Determine the time for you and all others to get to a safe place snapping or crackling ¾ Once in place, the plan should be followed without exception sound (small discharges of static electricity occur in a Basic Rules to Reduce the Risk area where Lightning is about to strike) of Being Struck by Lightning Outdoors ¾ You experience a tingling 1. If you hear thunder, move inside a safe shelter immediately sensation (electrical 2. If the sky looks threatening, move inside immediately charges may be moving 3. Stay inside a safe shelter for at least 30 minutes after the last stroke through your body) of lightning has been seen or the last thunder heard ¾ There is a sudden increase in the static on ¾ Monitor the latest weather forecasts and carry a portable radio with you (an AM radio, tuned to an unused station, will signal - with static - portable electronic distant lightning) devices (electrical charges may be moving through ¾ If caught by surprise in the outdoors, assume the Lightning Safety Position the devices)
¾ There is an abnormal
burning smell in the air Outdoors - Lightning Safety Position
(static charges within the ¾ Squat low to the ground air give off a burning ¾ Get on the balls of your feet smell) ¾ Place your hands on your knees ¾ Sparkles are visible in the ¾ Put you head between your knees air (static discharges in the ¾ Minimize your contact with the ground air may actually be seen in ¾ Do not place your hands on the ground low light situations) ¾ Make yourself the smallest target possible
State of New Hampshire Overall Lightning Hazard Mitigation Strategy
¾ Support the expansion of the availability of the NOAA/NWS SAME severe weather alert system ¾ Support Public Information dissemination regarding Lightning Hazards ¾ Support the production of educational materials and the distribution of same to the public ¾ Support the CEMPS program ¾ Support research into the specific NH vulnerability and risks associated with this hazard type ¾ Support research going to cost effective Hazard Mitigation Measures ¾ Support the execution of cost effective Hazard Mitigation Measures
66 State of New Hampshire, Natural Hazards Mitigation Plan, Executive Summary: October 2000 Edition Annual Frequency of Hailstorms Hailstorms in the United States (Source: Bryant, 1993, citing Eagleman, 1983) (See Plan, Section III., Appendix D.) http://206.251.19.76/weather/tg/whail/wds9.htm
Hailstones are balls of ice that grow as they're held up by winds, known as updrafts, that blow upward in thunderstorms. The updrafts carry droplets of supercooled water - water at a below freezing temperature - but not yet ice. The supercooled water droplets hit the balls of ice and freeze instantly, making the hailstones grow. The faster the updraft, the bigger the stones can grow. Most
hailstones are smaller in diameter than a dime but stones weighing more than a pound have been recorded. Details of how hailstones grow are complicated but the results are irregular balls of ice that can be as large as baseballs, sometimes even bigger. While crops are the major victims, hail is
also a hazard to vehicles and windows. FEMA Pu blication, Multi Hazard Identification and Risk Assessment Deaths are rare in the United States. The last known U.S. hail fatality was an infant killed in Fort Collins, Colo., in August 1979. Hailstorm Events can be severe to persons, property, livestock and agriculture. Althoug h New Hampshire’s overall exposure to this hazard type is considered to be relatively low by national standards, significant hailstorm events do occur in the State.
The SHMO, in association with NOAA/NWS, the State’s Climatologist, the Earth, Oceans and Space Institute of the Complex Systems Research Center at the University of New
Hampshire, the Meteorology Department at Plymouth State College, the Mount Washington Observatory and the USDA/USGS, is endeavoring to identify such information as may be useful with Graphics and slides above are reprinted form: regard to Hailstorm Hazard Mitigation planning. As http://whirlwind100.nssl.noaa.gov/~doswell/b such information becomes available, it will be arcelona/PPT_Severe_Storms/sld010.htm incorporated within this Plan. 67 State of New Hampshire, Natural Hazards Mitigation Plan, Executive Summary: October 2000 Edition
NH Strategic Severe Wind Mitigation Plan Overview (See Appendix of specific Goals, Objectives and Mitigation Measures)
¾ Develop the State’s Severe Wind Forecasting and Warning systems to their fullest potential including the acquisition and EAS distribution of the EMWIN capability
¾ Support the enhancement of the NHOEM Communications Capability ¾ Support the EAS and NOAA Weather Radio Signal expansion and SAME radio
distribution ¾ Support the establishment of redundant stand alone backup emergency power generators
at the State’s EAS facilities as necessary to support reliable signal transmission ¾ Support the construction of “Safe Rooms” in, or adjacent to, residential, commercial and
public buildings as may be warranted ¾ Continued support of the Position of Natural Hazards Program Officer with MAP
funding ¾ Support the CEMPS Program with MAP funding
¾ Continued support of the position of Hazard Mitigation Officer/Protection Planner with DPIG and MAP funding
¾ Identify and assess the State’s Critical Facilities as may be subject to Severe Wind loads ¾ Identify and assess the State’s Critical Infrastructure With Respect to such wind loading
¾ Support cost effective Hazard Mitigation measures to harden the State’s Critical Facilities and infrastructure with funding from HMGP, FMAP Project Impact, and
CDBG ¾ Support Severe Wind Mitigation Planning and programs with funding from DPIG, MAP,
Project Impact, HMGP, and CDBG. ¾ Support Project Impact
¾ Support Development of local Severe Wind Mitigation planning vis a vis: -- Project Impact Hazard Mitigation Planning - Development of a Planning Guide for NH Communities
- NFIP CAVs - Distribution of Planning Guides ¾ Support State and local officials with Emergency Preparedness, Response and Recovery
training ¾ Support Non-Commercial Service Announcements and public information initiatives
¾ Orient State and local officials as to cost effective Severe Wind Hazard Mitigation measures.
¾ Support and/or Provide Communities with Severe Wind Related Technical Assistance ¾ Produce and/or distribute informational materials going to cost effective Severe Wind
Related Hazards Mitigation ¾ Support the production of workshops to educate State and local officials as to cost
effective Severe Wind Hazards Mitigation strategies and measures ¾ Investigate the feasibility and desirability of enhancing State and/or local building codes
and land use codes as pertain to Severe Wind Hazards Mitigation ¾ Support research as may be useful in Severe Wind Hazards Mitigation Planning in the
areas of climate, meteorology, demographics, economics, forestry, agriculture, fish and wildlife etc., going to the impact upon New Hampshire from Severe Wind events.
¾ Support the State of New Hampshire, Division of Historical Resources in protecting the State’s Historical and Archaeological treasures from the effects of Severe Wind events
¾ Support the New Hampshire Coastal Program in Hurricane Mitigation activities including the preservation of the State’s marine, and adjacent environments
68 State of New Hampshire, Natural Hazards Mitigation Plan, Executive Summary: October 2000 Edition
Section IV. Winter Weather Related Hazards (RE: River Ice Jams, See Flood etc. Section I. page 76)
Heavy Snow Storms
A heavy snowstorm is generally considered to be one that deposits four or more inches of snow (or 10 cm) in a twelve-hour period.
The editor has drawn heavily for this Section from FEMA publication, *Multi Hazard, Identification and Risk Assessment, from: **Snowstorms Along the Northeastern Coast of the United States: 1955 to 1985, Kocin and Uccellini, American Meteorological Society and from ***New England’s Changing Climate, Weather and Air Quality, CCRC – EOS – UNH
***The recorded New England low of 50 degrees below zero Fahrenheit is colder than the record low temperature in Anchorage, Alaska or **Number of snowfall events exceeding 25 cm (9.98 in.) International Falls, Minnesota. by region by month from 1955-56 to 1984-85
*Winter Storm Facts:
¾ Between 1988 and 1991, a total of 372 deaths, an average of 93 each year, were attributed to severe winter storms. ¾ The “Superstorm” of March, 1993, considered among the worst non tropical events in the U.S., killed at least 79 people, injured more than 600 and caused $2,000,000,000 in property damage across 20 states and the District of Columbia. ¾ Snow volume exceeds that of rain by a factor of from 7 to 10. ¾ Generally, mean annual snowfall amounts depend on the geographical latitude of the area however, topography and other factors may influence mean annual snowfall and localized snowfall from a specific event. ¾ Snowfall accumulation may be augmented in areas adjacent to, or near large bodies of water such as the Oceans and the Great Lakes. This phenomenon is known as “Lake Effect Snow.” ¾ There is no way to be completely prepared for all such events. In areas in which the frequency of such events is less, communities are generally less well prepared, and the effects are therefore, heightened.
69 State of New Hampshire, Natural Hazards Mitigation Plan, Executive Summary: October 2000 Edition
”Nor’easters” (See page 58)
A large weather system traveling from South to North, passing along, or near the seacoast. As the storm approaches New England and its intensity becomes increasingly apparent, the resulting counterclockwise cyclonic winds impact the coast and inland areas form a Northeasterly direction. The sustained winds may meet or exceed hurricane force, with larger bursts and, may exceed hurricane events by many hours in terms of duration. As can be seen by the graphics to the right, these storm systems have complex **Factors contributing to heavy snowfall along the Northeast coast of the United States meteorological derivations.
Unlike the relatively infrequent hurricane, New Hampshire generally experiences at least 1 or 2 of these events each year on average, with varying degrees of severity. These storms have the potential to inflict more damage than many hurricanes because the high storm surge and high winds can last from 12 hours to 3 days, while the duration of hurricanes ranges from 6 to 12 hours.
Infrastructure, including critical facilities, may be impacted by these events. Power outages and transportation disruptions (i.e. snow and/or debris-impacted roads, as well as hazards Cold Conveyor Belt (blue, lower right), Warm Conveyor Belt (red, to navigation and aviation) are often associated foreground),dry airstream (divergent, in yellow), surface fronts, sea-level with such events. cyclone and anticyclone centers, and low- and upper-level streamlines.
Because of the potential coincidence of storm surge with the high winds from such an event, the coastline is particularly vulnerable. The coincidence of these events with high tides adds an additional layer of vulnerability and associated risk. New Hampshire’s coastline, although modest in size as compared with other coastal states, is highly developed, and consequently, is at significant risk from coastal storms.
In the winter months, the State may experience the additional coincidence of blizzard conditions with many of these events as well as the added impact of the masses of snow and/or ice upon infrastructure thus, impacting upon transportation and the delivery of goods and services for extended periods of time as well as various related impacts upon the economy.
The entire area of the State may be impacted by these events and, the coastline and tidal plain may experience the additional impact of storm surge. Heavy snow and/or rainfall may be experienced in different areas of the State and the heavy rains may contribute to flood conditions.
Nor’easters, which occur toward the end of a winter season, may exacerbate the spring flooding by depositing significant snowpack at a time of the season when spring rains are poised to initiate rapid snowpack melting.
70 State of New Hampshire, Natural Hazards Mitigation Plan, Executive Summary: October 2000 Edition
Blizzard
A blizzard is a winter storm characterized by high winds, low temperatures, and driving snow- according to the official definition given in 1958 by the U.S. Weather Bureau, the winds must exceed 35 miles (56 km) per hour and the must drop to temperature 20° F (-7° C) or lower. Therefore, intense Nor’easters, which occur in the winter months, are often referred to as Blizzards.
The definition includes the conditions under which dry snow, which has previously fallen, is whipped into the air and creates a diminution of visual range. Such conditions, when extreme enough, are called “white outs.”
Limited New Hampshire specific data as to the effects of temperature, economic and personal losses resulting from these events etc. was available to the editor at the time of the preparation of this Section of the Plan. The SHMO, in association with NOAA/NWS, the State’s Climatologist, elements from The University of New Hampshire - Complex Systems Research Center - Earth, Oceans and Space Institute, the Meteorology Department at The “Blizzard of 1978,” a “Nor’easter,” Plymouth State College, the Mount Washington Observatory, led to a Presidential Disaster Declaration in Massachusetts and and the USDA/USGS, is endeavoring to identify such related massive restoration activity in the State of New Hampshire. data and such climatological trends as may be useful in The Photo above is of Rt. 128 south of Boston, Mass. Hazard Mitigation planning. As such information becomes (Photo courtesy of Boston Globe/David Ryan) available, it will be incorporated within this Plan.
**(New Hampshire specific data **250 cm = 98.425 in. = 8.2 ft. 150 cm = 59.0 in. = 4.9 ft. 200 cm = 78.74 in. = 6.56 ft. 100.cm = 39.37 in. = 3.28 ft. not currently available)
71 State of New Hampshire, Natural Hazards Mitigation Plan, Executive Summary: October 2000 Edition
*History of Significant Snowstorms in the Northeast U.S.
( Reprinted from: Snowstorms Along the Northeastern Coast of the United States: 1955 to 1985, Kocin and Uccellini, American Meteorol ogical Society).
EIGHTEENTH CENTURY
27 February – 7 March 1717. “The Great Snow of 1717.” A series of four snowstorms, two relatively minor and two major, left depths in excess of 90 to 120 cm across most of southern New England, with drifts exceeding 750 cm (= 24.6 feet). The effects of these storms were so impressive that local historical accounts still singled out this storm period as the “The Great Snow” more than 100 years following the event.
24 March 1765. This storm affected the area from Pennsylvania to Massachusetts. From Philadelphia came this report: On Sunday night last there came on here a very severe snowstorm, the wind blowing very high, which continued all the next day, when it is believed there fell the greatest quantity of snow that has been known for many years past; it being generally held to be two feet [(60 cm)], or two feet and a half [(75 cm)], on the level, and in some places deeper.”
27-28 January 1772. “The Washington and Jefferson Snowstorm.” George Washington n Mount Vernon and Thomas Jefferson in Monticello were marooned by this storm. Snowfall was estimated at 90 cm on a level across Virginia and Maryland. Washington wrote,”. . . the deepest snow which I suppose the oldest living person ever remembers to have seen in this country.”
26 December 1778. “The Hessian Storm: was a severe blizzard accompanied by heaving snows, high winds, and bitter cold from Pennsylvania to New England, with drifts reported to 500 cm in Rhode Island. The storm was named for troops occupying Rhode Island during the Revolutionary War.
28 December 1779 – 7 January 1780. Three storms during one of the coldest winters of the past three centuries produced deep snows in much of New England. The first storm produced rain from New York City southward, but snow occurred in New England with 45 cm at New Haven, Connecticut. The second system was a violent snowstorm with extremely high tides from the Carolinas northward. The third storm was confined primarily to eastern New England. Snow depths in the wake of the three storms ranged between 60 and 120 cm from Pennsylvania to New England.
4 – 10 December 1786. This period featured another succession of three crippling snowstorms. Estimates in the local press placed snow depths form Pennsylvania to New England at 60 to 120 cm… In describing the third storm, a Boston newspaper notes, “snowstorm equally severe and violent with that we experienced on Monday and Tuesday preceding. The quantity of snow is supposed to be greater, now, than has been seen in this country at any time since that which fell seventy years ago, commonly terms. ‘The Great Snow.’”
19 - 21 November 1798. “The Long Storm: is described by Ludlum as the heaviest November snowstorm in the history of the coastal northeast from Maryland to Maine. Forth-five cm of snow reportedly fell in New York City.
72 State of New Hampshire, Natural Hazards Mitigation Plan, Executive Summary: October 2000 Edition
NINETEENTH CENTURY
26 - 28 January 1805. This cyclone brought a very heavy snowstorm to New York City and New England. Snow fell continuously for 48 hours in New York City, where 60 cm reported accumulated..
23-24 December 1811. Temperatures fell from well above freezing on 23 December to 15ºC on 24 December, while a storm intensified explosively off Long Island, New York. Snowfall in New York City, Long Island, and southern New England averaged 30 cm, as severe blizzard conditions prevailed. Strong winds and high tides caused extensive damage to shipping.
5 – 7 January 1821. An extensive snowstorm spread form Virginia to southern New England, leaving 30 cm at Washington, D.C, 35 cm at Baltimore, Maryland, 45 cm at Philadelphia, Pennsylvania, and 35 cm in New York City.
14 – 16 January 1831. “The Great Snowstorm” produced the heaviest snowfall over the largest area of any storm studied by Ludlum. Accumulations exceeded 25 cm from the Ohio Valley across much of the Atlantic cast north of Georgia. Washington, D.C., reported 33 cm, with 45 cm at Baltimore, Maryland, 45 to 90 cm near Philadelphia, Pennsylvania, 37 to 50 cm at New York City, and 50 to 75 cm over southern New England.
8-10 January 1836. This event became known as “The Big Snow” for interior New York, northern Pennsylvania, and western New England, where 75 to 100 cm fell. The storm also buried the coastal plan, with 37 cm at Philadelphia, Pennsylvania, 37 to 45 cm at New York City, and 60 cm across southern New Jersey.
18-19 January 1857. “The Cold Storm” combined snowfall in excess of 25 cm with temperatures near or below -15ºC and high winds to produce severe blizzard conditions from North Carolina to Maine. Snow totals ranged from 37 cm near Norfolk, Virginia, to 45 to 60 cm in Washington, D.C., and 60 cm at Baltimore, Maryland, with 30 cm at New York City, and 35 cm at Boston, Massachusetts.
11 – 14 March 1888. The “Blizzard of 88” produced severe blizzard conditions over a 2 – to 3-day period across Pennsylvania, New Jersey, New York, and central and western New England. Perhaps the most legendary of all historic snowstorms, it generated depths of 75 to 125 cm across sections of New York and New England, with extremely high winds and temperatures falling below -15ºC. New York City was particularly hard hit, with widespread destruction of shipping and communications. See Kocin (1983) for a meteorological analysis of the storm and Werstein (1960) and Caplovich (1987) for descriptive and photographic accounts of the storm.
26 – 27 November 1898. The “Portland Storm” was a rapidly developing system that yielded record early-season snowfalls from the Middle Atlantic States to New England, accompanied by high winds. New York and Boston received about 25 cm, which New London, Connecticut, measured 68 cm. The event was named for the S.S. Portland, which sand offshore of Cape Cod during the storm.
73 State of New Hampshire, Natural Hazards Mitigation Plan, Executive Summary: October 2000 Edition
12 – 14 February 1899. The “Blizzard of ‘99” formed along the leading edge of one of the greatest outbreaks of Arctic air ever experienced in the central and eastern United States. Snow fell from central Florida to Maine with 25- to 50-cm accumulations common from the Carolina to New England. See: Kocin et al. (1988) for a meteorological account of this episode.
TWENTIETH CENTURY
25-26 December 1909. The Christmas night storm produced heavy snow, high winds, and high tides throughout the Northeast. The snowfall of 53 cm in Philadelphia, Pennsylvania, was the greatest in modern records until 1983.
1 – 2 March 1914. This intense storm resulted in 30 to 60 cm of snow in Pennsylvania, New Jersey, and New York, along with high winds. The sea level pressure fell to 962 mb at New York City at the height of the storm, with near-hurricane-force winds and snow accumulations of 35 cm.
3 – 4 April 1915. A spring snowstorm produced accumulations of 25 to 50 cm throughout the Middle Atlantic States and southern New England with 48 cm at Philadelphia, Pennsylvania.
4 – 7 February 1920. This was a great snow and sleet storm that left an accumulation of 37 to 50 cm of ice, sleet, and snow in New York City and Boston, Massachusetts, stalling traffic for weeks.
27 – 29 January 1922. The “Knickerbocker Storm” affected the Middle Atlantic States on the 150th anniversary of the “Washington and Jefferson Storm.” Exceptionally heavy snow fell in Virginia and Maryland. 70 centimeters buried Washington, D.C., contributing to the collapse of the roof of the Knickerbocker Theatre where more than 100 people were killed.
19 – 20 February 1934. During the coldest February on record, this rapidly developing storm produced severe blizzard conditions throughout southern New England. This snowfall was one of Connecticut’s worst in modern times, with 50 cm accumulations, strong winds, and temperatures that dropped from near 0ºC to -15ºC during the course of the storm.
22 – 24 January 1935. This was a widespread storm that left snow accumulations of 30 cm or more from Pennsylvania northward through New England.
14 – 15 February 1940. The “St. Valentine’s Day Storm:” was a rapidly developing system that paralyzed Boston and the rest of New England with snow depths exceeding 30 cm and very high winds.
26 – 27 December 1947. A surprise snowstorm brought 65 cm, the heaviest 24-hour accumulation of snow in New York City’s modern records. Most of the snow actually fell within a 12-hour period. At White Plans, New York, 15 cm piled up in just 1 hour with 49 cm over a 6-hour span.
During the year s from 1955 through 1985, a number of winter storms have also attained historic stature in the Northeast. The blizzards of February 1958 and January 1966, the triple snowstorms of the 1960/1961 winter, the great New England wind and snowstorm of February 1978, the “Presidents’ Day Storm” of February 1979, and the paralyzing urban storm of February 1983 are the most notable events of this period.
74 State of New Hampshire, Natural Hazards Mitigation Plan, Executive Summary: October 2000 Edition
18-20 March 1956 Event Accumulations – southeastern New Hampshire – 10-15”
The heaviest snow occurred across the densely populated sections of eastern Pennsylvania, New Jersey, southeastern New York, and South New England.
14-17 February 1958 Event Accumulations – southeastern New Hampshire to 20” – western and central New Hampshire accumulations to 33”
The “Blizzard of ‘58” was a widespread storm that produced snow accumulation in excess of 25 cm form Alabama to Maine. Intense cold and high winds persisted after the snow ended, prolonging the severe effects of the storm.
Regions with snow accumulations exceeding 50 cm; eastern Pennsylvania, western and eastern New York, southern Vermont, eastern Massachusetts, and scattered areas of New Hampshire, Connecticut, New Jersey, and Maryland.
18-21 March 1958 Event Accumulations – up to 22” in south central New Hampshire and up to 24” in west central New Hampshire
Elevation played a very significant role in the snowfall distribution.
Regions with snow accumulations exceeding 50 cm: sections of north-central Maryland, eastern Pennsylvania, western New Jersey, and scattered areas of northern Virginia, northern Delaware, southeastern New York, Massachusetts, and New Hampshire.
2-5 March 1960 Event Accumulations up to 25” in south central and southeastern New Hampshire
Severe blizzard conditions occurred in eastern Massachusetts, as snow accumulations exceeded 50 to 75 cm and near-hurricane force winds battered the coast.
Regions with snow accumulations exceeding 50 cm: eastern Massachusetts, Rhode Island, and scattered areas of northern New Jersey, southeastern New York, Connecticut, and New Hampshire.
10-13 December 1960 Event Accumulations up to 17” in southeastern New Hampshire
This early-season storm was the first of three big snowstorms during the 1960/1961 winter season. Temperatures falling below -7º C created blizzard conditions across parts of the Middle Atlantic and New England States.
75 State of New Hampshire, Natural Hazards Mitigation Plan, Executive Summary: October 2000 Edition
18-20 January 1961 Event Accumulations up to 25” in southeastern and south-central New Hampshire The “Kennedy Inaugural Snowstorm” was the second of three major East Coast winter storms during the 1960/1961 season. Blizzard or near-blizzard conditions developed across the northeastern United States as the cyclone deepened rapidly offshore.
Regions with snow accumulations exceeding 50 cm: scattered parts of eastern Pennsylvania northern New Jersey, southeastern New York, northwestern Connecticut, northeastern Massachusetts, and southern New Hampshire.
2-5 February 1961 Event Accumulations up to 18” across southern New Hampshire
The third major snowstorm of the 1960/1961 winter season occurred at the end of one of the more prolonged cold spells experienced across the northeastern United States. It produced near-record snow cover in the major metropolitan areas since snow fell on unmelted accumulations from the previous storms. This storm also produced paralyzing gale- to hurricane-force winds on the coast, with wind gusts of 43 m s –1 at Blue Hill Observatory, Milton, Massachusetts. Temperatures rose to near freezing during the storm, producing heavy, wet snow accumulations along the cost.
11-14 January 1964 Event Accumulations up to 12” in southern and central New Hampshire
This system was a large, slow-moving storm that produced severe winter weather through much of the central and eastern United States. Blizzard conditions prevailed throughout the Middle Atlantic States and southern New England, as temperatures fell below -7º C and winds speeds increased to greater than gale force.
29-31 January 1966 Event Accumulations up to 10” across central New Hampshire
This storm is referred to as the “Blizzard of ’66” The storm was the third and most severe in a series of three snowstorms that occurred over a 10-day period along the Middle Atlantic Coast.
23-25 December 1966 Event Accumulations up to 15” in western central New Hampshire
This case is notable as a Christmas Eve snowstorm, which deposited heavy snow over a wide area extending from the southern Plans states to New England.
An intriguing aspect of this storm was the numerous reports of thunderstorms with heavy snow from the Middle Atlantic States to New England.
5-7 February 1967 Event Accumulations up to 13” in southeastern New Hampshire
Snowfall was produced from two separate low-pressure systems. The first cyclone produced a narrow band of snow across the northern Middle Atlantic States and southern New England, with accumulations generally less than 10 cm. It also ushered very cold air into New England and the Middle Atlantic States. The second storm produced heavy snowfall rates, but for a relatively short duration. As this storm moved rapidly northeastward along the East coast, blizzard conditions
76 State of New Hampshire, Natural Hazards Mitigation Plan, Executive Summary: October 2000 Edition developed across the middle Atlantic and southern New England states.
8-10 February 1969 Event Accumulations up to 27” in southeastern New Hampshire and up to 42” in northeastern New Hampshire
The rapid development and deceleration of the storm brought paralyzing snow and increasing winds from northern New Jersey through most of New England.
Regions with snow accumulations exceeding 50 cm: parts of the New York City and Boston metropolitan areas, western Connecticut, western and eastern Massachusetts, southern Vermont, northern Rhode Island, eastern New Hampshire, and southern Maine.
22-28 February 1969 Events Accumulations to 98” in Western Central New Hampshire, 34” in coastal areas and 2 to 3’ across New Hampshire generally
This was an unusual storm due to its slow movement, long duration, moderate intensity, erratic intensification, lack of large thermal contract at the surface, and chaotic upper-level geopotential height patterns. The storm produced excessive amounts of snow across New England with accumulations of greater than 75 cm across large sections of eastern Massachusetts, New Hampshire, and Maine.
25-28 December 1969 Event accumulations to 41” in Western Central New Hampshire and 12–18” generally
This storm was a near-miss for the large cities of the northeastern United States as heavy snow turned to rain (and back to snow in many areas). This system is one of the heaviest snowstorms on record for eastern and northern New York. Accumulations of greater than 50 cm covered a wide area of central and eastern New York into northwestern New England.
77 State of New Hampshire, Natural Hazards Mitigation Plan, Executive Summary: October 2000 Edition
18-20 February 1972 Event accumulations to 21” in southeastern New Hampshire, 14-19” in southern New Hampshire and 15-19” in Northeastern New Hampshire
This storm was another near miss for the major cities as the heaviest snow fell immediately to their west and north. This storm was one of the few to pose a threat of heavy snow in the Northeast urban corridor during the early and middle 1970s. Strong easterly winds and rough seas caused significant damage along the Middle Atlantic and New England costs.
19-21 January 1978 Events accumulations to 16” in southern and central New Hampshire
For many of the urban centers that span the northeastern United States, this was the most debilitating snowstorm since 1969. This storm was the last in a series of three, during a week that produced a variety of winter weather conditions across the Northeast.
The storm was accompanied by wind gusts exceeding 20 m s-1 from New Jersey to the New England coast.
5-7 February 1978 Events accumulations to 28” in northeast New Hampshire, 25” in west central New Hampshire and 33” along coastal New Hampshire
Hurricane-force winds and record-breaking snowfall made this storm one of the more intense to occur this century across parts of the northeastern United States.
Despite accurate predictions, many people were stranded on the roads in the New York City area because the onset of heavy snow occurred slightly later than predicted during the Monday morning rush hour. People were generally skeptical of the warnings issued by operational weather forecasters following a series of inaccurate forecasts of winter weather during the preceding month. The most severely affected regions were Long Island, Connecticut, Rhode Island, and Massachusetts, where business and schools were shut down for a week or more.
Regions with snow accumulations exceeding 50 cm: sections of northeastern Pennsylvania, northern New Jersey, western and southeastern New York, Connecticut, Rhode Island, Massachusetts, southern Vermont, and parts of New Hampshire and Maine.
5-7 April 1982 Event accumulations to 22” in coastal New Hampshire and to 18” over southern and central New Hampshire
This unusual late-season storm produced near-blizzard conditions over much of Pennsylvania, New York, and New England.
Thunderstorms with frequent lightning were reported in New York City during the heaviest snowfall. The storm was followed by one of the coldest air masses on record for April. The temperature at Boston, Massachusetts, remained near -10ºduring the afternoon of 7 April.
Regions with snow accumulations exceeding 50 cm: scattered portions of New York, southern Vermont, northeastern Massachusetts, and southeastern New Hampshire.
78 State of New Hampshire, Natural Hazards Mitigation Plan, Executive Summary: October 2000 Edition
10-12 February 1983 Event accumulations to 20” in extreme southeastern New Hampshire
This snowstorm was one of many cyclones to affect the eastern United States during a winter that was unusually warm and stormy, but it was one of the few storms accompanied by temperatures cold enough for snowfall.
The 24-hour snowfalls at Philadelphia, Pennsylvania, Harrisburg, Pennsylvania, Allentown, Pennsylvania, and Hartford, Connecticut, were the greatest on record. For many other cities, this was one of the heaviest snowstorms on record. Accumulations reach 75 cm in parts of northern Virginia, western Maryland, and the panhandle of West Virginia. Winds were still high enough to create blizzard or near- blizzard conditions from eastern Pennsylvania and North Delaware to Massachusetts.
79 State of New Hampshire, Natural Hazards Mitigation Plan, Executive Summary: October 2000 Edition
Ice Storm
(See Map on the preceding page)
When a mass of warm moist air collides with a mass of cold Arctic air, the less dense warm air will rise and the moisture may precipitate out in the form of rain. When this rain falls through the colder more dense air and comes in contact with cold surfaces, the latent heat of fusion is removed by convective and/or evaporative cooling. Ice forms on these cold surfaces and may continue to form until the ice is quite deep, as much as several inches. Ice Storm photos (including cover) courtesy of Judy and Gregg Champlin
This condition may strain branches of trees, powerlines and even transmission towers to the breaking point and often creates treacherous conditions for highway travel and aviation.
No twithstanding the unique beauty of such events, the weigh t of formed ice (especially with a following wind) may cause power and phone lines to snap and the towers that suppo rt them to fail under the load of ice and/or bending or broken tree limbs.
De bris impacted roads make emergency access, repair and cleanup extremely difficult.
Th e recent Ice Storm of January 1998 was not unique in either its spatial scope or its devastating consequences. A similar event in 1929 is believed to have been comparable to Recent History of Significant this event. New Hampshire Ice Storms The U.S. Army Corps of Engineers, Cold Regions (New Hampshire damages only) Research and Engineering Laboratory estimates a 40 – 90 year return period for an event with a uniform ice thickness January 7, 1998 FEMA DR-1199-NH 52 communities in nine counties impacted, six injuries and one fatality, of bet ween .75 and 1.25 inches. Other events with similar 20 major roads closures, 67,586 without electricity, accum ulations and smaller spatial ranges have been recorded 2,310 without phone service, one communication tower failure, since 1929 (See Plan: Winter Weather Related Hazards Section $17+ million in damages to Public Service of NH alone. IV, Appendix D, page 50 for a more complete Ice Storm (See Map on the preceding page) Histor ical Overview). http://www.crrel.usace.army.mil/valliere/CRREL_Reports MARCH 3-6, 1991 _web/reports/IceStorm98.pdf Numerous outages from ice-laden power lines in southern NH
FEBRUARY 14-15, 1986
Return Periods for Large Ice Loads Fiercest ice storm in 30 years over higher elevations e
c An (In Years) in the Monadnock Region in 10-mile-wide swath
from the MA border to New London om Uniform Upstate Coastal & s Mulherin
1998 I Ice New York Central JANUARY 8-25, 1979 Thickness And Maine Major disruptions to power and transportation
the Jan is taken fr e (in.) NW Vermont And New DECEMBER 22, 1969-JANUARY 17, 1970 CRREL, Jone ity of Hampshire Power disruption to many communities 0.5 15 5
land Sever g esented her 0.75 35 20 DECEMBER 29-30, 1942
the Glaze storm of severe intensity 1.0 65 40
Data pr 1.25 100 85 in New En DECEMBER 17-20, 1929 Unprecedented disruption and damage to aluation of bular 1.5 145 160 v a telephone,telegraph and power system T E Storm (From CRREL report: Evaluation of the 1998 Ice Storm) 80 State of New Hampshire, Natural Hazards Mitigation Plan, Executive Summary: October 2000 Edition The avalanche path is described as having three specific “Transition Zones;” *
*Snow Avalanches The Starting Zone is generally located near the top of the ridge, bowl or canyon with “A snow avalanche is a slope failure consisting of a steep slopes of 25 to 50 Degrees; mass of rapidly moving, fluidized snow that slides The Track Zone is the reach with mild down a mountainside. The flow can be composed of slopes of from 15 to 30 degrees and the area ice, water, soil, rock and trees.” * where the avalanche will achieve maximum
velocity and considerable mass; and “The amount of damage depends on the type of avalanche, the composition and consistency of the The Runout Zone is the gentler slopes of material contained in the avalanche, the velocity and from 5 to 15 degrees located at the base of the force of the flow and the avalanche path.” * path where the avalanche decelerates and massive snow and debris deposition occurs.
“Natural and human induced Snow Avalanches most often result from structural
weaknesses. They are caused by changes in the type and thickness of the snow cover
layer resulting from thermal fluctuations or multiple snowfall events. The potential for Snow Avalanches increases with significant temperature influences, which cause
metamorphic crystal change in the snow layer, and with the accumulation of dry and wet snow over time.” *
Snow Avalanches occur on slopes averaging from 25 to 50 degrees, the majority occurring on slopes of from 30 to 40 degrees. They are triggered by natural events such as thermal changes, blizzards, and seismic activity and by human activity such as that of skiers, hikers, snowmobilers, and elastic sound waves such as those created by explosions.*
One of the more common related hazards in New Hampshire is the formation of ice slabs which fall from cornices. The dynamic loading from these events may trigger an avalanche and/or may directly
impact upon persons In the vicinity of the fall (See Plan: Winter Weather Related Hazards, Section
IV., Appendix B.).**
“At the point the shear forces of the overburdened upper layer overcome the resistant forces of the underlayer, the mass slips and begins sliding downslope. The intensity and impact of the resultant avalanche depends on the volume of snow accumulated in the upper layer, the density of the material, the slope of the starting area, the avalanche path and the runout zone at the bottom of the slope.” *
The more common “dry snow” and “shear” avalanche events can reach speeds of from 45 mph to 157 mph depending on the vertical fall distance. However, it is the slower moving “wet” avalanche (from 22 mph to 78 mph) which may have the potential to be the more destructive given the weight of the snow and accumulated debris.*
NH Snow Avalanche Hazard Mitigation Strategies The State will support cost effective Avalanche Hazard Mitigation measures including:
¾ Hazard related public education and warning, ¾ Hazard Mitigation related zoning, ¾ Evacuation and, ¾ Controlled artificial release programs (as necessary)
*The editor has drawn heavily for this Section from FEMA publication, Multi Hazard, Identification and Risk Assessment (specifically, from Chapter 6 for this hazard type).
81 State of New Hampshire, Natural Hazards Mitigation Plan, Executive Summary: October 2000 Edition
Snow Avalanche Vulnerability Snow Avalanche Websites to Visit
in New Hampshire
Northwest Weather Snow Avalanches are not considered a major and Avalanche Center natural hazard nationally given the relatively limited http://www.nwac.noaa.gov/ geographic areas vulnerable to the effects of this type
of event, the proximity of population centers to Cyberspace Snow and vulnerable areas and the seasonal nature of the Avalanche Center – CSAC vulnerability in most regions (See Map below: “Areas http://www.csac.org/ Exposed to High Snow Avalanche Risk”*)
http://www.csac.org/Incidents/ However, Northern New Hampshire is an area (New Hampshire Event- 1998/99)** with particularly vulnerable areas (See Map below).
Over the past 140 years, at least 10 deaths** and many The American Association of significant injuries have been documented in the Avalanche Professionals (AAAP) Presidential Range and elsewhere due to snow http://www.avalanche.org/~aaap/ avalanches and related causes (See Plan: Winter
Weather Related Hazards Section IV., Appendix B.). The Canadian Avalanche ** As noted elsewhere, the terms “Vulnerability” Association (CAA) and “Risk” are often used interchangeably (See page 84). http://www.avalanche.ca/
US Avalanche Vulnerability (Source: Personal Communications, Knox Williams, 1995)
FEMA Publication, Multi Hazard Identification and Risk Assessment 82 State of New Hampshire, Natural Hazards Mitigation Plan, Executive Summary: October 2000 Edition NH Strategic Winter Weather Related Hazards Mitigation Plan Overview (See Appendix of specific Goals, Objectives and Mitigation Measures)
¾ Develop the State’s Winter Weather Forecasting and Warning systems to their fullest potential (interface all with the National Weather Service in real time as practical) ¾ Support the enhancement of the NHOEM Communications Capability ¾ Support the EAS and NOAA Weather Radio Signal expansion ¾ Continued support of the position of Hazard Mitigation Officer/Protection Planner with DPIG and MAP funding ¾ Continued support of the Position of Natural Hazards Program Officer with MAP funding ¾ Continued (and expanded where indicated) ) support of the Dam Safety Program ¾ Identify and assess the State’s Critical Facilities as may be subject to Winter Weather Hazards ¾ Identify and assess the State’s Critical Infrastructure subject to Winter Weather Hazards ¾ Support cost effective Hazard Mitigation measures to harden the State’s Critical Facilities, roads and other infrastructure with funding from HMGP, FMAP Project Impact, and CDBG ¾ Support Flood (River Ice Related) Hazard Mitigation Planning and programs with funding from FMAP, DPIG, MAP, Project Impact, HMGP, and CDBG ¾ Support Project Impact ¾ Support the Pemi River Project ¾ Extend lessons learned and milestones achieved with the Pemi River Project to all NH communities with similar needs ¾ Support Development of local Winter Weather Hazards Mitigation planning vis a vis: - Flood Mitigation Assistance Program - Project Impact Hazard Mitigation Planning - Development of a Planning Guide for NH Communities - NFIP CAVs - Distribution of Planning Guides ¾ Support CEMPS Program with MAP funding ¾ Support State and local officials with Emergency Preparedness, Response and Recovery training ¾ Continued support of Non-Commercial Service Announcements ¾ Orient State and local officials as to cost effective Winter Weather Hazards Mitigation measures. ¾ Support and/or Provide Communities with related Technical Assistance ¾ Produce and/or distribute informational materials going to cost effective Winter Weather Related Hazards Mitigation ¾ Support the production of workshops to educate State and local officials as to cost effective Winter Weather Hazards Mitigation Strategies and Measures ¾ Investigate the feasibility and desirability of enhancing State and/or local building codes and land use codes as pertain to Snow and Ice load Hazards Mitigation ¾ Support research as may be useful in Winter Weather Hazards Mitigation Planning in the areas of climate, meteorology, demographics, economics, forestry, agriculture, fish and wildlife etc., going to the impact upon New Hampshire of Winter Hazards related events. ¾ Support the State of New Hampshire Division of Historical Resources in protecting the State’s Historical and Archaeological treasures ¾ Support the New Hampshire Coastal Program in Nor’easter Mitigation activities and in the preservation of the State’s marine, and adjacent environments
83 State of New Hampshire, Natural Hazards Mitigation Plan, Executive Summary: October 2000 Edition
Vulnerability (= Exposure to a Given Natural or Man-made Hazard)
Inorganic Organic
Linear Objects: Fauna: ⇒ Aviation Facilities; Airports ⇒ Human Beings ⇒ Navigation Facilities; Ports, Docks, etc. ⇒ Livestock ⇒ Roads and Bridges ⇒ Pets ⇒ Railroads and Railbeds ⇒ Wildlife ⇒ Dams and Spillways ⇒ Zoo Creatures ⇒ Power and/or Fuel ⇒ Aquaculture Distribution Systems Risk
Flora: Point Objects: Commercial: ⇒ Hospitals, Schools, Prisons, ⇒ Agriculture ⇒ Fire, Police, EOC’s etc. ⇒ Forestry ⇒ Power Plants Products ⇒ Public Buildings ⇒ Sugarbush ⇒ Nursing Homes Natural: ⇒ Office Buildings ⇒ Forests
⇒ Archaeological sites ⇒ Dune Grass
RISK ANALYSIS Understanding Risk
The concepts of “Risk” and “Vulnerability” may require some distinction. Vulnerability refers to the possible exposure to the hazard and, Risk refers to the potential harm from the exposure. The graphic above illustrates the relationship between hazards, vulnerability, exposure (e.g. as associated with location) and ultimate risk.
Risk analysis often refers to estimates of the total population and property exposed to a given hazard at any given time. As few strategies exist which can isolate an entire population and its potential losses from most risks associated with natural hazards, concepts going to “acceptable levels of risk” are often contemplated.
In analyzing Risk, the probability of an event occurring and the potential for damage or destruction are weighed. The magni tude of past events may offer a moderately reliable measure for predicting future occurrences, depending on the scope, depth (e.g., over time) and reliability of the data.
When changes in population and exposed property (improved or unimproved) are considered, the potential risk in terms of injur y or loss of life and damage to, or destruction of property may be estimated with some degree orf reliability. Such assessments are subjective and inexact, but are tailored in accordance with the best probabilistic data available.
Altho ugh responsibility for planning, mitigation, response and recovery functions associated with natural disasters fall upon various levels of government, natural disasters do not conform nor confine themselves to our geo-politically defined border s. This reality, coupled with the relatively unpredictable nature of such events, necessitates that a principle focus with respect to Hazard Mitigation must lie in public education, training, and preparedness.
Next, a focus on making our structures more resistant to these hazards, removing them from harm’s way or inhibiting their construction in vulnerable areas (such as the Floodplains, or downslope of Snow Avalanche or possible Landslide sites) is indicated.
84 State of New Hampshire, Natural Hazards Mitigation Plan, Executive Summary: October 2000 Edition
New Hampshire Population by County Census Data to 1990, Estimates From 1990 to 2020
Counties / Year 1960 1970 1980 1990 2000 2005 2010 2015 2020 Belknap 28,912 32,367 42,884 49,216 53,753 56,142 57,524 60,433 62,847 Carroll 15,829 18,584 27,931 35,410 41,088 44,865 47,620 51,580 56,057 Cheshire 43,342 52,364 62,116 70,121 73,989 76,805 77,885 80,002 82,605 Coos 37,140 34,291 35,147 34,828 35,442 35,500 35,354 35,389 35,000 Grafton 48,857 54,914 65,806 74,929 80,800 82,796 83,657 85,135 87,585 Hillsborough 178,161 223,941 276,608 336,073 374,177 398,804 414,767 440,691 466,971 Merrimack 67,785 80,925 98,302 120,005 130,476 137,323 141,326 148,327 156,116 Rockingham 99,029 138,951 190,345 245,845 285,142 313,077 335,203 367,621 400,848 Strafford 59,799 70,431 85,408 104,233 113,409 119,451 122,431 128,048 134,249 Sullivan 28,067 30,949 36,063 38,592 40,521 41,874 42,979 44,448 45,600 New Hampshire 606,921 737,717 920,610 1,109,252 1,228,797 1,306,637 1,358,746 1,441,674 1,527,878
Data courtesy of New Hampshire Office of State Planning Publication April 16,1997
The Chart above indicates that New Hampshire’s population nearly doubled from 1960 to 1990. As is indicated in the graphs below, the rate of growth in 4 of the 5 most heavily populated counties is expected to continue to increase albeit, at a decreasing rate. As has been demonstrated above, the entire State is at Risk from all hazards identified, with the exception of Avalanche and Tsunami in most areas. Rockingham County for example, is at significant risk from Flooding, Seismic activity (both from the Ossipee and Cape Ann epicenters, including Tsunami incidents in the Coastal Zone), Tornadic activity and Hurricane Impact. River Ice is less an issue for these communities than in many other areas of the State.
Hazard Mitigation Planning must account for critical facilities and infrastructure as well as people in harm’s way. At the time of the submission of this Summary of the Plan, the State has no systematic evaluation of its critical facilities nor its critical infrastructure. The SHMO shall endeavor to facilitate such inventories and analyses immediately and, is expected to have meaningful programs in place to create and catalogue such inventories and perform assessments within the year (See HAZUS database statistics on page 88).
NH Population Change 1960-1997 By County
400000
350000
300000
250000 Hillsborough
200000 Merrimack Rockingham
Population 150000 Strafford 100000 Sullivan 50000
0 12345 1960 1970 1980 1990 1997
85 State of New Hampshire, Natural Hazards Mitigation Plan, Executive Summary: October 2000 Edition
NH Population Change 1960-1997 By County
90000 80000 70000 Grafton 60000 Cheshire 50000 Belknap 40000 Coos Population 30000 Carroll 20000 10000 0 12345 1960 1970 1980 1990 1997
In all but one New Hampshire County, the population has risen during the period from 1960 to 1967 (the exception being Coos). In all but two New Hampshire counties, the rise has been such that the population has nearly doubled or has exceeded that increase significantly.
The overall population trend for the State follows the trend in the majority of the counties.
Population Change 1960-1997 New Hampshire
1500000
1000000 New Hampshire 500000 Population 0 12345 1960 1970 1980 1990 1997
(NH Population data and graphs courtesy of James McLaughlin of the NHOSP)
86 State of New Hampshire, Natural Hazards Mitigation Plan, Executive Summary: October 2000 Edition
County Population (NH OSP Estimates: Year 2000)
BELKNAP 53,753
CARROLL 41,088
CHESHIRE 73,898
COOS 35,442
GRAFTON 80,800
HILLSBOROUGH 374,177
MERRIMACK 130,476
ROCKINGHAM 285,142
STRAFFORD 113,409
SULLIVAN 40,521 ______NEW HAMPSHIRE 1,228,757
87 State of New Hampshire, Natural Hazards Mitigation Plan, Executive Summary: October 2000 Edition
HAZUS NEW HAMPSHIRE ESSENTIAL FACILITY NUMBERS (Source: FEMA HAZUS Data Base) An abbreviation for MEDICAL “Hazards U.S.” COUNTIES COUNTY # EMERGENCY SCHOOLS CARE HAZUS is a loss BELKNAP 33001 1 33 34 estimation computer CARROLL 33003 2 35 25 program with data CHESHIRE 33005 4 27 69 COOS 33007 3 28 36 layers of facilities in each State. It was GRAFTON 33009 6 48 77 HILLSBOROUGH 33011 10 66 244 developed with MERRIMACK 33013 4 53 89 FEMA funding, to ROCKINGHAM 33015 8 75 149 assist in anticipating STRAFFORD 33017 3 34 58 the effects of SULLIVAN 33019 3 23 43 hazardous events. STATE TOTALS 44 422 824
Critical Facilities
As of the preparation of this Plan, the SHMO has convened with various parties to discuss the desirability and feasibility of conducting a systematic inven tory of critical facilities statewide as well as an assessm ent as to their relative condition with respect to loads from seismic, wind, snow and flood events.
A proposal to survey all of the structures identified above (and amend the list as indicated) has been favorably review by the State’s Hazard Mitigation Team and FEMA has approved a portion of that project as a 5% initiative. It is intended that this data will be organized and recorded in a manner that will enhance FEMA’s HAZUS risk modeling. The State will su pplement this inventory with Disaster Relief Initiative funding accruing from DR-1199 in a joint project with the University of NH.
Public Utilities
Due to schedul ing difficulties, the SHMO has yet to convene with representatives from the Utilities community. The SHMO shall convene such relevant parties within th e year and include such issues as are identified pursuant to those meetings in the annual update of the Plan
Local Planners are encouraged include considerations as to the utilities systems in their respective areas. Planners should contact the Public Utilities Commission for further information as to the locations of power production facilities, transmission facilities,. fuel distribution pipelines etc. 88 State of New Hampshire, Natural Hazards Mitigation Plan, Executive Summary: October 2000 Edition
New Hampshire Natural Hazards Vulnerability Overview by County
County Section I Section II Section III Section IV Flood/Drought/Wildfire Geologic Severe Wind Winter
Hazard Type Flood StrmSrge Tsunami Drght Ex Heat W/Fire Equake Ldslide Subsid Radon Tornado Hurri Nor’Est D’nbrst Light’g Hail HvySnow IceStrm Avlnche
BELKNAP H N N M M H M+ L L M M M H M M M H H L
CARROLL H N N M L H M+ M L H M M H M M M H H H
CHESHIRE H N N M M H M M L M H M H M M M H H L
COOS H N N M L H M+ H L H M L H M M M H H H
GRAFTON H N N M M H M M L M M L H M M M H H L
HILLSBOROUGH H N N M M H M+ M L M H M H M M M H H L
MERRIMACK H N N M M H M+ M L M H M H M M M H H L
ROCKINGHAM H H M M M H M+ M L H H H H M M M H H N
STRAFFORD H L L M M H M+ M L H M H H M M M H H L
SULLIVAN H N N M M H M M L M M M H M M M H H L
Vulnerability Code: H = High M = Moderate L = Low N = None
89 State of New Hampshire, Natural Hazards Mitigation Plan, Executive Summary: October 2000 Edition
BELKNAP COUNTY RISK ANALYSIS: 1999 Estimated Population – 53,753
Flooding: The County lies in the upper central portion of the Merrimack River Watershed. Flooding is experienced along the Pemigewasset River on its eastern border and within the Winnipesaukee Lake basin and the Winnipesaukee River and connecting lakes. The Winnipesaukee River drains Lake Winnipesaukee passing through the heart of downtown Laconia through Lake Winnisquam, Hutkins Pond, Silver Lake in Tilton, bifurcating Tilton and Northfield and emptying into the Merrimack.
River Ice: Effects of “Shove Ice” from lake forming ice are more a threat to property in this county than the effects of River Ice per se. The large lakes in the area form ice seasonally which may impact upon docks, wharfs, boathouses and nearby roads, bridges, culverts and other infrastructure (See page 16 and page 122 - CRREL Resourse Profile for contact information for event specifics).
Drought: The County was impacted by the Drought event of the 1960’s, as was the rest of the State. The county hosts significant agricultural and livestock assets that are negatively impacted by such events. At the time of the preparation of this Plan, the editor has located no specific data as to the losses from Drought events for this county.
Extreme Heat: At the time of the submission of this Plan, the editor was unable to locate any county specific data with respect to this hazard type. Additional research is ongoing (See Concord data, page 33).
Wildfire: Significant debris remains in the forests from the 1998 event. Aside from the data presented in Section I of this Plan, the editor was unable to locate any county specific data with respect to this hazard type. Additional research is ongoing.
Earthquake: New Hampshire lies in a zone of Moderate seismic vulnerability generally. The county is in an area of particularly high seismicity that is evident in a crescent of historical events beginning in the Ossipee Range and following the general contour of the Merrimack River Valley (See Section II., page 38 of this document).
Landslide: At the time of the submission of this Plan, the editor was unable to locate any county specific data with respect to this hazard type. Additional research is ongoing.
Subsidence: Communities such as Laconia and Meredith, which were industrialized in the nineteenth century, have underground canals to facilitate hydro-mechanical power to those preexisting mills. As of the writing of this Plan, the editor was unable to locate any loss data with respect to this hazard type.
Radon: From available data, it would appear that Radon is a Moderate risk in this county (See page 52 for more details).
Tornadic Activity: As may be gleaned from the data presented on page of this document, the county has experienced one known F2 event in the recent past (7/3/1972). The compilation of data from www.tornadoproject.com lists a total of 5 tornadic events (all additional are F 1 events) from 6/24/1960 to 7/23/1995.
Hurricane: The County has experienced high winds from some hurricane events but is at a more significant risk to flooding from the associated rainfall from hurricanes.
Nor’easter: At the time of the submission of this Plan, the editor was unable to locate any county specific data with respect to this hazard type. Additional research is ongoing.
Downburst: At the time of the submission of this Plan, the editor was unable to locate any county specific data with respect to this hazard type. Additional research is ongoing.
Lightning: At the time of the submission of this Plan, the editor was unable to locate any county specific data with respect to this hazard type. Additional research is ongoing.
Hail: At the time of the submission of this Plan, the editor was unable to locate any county specific data with respect to this hazard type. Additional research is ongoing.
Heavy Snow: At the time of the submission of this Plan, the editor was unable to locate any county specific data with respect to this hazard type. Additional research is ongoing. See pages 71 – 79 for a Regional overview of the State’s exposure.
Ice Storm: Significant debris remains in the forests from the 1998 event. During the recent 1998 Ice Storm, the only failure of a communications tower was in Belknap County. At the time of the submission of this Plan, the editor was unable to locate any county specific data with respect to this hazard type. Additional research is ongoing..
90 State of New Hampshire, Natural Hazards Mitigation Plan, Executive Summary: October 2000 Edition
CARROLL COUNTY RISK ANALYSIS: 1999 Estimated Population – 41,088
Flooding: In the Southern area of the county is Lake Winnipesaukee that feeds the Merrimack River watershed. The remainder of the county subsumes the Saco River Watershed, nearly in its entirety. Extremely large amounts of rainfall have been recorded in the mountainous areas of the county that contributes to the “flashy” nature of the flooding in the Saco and its tributaries. During the DR-1231-NH event of June-July 1998, the Ossipee Lake was reported to have risen 5 feet, the resulting floodwaters threatening the lake’s dam.
River Ice: Effects of “Shove Ice” from lake forming ice are more a threat to property in the Southern part of this county. The large lakes in the area form ice seasonally which may impact upon docks, wharfs, boathouses and nearby roads, bridges, culverts and other infrastructure. The Rivers to the North are vulnerable to River Ice conditions. Erosion accelerated by the destabilizing effects on riverbanks is a significant issue all along the Saco and other of the State’s Rivers (See page 16 and page 122 - CRREL Resourse Profile for contact information for event specifics).
Drought: The County was impacted by the Drought event of the 1960’s, as was the rest of the State. The county hosts significant agricultural and livestock assets that are negatively impacted by such events. At the time of the preparation of this Plan, the editor has located no specific data as to the losses from Drought events for this county.
Extreme Heat: At the time of the submission of this Plan, the editor was unable to locate any county specific data with respect to this hazard type. Additional research is ongoing (See Concord data, page 33).
Wildfire: Significant debris remains in the forests from the 1998 event. Aside from the data presented in Section I. of this Plan, the editor was unable to locate any county specific data with respect to this hazard type. Additional research is ongoing.
Earthquake: New Hampshire lies in a zone of Moderate seismic vulnerability generally. The county is in an area of particularly high seismicity that is evident in a crescent of historical events beginning in the Ossipee Range and following the general contour of the Merrimack River Valley (See Section II., page 38 of this document).
Landslide: At the time of the submission of this Plan, the editor was unable to locate any county specific data with respect to this hazard type. Additional research is ongoing.
Subsidence: At the time of the submission of this Plan, the editor was unable to locate any county specific data with respect to this hazard type. Additional research is ongoing.
Radon: From available data, it would appear that Radon is a relatively High risk in this county (See page 52 for more details).
Tornadic Activity: As may be gleaned from the data presented on page of this document, the county has experienced one known F2 event in the recent past (7/18/1963). The data from www.tornadoproject.com lists a total of 7 tornadic events (all additional are F 1 or less events) from 7/18/1986 to 8/7/1986.
Hurricane: The County has experienced high winds from some hurricane events but is at amore significant risk to flooding from the associated rainfall from hurricanes.
Nor’easter: At the time of the submission of this Plan, the editor was unable to locate any county specific data with respect to this hazard type. Additional research is ongoing.
Downburst: At the time of the submission of this Plan, the editor was unable to locate any county specific data with respect to this hazard type. Additional research is ongoing.
Lightning: At the time of the submission of this Plan, the editor was unable to locate any county specific data with respect to this hazard type. Additional research is ongoing.
Hail: At the time of the submission of this Plan, the editor was unable to locate any county specific data with respect to this hazard type. Additional research is ongoing.
Heavy Snow: At the time of the submission of this Plan, the editor was unable to locate any county specific data with respect to this hazard type. Additional research is ongoing. See pages 71 – 79 for a Regional overview of the State’s exposure.
Ice Storm: Significant debris remains in the forests from the 1998 event. At the time of the submission of this Plan, the editor was unable to locate any county specific data with respect to this hazard type. Additional research is ongoing.
91 State of New Hampshire, Natural Hazards Mitigation Plan, Executive Summary: October 2000 Edition
CHESHIRE COUNTY RISK ANALYSIS: 1999 Estimated Population – 73,989
Flooding: The county in the Southwestern corner of the State and is bounded by the Connecticut River to the West. The City of Keene lies in the center of the county and encompasses a significant area of the floodplain of the upper Ashuelot River. The Ashuelot also contributes to flooding in the towns of Winchester and Hinsdale
River Ice: River Ice related flooding along the Connecticut is a periodic issue in Chesterfield among others. Erosion accelerated by the destabilizing effects on riverbanks is a significant issue all along the Connecticut and other of the State’s Rivers. Additionally, River Ice may directly impact upon docks, wharfs, boathouses and nearby roads, bridges, culverts and other infrastructure (See page 16 and page 122 - CRREL Resourse Profile for contact information for event specifics).
Drought: The County was impacted by the Drought event of the 1960’s, as was the rest of the State. The county hosts significant agricultural and livestock assets that are negatively impacted by such events. At the time of the preparation of this Plan, the editor has located no specific data as to the losses from Drought events for this county.
Extreme Heat: At the time of the submission of this Plan, the editor was unable to locate any county specific data with respect to this hazard type. Additional research is ongoing. It should be noted here that the highest high temperature recorded in neighboring Massachusetts was higher than the highest highs of either Miami Fla., or Atlanta Ga. (See Concord data, page 33).
Wildfire: Aside from the data presented in Section I. of this Plan, the editor was unable to locate any county specific data with respect to this hazard type. Additional research is ongoing.
Earthquake: New Hampshire lies in a zone of Moderate seismic vulnerability generally.
Landslide: At the time of the submission of this Plan, the editor was unable to locate any county specific data with respect to this hazard type. Additional research is ongoing. Some land formations along the Connecticut are generally considered to be conducive to landslide activity.
Subsidence: Communities such as Keene, which was industrialized in the nineteenth century, have underground canals to facilitate hydro-mechanical power to those preexisting mills. As of the writing of this Plan, the editor was unable to locate any loss data with respect to this hazard type.
Radon: From available data, it would appear that Radon is a Moderate risk in this county (See page 52 for more details).
Tornadic Activity: Risk from tornadoes is considered to be high in this county. As may be gleaned from the data presented on page of this document, the county has experienced 5 known F2 events in the past. The compilation of data from www.tornadoproject.com lists a total of 13 tornadic events (all additional are F 1 or less events) from 8/27/1959 to 5/31/1991.
Hurricane: The County has experienced high winds from some hurricane events but is at a more significant risk to flooding from the associated rainfall from hurricanes. The 1938 event devastated this county that received a direct hit.
Nor’easter: At the time of the submission of this Plan, the editor was unable to locate any county specific data with respect to this hazard type. Additional research is ongoing.
Downburst: At the time of the submission of this Plan, the editor was unable to locate any county specific data with respect to this hazard type. Additional research is ongoing.
Lightning: At the time of the submission of this Plan, the editor was unable to locate any county specific data with respect to this hazard type. Additional research is ongoing.
Hail: At the time of the submission of this Plan, the editor was unable to locate any county specific data with respect to this hazard type. Additional research is ongoing.
Heavy Snow: At the time of the submission of this Plan, the editor was unable to locate any county specific data with respect to this hazard type. Additional research is ongoing. See pages 71 – 79 for a Regional overview of the State’s exposure.
Ice Storm: Significant debris remains in the forests from the 1998 event. At the time of the submission of this Plan, the editor was unable to locate any county specific data with respect to this hazard type. Additional research is ongoing.
92 State of New Hampshire, Natural Hazards Mitigation Plan, Executive Summary: October 2000 Edition
COOS COUNTY RISK ANALYSIS: 1999 Estimated Population – 35,442
Flooding: The county is divided North to South with the Connecticut River watershed to the West and the Androscoggin River Watershed to the East. The Connecticut River borders the county from its Southwestern most tip to the Canadian Border (near Stewartstown) where it is then bordered by the forests of the Province of Quebec, which also borders it to the North. In the West, it is bordered by the forests of Maine. The White Mountains to the South receive considerable amounts of rainfall and the snowpack which forms in both the high and mid elevations may present a significant flood hazard seasonally. The weather patterns north of the White Mountains may vary considerably from the rest of the State and this has led to significant losses from flooding which have gone “undeclared” as they were not in synchronicity with the Declared losses in the Southern areas of the State. Such was the case surrounding the recent DR-1231-NH Declared event.
River Ice: Flooding from River Ice is a significant issue throughout this county and effects of flooding as well as direct impacts on structures have been recorded in Lancaster, from the Israel River and in Gorham, from the Androscoggin, Moose and Peabody Rivers among other areas. Erosion accelerated by the destabilizing effects on riverbanks is a significant issue. (See page 16 and page 122 - CRREL Resourse Profile for contact information for event specifics).
Drought: The County was impacted by the Drought event of the 1960’s, as was the rest of the State. The county hosts significant agricultural and livestock assets that are negatively impacted by such events. At the time of the preparation of this Plan, the editor has located no specific data as to the losses from Drought events for this county.
Wildfire: Significant debris remains in the forests from the 1998 event. Aside from the data presented in Section I. of this Plan, the editor was unable to locate any county specific data with respect to this hazard type. Additional research is ongoing. Given the heavy forest cover countywide, this hazard type is of particular concern during dry periods.
Earthquake: New Hampshire lies in a zone of Moderate seismic vulnerability generally. Areas to the north of the county lie close to the St. Lawrence River Valley and areas of very significant seismicity. Toward the Southeastern portion of the county is the Ossipee Range, the center of the highest seismicity within the boundary of the State.
Landslide: Indications are that the land formations throughout large areas of this county predispose some areas to this hazard type. At the time of the submission of this Plan however, the editor was unable to locate any county specific data with respect to this hazard type. Additional research is ongoing.
Subsidence: At the time of the submission of this Plan, the editor was unable to locate any county specific data with respect to this hazard type. Additional research is ongoing.
Radon: From available data, it would appear that Radon is a relatively High risk in this county (See page 52 for more details).
Tornadic Activity: As may be gleaned from the data presented on page of this document, the county has experienced one known F2 event in the recent past (5/5/1929). The data from www.tornadoproject.com lists a total of 5 tornadic events (all additional are F 1 or less events) from 7/9/1956 to 7/2/1994.
Hurricane: The County has experienced high winds from some hurricane events but is at amore significant risk to flooding from the associated rainfall from hurricanes.
Nor’easter: At the time of the submission of this Plan, the editor was unable to locate any county specific data with respect to this hazard type. Additional research is ongoing.
Downburst: At the time of the submission of this Plan, the editor was unable to locate any county specific data with respect to this hazard type. Additional research is ongoing.
Lightning: At the time of the submission of this Plan, the editor was unable to locate any county specific data with respect to this hazard type. Additional research is ongoing.
Hail: At the time of the submission of this Plan, the editor was unable to locate any county specific data with respect to this hazard type. Additional research is ongoing.
Heavy Snow: At the time of the submission of this Plan, the editor was unable to locate any county specific data with respect to this hazard type. Additional research is ongoing. See pages 71 – 79 for a Regional overview of the State’s exposure.
Ice Storm: Significant debris remains in the forests from the 1998 event. At the time of the submission of this Plan, the editor was unable to locate any county specific data with respect to this hazard type. Additional research is ongoing.
93 State of New Hampshire, Natural Hazards Mitigation Plan, Executive Summary: October 2000 Edition GRAFTON COUNTY RISK ANALYSIS: 1999 Estimated Population – 80,800
Flooding: The County is bordered to the West and North by the Connecticut River, to the Northwest by the White Mountains and to the South by Sullivan and Belknap counties. Communities along the Connecticut River experience periodic flooding and the snowpack and rainfall captured by the White Mountains contributes to flash flood conditions along the Pemigewasset (Pemi) and the Ammonosuc and their tributaries. The Pemi, Baker, Beebe, Mad and other rivers, which drain the White Mountains, are well known to be extremely “flashy.”
River Ice: River Ice related flooding along the Connecticut is a periodic issue in Lebanon, Littleton and several of the smaller communities along the River. Erosion accelerated by the destabilizing effects on riverbanks is a significant issue all along the Connecticut and other of the State’s Rivers. Additionally, River Ice may directly impact upon docks, wharfs, boathouses and nearby roads, bridges, culverts and other infrastructure. River Ice is an issue for the Town of Plymouth, which lies at the confluence of the Pemi and Baker Rivers (See page 16 and page 122 - CRREL Resourse Profile for contact information for event specifics).
Drought: The County was impacted by the Drought event of the 1960’s, as was the rest of the State. The county hosts significant agricultural and livestock assets that are negatively impacted by such events. At the time of the preparation of this Plan, the editor has located no specific data as to the losses from Drought events for this county.
Extreme Heat: At the time of the submission of this Plan, the editor was unable to locate any county specific data with respect to this hazard type. Additional research is ongoing (See Concord data, page 33).
Wildfire: Significant debris remains in the forests from the 1998 event. Aside from the data presented in Section I. of this Plan, the editor was unable to locate any county specific data with respect to this hazard type. Additional research is ongoing. Given the heavy forest cover countywide, this hazard type is of particular concern during dry periods.
Earthquake: New Hampshire lies in a zone of Moderate seismic vulnerability generally.
Landslide: At the time of the submission of this Plan, the editor was unable to locate any county specific data with respect to this hazard type. Additional research is ongoing. Some land formations along the Connecticut are generally considered to be conducive to landslide activity.
Subsidence: Communities such as Lebanon and Littleton, which were industrialized in the nineteenth century, may have had underground canals to facilitate hydro-mechanical power to those preexisting mills. As of the writing of this Plan, the editor was unable to locate any loss data with respect to this hazard type.
Radon: From available data, it would appear that Radon is a Moderate risk in this county (See page 52 for more details).
Tornadic Activity: Risk from tornadoes is considered to be high in this county. As may be gleaned from the data presented on page of this document, the county has experienced 5 known F2 events in the past. The compilation of data from www.tornadoproject.com lists a total of 8 tornadic events (6 additional are F 1 or less events) from 7/14/1963 to 6/11/73.
Hurricane: The County has experienced high winds from some hurricane events but is at a more significant risk to flooding from the associated rainfall from hurricanes.
Nor’easter: At the time of the submission of this Plan, the editor was unable to locate any county specific data with respect to this hazard type. Additional research is ongoing.
Downburst: At the time of the submission of this Plan, the editor was unable to locate any county specific data with respect to this hazard type. Additional research is ongoing.
Lightning: At the time of the submission of this Plan, the editor was unable to locate any county specific data with respect to this hazard type. Additional research is ongoing.
Hail: At the time of the submission of this Plan, the editor was unable to locate any county specific data with respect to this hazard type. Additional research is ongoing.
Heavy Snow: At the time of the submission of this Plan, the editor was unable to locate any county specific data with respect to this hazard type. Additional research is ongoing. See pages 71 – 79 for a Regional overview of the State’s exposure.
Ice Storm: Significant debris remains in the forests from the 1998 event. At the time of the submission of this Plan, the editor was unable to locate any county specific data with respect to this hazard type. Additional research is ongoing. 94 State of New Hampshire, Natural Hazards Mitigation Plan, Executive Summary: October 2000 Edition
HILLSBOROUGH COUNTY RISK ANALYSIS: 1999 Estimated Population – 374,117
Flooding: The most heavily populated county, it is bordered to the South by Massachusetts and comprises much of the southern and western Merrimack River Watershed. The river flows through the eastern portion of this county through the heavily populated cities of Manchester, Merrimack and Nashua. Urban development and land use exacerbate storm water runoff issues in the eastern areas of the county while the western areas are moderately to heavily forested. Flooding in the Western portions of the county periodically occurs along the Contoocook from Peterborough to Hillsborough.
River Ice: River Ice is less significant a threat in this region than in other portions of the State but the communities in the Western regions, principally along the Contoocook, experience this hazard periodically (See page 16 and page 122 - CRREL Resourse Profile for contact information for event specifics).
Drought: The County was impacted by the Drought event of the 1960’s, as was the rest of the State. The county hosts significant agricultural and livestock assets that are negatively impacted by such events. At the time of the preparation of this Plan, the editor has located no specific data as to the losses from Drought events for this county.
Extreme Heat: At the time of the submission of this Plan, the editor was unable to locate any county specific data with respect to this hazard type. Additional research is ongoing. It should be noted here that the highest high temperature recorded in neighboring Massachusetts was higher than the highest highs of either Miami Fla., or Atlanta Ga. (See Concord data, page 33).
Wildfire: Significant debris remains in the forests from the 1998 event. Aside from the data presented in Section I. of this Plan, the editor was unable to locate any county specific data with respect to this hazard type. Additional research is ongoing. Given the heavy forest cover countywide, this hazard type is of particular concern during dry periods.
Earthquake: New Hampshire lies in a zone of Moderate seismic vulnerability generally. The county is in an area of particularly high seismicity that is evident in a crescent of historical events beginning in the Ossipee Range and following the general contour of the Merrimack River Valley (See Section II., page 38 of this document).
Landslide: At the time of the submission of this Plan, the editor was unable to locate any county specific data with respect to this hazard type. Additional research is ongoing. Some land formations along the Merrimack River are generally considered to be conducive to landslide activity.
Subsidence: Communities such as Nashua, Manchester, Merrimack and Peterborough, which were industrialized in the nineteenth century, had underground canals to facilitate hydro-mechanical power to those preexisting mills. As of the writing of this Plan, the editor was unable to locate loss data other than in Peterborough with respect to this hazard type.
Radon: From available data, it would appear that Radon is a Moderate risk in this county (See page 52 for more details).
Tornadic Activity: Risk from tornadoes is considered to be high in this county. As may be gleaned from the data presented on page of this document, the county has experienced 7 known F2 events and one F 3 event. The compilation of data from www.tornadoproject.com lists a total of 18 tornadic events (all additional are F 1or less events) from 7/27/1956 to 6/16/1986.
Hurricane: The County has experienced high winds from some hurricane events but is at a more significant risk to flooding from the associated rainfall from hurricanes. The 1938 event devastated this county, which received a direct hit.
Nor’easter: At the time of the submission of this Plan, the editor was unable to locate any county specific data with respect to this hazard type. Additional research is ongoing.
Downburst: At the time of the submission of this Plan, the editor was unable to locate any county specific data with respect to this hazard type. Additional research is ongoing.
Lightning: At the time of the submission of this Plan, the editor was unable to locate any county specific data with respect to this hazard type. Additional research is ongoing.
Hail: At the time of the submission of this Plan, the editor was unable to locate any county specific data with respect to this hazard type. Additional research is ongoing.
Heavy Snow: At the time of the submission of this Plan, the editor was unable to locate any county specific data with respect to this hazard type. Additional research is ongoing. See pages 71 – 79 for a Regional overview of the State’s exposure.
Ice Storm: Significant debris remains in the forests from the 1998 event. At the time of the submission of this Plan, the editor was unable to locate any county specific data with respect to this hazard type. Additional research is ongoing.
95 State of New Hampshire, Natural Hazards Mitigation Plan, Executive Summary: October 2000 Edition
MERRIMACK COUNTY RISK ANALYSIS: 1999 Estimated Population – 130,476
Flooding: As its name reflects, this county lies almost exclusively in the Merrimack River Watershed. At the confluence of the Pemigewasset, the Winnipesaukee and the Merrimack, the Town of Franklin has seen such significant flooding so as to be the site of a U.S. Army Corps of Engineers Flood Control Dam. Flash flooding along the Contoocook and its tributaries is repetitive. Related flooding is experienced at the confluence of the Contoocook and Merrimack during peak events.
River Ice: River Ice is less significant a threat in this region than in other portions of the State but the communities in the Western regions, principally along the Contoocook, experience this hazard periodically (See page 16 and page 122 - CRREL Resourse Profile for contact information for event specifics).
Drought: The County was impacted by the Drought event of the 1960’s, as was the rest of the State. The county hosts significant agricultural and livestock assets, which are negatively impacted by such events. At the time of the preparation of this Plan, the editor has located no specific data as to the losses from Drought events for this county (See Concord Data, page 33).
Extreme Heat: At the time of the submission of this Plan, the editor was unable to locate any county specific data with respect to this hazard type. Additional research is ongoing. It should be noted here that the highest high temperature recorded in neighboring Massachusetts was higher than the highest highs of either Miami Fla., or Atlanta Ga. (See Concord data, page 33).
Wildfire: Significant debris remains in the forests from the 1998 event. Aside from the data presented in Section I. of this Plan, the editor was unable to locate any county specific data with respect to this hazard type. Additional research is ongoing. Given the heavy forest cover countywide, this hazard type is of particular concern during dry periods.
Earthquake: New Hampshire lies in a zone of Moderate seismic vulnerability generally. The county is in an area of particularly high seismicity that is evident in a crescent of historical events beginning in the Ossipee Range and following the general contour of the Merrimack River Valley (See Section II., page 38 of this document).
Landslide: At the time of the submission of this Plan, the editor was unable to locate any county specific data with respect to this hazard type. Additional research is ongoing. Some land formations along the Merrimack River are generally considered to be conducive to landslide activity.
Subsidence: Communities such as Franklin and Concord, which were industrialized in the nineteenth century, may have had underground canals to facilitate hydro-mechanical power to those preexisting mills. As of the writing of this Plan, the editor was unable to locate loss data with respect to this hazard type.
Radon: From available data, it would appear that Radon is a Moderate risk in this county (See page 52 for more details).
Tornadic Activity: As may be gleaned from the data presented on page of this document, the county has experienced 5 estimated F2 events in the past of record. The compilation of data from www.tornadoproject.com lists a total of 3 additional tornadic events (all additional are F 1or less events) from 7/12/1967 to 8/15/1976.
Hurricane: The County has experienced high winds from some hurricane events but is at a more significant risk to flooding from the associated rainfall from hurricanes.
Nor’easter: At the time of the submission of this Plan, the editor was unable to locate any county specific data with respect to this hazard type. Additional research is ongoing.
Downburst: At the time of the submission of this Plan, the editor was unable to locate any county specific data with respect to this hazard type. Additional research is ongoing.
Lightning: At the time of the submission of this Plan, the editor was unable to locate any county specific data with respect to this hazard type. Additional research is ongoing.
Hail: At the time of the submission of this Plan, the editor was unable to locate any county specific data with respect to this hazard type. Additional research is ongoing.
Heavy Snow: At the time of the submission of this Plan, the editor was unable to locate any county specific data with respect to this hazard type. Additional research is ongoing. See pages 71 – 79 for a Regional overview of the State’s exposure.
Ice Storm: Significant debris remains in the forests from the 1998 event. At the time of the submission of this Plan, the editor was unable to locate any county specific data with respect to this hazard type. Additional research is ongoing.
96 State of New Hampshire, Natural Hazards Mitigation Plan, Executive Summary: October 2000 Edition
ROCKINGHAM COUNTY RISK ANALYSIS: 1999 Estimated Population – 285,142
Flooding: The second most heavily populated county, it is bordered to the South by Massachusetts. The county is divided between the southern portion of the Piscataqua and the southeastern Merrimack River Watersheds. The region is primarily low rolling hills and floodplain and consequently, inundation flooding is typical. The county also possesses the only direct seacoast in the State and is therefore positioned with exposure to coastal flooding damage from Hurricane, Nor’reaster and Tsunami.
River Ice: River Ice has not proven to be a significant hazard in this County in the recent past. At the time of the submission of this Plan, the editor was unable to locate any county specific data with respect to this hazard type. Given the moderating effects on the seasonal temperatures from the southern latitude and coastal exposure, the county is viewed as having a limited risk from this hazard type. (See page 16 and page 122 - CRREL Resourse Profile for contact information for event specifics).
Drought: The County was impacted by the Drought event of the 1960’s, as was the rest of the State. The county hosts significant agricultural and livestock assets, which are negatively impacted by such events. At the time of the preparation of this Plan, the editor has located no specific data as to the losses from Drought events for this county.
Extreme Heat: At the time of the submission of this Plan, the editor was unable to locate any county specific data with respect to this hazard type. Additional research is ongoing. It should be noted here that the highest high temperature recorded in neighboring Massachusetts was higher than the highest highs of either Miami Fla., or Atlanta Ga. (See Concord data, page 33).
Wildfire: Significant debris remains in the forests from the 1998 event. Aside from the data presented in Section I. of this Plan, the editor was unable to locate any county specific data with respect to this hazard type. Additional research is ongoing. Given the saltmarsh environments in the county, Wildland Fire hazards related to Phragmites Austrails are viewed as significant.
Earthquake: New Hampshire lies in a zone of Moderate seismic vulnerability generally. The county is in an area of particularly high seismicity that is evident in a crescent of historical events beginning in the Ossipee Range and following the general contour of the Merrimack River Valley (See Section II., page 38 of this document). Additionally, it is believed that the largest earthquake of record in New England was the 1755 “Cape Ann” event, just offshore of the NH coast.
Subsidence: Communities such as Exeter, which was industrialized in the nineteenth century, may have had underground canals to facilitate hydro-mechanical power to those preexisting mills. As of the writing of this Plan, the editor was unable to locate loss data with respect to this hazard type.
Radon: From available data, it would appear that Radon is a relatively High risk in this county (See page 52 for more details).
Tornadic Activity: Risk from tornadoes is considered to be high in this county. As may be gleaned from the data presented on page of this document, the county has experienced 6 known F2 events and one F 3 event in the past. The compilation of data from www.tornadoproject.com lists a total of 4 additional tornadic events (all additional are F 1or less events).
Hurricane: The county has experienced high winds from some hurricane events and is positioned to experience storm surge related flooding, beach erosion and significant wind damage from these events.
Nor’easter: The county has experienced high winds from some Nor’easter events and is positioned to experience storm surge related flooding, beach erosion and significant wind damage from these events. At the time of the submission of this Plan, the editor was unable to locate any county specific data with respect to this hazard type. Additional research is ongoing.
Downburst: As recorded in the appropriate subsection of Section III. Of this document, the community of Stratham received a Presidential Declaration from Downburst activity. As with tornadoes, this is perceived to be a significant hazard in this County. Additional research is ongoing.
Hail and Lightning: At the time of the submission of this Plan, the editor was unable to locate any county specific data with respect to this hazard type. Additional research is ongoing.
Heavy Snow: At the time of the submission of this Plan, the editor was unable to locate any county specific data with respect to this hazard type. Additional research is ongoing. See pages 71 – 79 for a Regional overview of the State’s exposure.
Ice Storm: Significant debris remains in the forests from the 1998 event. At the time of the submission of this Plan, the editor was unable to locate any county specific data with respect to this hazard type. Additional research is ongoing.
97 State of New Hampshire, Natural Hazards Mitigation Plan, Executive Summary: October 2000 Edition
STRAFFORD COUNTY RISK ANALYSIS: 1999 Estimated Population – 113,409
Flooding: Bordered to the North and West by the Salmon Falls and Piscataqua Rivers, the county lies primarily in the Piscataqua River Watershed. The region is primarily low rolling hills and floodplain and consequently, inundation flooding is typical. The county also possesses tidal river, estuarine and saltmarsh environments. Therefore, these areas are positioned with exposure to coastal flooding damage from Hurricane, Nor’reaster and possibly, Tsunami.
River Ice: River Ice has not proven to be a significant hazard in this county in the recent past. At the time of the submission of this Plan, the editor was unable to locate any county specific data with respect to this hazard type. Given the moderating effects on the seasonal temperatures from the southern latitude and coastal exposure, the county is viewed as having a limited risk from this hazard type (See page 16 and page 122 - CRREL Resourse Profile for contact information for event specifics).
Drought: The County was impacted by the Drought event of the 1960’s, as was the rest of the State. The county hosts significant agricultural and livestock assets that are negatively impacted by such events. At the time of the preparation of this Plan, the editor has located no specific data as to the losses from Drought events for this county.
Extreme Heat: At the time of the submission of this Plan, the editor was unable to locate any county specific data with respect to this hazard type. Additional research is ongoing. It should be noted here that the highest high temperature recorded in nearby Massachusetts was higher than the highest highs of either Miami Fla., or Atlanta Ga. (See Concord data, page 33).
Wildfire: Significant debris remains in the forests from the 1998 event. Aside from the data presented in Section I. of this Plan, the editor was unable to locate any county specific data with respect to this hazard type. Additional research is ongoing. Given the saltmarsh environments in the county, Wildland Fire hazards related to Phragmites Austrails are viewed as significant.
Earthquake: New Hampshire lies in a zone of Moderate seismic vulnerability generally. The county is in an area of particularly high seismicity that is evident in a crescent of historical events beginning in the Ossipee Range and following the general contour of the Merrimack River Valley (See Section II., page 38 of this document). Additionally, it is believed that the largest earthquake of record in New England was the 1755 “Cape Ann” event, just offshore of the NH coast.
Subsidence: Communities such as Rochester and Dover, which were industrialized in the nineteenth century, may have had underground canals to facilitate hydro-mechanical power to those preexisting mills. As of the writing of this Plan, the editor was unable to locate loss data with respect to this hazard type.
Radon: From available data, it would appear that Radon is a relatively High risk in this county (See page 52 for more details)..
Tornadic Activity: Risk from tornadoes is considered to be high in this county. As may be gleaned from the data presented on page of this document, the county has experienced 5 known F2 events in the past. The compilation of data from www.tornadoproject.com lists a total of 2 additional tornadic events (both additional are F 1or less events).
Hurricane: The county has experienced high winds from some hurricane events and is positioned to experience storm surge related flooding, beach erosion and significant wind damage from these events.
Nor’easter: The county has experienced high winds from some Nor’easter events and is positioned to experience storm surge related flooding, beach erosion and significant wind damage from these events. At the time of the submission of this Plan, the editor was unable to locate any county specific data with respect to this hazard type. Additional research is ongoing.
Downburst: As recorded in the appropriate subsection of Section III. Of this document, the neighboring community of Stratham received a Presidential Declaration from Downburst activity. As with tornadoes, this is perceived to be a significant hazard in this county. Additional research is ongoing.
Hail and Lightning: At the time of the submission of this Plan, the editor was unable to locate any county specific data with respect to this hazard type. Additional research is ongoing.
Heavy Snow: At the time of the submission of this Plan, the editor was unable to locate any county specific data with respect to this hazard type. Additional research is ongoing See pages 71 – 79 for a Regional overview of the State’s exposure..
Ice Storm: Significant debris remains in the forests from the 1998 event. At the time of the submission of this Plan, the editor was unable to locate any county specific data with respect to this hazard type. Additional research is ongoing.
98 State of New Hampshire, Natural Hazards Mitigation Plan, Executive Summary: October 2000 Edition SULLIVAN COUNTY RISK ANALYSIS: 1999 Estimated Population – 40,521
Flooding: The county in the Southwestern area of the State and is bounded by the Connecticut River to the West. The City of Claremont lies in the center of the county along the Connecticut River and encompasses a significant area of the floodplain of the upper Sugar River.
River Ice: River Ice related flooding along the Connecticut is a periodic issue in Charlestown among others. Erosion accelerated by the destabilizing effects on riverbanks is a significant issue all along the Connecticut and other of the State’s Rivers. Additionally, River Ice may directly impact upon docks, wharfs, boathouses and nearby roads, bridges, culverts and other infrastructure (See page 16 and page 122 - CRREL Resourse Profile for contact information for event specifics).
Drought: The County was impacted by the Drought event of the 1960’s, as was the rest of the State. The county hosts significant agricultural and livestock assets that are negatively impacted by such events. At the time of the preparation of this Plan, the editor has located no specific data as to the losses from Drought events for this county.
Extreme Heat: At the time of the submission of this Plan, the editor was unable to locate any county specific data with respect to this hazard type. Additional research is ongoing. It should be noted here that the highest high temperature recorded in nearby Massachusetts was higher than the highest highs of either Miami Fla., or Atlanta Ga. (See Concord data, page 33).
Wildfire: Significant debris remains in the forests from the 1998 event. Aside from the data presented in Section I. of this Plan, the editor was unable to locate any county specific data with respect to this hazard type. Additional research is ongoing. Given the heavy forest cover countywide, this hazard type is of particular concern during dry periods.
Earthquake: New Hampshire lies in a zone of Moderate seismic vulnerability generally.
Landslide: At the time of the submission of this Plan, the editor was unable to locate any county specific data with respect to this hazard type. Additional research is ongoing. Some land formations along the Connecticut are generally considered to be conducive to landslide activity.
Subsidence: Communities such as Claremont, which was industrialized in the nineteenth century, have underground canals to facilitate hydro-mechanical power to those preexisting mills. As of the writing of this Plan, the editor was unable to locate any loss data with respect to this hazard type.
Radon: From available data, it would appear that Radon is a Moderate risk in this county (See page 52 for more details)..
Tornadic Activity: Risk from tornadoes is considered to be high in this county. As may be gleaned from the data presented on page of this document, the county has experienced 4 known F2 events (estimated) in the past. The compilation of data from www.tornadoproject.com lists 4 additional tornadic events (all additional are F 1 or less events) from 10/24/1955 to 7/16/83.
Hurricane: The County has experienced high winds from some hurricane events but is at a more significant risk to flooding from the associated rainfall from hurricanes. The 1938 event impacted this county that received a near direct hit.
Nor’easter: At the time of the submission of this Plan, the editor was unable to locate any county specific data with respect to this hazard type. Additional research is ongoing.
Downburst: At the time of the submission of this Plan, the editor was unable to locate any county specific data with respect to this hazard type. Additional research is ongoing.
Lightning: At the time of the submission of this Plan, the editor was unable to locate any county specific data with respect to this hazard type. Additional research is ongoing.
Hail: At the time of the submission of this Plan, the editor was unable to locate any county specific data with respect to this hazard type. Additional research is ongoing.
Heavy Snow: At the time of the submission of this Plan, the editor was unable to locate any county specific data with respect to this hazard type. Additional research is ongoing. See pages 71 – 79 for a Regional overview of the State’s exposure.
Ice Storm: Significant debris remains in the forests from the 1998 event. At the time of the submission of this Plan, the editor was unable to locate any county specific data with respect to this hazard type. Additional research is ongoing.
99 State of New Hampshire, Natural Hazards Mitigation Plan, Executive Summary: October 2000 Edition
Associated and Secondary Risks
Critical facilities such as power stations, sub-stations and transmission lines may be impacted by Seismic, Flood, Winter Snow Storm, Ice Storm or Wildfire events. Emergency conditions, coupled with such disruptions in telephone service, would complicate the transmission of vital Emergency Management related data and serv ices which sustain life.
Fire, law enforcement and other critical services must be maintained in an Emergency and these services dese rve particular consideration when developing local Hazard Mitigation plans and strategies.
In addition to schools, facilities such as those which house daycare services, hospitals, nursing homes, adult congregate living facilities, correctional facilities etc. must be given special consideration. Provisions should be considered for non-English speaking populations, the blind, deaf, and non-ambulatory.
Residents of mobile/manufactured home parks, etc., may be at particularly high risk in some events given the locations of some such facilities and the type of construction (foundations etc.). Such facilities may require special attention when planning for Severe Wind events for example (e.g. tie down straps might be stipulated in local ordinances which may also provide some level of mitigation from the effects of flooding).
Secondary events must be weighed in the Risk equation such as the potential impact of hazardous chemical or radiological materials being released as a nearby facility is impacted.
In a coastal event, storm surge related flooding may accompany a Winter Blizzard in the form of a Nor’easter. Other areas of the State have experienced significant multiple events i.e., such as those which impacted the Town of Peterborough in association with the Hurricane of 1938, (i.e. wind, fire and flood. See Plan: Severe Wind Section III, Appendix C. page 9). In such cases, local emergency services and shelter facilities may become overwhelmed. Local plans should include an inventory of nearby assets.
As transportation routes such as roads and railways are impacted, evacuation routes may become unavailable and the ability to supply such communities with relief resources may be significantly compromised. Local plans should consider redundant methods of relief supply.
The impact of large-scale events upon the State’s Dams and historical buildings must be considered as well as the impact upon the State, regional and local economy as well as the tourism trade etc.
The reader is referred to New Hampshire’s State Historic Preservation Plan, prepared by the NH Division of Historical Resources, Department of Cultural Affairs for an overview of the State’s Historic Resources and the programs in place aimed at their preservation
Insured Losses
This information is being developed at the time of the submission of this Summary of the 409 Plan.
100 State of New Hampshire, Natural Hazards Mitigation Plan, Executive Summary: October 2000 Edition
Potential Impact of No Action
Given the historical and potential impact upon life and property with respect to the State’s Natural Hazards identified above, the option of “No Action” is not indicated generally, except as specified (e.g. as with respect to Volcanism).
For the State and/or Federal government to fail to act protect its citizens with respect to these events is unacceptable to the citizenry. Hazard Mitigation begins with public education and initiative and continues through to the development of sophisticated technology i.e., Doppler Radar.
Individuals and private organizations have, and will continue to mitigate in their own self- interest. It is the responsibility of government to assist in the coordination of these efforts, collect and organize available Hazard Mitigation information and other resources and offer planning and other guidance to communities so as to facilitate local initiatives. The function of government also extends to the development of strategies and initiation of such action as may be outside the scope of local authority and/or resources.
In the Capability Assessment and Goals and Objectives Sections of this Summary of the 409 Plan, an accounting of ongoing and proposed initiatives is discussed. The State will also encourage the development of public/private partnerships toward its Hazard Mitigation Goals and Objectives as encouraged by FEMA in its Project Impact program.
TRENDS
Climatological
The re is no indication that, from a Climatological point of view, the State’s exposure to these hazards will diminish in the near future. The SHMO, in association with NOAA/NWS, The University of New Hampshire – the State’s Climatologist and the Complex Systems Research Center - Earth, Oceans and Space Institute, the Meteorology Department at Plymouth State College, the Mount Washington Observatory and the USDA/USGS, is endeavoring to identify such climatological trends as may be useful in Hazard Mitigation planning. As such information becomes available it will be incorporated within this Plan. Just such a study going to the effects of sea level rise on coastal flooding has been funded by NHOEM with EMPG 2000 funding and will be conducted by the NHOSP Coastal Program in association with the Jackson Laboratory of the university of New Hampshire*.
The climatological trends and their impact are as yet unclear but, the evidence tends toward an understan ding that our region may be experiencing a warming trend, possibly accelerated by the effects of “Greenhouse Gases” (CO2) in the atmosphere, emissions from the abundant combustion of fossil fuels by modern man. The coincidence of the measurable rise of these gasses in the atmosphere since the onset of the Industrial Age and some measured rise in mean air temperature, gives rise to concern on the part of many climatologists and may constitute a call to action.
The reader is directed to Plan: Flood, Drought etc., Section I., Appendix I., excerpts from the New England Regional Climate Change Impact Workshop; Workshop Summary Report (September 3- 5, 1997) for further information as to these concerns.
The reader is also referred to New England Changing Climate, Weather and Air Quality (a copy is located in the pocket at the rear of the Flood Section of the Plan) for further information on this topic, or visit http://www.neci.sr.unh.edu/neccwaq.html
*Evidence of global warming may mean incremental rises in sea levels which would exacerbate Coastal flooding and may also produce more rain in the region, particularly in the winter months which may exacerbate the area’s exposure to Ice Storm events and winter snowpack melting related flooding.
101 State of New Hampshire, Natural Hazards Mitigation Plan, Executive Summary: October 2000 Edition
TRENDS (cont’d)
Demographic
It can be deduced that New Hampshire’s four most highly developed and most heavily populated counties (i.e. – and in order – Hillsborough, Rockingham, Merrimack, and Stafford) have also experience d the highest rate of population increase (See graphs on pages 85 and 86). The projections offered by the NH Office of State Planning are for a continued rise in these areas but at a decreasing rate. The reader will note an anticipated doubling of the population by the year 2000 census in the State since 1960 (See Table, on page 85).
The impact on this increased population must be taken into consideration from every aspect while conducting regional and local planning of all types and before making decisions as to land use etc. Issues such as encroachment on areas susceptible to Flooding, Landslide, Snow Avalanche etc. must be given good consideration by local planners as well as the impact on the region’s resources during periods of Drought. Emergency responders must factor such trends into considerations with respect to regional and local response plans including impacts on regional and local resources during emergency conditions and the implications with respect to local and regional evacuation plans.
Land Use and Development
This trend is currently under investigation by the SHMO who is working with representatives of NH Office of State Planning and the NOEM - NFIP Coordinator to identify related trends, their impact with respect to Hazard Mitigation and any and all cost effective Hazard Mitigation measures as may be indicated.
Local planners should evaluate these trends on the regional and local levels and give good consideration as to the effects of urban “sprawl” on regional resources as well as the potential impacts from such development on local and regional stormwater runoff patterns.
Deforestation
This trend is currently under investigation by the SHMO who is working with representatives of NH Department of Resources and Economic Development, Division of Forests and Lands to identify related trends, their impact with respect to Hazard Mitigation and any and all cost effective Hazard Mitigation measures as may be indicated.
Local planners should give considerations to the related impacts from deforestation on stormwater runoff amounts and surface and ground water quality including turbidly and adverse affects on water chemistry.
Economic
These trends are currently under investigation by the SHMO who is working with representatives of NH Department of Resources and Economic Development and Office of State Planning to identify related trends, their impact with respect to Hazard Mitigation and any and all cost effective Hazard Mitigation measures as may be indicated.
Local planners should give consideration to the FEMA estimates that as many as one third of private enterprises may fail subsequent to a disaster event. The concepts of “Sustainability” and “Sustainable Development” are at the core of Hazard Mitigation Planning (See http://www.sustainableamerica.org/).
102 State of New Hampshire, Natural Hazards Mitigation Plan, Executive Summary: October 2000 Edition
DATA ASSESSMENT
Historical Flood Data
At the time of the submission of this Summary of the 409 Plan, the SHMO is working with the NHP Officer and representatives from NOAA/NWS, the University of New Hampshire Complex Systems Department, Institute of Earth Oceans and Space, the State’s Climatologist, the Mount Washington Observatory and the USDA/USGS to continue to develop such data as may become useful in future Flood Mitigation planning initiatives with respect to all areas of meteorological and climatological phenomena. This data, when available, will reflect the best data available to these agencies and will be incorporated into this Plan at the given annual review.
The Flood data presented here is gleaned from da ta provided from these sources and, though incomplete, is reliable as presented. The principle sources of Historical Flood data presented herein have been collected from the USGS. To the extent that they represent empirical meas ured data from instrumentation, they are considered to be highly reliable. Historical anecdotal data is identified where presented. A systematic compilation of data regarding the impact upon the State by tsunamis will be commissioned as funding and/or other resources are identified.
Historical Seismic Data
The Geologic Hazards, Section II. of the Plan, contains a generous collection of articles and technical papers directly related to the seismicity of the Northeast U.S. This collection of Plan Appendices was reviewed by (and was, in some cases, authored by) John E. Ebel, Ph.D., Director of the 29 station Weston (seismic) Observatory and determined to be necessary and sufficient to offer a New Hampshire Hazard Mitigation Planner a proper overview of the seismicity of the area.
Historical Severe Wind Data
Tornado and Hurricane data was gleaned in part from a project funded by NHOEM and the Red Cross to create a history of disasters impacting New Hampshire. Additional data as to tornadic activity was gleaned from the Tornado Project as is offered on their website: www.tornadoproject.com and is considered highly reliable.
The data presented here as to Downburst activity was gleaned from the files going to FEMA DR-917-NH, from NHOEM Field representatives and other emergency management personnel and from information offered by the Warnings Coordinator and others at the National Weather Service in Gray, Maine. These data, although incomplete as to all such activity within the State, are deemed to be highly reliable as presented.
Winter Weather Related Hazards Data
Data for the Ice Storm sub-section of this Plan was obtained from the Inter Agency Hazard Mitigation Team Report going to FEMA DR-1199-NH and the CRREL Ice Storm Report presented as Appendix D. of Section IV. of the Plan, also available at http://www.crrel.usace.army.mil/valliere/CRREL_Reports_web/reports/IceStorm98.pdf The winter storm information was largely reprinted from Snowstorms Along the Northeastern Coast of the United States: 1955 To 1985, Paul J. Kocin and Louis Uccellini, American Meteorological Society. All data here is considered to be highly reliable. Some additional data on losses form Snow Avalanche was obtained from Bradley Ray, Lead Snow Ranger, Androscoggin Ranger Station at the USDA U.S. Forest Service, White Mountain National Forest in Gorham, NH and is considered highly reliable. Emergency Alert System Data
The quality of this data is quite high and originates from an exhaustive study by NHOEM Operations staff (and others) of the State’s EAS capability in association with a demonstration project designed to enhance the State’s overall communications capability. For further information the reader is directed to the publication entitled, The New Hampshire Office of Emergency Management Operations Section Capabilities Overview.
Loss Data
Aside from such flood loss data, which may originate from the NFIP, few resources were available to the SHMO as of the preparation of the Plan. Future data will likely originate from the insurance community in large part. Certain issues such as proprietary loss exposure information may affect the quality and/or completeness of the data. Efforts will be made to identify any data confidence shortfalls as may become apparent as that data is presented.
103 State of New Hampshire, Natural Hazards Mitigation Plan, Executive Summary: October 2000 Edition
Capability Assessment
Non-Commercial Service NATURAL HAZARDS PROGRAM Announcements NH Office of Emergency Management's Natural Hazards Program (NHP) was originally created to address the Th e NHP, together with the NHOEM Public earthquake risk in New Hampshire. In 1994, with the creation Information Officer, have produced a number of of the National Hurricane Program, NHP became the nation’s Non-comm ercial Service Announcements (NCSA). first all (natural) hazards program. These announcements, done in cooperation with the NH Association of Broadcasters, are carried by all New Ham pshire radio stations at least three times Comprehensive Emergency Management daily and must be aired during peak travel times. Planning for Schools (CEMPS) NHP/NHOEM has produced NCSA's for most natural hazard s. (See Geologic Hazards Section, page 44)
NH OEM has an excellent on-going Hurricane Tracking Chart Program relationship with New Hampshire’s news media, especially radio and television. This relationship Started during the 1996 hurricane season, the NHP/NHOEM, in cooperation with WMUR TV-9, the State's operates in both formal and informal channels. largest television station, has been giving away hurricane- The agency has a contract with the NH tracking charts. Utilizing the FEMA/ARC/NOAA chart, the Association of Broadcasters to produce and broadcast NHP has added (with permission) NHOEM's and WMUR's announcem ents dealing with emergency management logos. Announcements of the chart’s availability coincide with issues on all the State’s radio stations. weather broadcasts and serve to heighten public awareness of Announcements running this year have included hurricanes, the State's risk from natural hazards and information on family preparedness, school hazard NHOEM's programs. drills, terrorism and hurricanes. These are paid spots, not free pub lic service announcements, and they are Response to this program has been wonderful, more aired during peak listening hours. They are an than 10,000 responses in three seasons. The tracking chart serves as a leader to attract the public's attention. effective m eans of alerting the public to emergency management issues. Informational materials on mitigation and preparedness are included in the packages to better inform the citizenry on steps NHOEM has also participated in continuing they can take to reduce the impact from a damaging hurricane. education f or radio and television reporters through the NHAB and the NH Associated Press Family Preparedness Presentations Broadcasters Association, through their annual meetings and workshops. The NHP has been conducting Family Preparedness Presentations for over six years. On average, between 35 and There are also numerous informal contacts 45 presentations are conducted annually, each emphasizing between the agency and reporters. The PIO and other the four phases of emergency management (mitigation, agency personnel are frequently called on for preparedness, response and recovery), vulnerability to all interviews on talk shows and as part of news reports hazards as well as mitigation and preparedness actions that and features. The agency has a good reputation for can be taken before, during and after an event. In order to providing prom pt, accurate answers to media emphasize the many hazards New Hampshire citizens are inquiries. I n the past few months agency personnel vulnerable to, New Hampshire specific photographs are used have been interviewed on subjects including “year throughout the presentations (i.e. tornado, microburst and 2000” prob lems, earthquakes, terrorism, school hurricane damage). Target audiences for these presentations preparedness and potassium iodide (used in are schools, civic groups and governmental organizations. mitigating the effects of radioactive iodine). Presentations are tailored to the various audiences.
(Courtesy of Jim Van Dongen, PIO at NHOEM) (Courtesy of Gregg Champlin, NHP Officer at NHOEM)
104 State of New Hampshire, Natural Hazards Mitigation Plan, Executive Summary: October 2000 Edition
National Warning System (NAWAS)
NHOEM serves as the NAWAS State Alternate Warning Point (SAWP) while New Hampshire State Police (NHSP) functions as the State Primary Warning Point (SPWP). NAWAS provides NHOEM and NHSP with a back up link to the National Warning Center (NWC), the Alternate National Warning Center (ANWC), and National Weather Service (NWS) offices in Gray, ME and Taunton, MA via protected landline circuits in the event of an emergency. In addition, NHOEM and NHSP can communicate via NAWAS with 18 sites (Berlin, Claremont, Concord, Conway, Durham, Franklin, Grafton County, Hanover, Keene, Lakes Region Dispatch Center, Manchester, Nashua, Plymouth, Portsmouth, Rockingham County, NHSP Troop A, NHSP Troop F, and Mount Washington Observatory) within New Hampshire in the event of an emergency.
Emergency Alert System (EAS)
The State Emergency Communications Committee (SECC) and the New Hampshire Office of Emergency Management have spent the last two years designing and implementing the Emergency Alert System (EAS) which replaced the Emergency Broadcast System.
The EAS incorporated digital technology that allows emergency messages to be broadcast automatically (or manually ) to a specific area. The Federal Communication Commission has promulgated rules and regulations for the operation of EAS. The digital system will work with both new and established technologies, including satellite, broadcast, and cable systems, to make the disaster warning system more effective. The system emphasizes speed, reliability, and efficiency.
Because of the absence of a statewide commercial radio station, NHOEM and the New Hampshire State Police act as the Primary Warning Point in the state, both monitor WBZ radio for National Warning messages. Messages received from the National Weather Service are relayed to broadcast radio and television and other emergency messages may be originated at either site. Broadcasters are required to participate at the federal level, as mandated in the Cable Act of 1992, but participation at the state and local level is voluntary.
The major features (or goals) of EAS include:
• A digital system that allows broadcast, cable, satellite and other services to send and receive alerting information;
• Multiple monitoring sources for emergency alerts;
• Shorter alerting tones (eight second minimum);
• Automated and remote-control operations (including abilities to turn on specially-equipped radios and televisions); • Weekly tests which are unobtrusive to viewers and listeners and monthly on-air tests; • Capability to issue alerts in languages other than English; • Provisions for hearing and visually impaired people; and • Mandated protocol for sending messages.
The success of EAS will rely, too, on new equipment within the National Weather Service through its Specific Area Message Encoder (WRSAME). WRSAME is an encoding device that puts a special message at the beginning and end of selected messages broadcast over NOAA Weather Radio (NWR). The code specifies the type of message and area, by county, to which it applies. Users within listening range of the NWR signal with a matching decoding device can choose which site-specific hazardous weather alerts they will receive. WRSAME is currently connected to a limited number of NWR consoles, but will eventually be part of all NWR stations as consoles are upgraded. Radio stations, television outlets, and cable television providers can now receive and transmit appropriate NWS emergency messages automatically.
(Courtesy of Steve McCloy and Bill Skoglund, Operations Section, NHOEM)
105 State of New Hampshire, Natural Hazards Mitigation Plan, Executive Summary: October 2000 Edition
Hazard Mitigation Grant Program
The Hazard Mitigation Grant Program (HMGP) in New Hampshire is administered in accordance with the 404 HMGP Administration Plan that was derived under the authority of Section 404 of the Stafford Act in accordance with Subpart N. of 44 CFR.
The program, which has been active for ten years in the State, receives its funding pursuant to a Hazard Mitigation Grant Program Notice of Interest as is submitted by the Governor’s Authorized Representative (or GAR, i.e. the Minimum Project Criteria Director of NHOEM) to the FEMA Regional – Must conform with the State’s “409” Plan Director within 60 days of the date of a – Have a beneficial impact on the Declared area Presidentially Declared Disaster. Conform with: – The amount of funding that may be • NFIP Floodplain Regulations awarded to the State/Grantee under the HMGP may • Wetlands Protection Regulations not exceed 15% of (over and above) the overall • Environmental Regulations funds as are awarded to the State pursuant to the • Historical Protection Regulations Disaster Recovery programs as are listed in 44 – Be cost effective and substantially reduce the risk of CFR Subpart N. Section 206.431 (d) (inclusive of future damage all Public Assistance, Individual Assistance, etc.). – Not cost more than the anticipated value of the reduction of both direct damages and subsequent In accordance with 44 CFR Subpart M. negative impacts to the area if future disasters were to Section 106.404, within 15 days of the Disaster occur i.e., min 1:1 benefit/cost ratio Declaration, an Inter-Agency Hazard Mitigation – Both costs and benefits are to be computed on a “net Team is convened consisting of members of present value” basis various Federal, State, County, Local and Private Agencies with an interest in Disaster Recovery and – Has been determined to be the most practical, effective and environmentally sound alternative after a Mitigation. From this meeting, an Inter-Agency consideration of a range of options Hazard Mitigation Team Report is produced which evaluates the event and stipulates the State’s – Contributes to a long-term solution to the problem it is intended to address desired Mitigation initiatives (See Goals and Objectives following page 139 of this Plan – Considers long-term changes and has manageable future maintenance and modification requirements Summary).
Upon the Governor’s authorized Representative’s Eligible projects may be of any nature that will receipt of the notice of an award of such funding by result in the protection to public or private property and the FEMA Regional Director, the State Hazard include: Mitigation Officer (SHMO) publishes a Notice of – Structural hazard control or protection projects Interest (NOI) to all NH communities, State Agencies and others announcing the availability of – Construction activities that will result in protection HMGP funding. The SHMO solicits applications from hazards for grants from these communities, State agencies – Retrofitting of facilities and other qualifying applicants. – Certain property acquisitions or relocations -- Development of State and local mitigation standards
Eligible Subgrantees include: – Development of comprehensive hazard mitigation ¾ State and Local governments, programs with implementation as an essential component ¾ Certain Not for Profit Corporations -- Development or improvement of warning systems ¾ Indian Tribes or authorized tribal organizations ¾ Alaskan corporations not privately owned.
106 State of New Hampshire, Natural Hazards Mitigation Plan, Executive Summary: October 2000 Edition
The NH 404 Administrative Plan calls for a State Hazard Mitigation Team to review all HMGP applications. The Team is comprised of individuals from various State Agencies. Presently represented are: NH Office of Emergency Management (SHMO), NH Office of State Planning/National Flood Insurance Program (the CDBG Coordinator from OSP serving as first alternate), NH Department of Environmental Services; Water Supply and Water Resources Divisions, NH Department of Transportation and the NH Department of Resources and Economic Development; Division of Forests and Lands.
The 404 Administrative Plan is currently under review by the SHMO and upon identification of proposed modifications and review by the State’s Hazard Mitigation Team, an amended Plan may be forthcoming within the year.
This Plan, and the Inter-Agency Hazard Mitigation Team Reports, are utilized as guides by the State Hazard Mitigation Team in its review and prioritization of all applicant’s proposed mitigation initiatives in accordance with 44 CFR Section 206.434 (i.e. with respect to eligibility criteria such as effectiveness, practicality, benefit/cost ratio, environmental soundness, the State’s priorities etc.).
As of the submission of this Summary of the 409 Plan, there are five such Disaster Declarations “open,” or active from which funds have been made available and regarding which, various hazard mitigation initiatives are being funded. These HMGP funds are associated with:
NH HMGP Funding Status
Declaration Date Event Type FEMA # Total Grant Status
August 27, 1986 Severe Storms/Flooding DR-771-NH No HMGP N /A April 16, 1987 Severe Storms/Flooding DR-789-NH No HMGP N / A August 29, 1990 Severe Storms/Winds DR-876-NH $ 172,145 Closed
September 9,1991 Hurricane DR-917-NH $ 75,428 Closed November 13, 1991 Coastal Storm/Flooding DR-923-NH $ 61,670 Closed January 3, 1996 Heavy Snow DR-1077-NH $ 311,787 Open O*
October 29, 1996 Storms/Floods DR-1144-NH $ 647,753 Open O* January 15, 1998 Severe Storms/Flooding DR-1199-NH $ 1,584,709 Open O* July 2, 1998 Ice Storm DR-1231-NH $ 483,909 Open O*
October 18, 1999 Severe Storms DR-1305-NH $ 84,390 Open U**
* O = All Funds Are Obligated **U = All Funds Are Not Currently Obligated
On 10/7/98, 10/29/98, and 11/23/98, 3/15/99, 5/10/99, 6/10/99, 6/22/99, 8/24/99, 12/22/99, 4/11/00 and 7/6/00 the State Hazard Mitigation Team convened and reviewed all applications as had been submitted pursuant to the NOI’s with respect to DR-1199-NH, DR-1231-NH, and DR-1305-NH.
To date, the State has successfully submitted qualifying HMGP applications to allow FEMA to obligate all available funding from all declarations save DR-1305-NH. The deadline for submission of applications for DR-1305-NH is April 18, 2001.
During the course of the preparation of this Plan, the SHMO has convened with a variety of representatives from agencies involved in Hazard Mitigation statewide. From these conferences, several proposals are anticipated to be, or have been, forthcoming,. Two such proposals with statewide significance were FEMA approved:
1. A statewide river gauging and real-time flood forecasting network analysis and implementation, 2. A HAZUS compatible inventory and structural assessment (as to wind, flood, snow loading and seismic activity) for the State’s Critical Facilities
The SHMO has conducted several community visits to inform community officials of the existence of available funding and to provide technical assistance with respect to the grant application process. Additional community support visits/notification sessions are planned for the near future. 107 State of New Hampshire, Natural Hazards Mitigation Plan, Executive Summary: October 2000 Edition
Public Assistance and Hazard Mitigation
Stafford Act, Hazard Mitigation Section 406 Section
(*See 44 CFR 206.226 (c)) 406 Mitigation
Hazard Mitigation, as per Section 406 of the Stafford is Hazard Mitigation which Act is a funding source for cost-effective measures that would is specific to a given reduce or eliminate the threat of future damage to a facility Disaster Declaration, damaged during the disaster. specific to a given site, associated with a FEMA The measures must apply only to the damaged Damage Survey Report is elements of a facility rather than to other, undamaged parts of referred to as “406 the facility or to the entire system. For example, if flooding mitigation.” This Authority inundates a sanitary sewer and blocks the manholes with is derived under Section sediment, mitigation to prevent the blockage of the damaged 406 of the Stafford Act. manholes in a future event may be considered eligible. The Cost Share However, work to improve undamaged manholes associated with this using the same method would not be eligible, even though the program is the same as manholes are part of the same system. with the FEMA Public Assistance Program: Hazard Mitigation measures restore a facility beyond its pre-disaster condition. 75% FEMA
Section 406 mitigation measures are considered part of 12.5% State the total eligible cost of repair, restoration, reconstruction, or replacement of a facility. They are limited to measures of 12.5% Local permanent work, and the applicant may not apply mitigation funding to alternate projects or improved projects if a new replacement facility is involved.
Upgrades required to meet applicable codes and standards are not “mitigation measures” because such measures are part of eligible restoration work.
*For the text of 44 CFR, Section 206 See: http://frwebgate4.access.gpo.gov/cgi- bin/waisgate.cgi?WAISdocID=4228820631+1+0+0&WAISaction=retrieve
108 State of New Hampshire, Natural Hazards Mitigation Plan, Executive Summary: October 2000 Edition
National Flood Insurance Program
NH Office of State Planning
Description and mission NFIP in New Hampshire
RSA 4-C contains the Office of State Planning’s duties and The NFIP Program responsibilities for planning, grants management, technical assistance, Began in NH in 1969 data management and coordination. One such responsibility is as the state coordinator for the National Flood Insurance Program (NFIP). Total Eligible Communities 234 The one full-time position provides advice and technical assistance to municipalities in their effort to maintain eligibility in the NFIP. More Total participating recently OSP has agreed to assist in the administration of the Flood communities in 1989 89 Mitigation Assistance program with the Office of Emergency Total participating Management (OEM). OSP works directly with the Federal Emergency communities in 1998 192 Management Agency (FEMA) and the NH OEM to obtain and disseminate timely and accurate information and technical assistance Performs an average of 10 commu- with regard to the NFIP. See CFR 59-61, 77-78 (Flooded Property nity assistance visits each year Purchase Program and FMAP) for the NFIP’s legal authority. (including support of some adjoining communities in Vermont) Mitigation Involvement 9 recent presentations before the The Office of State Planning (OSP), in cooperation with OEM, Banking and Insurance Industry administers and coordinates the State’s role in the National Flood A Gubernatorial Declaration in place Insurance Program (NFIP). The NFIP is a grass roots approach to advising all State Agencies to abide reducing structural damage from flooding. Communities adopt by the local Floodplain Regulations floodplain regulations into their local zoning ordinances. The Model Floodplain Ordinance adopted by most of the 192 participating NHDES Solid Waste Permits are communities regulates development within the 100-year floodplain. The issued in accordance with Floodplain regulations mitigate flood damage by requiring new and substantially Regulations improved structures to be built or floodproofed to, or above the 100-year base flood elevation (BFE). OSP makes approximately 30 community Two NH Superior Court Decisions in visits a year to ensure that participating communities have the proper place upholding the communities’ regulations as well as to educate the local officials as to their NFIP responsibility to enforce its NFIP Floodplain Ordinance responsibilities. These community visits, along with annual workshops for local officials, land surveyors, engineers, lenders and insurers play a All 10 Counties are aware of their vital role in ensuring that the primary goal of the NFIP is implemented responsibilities to the NFIP that is, to reduce the loss of life and property due to flooding.
The Office of State Planning assists in the Administration of the Flood Mitigation Assistance (FMA) Program that was created by the Federal Emergency Management Agency (FEMA) in 1996. FMA monies are pre-disaster monies used to reduce the risk of flooding to insurable structures either through a planning grant or a project grant. Any community participating in the NFIP may apply for a planning grant to develop a flood hazard mitigation plan. Once a plan is adopted (and approved by FEMA), the community may apply for a project grant. Eligible types of mitigation projects include elevating or floodproofing insured structures, acquisition, relocation, demolition, beach nourishment activities or minor, localized structural projects that are not eligible under other State or Federal programs. Only projects that are mentioned in the mitigation plan may be funded (See page 111.).
(NFIP information in this Plan provided courtesy of Jane Hubbard and George Musler of the NFIP Program from NHOSP and NHOEM respectively) 109 State of New Hampshire, Natural Hazards Mitigation Plan, Executive Summary: October 2000 Edition
A representative from OSP/NFIP sits on the State’s Hazard Mitigation Team. The team convenes after a disaster has been declared to decide how Hazard Mitigation monies will be spent.
Spicket River (interstate) Planning
OSP, along with Massachusetts Department of Environmental Management (MADEM), has been instrumental in organizing an interstate committee to develop a Spicket River Flood Mitigation Plan. An executive committee representing Lawrence and Methuen, MA and Salem, NH has been created. The goal is to develop a flood mitigation plan for the entire watershed, thereby reducing the amount of flood damage along the Spicket River.
Mitigation goals and objectives:
With respect to hazard mitigation, the NFIP Coordinator’s goal is to reduce the loss of life and property damage due to flooding. A short-term goal is to assist the State Hazard Mitigation Team in approving HMGP and FMA grants in order to disseminate the grant monies in a timely manner. In addition, the NFIP Coordinator will continue to work with the Spicket River Task Force and ultimately use the process employed in Salem as an example for other similarly situated communities in New Hampshire. The NFIP Coordinator will conduct 20 Community Assistance Visits (CAVs). These CAVs will ensure that communities are properly enforcing the NFIP requirements. One of OSP’s intermediate goals is to increase the number of Flood Mitigation Assistance (FMA) applications, with several of the applications being for projects rather than plans. Long-term objectives will be the continuous education and training of local officials, engineers, surveyors, lenders, agents and others directly involved with the implementation of the National Flood Insurance Program (NFIP). Finally, what is always an issue when dealing with the NFIP is the accuracy of the Flood Insurance Rate Maps (FIRM) used to ensure proper regulation. Unfortunately, funding for map improvement limited. The NFIP coordinator would like to be involved in any considerations to improve the FIRMs.
Talent Capability:
Municipal planning experience, good relations with many local officials, access to GIS information, and access to the NH Coastal Program.
Projects/Planning Desired:
The NFIP coordinator’s position at OSP is entirely federally funded. It is highly unlikely that OSP will fund any mitigation projects. However, through the assistance of the NFIP Coordinator, OSP will provide in-kind assistance to mitigation projects that are applicable to the responsibilities of the NFIP coordinator:
OSP Resources with respect to hazard mitigation:
Funding sources managed: None. Personnel: One full time position - NFIP State Coordinator. The primary responsibility of this position is to administer the NFIP in the state. Planning Sources: OSP maintains information on demographics (populations, housing and building code info), land use regulations in all NH municipalities, local and regional water resource plans, and community participation in the NFIP. FEMA Publication, Multi Hazard Identification and Risk Assessment 110 State of New Hampshire, Natural Hazards Mitigation Plan, Executive Summary: October 2000 Edition Authority The Flood Mitigation Assistance Program derives its Authority pursuant to 42 U.S.C. 4001 et seq.: 42 U.S.C. 4104c, 4104d: Reorganization Plan No. 3 of 1978 Comp., p.329; E.O. 12127 of Mar. 31, 1979, 44 FR Flood Mitigation Assistance 19367, 3 CFR, 1979 Comp., p.376
Program See 44CFR Part 78
New Hampshire has been a participant in the Flood Mitigation Assistance Program Flood Mitigation Assistance Program (FMA or FMAP) since 1996/97. ⇒ NFIP Funded by a % of Policy Premiums ⇒ Planning Grants In 1997, the State was awarded funds to assist ⇒ Technical Assistance Grants to States communities in Flood Mitigation Planning and (10% of Project Grant) Projects. A prerequisite of accessing the project funds ⇒ Project Grants to communities under FMAP is that a community have a FEMA ⇒ Communities must have FEMA approved Flood approved Flood Mitigation Plan in place. Mitigation Plan to receive Project Funds ⇒ Maximum of a 75% Federal Share allowed A Plannin g Grant from 1996/97 was awarded to ⇒ 12.5% may be an in-kind match the City of Keene in 1998. In preparation for the ⇒ 12.5% must be from locally derived funding developm ent of the Flood Mitigation Plan, the Planning Department of the City of Keene created a Eligible Projects Include: GIS database of its floodplain and digitized its tax assessing maps as well as its Special Flood Hazard Elevation of NFIP insured residential structures Areas in GIS layers. The Keene Flood Hazard Elevation and dry-proofing of NFIP insured non- Mitigation Plan is considered a Model in the State residential structures and its Project development and prioritization Acquisition of NFIP insured structures and underlying approach is especially noteworthy. real property Relocation of NFIP insured structures from acquired or In 1998, the FMAP Planning Grant was awarded restricted real property to sites not prone to flood hazards to the Town of Salem. Given the complexity of the Demolition of NFIP insured structures on acquired or restricted real property issues in the Spicket River watershed, The Town of Other activities that bring NFIP insured structures into Salem subcontracted a substantial portion of the compliance with statutorily authorized floodplain developm ent of its Plan to a private engineering firm. management requirements Salem submitted the State’s first Plan and proposed Beach nourishment activities that include planting native projects in May, 1999 that were approved by FEMA. dune vegetation and/or the installation of sand fencing. Minor physical mitigation projects that do not duplicate The 1999 FMA Planning Grant was awarded to the flood prevention activities of other Federal agencies the Town of Hampton, the State’s highest policy- and lessen the frequency of flooding or severity of holding community and the highest “repetitive loss” flooding and decrease the predicted flood damages in comm unity. Hampton employed the services of a localized flood problem areas. These include: Planner from the Rockingham RPC and delivered its modification of existing culverts and bridges, installation or modification of flood gates, stabilization of stream Plan to FEMA for review in May 2000. banks, and creation of small debris or flood/storm water
The 2000 FMA Planning Grant was awarded to retention basins in small watersheds (not dikes, levees,
Gorham and a Plan is expected by December 2000. seawalls etc.)
Gorham is undertaking its Flood Hazard mitigation planning initiative under FMAP in coordination with its Project Impact inspired All Hazards Mitigation Flood Mitigation Assistance Program planning process. Funding Available to the State of New Hampshire
Fiscal Planning Technical Project Total The program has been (essentially) level funded Year Grant Assistance Grant Grant for federal fiscal year 2001 which began on October 1996 / 97 $ 10,900 $ 10,860 $ 97,740 $ 119,500 1, 2000. 1998 $ 11,000 $ 11,060 $ 99,540 $ 121,600 The State has received and approved a Planning grant application from the Town of Holderness. The 1999 $ 10,900 $ 11,160 $ 100,440 $ 122,500
Town intends to work with the Lakes region Planning 2000 $ 11,000 $ 11,180 $ 100,620 $ 122,800 Comm ission in the creation of their FMA plan. 2001 $ 10,900 $ 11,150 $ 100,350 $ 122,400 111 State of New Hampshire, Natural Hazards Mitigation Plan, Executive Summary: October 2000 Edition
PROJECT IMPACT
Beginning in Federal fiscal year (FY) 2000 and continuing through FY 2001, MAP, DPIG and Project State Administrative funds have been combined with • States nominate communities annually
other FEMA funding into the Emergency Management Performance Grant (EMPG). To date, the funds are being maintained in the original program lines by NHOEM. • Final selection by FEMA • Hazard Mitigation Planning and Technical New Hampshire began its participation in Project Impact with the Assistance Provided nom ination of the Town of Peterborough as Project Impact Community for 1998. The Town was awarded a $500,000.00 grant to initiate Hazard • Project and Planning Grants Awarded Mitig ation Planning and projects and to assist in building partnerships with (Totals: $500K in 1998 and $300K in 1999) local businesses and other entities interested in reducing the community’s Project Impact is designed to ”Build a Disaster losses resulting from various disasters to which the community has been, Resistant Community” by assisting them in the or m ay be exposed. formation of public/private partnerships with The State distinguished itself nationally at the Project Impact Summit held “seed” grants. Eligible grant activities include: in Washington, DC in December 1998 when its selection of three ¾ Mitigation for existing structures comm unities for participation in Project Impact 1999 was announced. ¾ Adoption of policies or practices going to On 10 /29/99, with referrals from the NHOEM Field Reps, the State mitigating effects of hazards Hazard Mitigation Team Nominated two communities for Project Impact ¾ Activities that lead to building and/or 1999 which were approved by FEMA. The Grant Award for Project sustaining public/private Hazard Mitigation Imp act 1999 was $300,000.00, which will be divided according to the partnerships follo wing formula: Project Impact also provides the States with an $200,000.00 will be awarded to the Town of Salem and administrative budget, which may be used to $100,000.00 will be awarded to the Town of Plymouth, which directly support Project Impact communities and to has formed a coalition with the adjacent Town of Holderness to convene statewide support for comprehensive conduct Hazard Mitigation Planning and address repetitive losses Hazard Mitigation strategies. Funds may be used from flooding. for:
The Town of Holderness (the State's 3rd highest NFIP repetitive loss ¾ Funding training initiatives community) is currently working with the Lakes Region Planning ¾ Support necessary travel expenses
Commission toward the development of a Flood Mitigation Planning ¾ Provide related mini-grants to Project Impact
Grant application through the FMA program. Communities
¾ Fund costs of information development and
On 3/15/99, the State’s Hazard Mitigation Team voted to nominate the dissemination in support of Project Impact
Communities of Gorham and Lancaster to participate in Project Impact ¾ Fund development of training packages for
2000, giving NH a total of six participating communities. State and local Officials These Project Impact 2000 communities were formally accepted by ¾ Fund expert short-term technical assistance to FEMA at the Project Impact Summit in Washington, DC in December communities 1999 .
On Ju ly 6, 2000, the State Hazard Mitigation Team met and considered nominations for Project Impact 2001. Recognizing the proactiv e initiatives of two specific communities, the Team nominated the Towns of Winchester and Hampton.
Since 1998, FEMA has sponsored annual mentoring “Summits” in Washington, D.C. and the State’s Project Impact communities have been well represented at each of these. In December 1999, the community of Salem was a national award nominee for its pro- activ e Project Impact initiatives.
The FEMA Region I office has offered two Regional mentoring Summits: in Stowe, VT in May of 1999 and most recently in Falm outh, MA in May of 2000.
The State, via the office of the SHMO, continues to offer Technical Assistance and Project Impact related mentoring meetings to
Project Impact community officials and other interested persons. NHOEM has contracted with several consultants to assist the
Project Impact communities with the Hazard Identification and Risk Assessment portions of their respective community All Hazards
Mitigation Plans.
With a $50,000 FEMA grant, NHOEM will continue to support the Project Impact concept by providing technical and related suppo rt to the participating communities in their planning and project identification/execution activities. This grant has facilitated such activities as a CRREL River Ice Workshop as was held at CRREL in Hanover in April of 1999. River Ice is a significant hazard in many Project Impact communities. The SHMO shall also endeavor to coordinate, catalogue and disseminate all information regarding any and all resources as may be developed as a result of Project Impact initiatives (as well as all other State/FEMA Hazard Mitigation initiatives) for prudent exploitation by all of New Hampshire’s State Agencies, communities and other interested parties. 112 State of New Hampshire, Natural Hazards Mitigation Plan, Executive Summary: October 2000 Edition
Mitigation Assistance Program
FEMA’s Hazard Mitigation Assistance Program supports Hazard Mitigation planning and implementation activities that reduce long-term hazard vulnerability and risk. Funding is provided pursuant to the Stafford Act.
(See 44 CFR, Part 361, Subpart A)
Beginning in Federal fiscal year (FY) 2000 and Mitigation Assistance Program
continuing through FY 2001, MAP, DPIG and Project State Administrative funds have been • Create and maintain comprehensive State combined with other FEMA funding into the Hazard Mitigation Programs i.e., centrally Emergency Management Performance Grant coordinate all State Hazard Mitigation activities (EMPG). To date, the funds are being maintained for all identified hazards, and provide financial in the original program lines by NHOEM. and technical assistance to communities and local governments This program supports the Natural Hazards • 75% FEMA - 25% State in-kind or cash Program) at NHOEM described on page 104, and provides funding for State and Local Eligible Activities planning, training and administrative support ¾ Preparedness and Response Planning to both the Natural Hazards Program Officer ¾ Mitigation Planning and Implementation and the State Hazard Mitigation Officer, as ¾ Public Awareness and Education well as grants which promote hazard mitigation locally and statewide.
Technical Assistance sessions are provided to communities and State agencies through individual community outreach visits and regional seminars.
Past MAP Funded Mitigation Initiatives
MAP funds have been, and are presently being used to support the Natural Hazards Program including: - Support CEMPS, Hurricane Program and other initiatives of the Natural Hazards Program Office - Support for Non-Commercial Service Announcements - Support State and local officials with training and travel expenses - Support the development of a NH Guide to Local Community Hazard Mitigation Planning and - To bring training in community Hazard Mitigation Planning to members of the nine Regional Planning Commissions throughout the State
Present MAP Funded Mitigation Initiatives
¾ Support CEMPS, Hurricane Program and other initiatives of the Natural Hazards Program Office ¾ Support a cooperative effort between NHOEM, NHDES-WRD and NH GRANIT, to digitize the State’s Class B and Class C dams including digitization of the inundation pathways in a GIS format ¾ Support State and local officials with training and travel expenses ¾ Support continued State and local Hazard Mitigation Planning and Projects ¾ Support the SHMO with training and travel ¾ Provide Technical Assistance to State and local officials
Future Initiatives Intended with MAP Funding
¾ Continued support of the Natural Hazards Officer’s program initiatives ¾ Extend the support for the creation of local community planning ¾ Continued Support of State and local officials with training and travel expenses ¾ Provide Technical Assistance to State and local officials 113 State of New Hampshire, Natural Hazards Mitigation Plan, Executive Summary: October 2000 Edition
Disaster Preparedness Improvement Grant (DPIG)
FEMA and the State co-sponsor the DPIG Program, which supports the development and updating of disaster assistance plans and capabilities and promotes educational opportunities with respect to preparedness and mitigation.
Authority: See Subchapter E. of 44 CFR.
B eginning in Federal fiscal year (FY) 2000 and continuing through Disaster FY 2001, MAP, DPIG and Project State Administrative funds have been combined with other FEMA funding into the Emergency Preparedness M anagement Performance Grant (EMPG). To date, the funds are be ing maintained in the original program lines by NHOEM. Improvement
Past DPIG initiatives include: Grant
¾ Support of the position of Protection Planner/Hazard Evaluate natural hazards on a Mitigation Officer • continuing basis and develop ¾ Installation of river gauges programs and actions required to ¾ Support of the NH State Environthon School Program mitigate such hazards ¾ Coordinate the Voluntary Organizations Active in Disasters (VOAD) Program (See Resource Profile Annex) NHOEM via • Provide Technical Assistance the DPIG has sponsored annual meetings with training Grants to States of up to $50,000 workshops • annually ¾ Sponsoring Dam Safety Training initiatives and workshops ¾ Production and distribution of a handbook for small • 50% State match - cash or in kind embankment dam owners ¾ Inventory of the State’s Dams Eligible Projects Include: ¾ Review of Dam Plans ¾ Sponsored extensive statewide, two day workshops for Granite State Incident Stress Debriefing Teams and funded educational ¾ Evaluations of Natural Hazards materials ¾ Hazard Mitigation activities (i.e. Plan/ ¾ Community visits and production of informational materials policy/program/strategy development ¾ Assist with Plan Annex update for local Haz Mat planning. ¾ Plan updates ¾ Funding workshops for NH Road Agents in cooperation with ¾ Handbooks: publication & distribution the T2 program of the Technology Transfer Center at the ¾ Creating exercise materials University of New Hampshire ¾ Developing Standard Operating Procedures Present DPIG funded Hazard Mitigation initiatives ¾ Training state employees ¾ Report of formal analysis of State ¾ Support the position of Protection Planner/Hazard Mitigation enabling legislation and authorities Officer ¾ Update inventory of State/local ¾ Continued support of the Environthon Program Critical Facilities ¾ Development of this Plan ¾ Develop a tracking system of critical ¾ Providing Technical Assistance to State and local officials actions to be taken post-event ¾ Development of Emergency Operations Plans (EOPs) for ¾ Creating Damage Assessment Plans Significant and High Hazard dams and defining procedures
¾ Developing Plans for procedures Future DPIG funded Hazard Mitigation initiatives when no Federal Aid is forthcoming ¾ Continued Support the position of Protection Planner/Hazard ¾ Creating Plans for Search and Mitigation Officer Rescue Operations ¾ Continued support of the Environthon Program ¾ Developing Disaster accounting ¾ Update and maintenance of this Plan procedures ¾ Provide Technical Assistance to State and local officials This list is not exhaustive ¾ Support of other planning, technical assistance and training as indicated ¾ Digitization of EOPs for the State’s “Significant” and “High Hazard” dams to provide rapid access to information in Emergency situations and to facilitate Plan maintenance.
114 State of New Hampshire, Natural Hazards Mitigation Plan, Executive Summary: October 2000 Edition
Disaster Relief Initiatives (DRI)
Pursuant to a given Presidential Declaration of Disaster, the state(s) may apply to the U.S. Congress for assistance with needs as may yet be “unmet.” Following DRs 1144, 1199 and1231, this State has received the following:
Community Development Block Grant (CDBG)
These Federal funds are provided through the U.S. Department of Housing and Urban Development (HUD) and are administered by the CDBG Program of the New Hampshire Office of State Planning.
The specific CDBG funds designated for Hazard Mitigation purposes are made available to address “unmet needs” pursuant to a given Disaster Declaration to States which request them and forward Community Development a proposed list of expenditures. For these funds, project selection Block Grant guidance is provided by NHOEM and NHOSP administers the grant. Funds are provided through theUSDA, Pursuant to Declaration DR-1144-NH, $557,000.00 was Dept. of Housing and Urban Development made available to the State. The Town of Salem applied for, and has for a Declared Disaster’s “Unmet Needs” been designated to receive these funds toward the acquisition of a 19 Projects must meet one of three National unit mobile home park that lies in the floodplain and floods regularly. Objectives:
Pursuant to DR-1199-NH and DR-1231-NH, the DRI grant ¾ Provide a direct benefit to low and award was $1,500,000.00 for each event. moderate income persons or households In October of 1998, HUD announced the program ¾ Prevent or eliminate slums and blight guidelines for the expenditure of the DRs1199 and 1231-NH related ¾ Eliminate conditions which seriously funding awards. Projects were submitted from four communities. and immediately threaten the public health and welfare Community Development Block Grant Additional conditions with respect to the Unmet Needs Disaster Relief Funding Summary expenditure of these funds includes the provision that at least 50% of the grant award must be Declaration Date FEMA # Total Grant Status expended in a manner which benefits individuals
October 29, 1996 DR-1144-NH $557,000 Open / Obligated who earn 80% or less than the area’s (county’s) median income.
January 15, 1998 DR-1199-NH $ 1,500,000 Open / Obligated (for more on CDBG see NHHFA-CDBG Website http://nhhfa.sr.unh.edu/)
July 2, 1998 DR-1231-NH $1,500,000 Open / Obligated
FEMA-Administered CDBG DRI Funding Authorities: Disaster Relief Initiative Funding As of August 1999, additional funding has been made available to 1997 Flood DR-1144-NH: The 1997 Emergency the State pursuant to DR-1199-NH that will be expended for a Supplemental Appropriations Act for Recovery from Natural Disasters variety of statewide Hazard Mitigation initiatives including: (Public Law 105-18; approved June 12, 1997) ¾ Statewide Fleet of Emergency Power Generators 1998 Ice Storm DR-1199-NH: “The 1997 Emergency ¾ Essential Facilities Inspection Supplemental Appropriations and Redecisions Act ¾ High Elevation Precipitation Modeling/Flood Forecasting (Public Law 105-174, 112 Stat. 52 et, seq., Approved ¾ Wildland Fire Suppression initiatives/debris related May 1,1998). ¾ River Corridor Stewardship/Hazard Mitigation Planning ¾ Communications Enhancements initiatives FEMA Administered DRI FEMA Administered Disaster Relief Initiative Grant Grant Authority Unmet Needs Disaster Relief Funding Summary
Federal Register / Vol. 64. No. 151 / Friday,
Total Grant August 6, 1999 / Notices. Declaration Date FEMA # Status P.L. 106-31 Emergency Supplemental Open January 15, 1998 DR-1199-NH $ 3,937,000 (HMGP guidelines) Appropriations Act for Fiscal Year 1999.
115 State of New Hampshire, Natural Hazards Mitigation Plan, Executive Summary: October 2000 Edition
Pemigewasset River Corridor Stewardship Program
Long-range Planning • Form a local watershed corridor working group. Findings: • Develop a corridor reference center for flood information for local and state use. General Corridor field observations: • Compile local information on the river corridor, such as historic data, photographs and hydrologic studies. • Flood safety is a serious concern. • Provide motel flood safety regulations for the corridor. • Communities desire additional assistance • Reduce flooding potential as recommended by NHDOT by • More corridor planning would be helpful conducting: independent flood analysis of corridor.” • Completion of flood mapping and revision of existing mapping are needed. Flood Awareness and Warning • Workshops are needed to help communities • Use phase two public information video for general information • River dynamics is a major in flood safety. and training. • Erosion is taking place at many urban and rural reaches. • Develop a flood hazard booklet for municipal officials. • There is a potential for accelerated erosion and raw banks. • Supplement flood hazard information for Plymouth State • Flooding is a potential problem in many locations. College. • Flooding appears to be a potential problem at some recent • Install flood warning signs. construction.
• Deep and fast flooding is probable in some areas. Forecasting and Data Collection • Potential ice jams could raise flood levels higher than anticipated • Install transmitting rain gages in Upper Basin and river gauges in several locations and reduce warning time. on bridge abutments. • Public safety issues include steep banks, stability of riverbanks and • Form a local working group to investigate and develop a structures and deep flooding. corridor-based river stage monitoring and flood prediction computer network. • There are no warning signs for deep flood hazard areas flood plain sewage plants and water supplies are susceptible to damage from MILESTONES ice jams and storms greater than the 100-year (1% chance). • Large amounts of sediment are in some urban reaches. Milestones include: • Sediment and debris may plug flow areas and culverts. • First project in NH to study a river corridor for flood safety and • Main channels may shift in some depositional reaches with flood hazard mitigation. potential to cause severe erosion and damage. • Three successful data gathering workshops held in corridor • Streambank protection at most major bridges appears satisfactory. communities. • Continued erosion of some areas downstream of streambank riprap • Workshops provided a beneficial forum for discussion of may cause future problems. problems and solutions. • Some streambank protection consists of small river rock and may • Community and landowner flood safety and hazard mitigation not provide sufficient protection during high flows. needs identified. • Field examination of the corridor to observe community urban Recommendations: flood safety problems and potential problems. • Photographs of general and potential problem areas. Interim conclusions and recommendations:
• Aerial video of the River from Lincoln to Franklin. Stream Maintenance • Stronger communications and working relationships between • Develop a broad program for implementation of maintenance. communities and agencies and between agencies. • Consider revising permit process and develop Best Management • Cooperation to proceed with guidelines, checklist and Best Practices to ensure “looking ahead.” Management Practices for stream maintenance and emergency and long-term permitting. • Determine flooding potential where studies were done after development and for buildings with unknown vertical datum. PHASE TWO • Calculate approximately flood potential where details studies are not available. Phase Two will provide the “solution” for mitigation and flood safety. • Provide training to towns on liability issues and possible specific- Phase two will provide working tools and planning solutions to type planning solutions and mitigation measures. communities and landowners and includes: National Flood Insurance Program STREA M MAINTANNCE AND PLANNING • Complete Flood studies with large-scale mapping. • Develop pilot for enhancing existing mapping. • Developing guidelines and checklists for routine preventative • Towns frequently review maps and profiles for training and checks stream maintenance. on accuracy. • Simplifying emergency and long-term permitting processes. • Review FIRM maps in terms of ice jam potential. • Recommending flood hazard mitigation strategies to towns. • Notify citizens of flooding potential and availability of insurance. • River corridor flood safety “solutions” workshops. • Framework and workshop for continued planning. Maintenance of Public Facilities • Give priority to sewage and water supply facilities. FLOOD HAZARD INFORMATION, AND RIVER CORRIDOR • Incrementally flood proof sewage and water facilities as near to AWARENESS AND TRAINING the 500-year flood level as possible. • Inspect and analyze sewage dikes for dam safety. • Public flood safety information and training video. • Review elevations of power substations in flood plains. • River documentation videos for planning upper, upper middle and lower parts of the corridor. 116 State of New Hampshire, Natural Hazards Mitigation Plan, Executive Summary: October 2000 Edition
New Hampshire Mutual Aid for Public Works
Description and Mission
The goal of New Hampshire Mutual Aid for Public Works is to facilitate quick response to public works emergencies by creating a intercommunity cooperative. The program creates a network of communities that will assist one another during emergency situations. This is done through the creation of partnering agreements and fashioning a protocol for requesting and receiving mutual aid. The program provides for the compilation of a list of resources available from participating communities. The resources list is a time saver because it enables participants to contact communities directly that may have the resources required to assist with emergencies at hand.
Mitigation Goals and Objectives:
Goals: short term (1-3 years).
Goal I. Create a mutual aid program for New Hampshire Public Works.*
Goal II. Enhance program to include full-participation.
Goal III. Provide training to program participants.
Goal IV. Seek funding for support personnel.
Goals: long term (3-5 years).
Goal I. Extend program statewide Goal II. Extend program regionally, beginning with contiguous states. Goal III. Provide additional training for program participants as indicated
Resources
The Mutual Aid Program for Public Works has a board consisting of nine people with four ex-officio members. Membership includes: 4 members of the New Hampshire Road Agents Association, 2 members of the New Hampshire Public Works and Municipal Engineers, 1 member of the New Hampshire Municipal Management Association, 1 member of the New Hampshire Association of Fire Chiefs, and 1 member of the New Hampshire Association of Chiefs of Police. The ex-officio members include: the Commissioner of the New Hampshire Department of Transportation, or designee, the Director of the New Hampshire Office of Emergency Management, or designee, the Director of the University of New Hampshire Technology Transfer Center, or designee, and the Executive Director of the New Hampshire Municipal Association, or designee. The New Hampshire Technology Transfer Center is responsible for the training aspect of the program. The Center has the resources of two full-time staff members along with two part-time people. It is situated at the University of NH and has access to the resources of the University of New Hampshire. The program also has the full support of the New Hampshire Road Agents Association, the State Office of Emergency Management along with the New Hampshire Municipal Association which is fiscally responsible for the program.
In its first two years of existence, the program has managed to recruit 60 communities and catalogue their respective resources. This publication is posted to the web.
117 State of New Hampshire, Natural Hazards Mitigation Plan, Executive Summary: October 2000 Edition
Hazard Mitigation Resource Profiles
As an element going to the development of this Plan, the SHMO created a Hazard Mitigation Resource Profile Outline and circulated it to representatives of various Federal, State and private agencies that contribute to Hazard Mitigation Planning and/or the execution of Hazard Mitigation Measures throughout the State.
The response from these agents was encouraging and several Profiles are included in this Executive Summary for the purpose of providing the reader with an opportunity to gauge the scope and content of respective Profiles.
The specific selections herein were Resource Profile Annex Index (as of 8/1/99) chosen because they delineate resources Federal Agencies available to New Hampshire State and/or local U.S. Army Corp of Engineers officials (material for the Dam Failure, Cold Regions Research and Engineering Laboratory NHOSP/NFIP and Coastal Programs USDA, Natural Resources Conservation Service U.S. Geological Survey, New Hampshire Vermont District subsections above was taken directly from the National Weather Service, Taunton, MA NHDES – Water Resources Division’s and the U.S. Fish and Wildlife Service NHOSP – Coastal and NFIP Programs’ State of New Hampshire Resource Profiles). NH Office of Emergency Management Office of Protection Planner/Hazard Mitigation Terrorism Consequence Management A copy of any or all such Profiles may be Preparedness Assistance Program obtained by postal service or by email by Technological Hazards contacting the SHMO. Training Section NH Office of State Planning National Flood Insurance Program Contact: John Shaughnessy NH Coastal Program Community Development Block Grant Program By mail: NHOEM, 107 Pleasant Street, NH Department of Transportation Concord, NH 03301 NH Department of Environmental Services Wastewater Engineering Bureau By telephone at (603) 223-3637, Water Resources Division By facsimile transmission at (603) 225-7341 NH Department of Health and Human Services Office of Community and Public Health – Or by Email at: Public Health Laboratories [email protected]. Licensing and Regulation Services – Bureau of Food Protection NH Department of Safety Division of Fire Standards and Training NH Division of Historical Resources Visit the Hazard Mitigation Section of the State Historic Preservation Office NHOEM website and view the list and text of University of New Hampshire Technology Transfer Center all existing Resource Profiles at GRANIT GIS System www.nhoem.state.nh.us/mitigation Complex Systems Research Center
Regional Planning Commissions Southwest Regional Planning Commission
Private Organizations Northeast States Emergency Consortium NH Association of Broadcasters National Voluntary Organizations Active in Disasters (VOAD) NH Mutual Aid
118 State of New Hampshire, Natural Hazards Mitigation Plan, Executive Summary: October 2000 Edition
Hazard Mitigati on Resource Profile
U.S. Army Corps of Engineers Contacts:
John Kennelly, Chief, Special Studies Section (for Flood Plain Management Services activities), tel. 978-318-8505, fax 978-318-8080, e-mail, [email protected]
Mike Keegan, Chief, Project Planning Section (for Section 14, 103, and 205 authorities), tel. 978-318-8087, fax 978-318-8080, e-mail, [email protected]
Address: US Army Corps of Engineers New England District 696 Virginia Road Concord, Massachusetts 01742-2751
Description and Mission:
The Corps of Engineers is a multi-disciplinary engineering and environmental organization that has been identifying and meeting the water resources needs of the nation. These needs have been in the areas of flood damage reduction, flood plain information and management, navigation, shore protection, environmental restoration, water supply, streambank protection, recreation, and fish and wildlife resources conservation, as well as technical assistance in other water resources areas.
The New England District (NAE) of the Corps of Engineers is responsible for managing the Corps' civil responsibilities in a 66,000 square-mile region encompassing the six New England states east of the Lake Champlain drainage basin. The District and its leadership are headquartered in Concord, Massachusetts. The missions of the New England District are many and varied. They include:
• flood damage reduction • navigation improvements and maintenance • natural resource management • streambank and shoreline protection • disaster assistance • environmental remediation and engineering • engineering and construction management support to other agencies
Flood Mitigation Involvement:
As a result of the catastrophic floods in 1936, 1938 and 1955, the Corps was called upon to undertake a comprehensive flood damage reduction program. Since then the Corps has built many flood control structures throughout New England. These include 35 dams and reservoirs, five hurricane protection barriers (two are operated by the Corps) and approximately 60 local flood protection projects. The New England District has also completed two nonstructural projects involving the relocation of flood prone property and the acquisition of natural flood storage areas. The Corps also provides technical assistance to states and municipalities in locally
119 State of New Hampshire, Natural Hazards Mitigation Plan, Executive Summary: October 2000 Edition
constructed flood damage mitigation projects and to promote wise and informed use of floodplain and natural retention areas in order to minimize potential future flood damages.
Mitigation Goals and Objectives:
The New England District has two primary mitigation objectives with respect to flood damage reduction. The first objective is the operation and maintenance of the 35 flood control reservoirs and two hurricane barriers that provide protection to the Connecticut, Merrimack, Thames, Naugatuck, and Blackstone River Basins. The second objective is to continue to work with the states and communities in New England to address flooding problems affecting the region.
Projects Desired: The Corps of Engineers has several programs available under its Civil Works authorities to address flooding problems. These programs provide assistance either through the construction of structural and nonstructural projects to mitigate the flooding problem or by providing technical information to assist mitigation performed at the state or local level. Flood damage reduction projects constructed by the Corps of Engineers must demonstrate, based on current Federal guidelines, that the flood damages prevented by the project's construction exceed its total cost. The Corps must also demonstrate that the 10-year frequency flood discharge at the point of concern is equal to or greater than 800 cubic-feet per second (cfs). Technical assistance provided by the Corps does not need to meet the above criteria.
COE Resources with Respect to Hazard Mitigation
The New England Division assists in meeting national, regional and local needs through a variety of means. Congressionally authorized water resources investigations have resulted in the planning, design and implementation of many flood control and flood damage reduction projects. Work conducted under a Congressional authorization can be extensive and there is currently no monetary limit of funding. Typically there is a 1-2 year minimum delay in the identification of a proposed investigation and the funding of that work. The first phase of study, the Reconnaissance investigation, is 100 percent Federally funded and must be completed within twelve months. The second phase, the Feasibility investigations, must be cost-shared with a local sponsor where the sponsor provides 50 percent of the cost of the feasibility study. Congress in a Water Resources Development Act must specifically authorize construction of any project resulting from a General Investigation study. The cost of implementation for flood damage reduction projects is generally 65 percent Federal and 35 percent non-Federal.
Through the Continuing Authorities Programs of the Corps many structural and non-structural local protection project reducing or eliminating damages from flooding have been constructed. Investigations initiated under the Corps Continuing Authorities do not require specific congressional authorization are initiated simply with a request from the State or community to the New England District. The following is a list of Continuing Authorities applicable to flood mitigation:
120 State of New Hampshire, Natural Hazards Mitigation Plan, Executive Summary: October 2000 Edition
Section 14 - Emergency Stream Bank & Shoreline Protection: This work consists of evaluating alternatives to provide emergency protection to public facilities, such as highways and bridges that are threatened due to erosion. The current Federal limit on Section 14 projects is $500,000. The local sponsor is required to provide 25 percent of the cost of developing plans and specifications and of construction.
Section 103 - Beach Erosion: Investigations conducted under this authority are to determine methods of protecting public facilities that have been threatened by beach erosion. Currently there is a Federal limit of $2,000,000 and the local sponsor is required to contribute 35 percent of plans, specifications and construction. The local sponsor is also required to cost-share equally the cost of the feasibility investigation that exceeds $100,000. The first $100,000 is at full Federal expense.
Section 205 - Flood Damage Reduction: Investigations are conducted under this program to assist local communities to identify flooding problems and to formulate and construct alternatives for flood damage reduction. The local sponsor is required to cost-share equally in the cost of the feasibility investigation that exceeds $100,000 and the Federal limit is $5,000,000. The local sponsor is required to contribute 25 percent of the cost of plans, specifications and construction.
Section 208 - Snagging and Clearing: This emergency program is designed to reduce flood damage potential by identifying and removing obstructions that contribute to flooding by causing higher flood stages in the floodways. The Federal limit under this program is $500,000 and the local sponsor is required to contribute 25 percent of the cost of plans, specifications and construction.
The New England Division also has two Planning Assistance Programs, which provide opportunities for the States to obtain assistance in addressing water resource issues. These programs are the Section 22, Planning Assistance to the States (PAS) program and the Section 206, Flood Plain Management Services (FPMS) program.
Planning Assistance to States Program (PAS): The Planning Assistance to States Program is designed to assist the States in developing comprehensive plans to meet State planning goals. The program is extremely flexible in the type and the methodology of investigations. Studies conducted under the PAS program require a 50/50 cost share with a local sponsor. The existing funding limits are $300,000 per state and a national budget not to exceed $5,000,000.
Flood Plain Management Services (FPMS): The FPMS Program is designed for the Corps to assist States and local communities improve management of flood plains by performing technical assistance and conducting special investigations. Cost recovery has been implemented in this program effective in FY 1991. Under cost recovery, assistance provided to Federal agencies and private interests must be fully reimbursed by those customers. States and local communities are still provided technical assistance at 100 percent Federal cost. One of the major efforts being conducted under the FPMS program at this time is the preparation of Hurricane Evacuation Studies. These studies are jointly funded with the Federal Emergency Management Agency.
121 State of New Hampshire, Natural Hazards Mitigation Plan, Executive Summary: October 2000 Edition
Hazard Mitigati on Resource Profile
Ice Engineering Research Division U.S. Army Cold Regions Research and Engineering Laboratory
Contacts:
Dr. J-C Tatinclaux, Chief, Ice Engineering Research Division, tel. 603-646-4187, fax 603-646- 4477, e-mail, [email protected], web site http://www.crrel.usace.army.mil/ierd/
Address: US Army Cold Regions Research and Engineering Laboratory Ice Engineering Research Division 72 Lyme Road Hanover, NH 03755-1290
Description and Mission:
The US Army Cold Regions Research and Engineering Laboratory (CRREL) is a Corps of Engineers’ research laboratory that is dedicated to multi-disciplinary engineering and research that addresses the problems and opportunities unique to the world's cold regions. CRREL exists largely to solve the technical problems that develop in cold regions, especially those related to construction, transport, and military operations. Most of these problems are caused by falling and blowing snow, snow on the ground, ice in the air and in the ground, river ice, ice on seas and lakes, and ice affects on manmade materials. CRREL serves the Corps of Engineers and its clients in three main areas: • Traditional military engineering, which deals with problems that arise during conflict; • Military construction and operations technology, i.e., the building and maintenance of military bases, airfields, roads, ports, and other facilities; and • Civil works, which involves the Corps in such things as flood protection, navigation on inland waterways and coastal engineering. CRREL also deals with cold regions problems for the other defense services, for civilian agencies of the federal government, and to some extent for state agencies, municipalities, and private industry.
CRREL’s Ice Engineering Research Division (IERD) was created to research, analyze and solve ice problems in and around water bodies, including ice jam flooding and ice accumulation in lock chambers, to ice buildup at water intakes and the destructive forces that moving ice exerts on riverine or coastal structures. In cooperation with the New England District (NAE) of the Corps of Engineers (located in Concord, MA), IERD personnel provide technical assistance before, during, and after ice jam flood emergencies. IERD research has resulted in the design and construction of a number of low-cost ice control structures as well as nonstructural mitigation measures. IERD also provides instruction on dealing with river ice problems to local emergency management agencies.
122 State of New Hampshire, Natural Hazards Mitigation Plan, Executive Summary: October 2000 Edition
Flood Mitigation Involvement: IERD is frequently called upon by the various Corps Districts to provide technical assistance to states and municipalities in the form of emergency mitigation. IERD is also involved with Corps and local agencies in developing locally constructed flood damage mitigation projects and promoting wise and informed use of floodplain areas in order to minimize potential future flood damages.
Mitigation Goals and Objectives:
The IERD has two primary mitigation objectives with respect to flood damage reduction. The first objective is to work with the Corps and other federal, state, and local agencies to design and implement ice control methods to reduce ice-related flood potential. The second is to work with the states and communities in nationwide as well as in New England to address ice-related emergency flooding problems affecting the region.
Projects Desired:
CRREL and IERD are a national resource ready to apply our unique facilities and capabilities to solve problems and conduct innovative, state-of-the-art research and technical support. There are a number of mechanisms that enable IERD and the rest of CRREL to partner with various Federal, non-DoD and private sector entities. The Federal Technology Transfer Act of 1986 (15 USC 3710a) allows CRREL to collaborate with any non-Federal partner on research and technical support consistent with the mission of the laboratory. The Intergovernmental Cooperation Act (31 USC 6505) lets CRREL work with state and local governments on a broad range of reimbursable projects. Under the "Authority to Sell" (10 USC 2539b), CRREL can provide test and evaluation services to the states and the private sector. This includes the testing and evaluation of materials, equipment, models, computer software, and other items. The laboratory can also provide support to other Federal agencies via the Economy in Government Act (31 USC 1535) through MOUs/MOAs that establish a framework for the partnership and provide a concise description of the planned work. CRREL’s 35 active Cooperative Research and Development Agreements (CRADAs) with industry and academia and 17 Intergovernmental Cooperation Agreements with states and local governments in 1998 demonstrate a robust program in this area and the relevance of CRREL’s research to many segments of American society beyond DoD.
The Corps of Engineers has several programs available under its Civil Works authorities to address flooding problems. These programs provide assistance either through the construction of structural and nonstructural projects to mitigate the flooding problem or by providing technical information to assist mitigation performed at the state or local level. Flood damage reduction projects constructed by the Corps of Engineers must demonstrate, based on current Federal guidelines, that the flood damages prevented by the project's construction exceed its total cost. The Corps must also demonstrate that the 10-year frequency flood discharge at the point of concern is equal to or greater than 800 cubic-feet per second (cfs). Technical assistance provided by the Corps does not need to meet the above criteria. Through the Corps, IERD has been involved in Section 205 Flood Damage Reduction program, Section 22 Planning Assistance to States Program (PAS)) projects, the Section 206 Flood Plain Management Services (FPMS) program funded jointly with FEMA, and numerous instances of technical assistance.
123 State of New Hampshire, Natural Hazards Mitigation Plan, Executive Summary: October 2000 Edition
CRREL IERD Resources with Respect to Hazard Mitigation
Corps: CRREL works jointly with the Corps’ New England Division to address regional and local ice-related hazard mitigation needs through a variety of means. Congressionally authorized water resources investigations have resulted in the planning, design and implementation of many flood control and flood damage reduction projects. Work conducted under a Congressional authorization can be extensive and there is currently no monetary limit of funding. Typically there is a 1-2 year minimum delay in the identification of a proposed investigation and the funding of that work. The first phase of study, the Reconnaissance investigation, is 100 percent Federally funded and must be completed within twelve months. The second phase, the Feasibility investigations, must be cost-shared with a local sponsor where the sponsor provides 50 percent of the cost of the feasibility study. Congress in a Water Resources Development Act must specifically authorize construction of any project resulting from a General Investigation study. The cost of implementation for flood damage reduction projects is generally 65 percent Federal and 35 percent non-Federal.
Through the Continuing Authorities Programs of the Corps many structural and non-structural local protection project reducing or eliminating damages from flooding have been constructed. Investigations initiated under the Corps Continuing Authorities do not require specific congressional authorization are initiated simply with a request from the State or community to the New England District. The following is a list of Continuing Authorities applicable to flood mitigation:
Section 205 - Flood Damage Reduction: Investigations are conducted under this program to assist local communities to identify flooding problems and to formulate and construct alternatives for flood damage reduction. The local sponsor is required to cost-share equally in the cost of the feasibility investigation that exceeds $100,000 and the Federal limit is $5,000,000. The local sponsor is required to contribute 25 percent of the cost of plans, specifications and construction.
Section 22 - Planning Assistance to States Program (PAS): The Planning Assistance to States Program is designed to assist the States in developing comprehensive plans to meet State planning goals. The program is extremely flexible in the type and the methodology of investigations. Studies conducted under the PAS program require a 50/50 cost share with a local sponsor. The existing funding limits are $300,000 per state and a national budget not to exceed $5,000,000.
Section 206 - Flood Plain Management Services (FPMS): The FPMS Program is designed for the Corps to assist States and local communities improve management of flood plains by performing technical assistance and conducting special investigations. Cost recovery has been implemented in this program effective in FY 1991. Under cost recovery, assistance provided to Federal agencies and private interests must be fully reimbursed by those customers. States and local communities are still provided technical assistance at 100 percent Federal cost. One of the major efforts being conducted under the FPMS program at this time is the preparation of Hurricane Evacuation Studies. These studies are jointly funded with the Federal Emergency Management Agency.
124 State of New Hampshire, Natural Hazards Mitigation Plan, Executive Summary: October 2000 Edition
Personnel: IERD was created to research, analyze and solve ice problems in and around water bodies. The technical experience of the staff and their in-depth research and field capabilities combine with CRREL's unique Ice Engineering Facility to form one of the premier ice engineering organizations in the world. IERD has a staff of 15 engineers and technicians experienced in technical analyses, methods, and engineering solutions to ice problems -- that is, any situation where the effects of ice cause flooding, increase operational and maintenance requirements of water control projects, impede navigation, or adversely impact the environment in cold regions.
Equipment and facilities: The Ice Engineering Facility was built to increase the research capabilities of the U.S. Army Cold Regions Research and Engineering Laboratory. It is a two-story building approximately 160 by 210 feet containing three primary cold spaces: the test Basin, Flume, and Research Area. We have recently designed and built a new Wind Tunnel Facility. In addition there is a machine room in the basement, an instrumentation corridor separating the flume and test basin spaces, a shop/storage area, and one sample-storage cold room.
The Test Basin was designed primarily for large-scale work on ice forces on structures, such as drill platforms and bridge piers, and for tests using model icebreakers. The Basin is 30 feet wide, 8 feet deep and 120 feet long. The room is designed to operate at any temperatures between +65° and -10°F with very even temperature distribution, which results in uniform ice thickness. Other studies conducted in the Test Basin concern the formation of ice pressure ridges, ice problems in and around navigation locks, and vertical uplift forces.
The Flume is situated in a room where the temperature can be regulated between +65° and -20° F. The Flume is 2 by 4 feet in cross section and 120 feet long. It can tilt from +2° to -1° slope, have a flow capacity of nearly 14 cubic feet per second and have a refrigerated bottom. Some other studies conducted in the Flume are the formation of ice covers and frazil ice, the hydraulics of ice-covered rivers, the formation of ice jams, and the effect of ice covers on sediment transport and scour.
Possibly the most versatile portion of the Ice Engineering Facility is the Research Area. This room is 80 by 160 feet clear span and has a temperature range of +65° to -10°F. Piping capable of providing a flow of 1, 2, 4 or 8 cubic feet per second is located on one side of the room, and a large drain trough is on the other. The floor is designed for loads up to 400 pounds per square foot. Models of reaches can be constructed in this area to test ways to alleviate ice jams through channel modification. Tests of the bearing capacity of large ice sheets and cold-testing of vehicles and structures are a few of the other potential uses of this space. Tests conducted in this room will help to alleviate much of the flooding caused by ice jams.
125 State of New Hampshire, Natural Hazards Mitigation Plan, Executive Summary: October 2000 Edition
Hazard Mitigati on Resource Profile
USDA, Natural Resources Conservation Service
Contacts: Gerald J. Lang, Technology Leader Secondary: Edward Hansalik, Civil Engineer
Address: Federal Building, 2 Madbury Road, Durham, NH 03824
Phone: (603) 868-7581 Fax: (603) 868-5301 E-mail: [email protected] or [email protected] Description and Mission:
The Natural Resources Conservation Service (NRCS) is a federal agency within the US Department of Agriculture. The mission of the NRCS is to help people conserve, improve and sustain our natural resources and environment. NRCS, formerly the Soil Conservation Service, is the lead federal agency for conservation on private land. NRCS provides conservation technical assistance through local conservation districts and Resource Conservation and Development (RC&D) Councils to individuals, communities, watershed groups, tribal governments, federal, state, and local agencies, and others. NRCS has an interdisciplinary staff of professional engineers, planners, biologists, foresters, agronomists, and soil scientists working together to provide the necessary technical assistance to solve resource or environmental problems. NRCS products typically include conservation plans, study reports, engineering designs, and resource maps.
Authorities and Funding:
NRCS state and field offices derive funding from two possible sources, direct Federal appropriations and reimbursable agreements with agencies and units of government. NRCS manages several programs; Environmental Quality Incentive Program (EQIP), Wildlife Habitat Incentives Program (WHIP), Wetland Reserve Program (WRP), Forestry Incentives Program (FIP), and Farmland Protection Program (FPP) which provide cost-share assistance to landowners and users (primarily agricultural or forestry land) to install conservation practices to restore and protect natural resources. NRCS can also provide technical assistance ranging from preliminary reviews to complete detail designs to landowners/users solving resource problems even if financial assistance is not being provided for the installation of conservation practices. This assistance is dependant on staff availability and priorities.
NRCS also manages the Emergency Watershed Protection (EWP) program, which can provide financial and technical assistance to units of government and groups to repair damages sustained from a natural disaster (flood, fire, hurricane, tornado) creating an imminent hazard to life and property. The restoration efforts must be environmentally and economically cost effective and typically includes clearing debris from clogged stream channels, stabilizing eroded stream banks and restoring vegetation for stabilization purposes. NRCS can also provide technical assistance to watershed associations or groups to develop comprehensive plans for improving or protecting the watershed environment (water quality, flood reduction, wildlife habitat).
126 State of New Hampshire, Natural Hazards Mitigation Plan, Executive Summary: October 2000 Edition
Mitigation Involvement:
The NRCS can provide technical assistance to conduct inventories, to complete watershed or site-specific plans, or to develop detail engineering and construction designs for conservation applications that will help reduce future damages from natural disasters. Some examples of past mitigation efforts include: floodplain management studies for towns, site assessments of stream flow impairments, stabilization designs to protect structures which could sustain severe damages from another storm event, and small watershed plans addressing flooding problems. Some of these products can be provided through other conservation assistance efforts. However, the major jobs would require a reimbursable agreement with the state or towns to complete the work.
Mitigation Goals and Objectives:
With respect to hazard mitigation, the goal of the NRCS in New Hampshire is to meet the needs of the State and local governments by providing timely technical assistance to support recovery and restoration efforts. NRCS can contribute this technical assistance by interacting directly with NHOEM at the state level and having our field staff working directly with Town Emergency Management officials at the local level. Short-term goals are to establish contacts with local officials and the conservation districts at the field office level to facilitate quicker response times. Intermediate and long-term objectives are to improve the cooperative efforts of working with NHOEM and establish additional contacts for providing timely technical assistance at the local level.
Projects/Planning Desired:
NRCS would like to work with local watershed associations to develop comprehensive plans addressing resource and environmental needs and opportunities in the priority watersheds as identified in the Unified Watershed Assessment. These plans can provide the basis for targeting and requesting special funding to meet the needs of the local watershed association. Technical assistance for planning and designing along with public information dissemination are the typical activities our agency can provide in this effort.
NRCS Resources with respect to Hazard Mitigation:
Personnel: NRCS in New Hampshire has a workforce of 45 staff members along with 5 multi-state staff members. Approximately 22 staff members consisting of engineers, biologists, foresters, conservation planners, and technicians are available to provide some assistance in mitigation efforts. Support staff of a GIS specialist, computer specialist, and public information specialist could assist in providing information for public outreach. This staff is available to provide limited assistance under our present program funding authorities. However, larger projects would require reimbursement for planning and design assistance.
Equipment, Physical Facilities and Other Capabilities:
All of our field offices and state office have computers and access to the Internet. All of the field offices have survey equipment and all engineers have the use of CADD software. All field offices have access to small meeting rooms and access to the Federal Telecommunications System. Government vehicles are located at all field offices for use by government employees and could be made available in emergencies.
127 State of New Hampshire, Natural Hazards Mitigation Plan, Executive Summary: October 2000 Edition
Hazard Mitigation Resource Profile
Organization Name: Northeast States Emergency Consortium (NESEC)
Contacts: Edward S. Fratto, Executive Director Kristin M. O’Brien. Assistant to Executive Director
Address: 419 Main Street, Suite 5, Wakefield, MA 01880 (effective 1/15/99)
Phone: (781) 224-9876 Fax: (781) 224-4350 E-Mail: www.nesec.org
Organization Description: The Northeast States Emergency Consortium, Inc. (NESEC) is a 501(c)(3) not for profit natural disaster mitigation and emergency management organization, located in Wakefield, Massachusetts. NESEC is the only multi-hazard consortium of its kind in the country and is supported and funded by the Federal Emergency Management Agency (FEMA).The eight Northeast States of Connecticut, Maine, Massachusetts, New Hampshire, New Jersey, New York, Rhode Island and Vermont form the consortium. NESEC has a full-time Executive Director, and Assistant. It is governed by a Board of Directors. The Board is comprised of the Directors of the State Emergency Management Agencies from each of the six New England States and the states of New York and New Jersey.
Organization Mission: NESEC works in partnership with government and private organizations to reduce losses of life and property from natural disasters in the Northeast United States. The Northeast States are vulnerable to most of the natural hazards, including hurricanes, earthquakes, coastal and inland flooding, tornadoes and micro-bursts, forest fires, drought, lighting, blizzards and other forms of severe weather. Our developed urban areas and the desire to build and live on waterfront property have increased our degree of risk from natural hazards.
Mitigation Programs:
Grants
NESEC raises funds from government and private sources to support local mitigation projects. These funds are awarded on a competitive basis in the form of grants in the range of $500-5,000. The name of this program is called the Power of Prevention. This program was funded at about $50,000 in 1998 and $35,000 in 1997. NESEC is pursuing 1999 funding. The program is presently unfunded. All grant programs are administered in cooperation with the New Hampshire Office of Emergency Management (NHOEM). Communities interested in participating should contact NHOEM.
128 State of New Hampshire, Natural Hazards Mitigation Plan, Executive Summary: October 2000 Edition
Project Impact
NESEC supports FEMA PROJECT IMPACT Communities in the identification of private and public partners. NESEC will meet with the community to develop a plan to help identify and contact potential private sector partners using worksheets we have developed. The meeting takes approximately 4 hours. There is no fee or charge for this partnership meeting. All meetings are arranged in cooperation with the New Hampshire Office of Emergency Management (NHOEM). Communities interested in participating should contact NHOEM.
HAZUS NESEC assists FEMA PROJECT IMPACT Communities in the use of HAZUS as a planning platform for incorporating multi-hazard disaster prevention initiatives. NESEC can produce a HAZUS report using default data for each of the initial PROJECT IMPACT Communities. Priority is given to PROJECT IMPACT communities, however assistance may be provide to other communities as resources allow. This report provides an excellent starting point for communities wishing to utilize HAZUS to identify potential hazards. The NESEC HAZUS Report is multi-hazard and usually contains information on earthquakes, tornadoes, flood and wind. There is no fee or charge for producing the default HAZUS Report and meeting with the community to discuss the results. All HAZUS support is arranged in cooperation with the New Hampshire Office of Emergency Management (NHOEM). Communities interested in participating should contact NHOEM.
Emergency Generators NESEC assists communities to establish a partnership with their electric utilities and service companies. The partnership would conduct an energy efficiency audit of the community, recommend cost saving measures, and implement a cost saving plan. Monthly savings could be used to fund emergency generator(s) for local critical facilities. The utility or energy service company could then lease, install, and maintain generator(s) in a community. The community would pay a monthly charge for the lease agreement. This charge would not exceed the savings derived through energy efficiency measures, so there would be no capital outlay or additional cost to the community. In fact, some communities may be able to reduce their monthly electric bills in an amount that exceeds the cost of the generator(s) lease agreement. Monthly savings and utility participation will vary from state to state and community-to-community depending on present electric power usage and efficiency measures and deregulation. There is no fee or charge for assisting communities in establishing partnerships with electric utilities. NESEC assistance will be provided as resources allow. All emergency generator support is arranged in cooperation with the New Hampshire Office of Emergency Management (NHOEM). Communities interested in participating should contact NHOEM.
129 State of New Hampshire, Natural Hazards Mitigation Plan, Executive Summary: October 2000 Edition
PLAN IMPELEMENTATION AND MAINTENANCE
IMPLEMENTATION AND MONITORING
The implementation of the Plan shall be an ongoing effort on the part of the NHOEM Director, the State Hazard Mitigation Team and the SHMO. The SHMO shall be responsible for monitoring Plan maintenance and reporting with respect to such conformity and/or divergences as necessary to the Hazard Mitigation Team and to the NHOEM Director periodically. Such reports shall be incorporated into the Hazard Mitigation Team agendas and conveyed to the NHOEM Director as necessary.
With respect to any ongoing mitigation activity, the lead and support agencies for such activity shall be tasked with implementing the Plan’s Goals and Objectives and monitoring compliance. All lead and support agencies shall be requested to identify an individual Point of Contact (POC). The POC shall convene with, and/or report to the SHMO periodically as to the activity’s progress and compliance with the Goals and Objectives of the Plan.
EVALUATION
CONTINUING RELEVANCY OF GOALS AND OBJECTIVES
The SHMO and the State Hazard Mitigation Team shall continually monitor the relevancy of the Plan’s stated Goals and Objectives and shall take this step upon consideration of any and all HMGP applications or other mitigation measure initiative considerations.
EFFECTIVENESS OF MITIGATION STATEGIES AND MEASURES
The SHMO and the State Hazard Mitigation Team shall work corporately to identify and evaluate the effectiveness of all prior existing Hazard Mitigation measures and assess and adjust the mitigation strategy accordingly.
Where such adjustment requires the modification of the State’s Plan, the procedure for Plan amendment shall be followed in all cases unless the NHOEM Director and/or the State Hazard Mitigation Team identify the adjustment as an emergency measure. In all cases where an apparent departure from the Plan may have been initiated, at the earliest practical opportunity, or within 30 days, whichever is less, the SHMO shall prepare a report as to the emergency measures and amendments undertaken and shall submit the Plan amendment to FEMA for amendment approval.
IDENTIFICATION AND EVALUATION OF TRENDS
Economic, demographic, climatological, land use and other trends as may pertain to the impact of the hazard events identified in this Plan on structures and persons are currently being researched by the SHMO for inclusion into the 409 Plan.
The identification and evaluation of trends as may impact upon the State’s Goals and Objectives will be monitored by the SHMO who shall report on such assessment to the Hazard Mitigation Team. The Team, in turn, shall review and evaluate such assessment upon consideration of any and all HMGP applications or other mitigation measure/initiative considerations.
130 State of New Hampshire, Natural Hazards Mitigation Plan, Executive Summary: October 2000 Edition
MAINTENANCE
PLAN REVIEW
This plan will be reviewed in accordance with the schedule for review in accordance with 44 CFR, Subpart M. i.e., annually, or pursuant to a Presidential Disaster Declaration.
The process for review shall be the responsibility of the SHMO and shall consist of the convening of appropriate Plan contributors and/or meetings with contributors individually as practical. Such meetings shall be recorded, and such recommendations as may be forthcoming shall be evaluated and forwarded by the SHMO to the State’s Hazard Mitigation Team for consideration and comment.
Such recommendations for Plan amendment and all Hazard Mitigation Team comments shall be forwarded to the NHOEM Director for consideration and Plan amendment approval.
Any Section of the 409 Plan, which is recommended for amendment by the NHOEM Director, shall be forwarded to the FEMA Regional Office Hazard Mitigation Division staff for review and final adoption in accordance with 44 CFR, Subpart M.
PLAN MAINTENANCE
The SHMO and the State’s Hazard Mitigation Team shall assure maintenance of the Plan and shall consider and approve such projects as are submitted for HMGP funding in accordance with the Plan’s Goals and Objectives.
FUTURE ENHANCEMENT
The SHMO and the State Hazard Mitigation Team shall endeavor to develop appropriate and cost effective Hazard Mitigation strategies as may be consistent with the achievement of the stated FEMA and State of New Hampshire overall Goal to wit: “To substantially reduce the loss of life and damage to property” stemming from these events.
The SHMO and the State Hazard Mitigation Team will continue to study the impact of such hazard events as are outlined above as may impact upon the State’s citizens and guests as well as its infrastructure, critical facilities, aviation and navigation facilities, agriculture, aquaculture, forests, ecology, economy (e.g. tourism industry, forest products, etc.) Historical treasures and quality of life and endeavor to develop cost effective strategies to mitigate losses associated with these events.
131 State of New Hampshire, Natural Hazards Mitigation Plan, Executive Summary: October 2000 Edition
Tables of Plan Appendices
Table of Appendices: Plan Section I., Flood, Drought, Wildfire and Extreme Heat
A. Selected pages from NHOEM website, www.nhoem.state.nh.us B. Major Recorded Floods in New Hampshire. A summary of events from 1927 to 1991 with additional information on evens from 1770 to 1896. C. Information going to the National Flood Insurance Program in the State of N.H. including a list of participants and their standing in the NFIP, a list of high policy holding communities and a list of repetitive loss communities. D. Water Fact Sheet, a publication of the USGS and Stream Gauging and Flood Forecasting, a publication of NOAA/USGS. E. Inter Agency Hazard Mitigation Team Report going to DR-1231-NH, the flood event of June, 1938. F. Inter Agency Hazard Mitigation Team Report going to DR-1144-NH, the Flood event of October, 1996. G. Inter Agency Hazard Mitigation Team Report going to DR-1231-NH, the Flood event of January 1996. H. Various excerpts from the National Drought Mitigation Center website. http://enso.unl.edu/ndmc/watch/watch.htm I. New England Regional Climate Change Impact Workshop: WORKSHOP SUMMARY REPORT, September 3-5, 1997 at the Institute for the Study of Earth, Oceans, and Space of the University of New Hampshire in Durham). J. New England’s Changing Climate, Weather and Air Quality, a publication of the Climate Change Research Center at the Institute for the Study of Earth, Oceans, and Space of the University of New Hampshire in Durham). http://www.neci.sr.unh.edu/neccwaq.html
Table of Appendices: Plan Section II., Geologic Hazards
A. Earthquakes in New Hampshire. Overview of vulnerability and risk, NHP Officer, Gregg Champlin, NHOEM webpage, www.nhoem.state.nh.us . B. New England Earthquakes, New England States Earthquake Consortium. Seismic hazard analysis. April 28, 1992. C. Earthquake History of the United States, USGS and NOAA cooperative publication. Summary of Earthquake related damage in the Northeast form 1638 to 1969. D. Seismic Hazard in the Central and Eastern United States. Arthur Frankel, USGS, Denver, Colorado. E. Earthquake Activity in the Northeastern United States, John E. Ebel and Alan L. Kafka (1991) F. The New Hampshire Earthquakes of December, 1940. Including three papers published under the auspices of the Committee on Geophysical Research and the Division of Geological Sciences at Harvard University. G. The Seventeenth Century Seismicity of Northeast North America, John E. Ebel, Ph.D., Director, Weston Observatory. H. Historical Notes on the Earthquakes of New England, William T. Bringham, A.M., A.A.S. I. Seismicity of New England and the Earthquake Hazard in Massachusetts. Final report on the Seismic Risk Subcommittee. Prepared by MIT for the Massachusetts Civil Defense. J. Metropolitan Boston Area Earthquake Loss Study, Loss Analysis Committee Report and Recommendations Feb., 1990. K. A Survey of Great Tsunamis and related material from NOAA and PBS Online websites. http://www.geophys.washington.edu/tsunami/general/historic/historic.html http://www.pbs.org/wnet/savageearth/ L. Tsunami Hazard Mitigation, A report to the Senate Appropriation Committee and associated material. M. Geomagnetic information downloaded form the Commonwealth of Australia, United States Geologic Survey and the Geological Survey of Canada websites. http://www.geolab.nrcan.gc.ca/geomag/, http://geohazards.cr.usgs.gov/, http://wwwrses.anu.edu.au/research-areas.html N. Savage Earth: Volcanoes, series from PBS online website. http://www.pbs.org/wnet/savageearth/
132 State of New Hampshire, Natural Hazards Mitigation Plan, Executive Summary: October 2000 Edition
Table of Appendices: Plan Section III., Severe Wind Hazards
A. Letter form FEMA Region I Director Jeffrey Bean to NHOEM Director Woodbury P. Fogg of 8/26/99. B. New Hampshire Tornadoes, 1680 – 1972. (Draft of a cooperative research project funded by NHOEM and the American Red Cross). C. Hurricane. (Draft of a cooperative research project funded by NHOEM and the American Red Cross D. Cabinet of Curiosities, Natural, Artificial and Historical, E. & H. Clark Printers, 1822 (excerpts: Hail and Hurricanes in New Hampshire – including apparent tornadic activity). E. Public Service Announcement – NHOEM website. www.nhoem.st.nh.us F. Severe Thunderstorms/downburst information – www.weather.com. G. Stormchasers, Weather Facts and Events – NOVA Online. http://www.pbs.org/science/ H. Tornado Safety and Fact Sheets (Source: FEMA website) www.fema.gov I. FEMA PSAs (various PSA’s from the FEMA website, www.fema.gov ). J. FEMA for Kids (various publications from the FEMA website). http://www.fema.gov/kids/ K. “FEMA and Texas Tech Team up for Tornado Protection in the Home: (Source: FEMA website: www.fema.gov FEMA News Room). L. Extreme Wind Damage Reduction Techniques brochure and related materials (Source: FEMA publication). M. Examples of hardware applications utilized in mitigating against wind damage (Source: FEMA Publication). N. Hazard Mitigation Resource Profiles (USGS and NHOSP Coastal Program exhibited only). EMWIN promotional and descriptive literature. http://www.weathernode.com/emwin.asp O. The Reader is also directed to FEMA/Texas Tech University publication #320, Taking Shelter from the Storm for additional information on vulnerability, risk and the construction of “Safe Rooms” or areas. http://www.fema.gov/nwz99/tsfs706.htm P.
Table of Appendices: Plan Section IV., Winter Weather Related Hazards
A. Winter Weather related selections form the NHOEM website. www.nhoem.state.nh.us B. Information provided by the U.S. Forest Service with respect to Avalanche risk and mitigation. C. Inter-Agency Hazard Mitigation Team Report from Presidential Disaster Declaration DR-1199-NH. D. An Evaluation of the Severity of the January 1998 Ice Storm in Northern New England, Report to FMA Region I. Prepared by the U.S. Army Corp of Engineers, Cold Regions Research Engineering Laboratory. http://www.crrel.usace.army.mil/valliere/CRREL_Reports_web/reports/IceStorm98.pdf E. New Hampshire’s Ice Storm Forest Recovery Program, Phase I. Prepared by NHDRED, Division of Forestry and Lands and UNH Co-op Extension, Forestry and Wildlife Program, August 1998. F. Summary of the Ice Storm Forest Recovery Program, October 21, 1998. http://www.crrel.usace.army.mil/valliere/CRREL_Reports_web/reports/IceStorm98.pdf G. 98 Ice Storms, Regional Approaches for Local Actions. Prepared by the Northeast Center for Urban and Community Forestry at Umps/Amherst.
See also: Snowstorms Along the Northeastern Coast of the United States: 1955 To 1985, Paul J. Kocin and Louis Uccellini, American Meteorological Society
Snow Avalanche Websites to Visit
Northwest Weather and Avalanche Center: http://www.nwac.noaa.gov/
Cyberspace Snow and Avalanche Center – CSAC: http://www.csac.org/ http://www.csac.org/Incidents/ (New Hampshire Event- 1998/99)**
The American Association of Avalanche Professionals (AAAP): http://www.avalanche.org/~aaap/
The Canadian Avalanche Association (CAA): http://www.avalanche.ca/
133 State of New Hampshire, Natural Hazards Mitigation Plan, Executive Summary: October 2000 Edition
ACRONYMS and ABBRIVIATIONS
ACD Association of Conservation Districts FPMS Floodplain Management Services NHDOT New Hampshire Department of Transportation AIA American Institute of Architechs FPP Farmland Protection Program NHDRED NH Department of Resources and ANWC Alternate Warning Center GAR Governor’s Authorized Representative Economic Development
ARC American Red Cross GIS Georaphical Information System NHHFA NH Housing Finance Authority
BEIR Biological Effects of Ionizing Radiation GRANIT NH Geographic Information System NHOEM New Hampshire Office of Emergency Management CADD Computer Aided Design HAZUS Hazards U.S. (FEMA Risk program) NHP National Hazards Program CAV Community Assistance Visit HIRA Hazard Identification and Risk Assessment NHSP New Hampshire State Police CDBG Community Development Block Grant HMGP Hazard Mitigation Grant Program NOAA National Oceanic and Atmospheric CEMPS Comprehensive Emergency Management Administration Planning for Schools HUD U.S. Dept. of Housing and Urban Development NOI Notice of Interest CEO Code Enforcement Officer IERD Ice Engineering Research Division NWC National Warning Center CFR Code of Federal Regulations MAP Mitigation Assistance Program NWR NOAA Weather Radio cfs Cubic feet per second Mb Body-wave magnitude NWS National Weather Service cm Cubic centimeter (2.54 cm 1 inch MIC Meteorologist in Charge PAS Public Assissatace to the States CRADA Cooperative Research Cooperative Agreements MM Modified Mercalli Intensity Scale pCi/l Picocuries per liter
CRREL Cold Regions Research and Engineering MOA Memorandum of Agreement P.E. Professional Engineer Laboratory MOU Memorandum of Understanding Ph.D. Doctor of Philosophy CRS Community Rating System NAE (USACoE) New England (Atlantic) PIO Public Information Officer CZMA Coastal Zone Management Act NASA National Areonautics and Space POC Point of Contact DoD (United States) Department of Defense Administration RC&D Resource Conservation and DPIG Disaster Preparedness Improvement Grant NAWAS National Warning System Development Council
DPW Department of Public Works NCSA Non Commercial Service RSA (NH) Revised Statutes Annotated Announcemt(s) EAS Emergency Alert System SECC State Emergency Communications NDMC National Drought Mitigation Center Committee EMPG Emergency Management Performance Grant NERFC Northeast Rivers Forecast Center SHMO State Hazard Mitigation Officer
EMWIN Emergency Manager’s Weather NESEC (Formally) Northeast States UNH University of New Hampshire Information Network Earthquake Consortium (Now) Northeast States Emergency USC United States Code EOC Emergency Operations Center Consortium USDA United States Department of EOS (Institute for the study of) Earth, Oceans NFIP National Flood Insurance Program Agriculture and Space, University of NH NHAB New Hampshire Asociation of USGS Unites States Geological Survey EPA Environmental Protection Agency Broadcasters USSR Union of Soviet Socialist Republics EQIP Environmental Quality Incentive Program NRCS Natural Resources Conservation Service VOAD Volunteer Organizations Active in EWP Emergency Watershed Protection Disasters NHCP New Hampshire Coastal Program FEMA Federal Emergency Management Agency WHIP Wildlife Habitat Incentives Program NHDES New Hampshire Department of FIP Forestry Incentive Program Environmental Services WRP Wetland Reserve Program - WRD Water Resources Division FIRM Flood Insurance Rate Map WRSAME Weather Radio Specific Area Message Encode FMAP (FMA) Flood Mitigation Assistance Program 134 State of New Hampshire, Natural Hazards Mitigation Plan, Executive Summary: October 2000 Edition 409 Planning Contributors
Flood Forecasting &Warning Systems Climatological Interests
John S. Jensenius Jr., Warning Coordinator/ Barry Kiem, NH State Climatologist, UNH Mteorologist, NOAA/NWS (207) 688-3222 862-3136 James P. Koemer, Ph.D., Chair, Natural Sciences Thomas S. Hawley, Service Hydrologist, Dept., Meteorology, PSC 535-2325 NOAA/NWS, Gray Maine (207) 688-3223 Barry N. Rock, Ph.D. Director, Complex Gerry Lang , USDA NRCS Fed Bldg, 2 Systems, Institute for the Study of Earth Oceans Madbury Rd. Durham, NH 03824 & Space/Forest Resources, UNH 862-2949 868-7581 Donald S. LaTourette, Greenhouse Gas/Global Brian R. Mrazik, PhD., District Chief, USGS Warming Specialist 271-5552 Pembroke, NH 226-7807 NH DES, Air Resources Division
Kenneth Toppin, USGS, Chief, Hydrologic App Mount Washington Observatory & Network Ops, Pembroke, NH 226-7808 Ken Rancort, Assistant Director 466-3388 David R. Knowles, P.E. Hydrologist, FEMA Peter Crane, Ph.D., Opns Manager 356-8345 Region I (617) 223-9575 Seismic and Related Interests David R. Vallee, Service Hydrologist, Hurricane Program Director (508) 823-1900 John E. Ebel, Ph.D. Director, Weston NWS, Northeast River Forecast Center, 446 Observatory, Boston College (617) 552-8300 Myles Standish Blvd., Taunton MA 02780 381, Concord Road, Weston MA 02493
Professor of Geophysics, Dept of Geology and Joe Delli Carpini, Meteorologist , NOAA/ Geophysics, (617) 552-3399 NWS/NERFC, Taunton, Mass. (508) 823-2262 Boston College, Chestnut Hill, MA 02467 [email protected] Mike Winchell, Hydrologist, NOAA/NWS/ NERFC (508) 824-5116 Louis H. Klotz, Ph.D., P.E., President, Klotz Consultants Group, 90 Mainmast Circle, New Steve N. Doyon, P.E. Administrator, NHDES Castle, NH 03854-0204 436-5697 Water Division 271-3406 Gregg Champlin, NHOEM Nat Haz Officer Jimmy M. Leung, P.E. Dam Safety Engineer, NHDES 271-3406 Transportation and Roads
Grace Levergood, Dam Safety Engineer, Edward E. Kyle, P.E. Assist. Admin, NHDOT NHDES Bureau of Highway Maintenance 271-2693 Kenneth N. Kettenring, PhD. Wetlands Bureau Administrator NHDES 271-2147 David E. Powelson, Chief, Existing Bridge Section, NHDOT, Bridge Design 271-3714 Sandra J. Crystall Wetlands Inspector, NHDES 271-2147 David H. Fluharty Director, Technology Transfer Center T2 UNH 862-4348 Gary Springs, Shoreland Outreach Coordinator, NHDES 271-7109 Kathy DesRoches Program Assistant (Mutual Aid Coordinator) TTC T2 @ UNH 862-2826 Fay A. Rubin GIS Coordinator Complex
Systems Research Center, UNH 862-1792 Leighton Cleverly, Dir. PW, Bow 228-2207
John R. Lavigne, Jr., P.E., Judith E. Houston, P.E. Edward L. Chase, P.E., Director, Public Works, SFC Engi. Partnership Inc. 647-8700 Town Engineer, Peterborough 924-8008 Member at Large. NH Public and Municipal Engineering Association 135 State of New Hampshire, Natural Hazards Mitigation Plan, Executive Summary: October 2000 Edition
U.S. Army Corps of Engineers NH Department of Resources and Economic Development John R. Kennelly, III., Chief, Special Studies Section (978) 318-8505 Bud Nelson, Division of Forests and Lands 271-2217 Kate White, CRREL, 72 Lime Road, Hanover, NH 03755 646-4187 J.B. Cullen, Administrator, Forest Information Cold Regions Research & Engineering Lab.. and Planning Bureau, NHDRED 271-3457 New Hampshire NH Fire Training Academy Department of Environmental Services – Water Supply and Pollution Control Division Richard Mason, Director 271-6099
Russell A. Nylander 271-2981 Capt. Charles Roffo 271-2661 George C. Neill, P.E., Sanitary Engineer New Hampshire Office of 271-3503 Emergency Management 271-2231 Benard Lucey, Water Supply Engineer 271-2952
Lee Kimball State and Local Planning Chief N.H Office of State Planning and National Flood Insurance Program Mead Herrick , Chief, Operations Section 271-2155
Michael Poirier, Assistant Planning Chief, George Musler, NFIP Coordinator at NHOEM Public Assistance Coordinator
Jim McLaughlin, Assistant Director Grace Walker, Haz Mit Assistant Jane E. Hubbard, Assistant Planner NHOSP Steve McLoy, Assistant Chief
Kristin Mullen, Assistant Planner NHOSP Herb (Cal) Calvitto, Communications Specialist Patrick C. Herlihy, Community Development Greg Champlin Natural Hazards Coordinator Program Manager NHOSP (Earthquake/Hurricane) Ted Diers, Coastal Program NHOSP Bob Pariseau Assistant Chief, Tech Hazards Regional Planning Commissions Dave Vaillancourt, Field Representative Pete B. Davis, Planner, Southwest Region Nancy Wurtz, Field Representative Planning Commission 357-0557
James Van Dongen, Public Information Officer Timothy P. Murphy, Executive Director, Southwest Regional Planning Commission FEMA Ray Wenninger, P.E., Pemi River Project Project John D. Knott Jr., DAE (978) 461-5629 Engineer
Stephen Jeffery, DAE (603) 664-9002 Community Input
Scott Erickson (617) 223-4175 Peter Ryner, Community Development Director, Peterborough 924-8035 G. Fred Vanderschmidt (617) 223-4184 Raymond King, DPW Director, Town of Salem Robert K. Sullivan (617) 223-4180 890-2150
NH Dept. of Health and Human Services Roger Guilmette, Director, DPW, Gorham, NH 466-5025 David S. Chase, Ph.D. Bureau of Radiological Health 271-3764 Plan Production Assistance
Wallene Foote, Word Procesor NHOEM 271-2231 Peter S. Paiton, Super, Office of Health Mgt., Heather Daniel, Haz Mit tech Assistant 223-4152 Bureau of Radiological Health 271-4656 Paul Knight, Contractor, Internet Access 786-9480 136 State of New Hampshire, Natural Hazards Mitigation Plan, Executive Summary: October 2000 Edition
Civil Air Patrol NH Division of Historical Resources
Captian Ronald A Hemond, Director of Emerg. Nancy A. Dutton, Director, NH Div. Of Historical Services, NH Civil Air Patrol 746-4482 Resources 271-6435
Mead Herrick, Wing Disaster Preparedness James L. Garvin, State Architectural Historian Officer (NHOEM Operations Chief) 271-2231 271-6436 Linda Ray Wilson, Deputy State Historic Preservation Officer 271-6434 Volunteer Organizations Active in Disaster (VOAD) Fish and Wildlife
Walter Brown Phillip Morrison, Biologist, U.S. Fish and Wildlife (Hm) 880-4179 (Off) 885-5893 225-1411
Bill Ingham, N.H. Fish and Game American Red Cross 271-3422
Betsy C. Fitts, Director of Emergency Services USDA U.S. Forest Service 225-6697 White Mountain National Forest
Bradley Ray, Lead Snow Ranger, Androscoggin Public Utilities Ranger Station, 300 Glen Road, Groham, NH (yet to be convened) 466-2714 ext 218 Dena Lee Delucca, Director of Public Relations, NH Electric Co-op 536-8658 Building/Architectural
Jeaneen M. Coolbroth, Commercial Sales Gary Meehan, Meehan Architects, President, AIA Manager, Public Service of N.H. 634-2519 668-6802
Lee Cummings John R. Lavigne, Jr., P.E., SFC Engineering Judy Huston Karen Mackey Partnership Inc. 647-8700
Bill Beauprey, Granite State Electric, 9 Lowell Nicholas J. Cricenti, Jr. P.E., SFC Engineering Rd., Salem 03079 890-7122 Mike Santa, CEO, Nashua (President, Code Richard Homes, Operations Supervisor, Enforcement Offficer’s Association 594-3351 Granite State Electric 443-4252 Northeast States Emergency Consortium Bob Bisson, Manager of Operations, Unitil 773-6464 Ed Fratto, Director (781) 224-9876
NH Association of Broadcasters New England Floodplain Managers and Stormwater Managers Association Inc. B. Allan Sprague, President, 10 Chestnut Drive, Bedford, NH 472-9803 W. Louis Sidell, Jr. Senior Planner, Floodplain Management Coordinator (207) 287-8063 State Planning Office, 184 State Street, 38 State NH National Guard House Station, Agusta, ME 04333-0038
Maj. Charles Welch, Military Support to Civil Michele Steinberg , Secretary (also, Institute for Authority (Retired) 225-1242 Business and Home Safety (617) 292-2003 ext. 218
SFC David R. Stevens, Phys Security 225-1242
137 Natural Hazards Mitigation Plan, Executive Summary: October 2000 Edition
Sponsor Internet Address Summary of Contents
New Hampshire Office of Emergency http://www.nhoem.state.nh.us NHOEM’s Home Page with many related links Management Click “Hazard Mitigation” on the sidebar… ………..Scroll down to “Index of Useful Websites” State of New Hampshire http://www.state.nh.us State Government Home Page. Links to all State Agencies, services, Statutes etc. Federal Emergency Management Agency http://www.fema.gov FEMA’s Home Page with many related links
National Emergency Management http://nemaweb.org Site of association of state emergency mgt.directors. Has Association list of mitigation projects NASA http://ltpww.gsfc.nasa.gov/ndrd/main.html A searchable database of web sites (world wide) on natural Natural Disaster Reference Database disasters. U.S. State and Local Gateway http://www.statelocal.gov/ General Federal information through the federal-state partnership National Weather Service National Warning http://iwin.nws.noaa.gov/iwin/nationalwarning Central page for National Weather Warnings, updated Page s.html every 60 seconds
USGS http://h2o.usgs.gov/public/realtime.html Contains provisional hydrological data Real Time Hydrologic Data Dartmouth Flood Observatory http://www.dartmouth.edu/artsci/geog/floods/ Observations of flooding situations
The Floodplain Management Association http://www.floodplain.org/ Site of the Floodplain Management Association. FEMA http://www.fema.gov/fema/csb.htm Searchable site for access of Community Status Books The National Flood Insurance Program Community Status Book Earth Satellite Corporation http://www.earthsat.com/flood/maps/ffgusa.gif U.S. Flood potential map updated daily National Lighting Safety Institute http://www.lightsafety.com/ Information and listing of appropriate publications regarding lightning safety. NASA http://www.ghcc.msgc.nasa.gov/otd.html Space based sensor of lightning strikes Optical Transient Detector LLNL Geological & Atmospheric Hazards http://www.ep.es.llnl.gov/www-ep/ghp.html General hazard information developed for the DOE
The Tornado Project Online http://www/tornadoproject.com/ Information on tornadoes including details of recent impacts Public Broadcasting http://www.pbs.org Information on various topics. Search the “Savage Earth” series Canadian National Geomagnetism Program http://www.geolab.nrcan.gc.ca/geomag/ Monitors and predicts the Earth's ever-changing magnetic field throughout Canada National Severe Storms Laboratory http://www/nssl.uoknor.edu/ Information including tracking of severe storms Independent Insurance Agents of America http://www.iiaa.iix.com/ndcmap.htm Site contains a multi-disaster risk map. IIA Natural Disaster Risk Map National Drought Mitigation Center http://enso.unl.edu/ndmc/ Information regarding drought mitigation
Weston Observatory of Boston College http://www.bc.edu/bc_org/avp/cas/wesobs/ New England Seismic Information
New England Seismic Network http://www-erl.mit.edu/NESN/homepage.html Reports on New England Seismic Activity etc.
USDA Forest Service Web http://www.fs.fed.us/land Information regarding Forrest fire and land management International Association of Wildland Fire http://www/teleport.com/~wildfire Information on wildfire management
Natural Hazards Research Center, U. of http://www.colorado.edu/hazards/ Searchable database of references and links to many Colo. disaster-related web sites. NASA – Goddard Space Flight Center http://ltpwww.gsfc.nana.govn/ndrd/disaster/ A searchable database of sites that encompass a wide range “Disaster Finder” of natural disasters. Institute for Business and Home Safety http://www.ibhs.org Natural Hazards links and remedial actions information NH Office of State Planning – http://www.state.nh.us/coastal NH Coastal Program’s Home Page with related links Coastal Program Atlantic Hurricane Tracking Data Yearly http://wxp.eas.purdue.edu/hurricane Hurricane track maps for each year, 1886 - 1996 Skymax Hurricane Center http://www.nhc.noaa.gov/pastall.html Historical Hurricane track maps and lots more
CIT Center for Geography, Geology etc. http://www.geog.le.ac.uk/cti/tect.html Earthquake sites galore! Landings: Weather Satellite Information http://www1.drive.net/evird.acgi$pass*140864 Popular Aviation site with very good real time and current 96!_h- weather images and information www.landings.com/_landings/pages/wthr/wx_ pict-namerica.html The Weather Channel http://www.weather.com Current Doppler images and in motion. Also; Blizzard, Hurricane, Tornado, Tsunami etc info Cold Regions Research & Engineering http://www.crrel.usace.army.mil/ Technical Publications on all manner of Cold Regions Laboratory (USACoE-CRREL) issues including active models
138 Natural Hazards Mitigation Plan, Executive Summary: October 2000 Edition
Contact Information:
This Plan was prepared by John J. Shaughnessy, Protection Planner for the State of New Hampshire and the State’s designated Hazard Mitigation Officer with the New Hampshire Governor’s Office of Emergency Management (NHOEM) with offices at 107 Pleasant Street, Concord, NH 03301.
With respect to questions, comments or requests for copies of this plan, Mr. Shaughnessy may be reached by telephone at (603) 271-2231 or (in NH) (800) 852-3792 (operator), direct at (602) 223-3637 (with voice mail) or, by facsimile transmission at (603) 225-7341 or, by Email at [email protected].
Visit the NHOEM website and view this Plan and other Hazard Mitigation related materials/sites at http://www.nhoem.state.nh.us/mitigation
This Publication will be made available in alternative formats upon request. Please contact the New Hampshire Office of Emergency Management ADA Coordinator at (603) 271-2231, 1- (800) 852-3792 or TDD Access, Relay NH, 1- (800) 735-2964 with your request
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