Peterson, Julia

Wake, Cameron P

English

University of New Hampshire

University of New Hampshire
University of New Hampshire Scholars' Repository
The Sustainability Institute Research Institutes, Centers and Programs
2-2018
Changing Flood Risk in the Lamprey River
Watershed: Raymond
Cameron P. Wake
University of New Hampshire - Main Campus, cameron.wake@unh.edu
Julia Peterson
University of New Hampshire, Julia.Peterson@unh.edu
Follow this and additional works at: https://scholars.unh.edu/sustainability
This Article is brought to you for free and open access by the Research Institutes, Centers and Programs at University of New Hampshire Scholars'
Repository. It has been accepted for inclusion in The Sustainability Institute by an authorized administrator of University of New Hampshire Scholars'
Repository. For more information, please contact nicole.hentz@unh.edu.
Recommended Citation
Wake, Cameron P. and Peterson, Julia, "Changing Flood Risk in the Lamprey River Watershed: Raymond" (2018). The Sustainability
Institute. 53.
https://scholars.unh.edu/sustainability/53
Have destructive floods in Lamprey River communities 
increased over the past two or three decades? 
Yes. The five largest floods recorded along the Lamprey River have 
all occurred since 1987, three of the five since 2006. (Figure 1). 
Will destructive floods along the Lamprey River 
increase in the future? 
Floods along the Lamprey will very likely be bigger and more 
common for two reasons. One: Extreme precipitation events 
resulting from global climate change are projected to become more 
frequent. Two: Continued development will increase the area of 
paved and hardened surfaces that prevent rain and snowmelt from 
soaking into the ground and force it to run off into rivers and streams 
instead. The peak discharge at Packers Falls during a 1 percent 
annual chance flood could increase over 60 percent by 2050 if 
current trends in land development and emissions of heat-trapping 
greenhouse gases continue. The area covered by flood waters 
could expand by 10 percent to 17 percent (Figure 2). And the 10 
miles of road covered by more than 6 inches of water in 2005’s  
1 percent annual chance flood could increase to 15 miles in 2050.
How will economic damage from floods change in  
the future?
Damage is likely to increase as floods become bigger and more 
frequent.1 The maps in Figures 3 and 4 show the estimated 
replacement value of buildings and their contents damaged by 
the 1 percent annual chance flood in Raymond during 2005 and 
2050. (These estimates come from the Federal Emergency 
Management Agency [FEMA] Hazus model, which estimates 
flood damage based on base-flood elevation and building type.) 
Damages associated with a 1 percent annual chance flood in 
five Lamprey River communities are expected to increase by 33 
percent, from $164 million in 2005 to $219 million in 2050. 
Approximately 40 percent of the damage occurs in Raymond.
Figure 1. Daily peak discharge measured on the Lamprey River at Packers 
Falls. The five largest flood events were: 1) May 2006, 2) April 2007,  
3) April 1987, 4) March 2010, 5) October 1996.
Newmarket, NH during the April 2007 flood. Image from Susan Spierre Clark. 
Figure 2. Comparison of current and potential future 1 % annual chance 
floodplain.
Changing Flood Risk in  
the Lamprey River Watershed
Of all the natural disasters that hit New Hampshire, 
floods happen the most frequently and cause the most 
economic damage.
From 2005 to 2015, the state suffered 16 floods that 
were presidentially declared disasters or emergencies. 
Federal expenditures related to these floods totaled more 
than $120 million (adjusted for inflation) and accounted 
for 73 percent of all federal spending for disasters and 
emergencies in New Hampshire during that period.
Town
Flooded Area (sq. mi.) Percent  
Increase2005 2050
Raymond 1.5 1.7 10%
Epping 1.5 1.7 14%
Lee 1.2 1.5 17%
Newmarket 1.1 1.2 13%
Durham 0.9 1.0 11%
TOTAL 6.2 7.0 13%
1
2
3
1  Economic impacts data from: Geosyntec Consultants (2016) Analysis of flood damage cost avoidance in the Lamprey River watershed of New Hampshire. Available at  
http://100yearfloods.org.
Why are these estimated damages so much larger than the 
federal payouts associated with presidentially declared disasters or 
emergencies? There are several reasons:
l  Insured losses — private or National Flood Insurance Program 
(NFIP) — are NOT reported as part of federal disaster related 
expenditures.
l  Without NFIP, the maximum disaster-related FEMA payout for 
an individual household is $34,000 (for 2017). Rarely does any 
household get the maximum amount.
l  FEMA reimbursements are much less than the total property 
damage and much less than the unreimbursed losses. Disaster 
assistance is not meant to make property owners “whole.”
l  Business losses are not covered by federal disaster programs. 
How can municipalities along the Lamprey River be 
more resilient when it comes to floods?
Many community leaders who work on flooding issues in the 
Lamprey River watershed accurately recognize that flood risk has 
increased over the recent past and are concerned about future 
flooding in their communities. They expect municipal officials, 
regional planners, state agencies, engineers, and developers to use 
up-to-date floodplain maps and analyses to better understand flood 
risk and impacts.1 Municipal officials do have the legal authority to act 
and are best prepared when they use sound planning techniques and 
state their rationale for managing development in flood-prone areas.2
Here’s what community  
leaders within the Lamprey River 
watershed said:
“In our town, even post severe flooding episodes, 
it was difficult to communicate the necessity to 
take long-term preventative action. As soon as 
the disaster is over, people forget and do not want 
to make the investment to, for example, conserve 
floodplain land.”
“There should be a significant effort put forth 
to prevent new construction within the newly 
defined floodplains.”
“[Economic information should be used] to justify 
more generous setbacks and stricter zoning laws. 
The regulations are set by people who need to 
understand the cost that inaction will incur.”
Raymond NH during the April 2007 flood. Image from Jennifer Gilbert.
1 Results from an October 2016 online survey completed by 35 community leaders who work on flooding issues in the Lamprey River watershed.
2 Vermont Law School. New Floodplain Maps for a Coastal New Hampshire Watershed and Questions of Legal Authority, Measures and Consequences. (2012).  
Available through http://100yearfloods.org.
4
Raymond
Candia
Epping
UV27
UV101
UV156
UV102
UV107
UV101
UV102
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Figure
Portsmouth, NH August 2016
 
Lamprey River Hazus Study
Raymond, NH
0.25 0 0.250.125 MilesLegend
:ú Damaged Bridges
Undamaged Facilities
:ú Undamaged Bridges
Main Stream of Lamprey River
Waterbodies
Lamprey River Watershed
Municipal Boundary
³
Estimated Full
Replacement Value
Estimated Innudation Depth and Full
Replacement Value for 100 Year Storm in 2005
without Build-Out Conditions
Notes:
1. Estimated full replacement value per census block
includes building loss, contents loss, and other losses
(e.g., inventory, relocation, etc.)
2. Inundation depth limited by model coverage of
HEC-RAS/HMS.
3. Facilities include essential facilities (e.g., schools,
fire stations, police stations) and utilities (e.g., electric
facility, waste water facility).
0 - 1,000 (Thousand Dollars)
1,000 - 2,000 (Thousand Dollars)
2,000 - 5,000 (Thousand Dollars)
>5,000 (Thousand Dollars)
Modeled Innudation
Depth
>25 (ft)
0 (ft)
5
Raymond
Candia
Epping
UV27
UV101
UV156
UV102
UV107
UV101
UV102
Q
:\
G
IS
Pr
o
je
ct
s\
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02
79
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Figure
Portsmouth, NH August 2016
 
Lamprey River Hazus Study
Raymond, NH
0.25 0 0.250.125 MilesLegend
:ú Damaged Bridges
Undamaged Facilities
:ú Undamaged Bridges
Main Stream of Lamprey River
Waterbodies
Lamprey River Watershed
Municipal Boundary
³
Estimated Full
Replacement Value
Estimated Innudation Depth and Full
Replacement Value for 100 Year Storm in 2050
with Build-Out Conditions
Notes:
1. Estimated full replacement value per census block
includes building loss, contents loss, and other losses
(e.g., inventory, relocation, etc.)
2. Inundation depth limited by model coverage of
HEC-RAS/HMS.
3. Facilities include essential facilities (e.g., schools,
fire stations, police stations) and utilities (e.g., electric
facility, waste water facility).
0 - 1,000 (Thousand Dollars)
1,000 - 2,000 (Thousand Dollars)
2,000 - 5,000 (Thousand Dollars)
>5,000 (Thousand Dollars)
Modeled Innudation
Depth
>25 (ft)
0 (ft)
15
Figure 3. Estimated damage associated with the 1 percent annual chance flood in Raymond in 2005. The orange to red colors represent estimates 
of full replacement value in thousands of dollars. Figure from Geosyntec Consultants 2016 Report. Available at http://100yearfloods.org
Figure 4. Estimated damage associated with the 1 percent annual chance flood in Raymond in 2050. The orange to red colors represent estimates 
of full replacement value in thousands of dollars. Figure from Geosyntec Consultants 2016 Report. Available at http://100yearfloods.org
The 1% annual chance flood3 
The “100-year flood” is confusing because it leads people to 
believe that it only happens once every 100 years. The term 
“100-year flood” is sometimes used to simplify the definition 
of a flood that statistically has a 1% chance (or 1-in-100 
chance) of occurring in any given year. The technical term 
used by hydrologists for this extreme hydrologic event is the 
1% annual chance flood and is based on the probability that the 
given event will be equaled or exceeded in any given year.
The 1% annual chance flood is calculated for a single year. 
However, one might be interested to know the probability of 
the 1% annual chance flood over a longer time period – say 
the 30-year lifetime of a standard mortgage on an individual 
property. The probability of 1% annual chance flood occurring 
over a 30-year period is 26%! 4
Is your community looking for help with any of the steps outlined above?
If so, contact the NH Coastal Adaptation Workgroup (www.nhcaw.org), your local planner, Rockingham Planning Commission  
(www.rpc-nh.org), Strafford Regional Planning Commission (www.strafford.org), or NH’s Office of Strategic Initiatives – Floodplain Program 
(www.floods.org/index.asp?menuID=460). 
Looking for more details? Recommendations for assessing and reducing flood hazards in coastal areas are available for both  
New Hampshire and Maine. Many of the recommendations are also relevant for freshwater river watershed communities. 
l   New Hampshire Coastal Risk and Hazard Commission Report and Recommendations (www.nhcrhc.org)
l   Maine Flood Resilience Checklist: A self-assessment tool for Maine’s coastal communities to evaluate vulnerability to flood  
hazards and increase resilience (http://digitalmaine.com/mgs_publications/521)
Each town along the river faces different  
flood risks and has different priorities. 
The following steps outline an approach that municipal leaders can 
take based on their risks, priorities, time-frames, and budgets in 
order to protect human health, property, and local economies. 
Recognize that the risk of floods may be changing for 
your community
l  Review historical records and explore local knowledge
l   Review FEMA flood insurance rate maps (FIRM)  
http://msc.fema.gov/portal
l   Review UNH Lamprey flood risk maps and Hazus results 
http://100yearfloods.org
Assemble the human, technical, and financial  
resources needed to act 
l   Gain knowledge and information; participate in trainings; host 
public outreach events
l   Identify community champions and partners
l   Explore what other NH communities are doing to reduce flood risk 
www.nh.gov/osi/planning/programs/fmp/documents/communities-
enforcing-nfip.pdf
l   Locate relevant grants, bond measures, and municipal budget options
Plan
l   Acknowledge a changing climate, its effects, and uncertainty  
in Town Master Plans
l   Include current and projected flooding impacts in Hazard 
Mitigation Plans
l   Use conservation plans to identify critical areas that provide 
important benefits to society, such as flood storage
l   Use municipal asset management and capital improvement plans 
to prepare financially 
Implement
l   Use non-regulatory tools such as floodplain property buyouts and 
easements to establish no-build areas 
l   Develop and use regulatory tools such as zoning, freeboard 
requirements, and development setbacks; redirect development to 
lower risk areas; create floodplain overlay districts; and proactively 
manage stormwater
l   Allow “No Adverse Impact” principles to guide regulations  
 www.floods.org/index.asp?menuID=460
l   Design infrastructure projects such as replacing or upgrading 
culverts and elevating, fortifying, or moving critical, at-risk 
facilities to accommodate current and future flood risk 
l   Support natural resource conservation projects such as maintaining 
and restoring vegetative buffers conserving land, and living shorelines
3 From:  i) USGS, Floods: Recurrence Intervals and 100-year floods. https://water.usgs.gov/edu/100yearflood.html;  
ii) USGS, Questions and answers about floods. https://water.usgs.gov/edu/qafloods.html
4 Statistical analysis to calculate these values is provided at Geology Labs-On-line Project: www.sciencecourseware.com/VirtualRiver/FloodingDemo/Files/page13.html
4
1
3
2
This summary written by Cameron Wake (UNH Sustainability Institute and Institute for the Study of Earth, Oceans, and Space) and  
Julia Peterson (NH Sea Grant and UNH Cooperative Extension), February 2018.


Changing Flood Risk in the Lamprey River Watershed: Raymond

UNH Scholars' Repository

University of New HampshireUniversity of New Hampshire Scholars' RepositoryThe Sustainability Institute Research Institutes, Centers and Programs2-2018Changing Flood Risk in the Lamprey RiverWatershed: RaymondCameron P. WakeUniversity of New Hampshire - Main Campus, cameron.wake@unh.eduJulia PetersonUniversity of New Hampshire, Julia.Peterson@unh.eduFollow this and additional works at: https://scholars.unh.edu/sustainabilityThis Article is brought to you for free and open access by the Research Institutes, Centers and Programs at University of New Hampshire Scholars'Repository. It has been accepted for inclusion in The Sustainability Institute by an authorized administrator of University of New Hampshire Scholars'Repository. For more information, please contact nicole.hentz@unh.edu.Recommended CitationWake, Cameron P. and Peterson, Julia, "Changing Flood Risk in the Lamprey River Watershed: Raymond" (2018). The SustainabilityInstitute. 53.https://scholars.unh.edu/sustainability/53Have destructive floods in Lamprey River communities increased over the past two or three decades? Yes. The five largest floods recorded along the Lamprey River have all occurred since 1987, three of the five since 2006. (Figure 1). Will destructive floods along the Lamprey River increase in the future? Floods along the Lamprey will very likely be bigger and more common for two reasons. One: Extreme precipitation events resulting from global climate change are projected to become more frequent. Two: Continued development will increase the area of paved and hardened surfaces that prevent rain and snowmelt from soaking into the ground and force it to run off into rivers and streams instead. The peak discharge at Packers Falls during a 1 percent annual chance flood could increase over 60 percent by 2050 if current trends in land development and emissions of heat-trapping greenhouse gases continue. The area covered by flood waters could expand by 10 percent to 17 percent (Figure 2). And the 10 miles of road covered by more than 6 inches of water in 2005’s  1 percent annual chance flood could increase to 15 miles in 2050.How will economic damage from floods change in  the future?Damage is likely to increase as floods become bigger and more frequent.1 The maps in Figures 3 and 4 show the estimated replacement value of buildings and their contents damaged by the 1 percent annual chance flood in Raymond during 2005 and 2050. (These estimates come from the Federal Emergency Management Agency [FEMA] Hazus model, which estimates flood damage based on base-flood elevation and building type.) Damages associated with a 1 percent annual chance flood in five Lamprey River communities are expected to increase by 33 percent, from $164 million in 2005 to $219 million in 2050. Approximately 40 percent of the damage occurs in Raymond.Figure 1. Daily peak discharge measured on the Lamprey River at Packers Falls. The five largest flood events were: 1) May 2006, 2) April 2007,  3) April 1987, 4) March 2010, 5) October 1996.Newmarket, NH during the April 2007 flood. Image from Susan Spierre Clark. Figure 2. Comparison of current and potential future 1 % annual chance floodplain.Changing Flood Risk in  the Lamprey River WatershedOf all the natural disasters that hit New Hampshire, floods happen the most frequently and cause the most economic damage.From 2005 to 2015, the state suffered 16 floods that were presidentially declared disasters or emergencies. Federal expenditures related to these floods totaled more than $120 million (adjusted for inflation) and accounted for 73 percent of all federal spending for disasters and emergencies in New Hampshire during that period.TownFlooded Area (sq. mi.) Percent  Increase2005 2050Raymond 1.5 1.7 10%Epping 1.5 1.7 14%Lee 1.2 1.5 17%Newmarket 1.1 1.2 13%Durham 0.9 1.0 11%TOTAL 6.2 7.0 13%1231  Economic impacts data from: Geosyntec Consultants (2016) Analysis of flood damage cost avoidance in the Lamprey River watershed of New Hampshire. Available at  http://100yearfloods.org.Why are these estimated damages so much larger than the federal payouts associated with presidentially declared disasters or emergencies? There are several reasons:l  Insured losses — private or National Flood Insurance Program (NFIP) — are NOT reported as part of federal disaster related expenditures.l  Without NFIP, the maximum disaster-related FEMA payout for an individual household is $34,000 (for 2017). Rarely does any household get the maximum amount.l  FEMA reimbursements are much less than the total property damage and much less than the unreimbursed losses. Disaster assistance is not meant to make property owners “whole.”l  Business losses are not covered by federal disaster programs. How can municipalities along the Lamprey River be more resilient when it comes to floods?Many community leaders who work on flooding issues in the Lamprey River watershed accurately recognize that flood risk has increased over the recent past and are concerned about future flooding in their communities. They expect municipal officials, regional planners, state agencies, engineers, and developers to use up-to-date floodplain maps and analyses to better understand flood risk and impacts.1 Municipal officials do have the legal authority to act and are best prepared when they use sound planning techniques and state their rationale for managing development in flood-prone areas.2Here’s what community  leaders within the Lamprey River watershed said:“In our town, even post severe flooding episodes, it was difficult to communicate the necessity to take long-term preventative action. As soon as the disaster is over, people forget and do not want to make the investment to, for example, conserve floodplain land.”“There should be a significant effort put forth to prevent new construction within the newly defined floodplains.”“[Economic information should be used] to justify more generous setbacks and stricter zoning laws. The regulations are set by people who need to understand the cost that inaction will incur.”Raymond NH during the April 2007 flood. Image from Jennifer Gilbert.1 Results from an October 2016 online survey completed by 35 community leaders who work on flooding issues in the Lamprey River watershed.2 Vermont Law School. New Floodplain Maps for a Coastal New Hampshire Watershed and Questions of Legal Authority, Measures and Consequences. (2012).  Available through http://100yearfloods.org.4RaymondCandiaEppingUV27UV101UV156UV102UV107UV101UV102Q:\GISProjects\BW0279_Hazus\MXD\Figures_2016\Town_Maps\Raymond_Epping_LND.mxdFigurePortsmouth, NH August 2016 Lamprey River Hazus StudyRaymond, NH0.25 0 0.250.125 MilesLegend:ú Damaged BridgesUndamaged Facilities:ú Undamaged BridgesMain Stream of Lamprey RiverWaterbodiesLamprey River WatershedMunicipal Boundary³Estimated FullReplacement ValueEstimated Innudation Depth and FullReplacement Value for 100 Year Storm in 2005without Build-Out ConditionsNotes:1. Estimated full replacement value per census blockincludes building loss, contents loss, and other losses(e.g., inventory, relocation, etc.)2. Inundation depth limited by model coverage ofHEC-RAS/HMS.3. Facilities include essential facilities (e.g., schools,fire stations, police stations) and utilities (e.g., electricfacility, waste water facility).0 - 1,000 (Thousand Dollars)1,000 - 2,000 (Thousand Dollars)2,000 - 5,000 (Thousand Dollars)>5,000 (Thousand Dollars)Modeled InnudationDepth>25 (ft)0 (ft)5RaymondCandiaEppingUV27UV101UV156UV102UV107UV101UV102Q:\GISProjects\BW0279_Hazus\MXD\Figures_2016\Town_Maps\Raymond_Epping_LND.mxdFigurePortsmouth, NH August 2016 Lamprey River Hazus StudyRaymond, NH0.25 0 0.250.125 MilesLegend:ú Damaged BridgesUndamaged Facilities:ú Undamaged BridgesMain Stream of Lamprey RiverWaterbodiesLamprey River WatershedMunicipal Boundary³Estimated FullReplacement ValueEstimated Innudation Depth and FullReplacement Value for 100 Year Storm in 2050with Build-Out ConditionsNotes:1. Estimated full replacement value per census blockincludes building loss, contents loss, and other losses(e.g., inventory, relocation, etc.)2. Inundation depth limited by model coverage ofHEC-RAS/HMS.3. Facilities include essential facilities (e.g., schools,fire stations, police stations) and utilities (e.g., electricfacility, waste water facility).0 - 1,000 (Thousand Dollars)1,000 - 2,000 (Thousand Dollars)2,000 - 5,000 (Thousand Dollars)>5,000 (Thousand Dollars)Modeled InnudationDepth>25 (ft)0 (ft)15Figure 3. Estimated damage associated with the 1 percent annual chance flood in Raymond in 2005. The orange to red colors represent estimates of full replacement value in thousands of dollars. Figure from Geosyntec Consultants 2016 Report. Available at http://100yearfloods.orgFigure 4. Estimated damage associated with the 1 percent annual chance flood in Raymond in 2050. The orange to red colors represent estimates of full replacement value in thousands of dollars. Figure from Geosyntec Consultants 2016 Report. Available at http://100yearfloods.orgThe 1% annual chance flood3 The “100-year flood” is confusing because it leads people to believe that it only happens once every 100 years. The term “100-year flood” is sometimes used to simplify the definition of a flood that statistically has a 1% chance (or 1-in-100 chance) of occurring in any given year. The technical term used by hydrologists for this extreme hydrologic event is the 1% annual chance flood and is based on the probability that the given event will be equaled or exceeded in any given year.The 1% annual chance flood is calculated for a single year. However, one might be interested to know the probability of the 1% annual chance flood over a longer time period – say the 30-year lifetime of a standard mortgage on an individual property. The probability of 1% annual chance flood occurring over a 30-year period is 26%! 4Is your community looking for help with any of the steps outlined above?If so, contact the NH Coastal Adaptation Workgroup (www.nhcaw.org), your local planner, Rockingham Planning Commission  (www.rpc-nh.org), Strafford Regional Planning Commission (www.strafford.org), or NH’s Office of Strategic Initiatives – Floodplain Program (www.floods.org/index.asp?menuID=460). Looking for more details? Recommendations for assessing and reducing flood hazards in coastal areas are available for both  New Hampshire and Maine. Many of the recommendations are also relevant for freshwater river watershed communities. l   New Hampshire Coastal Risk and Hazard Commission Report and Recommendations (www.nhcrhc.org)l   Maine Flood Resilience Checklist: A self-assessment tool for Maine’s coastal communities to evaluate vulnerability to flood  hazards and increase resilience (http://digitalmaine.com/mgs_publications/521)Each town along the river faces different  flood risks and has different priorities. The following steps outline an approach that municipal leaders can take based on their risks, priorities, time-frames, and budgets in order to protect human health, property, and local economies. Recognize that the risk of floods may be changing for your communityl  Review historical records and explore local knowledgel   Review FEMA flood insurance rate maps (FIRM)  http://msc.fema.gov/portall   Review UNH Lamprey flood risk maps and Hazus results http://100yearfloods.orgAssemble the human, technical, and financial  resources needed to act l   Gain knowledge and information; participate in trainings; host public outreach eventsl   Identify community champions and partnersl   Explore what other NH communities are doing to reduce flood risk www.nh.gov/osi/planning/programs/fmp/documents/communities-enforcing-nfip.pdfl   Locate relevant grants, bond measures, and municipal budget optionsPlanl   Acknowledge a changing climate, its effects, and uncertainty  in Town Master Plansl   Include current and projected flooding impacts in Hazard Mitigation Plansl   Use conservation plans to identify critical areas that provide important benefits to society, such as flood storagel   Use municipal asset management and capital improvement plans to prepare financially Implementl   Use non-regulatory tools such as floodplain property buyouts and easements to establish no-build areas l   Develop and use regulatory tools such as zoning, freeboard requirements, and development setbacks; redirect development to lower risk areas; create floodplain overlay districts; and proactively manage stormwaterl   Allow “No Adverse Impact” principles to guide regulations   www.floods.org/index.asp?menuID=460l   Design infrastructure projects such as replacing or upgrading culverts and elevating, fortifying, or moving critical, at-risk facilities to accommodate current and future flood risk l   Support natural resource conservation projects such as maintaining and restoring vegetative buffers conserving land, and living shorelines3 From:  i) USGS, Floods: Recurrence Intervals and 100-year floods. https://water.usgs.gov/edu/100yearflood.html;  ii) USGS, Questions and answers about floods. https://water.usgs.gov/edu/qafloods.html4 Statistical analysis to calculate these values is provided at Geology Labs-On-line Project: www.sciencecourseware.com/VirtualRiver/FloodingDemo/Files/page13.html4132This summary written by Cameron Wake (UNH Sustainability Institute and Institute for the Study of Earth, Oceans, and Space) and  Julia Peterson (NH Sea Grant and UNH Cooperative Extension), February 2018.

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Changing Flood Risk in the Lamprey River Watershed: Raymond

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