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Flood- and Drought-Related Natural Hazards Activities 

of the U.S. Geological Survey in New England

The U.S. Geological Survey (USGS) has many ongoing and recent water-related natural hazard activities in New England that can be 

used to help mitigate the effects of natural hazards in cooperation with other agencies. The themes related to potential hazards and 

the tools and science to better understand and address them include the following:

Erosion and landslides

• Fluvial erosion (sediment transport, bridge scour, and 

bankfull channel geometry characterization)

• Current and historic landslide mapping

Flood documentation and assessment

• Flood high-water marks

• Flood modeling and frequency analysis

• Flood inundation mapping

• Peak-flow regression equations

Drought documentation and assessment

• Drought frequency analysis

• Low-flow frequency and flow duration statistics

• Water use and availability during drought

Hydrologic monitoring

• Streamflow monitoring network

• Groundwater monitoring network

• Tidal monitoring network

• Snow surveys and ice jam monitoring

Tools for natural hazard assessment and mitigation

• Light detection and ranging (lidar) remote 

sensing technology

• StreamStats Web-based tool for streamflow statistics

• Flood inundation mapping

Erosion and Landslides

Fluvial Erosion

Fluvial geomorphic hazards, such as erosion and sediment 

transport, can damage infrastructure, such as buildings, bridges, 

dams, and roads, degrade aquatic habitats, compromise water 

supplies, and transport chemical constituents. Storm runoff can 

transport large quantities of suspended and bedload sediments. 

The transport happens through streambed and streambank 

scour, overland flow inputs to a river, and scour around 

structures.

Sediment Transport

The USGS, the Federal 

Emergency Management Agency 

(FEMA), and the New Hampshire 

Department of Environmental 

Services studied sediment 

transport in the Suncook River 

in Epsom, New Hampshire, 

from a breach in the river’s 

banks following a flood in 2006. 

Publication at 

http://pubs.er.usgs.gov/

publication/sir20115088.

Bankfull Channel Geometry Characterization

The USGS has developed 

regression equations for 

estimating bankfull width, mean 

depth, cross-sectional area, 

and discharge for streams in 

Massachusetts and Maine. 

Publications at

http://pubs.er.usgs.gov/

publication/sir20045042 and 

http://dx.doi.org/10.3133/sir20135155.

Landslide Mapping

Landslides occur in all 50 States 

and annually cause $1 to 2 billion in 

damages and more than 25 fatalities 

on average. Several landslides 

occurred in Massachusetts, New 

Hampshire, and Vermont as a result 

of Tropical Storm Irene on August 28, 

2011. The USGS Landslides Hazards 

Program (http://landslides.usgs.gov/) 

strives to improve the understanding of landslide hazards to 

help protect communities and reduce associated and repetitive 

losses. The National Cooperative Geologic Mapping Program 

(http://ncgmp.usgs.gov/) is a critical asset in mapping historical 

landslides as well as recent occurrences.

U.S. Department of the Interior

U.S. Geological Survey

Fact Sheet 2016–3008

March 2016
Flood Documentation and Assessment

Flooding is New England’s most frequent and costly natural disaster (U.S. Geological Survey, 1995). 

The USGS provides data and analyses for emergency preparedness, response, and mitigation. Following 

flood disaster declarations by FEMA, the USGS has documented flood elevations with high-water marks, 

modeled streamflows and recurrence intervals, created flood recovery maps to document the areal extent 

of flooding, and provided communities with information to aid in rebuilding. Following record rainfall 

totals in the Northeast from severe storms in 2005, 2006, and 2010 and Tropical Storm Irene in 2011, the 

USGS published flood recovery reports throughout New England.

Publications at

http://pubs.er.usgs.gov/publication/ofr20111029,

http://pubs.er.usgs.gov/publication/ofr20101315,

http://dx.doi.org/10.3133/sir20135187, and

http://pubs.er.usgs.gov/publication/sir20045160.

Flood Inundation Mapper

Flood-inundation maps show current and forecasted flood-inundated areas 

overlaid on high-resolution, georeferenced aerial photographs of an area. The maps provide emergency management personnel and 

communities with flood potential information that is critical for response activities, such as building evacuations, road closures, 

disaster declarations, and recovery efforts. Flood inundation maps (http://wimcloud.usgs.gov/apps/FIM/FloodInundationMapper.html) 

can easily be created for any stream reach that has a National Weather Service (NWS) flood forecast streamgage, lidar, and a hydraulic 

model. Roughly 55 percent of all USGS streamgages nationwide are also NWS forecast gages (U.S. Geological Survey, 1995). Recent 

New England flood inundation work is listed below. The USGS cooperated with FEMA in 2015 to develop flood inundation maps for 

portions of the Hoosic, Deerfield, North, and Green Rivers in northwestern Massachusetts and the Winooski River in central Vermont. 

Publications at

http://dx.doi.org/10.3133/sir20155077,

http://pubs.er.usgs.gov/publication/sim3157,

http://pubs.er.usgs.gov/publication/sim3196,

http://dx.doi.org/10.3133/sir20155104,

http://dx.doi.org/10.3133/sir20145236, and

http://dx.doi.org/10.3133/sir20155108.

Drought Documentation and Assessment

Although floods are relatively short-term phenomena, droughts can persist for months and even 

years during precipitation deficits. In New England, droughts can cause private drinking-water wells 

to go dry, limit surface-water and groundwater withdrawals for municipal and commercial uses, affect 

aquatic habitat, and result in severe stream water-quality issues downstream of pollution sources.

The USGS analyzes data from streamgages and groundwater wells (http://waterdata.usgs.gov/nwis) 

to develop statistical summaries of low flow and groundwater levels during periods of drought. Real-time 

data and statistics are important for determining drought warnings by state agencies, planning and allocating water resources across New England, and managing and protecting fish and wildlife populations.

Publications at 

http://pubs.er.usgs.gov/publication/wri024298, 

http://pubs.er.usgs.gov/publication/sir20075270, 

http://pubs.er.usgs.gov/publication/sir20145010, and 

http://dx.doi.org/10.3133/sir20155151.
Hydrologic Monitoring

The USGS has cooperated for many years with multiple Federal and State agencies to establish, 

maintain, and expand streamflow, groundwater, and tidal monitoring networks throughout New England 

(http://newengland.water.usgs.gov/index.html) to assess and investigate floods and droughts.

Streamflow Monitoring Network

The USGS operates more than 400 streamgages in New England 

(http://waterwatch.usgs.gov/). Streamgage data are transmitted in real time through cellular telephone and 

satellite technology to the Internet to assist Federal and State emergency management agencies in monitoring 

flow levels and dams and flood control systems and in forecasting flood stages and timing.

Groundwater Monitoring Network

The USGS operates 57 groundwater monitoring wells in New England that collect data on an hourly 

basis and disseminate the data in near real time. The USGS also provides data from 180 groundwater wells in 

New England that are measured monthly. The groundwater monitoring data are available on the USGS New 

England Groundwater Network (http://groundwaterwatch.usgs.gov/netmapT2L1.asp?ncd=NEN).

Tidal Monitoring Network

The USGS operates 10 permanent tidal gages to continuously monitor water levels in coastal 

New England. In addition, the USGS has installed 245 mounting stations for temporary storm surge 

sensors and 17 rapid-deployment gages along the coast of New England. Monitoring equipment is installed 

quickly at these stations in the hours and days prior to a storm. The Hurricane Storm Tide Sensor Map 

(http://waterwatch.usgs.gov/hsss/index.php) displays tide and flood data collected since 2005. In 2015, the 

USGS monitored and reported on the tidal surge associated with a major Nor’easter storm. Publication at 

http://dx.doi.org/10.3133/ofr20151081.

Snow Surveys and Ice Jam Monitoring

The USGS, in cooperation with other Federal, State, and local agencies and businesses, collects, 

interprets, and distributes snow depth and water content data in parts of New England during the late 

winter and early spring when the danger of riverine flooding is greatest due to snowmelt. Information 

such as that from the Maine cooperative snow survey (http://www.maine.gov/rfac/rfac_snow.shtml) is 

transmitted to the NWS for preparing flood potential statements and running flood forecast models.

The USGS works with Federal and local emergency management officials to monitor hazardous 

ice accumulation on rivers in northern New England. The USGS provides real-time river stage 

data and monitoring on the Internet through online live-broadcasting cameras of ice conditions 

at vulnerable locations, such as the Kennebec River at Calumet Bridge at Augusta, Maine station 

(http://waterdata.usgs.gov/me/nwis/uv/?site_no=01049320). The U.S. Army Corps of Engineers and the NWS evaluate these locations 

for potential ice jam formation and river flooding.

Flooded bridge on the St. John River in Maine. A major flood in 

2008 was the highest flow measured at the U.S. Geological Survey 

St. John River at Fort Kent, Maine station (01014000), based on a 

record going back to the 1920s. Photograph by the U.S. Geological 

Survey.
Tools for Natural Hazard Assessment and Mitigation

The USGS is at the forefront of technological advances and water resources tools to assess and mitigate natural hazards.

Lidar

Lidar is an essential remote sensing technology for applications that rely on highquality elevation data. The USGS and other scientific organizations researching hazards 

need accurate topographic and bathymetric information. The USGS has responded to 

the growing need for high-quality topographic data with the 3D Elevation Program 

(3DEP; http://nationalmap.gov/3DEP/), which provides elevation products that can 

be used to create 2- to 4-foot contour intervals. As a result of 3DEP, scientists and 

managers can access accurate elevation information through The National Map 

(http://viewer.nationalmap.gov/viewer/) and can plan projects to fly new lidaracquisition missions in cooperation with the USGS when existing data are not adequate.

StreamStats

The USGS has worked with multiple agencies to develop equations for estimating streamflow statistics 

throughout New England. Users can estimate peak streamflow statistics with 2- to 500-year recurrence 

intervals, low-flow durations and frequencies, monthly and annual flows, probability of a stream flowing 

perennially, and bankfull discharge. StreamStats (http://water.usgs.gov/osw/streamstats/) is a tool that any 

user with Internet access can use to quickly delineate a basin and estimate streamflow statistics for ungaged 

sites on streams throughout New England.

Flood Inundation Mapper

All USGS flood inundation mapping projects are integrated in the Flood Inundation Mapper 

(http://wimcloud.usgs.gov/apps/FIM/FloodInundationMapper.html). Users can zoom to a specific 

area of interest and print maps that will help them identify specific areas of flooding related to flood 

forecast streamgages.

Reference Cited

U.S. Geological Survey, 1995, Stream gaging and flood forecasting: U.S. Geological Survey Fact Sheet 95–209, 4 p., accessed 

at http://water.usgs.gov/wid/FS_209-95/mason-weiger.html.

For more information, contact:

Director, New England Water Science Center

U.S. Geological Survey

331 Commerce Way, Suite 2

Pembroke, NH 03275

Email: dc_nweng@usgs.gov

or visit our Web site at

http://newengland.water.usgs.gov/

Aerial view of damage along U.S. Route 4 in Mendon, Vermont, as 

a result of floodwaters from Mendon Brook during Tropical Storm 

Irene in August 2011. Photograph by the U.S. Geological Survey.

ISSN 2327-6916 (print)

ISSN 2327-6932 (online)

http://dx.doi.org/10.3133/fs20163008