Transportation and Hydrology Studies of the

U.S. Geological Survey in New England

The U.S. Geological Survey (USGS) has a long history of working with the Federal Highway Administration (FHWA) and 

State transportation agencies to provide data and information to address various issues related to water resources and 

the Nation’s transportation infrastructure. These issues include the following:

• Streamgaging data networks

• Flow frequencies and flow statistics

• Water-quality investigations

• Bridge scour and sediment transport

• Hydrologic and hydraulic flood modeling

In New England, the USGS is conducting investigations to improve flood flow estimation techniques, to define channel 

characteristics at bankfull discharge, and to document storm tide as a result of major coastal storms. Current locally 

focused investigations include examination of flow frequency in rural, urban, and small watersheds; documentation 

of extreme inland floods along with flood-frequency updates; examination of the effects of roadway blasting on 

groundwater quality; and determinations of the effects of road salting on the quality of runoff and receiving waters.

New Focus Areas for Science

The USGS New England Water Science Center 

(http://newengland.water.usgs.gov/index.html) has identified 

five focus areas for new work with the FHWA and State 

transportation agencies in New England, including

the Connecticut Department of Transportation (CTDOT),

the Maine Department of Transportation (MEDOT),

the Massachusetts Department of Transportation (MassDOT), 

the New Hampshire Department of Transportation (NHDOT), 

the Rhode Island Department of Transportation (RIDOT), and 

the Vermont Agency of Transportation (VTrans).

Streamgaging Data Networks

• Expand network coverage to include more small, urban, 

and steep watersheds

• Replace crest stage gages with recording stage gages to 

collect continuous data

• Add gages at critical transportation infrastructure

Flow Frequencies and Flow Statistics

• Ensure peak flow equations are updated regularly

• Determine potential effects of transportation infrastructure on quantity and quality of stormwater

• Define culvert slopes and velocities needed for fish passage at full range of flows

Water-Quality Investigations

• Define acute and chronic levels of constituents coming 

off of roadways and determine relative contribution to 

total maximum daily loads

• Develop empirical approaches for estimating chloride 

and sodium concentrations in dry weather snowmelt to 

estimate loading

• Use of the FHWA/USGS Stochastic Empirical 

Loading and Dilution Model (SELDM) for estimating concentrations and loads based on land use and 

impervious surfaces

Bridge Scour and Sediment Transport

• Develop regional equations for assessing risk of 

bridge scour

• Monitor peak flows and velocities for bridges at risk 

of scour

• Define bed movement in streams during high flow

Hydrologic and Hydraulic Modeling

• Increase flood inundation mapping with light imaging 

and detection (lidar)

• Improve understanding of high flows around structures 

through use of two-dimensional models.

• Improve ice jam assessment tools

• Enhance regional field calibration of friction values

Printed on recycled paper U.S. Department of the Interior

U.S. Geological Survey

Fact Sheet 2016–3009

March 2016
Completed and Ongoing Projects

Examples of recent investigations across New England 

in cooperation with Federal and State transportation agencies 

are presented below, along with respective publications 

where available.

Streamgaging Data Networks

The USGS has cooperated for many 

years with Federal and State transportation agencies to establish, maintain, and 

expand streamflow monitoring networks 

throughout New England. Information at 

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

Flow Frequencies and Flow Statistics

The USGS has worked with Federal and State 

transportation agencies to develop equations for estimating 

streamflow statistics with between 50- and 0.2 percent annual 

exceedance probabilities (AEPs) throughout New England; these 

are equivalent to flows with between 2- and 500-year recurrence 

intervals, respectively. State transportation agencies have helped 

improve methods and equations for estimating peak flows for 

many years and have ensured that new streamgaging data are 

available throughout New England to support these updates.

Flow Statistics in Maine

The USGS, in cooperation with the 

MEDOT, derived equations to estimate 

monthly and annual mean streamflows and 

streamflows with 99- to 1-percent AEPs 

at streamgages and for ungaged rivers in 

Maine. Only streamflow data collected 

during recent years were used, thereby 

representing contemporary hydrologic 

conditions in Maine. Publication at 

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

Flow Statistics in New Hampshire

The USGS, in cooperation with the 

NHDOT, calculated flood flows with 50- 

to 0.2-percent AEPs at streamgages in 

New Hampshire and developed equations 

to estimate flood discharges for ungaged, 

unregulated streams in New Hampshire. 

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

publication/sir20085206.

Flow Statistics in Rhode Island

The USGS, in cooperation with the 

Federal Emergency Management Agency 

(FEMA), calculated flood flows with 

20- to 0.2-percent AEPs for streamgages 

in Rhode Island and developed equations 

to estimate flood flows for ungaged, 

unregulated streams in Rhode Island. 

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

publication/sir20125109.

Flow Statistics in Massachusetts

The USGS is cooperating with the MassDOT to improve 

estimates of flood flows with 20- to 0.2-percent AEPs at 

streamgages and ungaged sites in Massachusetts.

Peak Flow Regression Equations for Small, Ungaged Streams 

in Maine

The USGS, in cooperation with the 

MEDOT, developed equations to estimate streamflows with 100- to 0.2-percent AEPs for small, ungaged streams in 

Maine. Publication at 

http://dx.doi.org/10.3133/sir20155049.

Flow Statistics in Vermont

The USGS, in cooperation with 

FEMA, calculated flood flows with 50- 

to 0.2-percent AEPs for streamgages 

in Vermont and developed equations 

to estimate flood flows for ungaged, 

unregulated streams in Vermont. 

Publication at http://dx.doi.org/10.3133/

sir20145078.

StreamStats—A Water-Resources Web Application

StreamStats (http://water.usgs.gov/

osw/streamstats/) is a tool that any user 

with Internet access can use to delineate 

quickly a basin and estimate a wide variety of streamflow statistics for ungaged 

sites on rivers and streams throughout 

New England. The USGS, in cooperation with the MEDOT, implemented 

StreamStats for Maine. Publication at 

http://dx.doi.org/10.3133/fs20153014.

Impounded freshwater basin on the lower Charles River, Boston and Cambridge, Massachusetts. 
Water-Quality Investigations

Runoff and snowmelt from roadways, parking lots, and 

construction sites can convey sediment, nutrients, metals, 

deicing chemicals, and other constituents of concern. The 

quality and quantity of runoff from transportation infrastructure 

and other developed land uses are of continuing concern for 

transportation agencies, regulators, and interested citizens, 

especially in areas where runoff contributes to impaired waters 

or water supplies. The USGS, in cooperation with the FHWA 

and State transportation agencies across New England, has 

assessed flows, concentrations and loads of such constituents, the 

potential for adverse effects in receiving waters, and the potential 

effectiveness of mitigation measures for reducing these effects.

Stormwater Runoff Discharge From Massachusetts Highways

The USGS, in cooperation with the 

FHWA and MassDOT, characterized 

concentrations of sediment, nutrients, 

trace metals, deicing chemicals, and other 

constituents of concern in samples from 

13 highway-runoff monitoring stations in 

4 New England ecoregions from 2005 to 

2007. Runoff volume and water quality 

was monitored for a total of 1,523 runoff 

events. Publication at 

https://pubs.er.usgs.gov/publication/sir20095269.

Total Nutrients and Suspended Sediment in Stormwater Runoff 

From Bridge Decks in Eastern Massachusetts

The USGS is cooperating with MassDOT in an ongoing 

study to evaluate concentrations and loads of total phosphorus 

and suspended sediment from bridges in eastern Massachusetts 

over a 2-year period and the potential transferability of these data 

to other highway sites.

Nitrate Contamination of Groundwater From Roadway Rock 

Blasting in New Hampshire

The USGS in cooperation with the 

NHDOT performed a study to evaluate 

concentrations and isotopic compositions 

of nitrate and other nitrogen compounds 

in groundwater in response to roadway 

rock blasting. The study identified 

the sources of nitrogen (nitrate) 

contamination of groundwater and its 

appropriate mitigation at roadway rock 

blasting sites.

Publication at http://dx.doi.org/10.1021/

acs.est.5b03671.

Chloride Concentrations in Streams Along Interstate 95 in 

Southeastern Connecticut

The USGS, in cooperation with 

the FHWA and the CTDOT, evaluated 

the effects of road-deicer applications 

on stream water-quality upstream and 

downstream of Interstate 95 (I–95) in 

four small watersheds in southeastern 

Connecticut from 2008 to 2011. 

Publication at https://pubs.er.usgs.gov/

publication/sir20155057.

Chloride Concentrations in Streams Along State Highways in 

Northwestern Vermont

The USGS, in cooperation with 

the VTrans, quantified changes in 

concentrations and loads of road-deicing 

chloride upstream and downstream 

of highway bridges in three small 

watersheds in Chittenden County from 

2005 to 2008. Publication at

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

sir20095236.

Pollutant Loadings Model for Highway Stormwater Runoff

The USGS, in cooperation with 

the FHWA, developed the SELDM, 

which uses available data and stochastic 

Monte Carlo methods to generate 

planning-level estimates of event mean 

concentrations, discharges, and loads 

from highways or other land uses and 

in the receiving waters upstream and 

downstream of the highway-runoff 

outfall by mass-balance methods. 

Estimates can be used to evaluate 

highway-runoff discharges as a potential source of water-quality 

constituents, the potential effects of runoff loads on receiving 

water quality, and the potential effectiveness of best management 

practices for reducing the effects of highway runoff on receiving 

waters. Publication at http://pubs.er.usgs.gov/publication/tm4C3.

Additional Water-Quality Publications

Publications at http://webdmamrl.er.usgs.gov/g1/FHWA/FHWAHEP-09-004/FHWA-HEP-09-004.pdf, http://dx.doi.org/10.3133/

sir20145037, http://pubs.er.usgs.gov/publication/sir20125110, and 

http://pubs.er.usgs.gov/publication/sir20125205.

Water entering Holden Pond #1 from Kendall Reservoir in Holden, Massachusetts.
Bridge Scour and Sediment Transport

The USGS has worked with Federal and State 

transportation agencies to develop techniques and data to 

measure and quantify bridge scour in New England and 

across the Nation through the National Bridge Scour Program 

(http://water.usgs.gov/osw/techniques/bs/sed.bs.html). 

Publications at http://pubs.er.usgs.gov/publication/sir20085099

and http://pubs.er.usgs.gov/publication/wri004035.

Hydrologic and Hydraulic Modeling

Flood Study for the Cold River and Warren Brook, New Hampshire

The USGS, in cooperation with 

the NHDOT, prepared flood elevations 

for the Cold River and Warren 

Brook to aid in the replacement of 

infrastructure damaged during the 

flood of October 8–9, 2005, and to 

provide data for updating future flood 

maps. Publication at 

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

ofr20061313.

Additional Hydrologic and Hydraulic Modeling Publications

Publications at http://pubs.er.usgs.gov/publication/sir20135080

and http://dx.doi.org/10.3133/sir20145146.

Flooding in March and April 2010 along the Woonasquatucket River at 

Valley Street in Providence, Rhode Island, looking northward toward 

Atwells Avenue (traffic light) from Helme Street. Photograph by the 

U.S. Geological Survey.

The Suncook River at Main Street in the Village of Suncook, New 

Hampshire, during the flood of May 2006. Photograph by the 

U.S. Geological Survey.

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/

ISSN 2327-6916 (print)

ISSN 2327-6932 (online)

http://dx.doi.org/10.3133/fs20163009