Framework for a Hydrologic Climate-Response 

Network in New England

Open-File Report 2015–1062

U.S. Department of the Interior

U.S. Geological Survey

Framework for a Hydrologic ClimateResponse Network in New England

By Robert M. Lent, Glenn A. Hodgkins, Robert W. Dudley, and Luther F. Schalk

Open-File Report 2015–1062

U.S. Department of the Interior

U.S. Geological Survey
U.S. Department of the Interior

SALLY JEWELL, Secretary

U.S. Geological Survey

Suzette M. Kimball, Acting Director

U.S. Geological Survey, Reston, Virginia: 2015

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Suggested citation:

Lent, R.M., Hodgkins, G.A., Dudley, R.W., and Schalk, L.F., 2015, Framework for a hydrologic climate-response network 

in New England: U.S. Geological Survey Open-File Report 2015–1062, 34 p., http://dx.doi.org/10.3133/ofr20151062.

ISSN 2331-1258 (online)
iii

Contents

Abstract...........................................................................................................................................................1

Introduction.....................................................................................................................................................1

Climate and Hydrology of New England ....................................................................................................1

Historical Climate and Hydrologic Changes in New England .......................................................2

Annual ...........................................................................................................................................2

Winter and Spring........................................................................................................................2

Summer and Fall...........................................................................................................................4

Drivers of Climate-Response Network Hydrologic Variables .......................................................5

Future Hydrologic Changes in New England ...................................................................................6

Potential Effects of Hydrologic Changes ..........................................................................................6

Framework for a Hydrologic Climate-Response Network ......................................................................7

Climate-Response Regions .................................................................................................................7

Primary Components and Associated Key Variables of a Hydrologic Climate-Response 

Network.....................................................................................................................................9

Streamflow..................................................................................................................................11

Groundwater...............................................................................................................................11

Lake Ice .......................................................................................................................................18

Snowpack....................................................................................................................................19

Meteorological Stations ...........................................................................................................22

Process-Based Studies .....................................................................................................................22

Summary........................................................................................................................................................30

References Cited..........................................................................................................................................31

Figures

1. Graph showing historical winter-spring streamflow timing for the Piscataquis River 

in central Maine............................................................................................................................3

2. Graph showing historical ice-out dates for Damariscotta Lake in midcoastal Maine .....5

3. Map showing hydrologic climate-response regions in New England ................................8

4. Smoothed plots of winter-spring streamflow timing for streams in New England..........10

5. Smoothed plots of historical lake ice-out dates in New England ......................................10

6. Map showing streamflow-gaging stations in New England that drain relatively 

natural watersheds ....................................................................................................................12

7. Map showing groundwater wells in New England minimally affected by human 

disturbance..................................................................................................................................15

8. Graph showing relation of August groundwater levels and annual mean 

streamflows .................................................................................................................................19

9. Map showing lakes in New England with substantial amounts of ice-out data..............20

10. Map showing location of long-term snowpack sites in New England..............................23

11. Map showing U.S. Historical Climatology Network meteorological stations in 

New England ...............................................................................................................................26
iv

12. Map showing basin sites appropriate for process-based studies ....................................28

13. Map showing an example of rainfall-runoff-model subareas for two basins in 

eastern coastal Maine...............................................................................................................29

Tables

1. Annual and seasonal climatic drivers of hydrologic variability in New England ..............5

2. Description of hydrologic climate-response regions in New England................................9

3. Streamflow-gaging stations in New England that drain relatively natural 

watersheds. .................................................................................................................................13

4. Groundwater wells in northern New England that meet climate-network criteria.........16

5. Lakes in New England with substantial amounts of ice-out data ......................................21

6. Long-term snowpack sites in New England...........................................................................24

7. Long-term meteorological stations in New England ............................................................25

8. Basin sites appropriate for process-based studies..............................................................27

Conversion Factors

Inch/Pound to International System of Units

Multiply By To obtain

Length

inch (in.) 2.54 centimeter (cm)

mile (mi) 1.609 kilometer (km)

Area

square mile (mi2

) 259.0 hectare (ha)

square mile (mi2

) 2.590 square kilometer (km2)

Flow rate

cubic foot per second (ft3

/s) 0.02832 cubic meter per second (m3/s)

inch per year (in/yr) 25.4 millimeter per year (mm/yr)

Temperature in degrees Fahrenheit (°F) may be converted to degrees Celsius (°C) as 

°C = (F – 32) / 1.8.

Datum

Vertical coordinate information is referenced to the North American Vertical Datum of 1988 

(NAVD 88).

Horizontal coordinate information is referenced to the North American Datum of 1983 (NAD 83).

Elevation, as used in this report, refers to distance above the vertical datum.
v

Abbreviations

GAGES II Geospatial Attributes of Gages for Evaluating Streamflow, version II

GCM general circulation model

HCDN–2009 Hydro-Climatic Data Network 2009

MGS Maine Geological Survey

PRMS Precipitation-Runoff Modeling System

USGS U.S. Geological Survey

USHCN U.S. Historical Climatology Network

WSCV winter-spring center of volume

WSV winter-spring runoff volume

Framework for a Hydrologic Climate-Response Network 

in New England

By Robert M. Lent, Glenn A. Hodgkins, Robert W. Dudley, and Luther F. Schalk

Abstract

Many climate-related hydrologic variables in New 

England have changed in the past century, and many are 

expected to change during the next century. It is important 

to understand and monitor these changes because they can 

affect human water supply, hydroelectric power generation, 

transportation infrastructure, and stream and riparian ecology. 

This report describes a framework for hydrologic monitoring 

in New England by means of a climate-response network. 

The framework identifies specific inland hydrologic variables 

that are sensitive to climate variation; identifies geographic 

regions with similar hydrologic responses; proposes a fixedstation monitoring network composed of existing streamflow, 

groundwater, lake ice, snowpack, and meteorological datacollection stations for evaluation of hydrologic response 

to climate variation; and identifies streamflow basins for 

intensive, process-based studies and for estimates of future 

hydrologic conditions.

Introduction

Seasonal, annual, and longer term variations in 

precipitation and air temperature can affect the timing and 

magnitude of numerous hydrologic processes that, in turn, 

affect natural resources, ecosystems, and society. Recent 

investigations conclude that many different hydrologic 

processes in New England are sensitive to variations in 

precipitation and air temperature. Various hydrologic 

variables, such as peak flows and the timing of winterspring streamflows, have changed during the last century 

and are expected to change in the future. Observed trends 

during winter and spring are largely related to changes in 

air temperature because of the sensitivity of snowpack to air 

temperature changes in New England. Trends during summer 

and fall are largely related to changes in precipitation.

The U.S. Geological Survey (USGS) published a framework for a hydrologic climate-response network in Maine 

(Hodgkins and others, 2009). The framework benefitted from 

a decade of climate-change-related investigations into many 

components of the water cycle in Maine and New England and 

demonstrated how relevant hydrologic data describing various 

components of the regional water cycle can be key indicators 

of climate change. This report expands the Maine framework 

to cover the New England region—a larger, more climatologically diverse area with a much greater population than Maine. 

The New England framework has four purposes:

• Identify specific hydrologic variables for inland areas 

that are sensitive to climate variation.

• Identify geographic regions with similar hydrologic 

responses.

• Propose a fixed-station monitoring network composed 

of existing streamflow, groundwater, lake ice, snowpack, and meteorological data-collection sites for 

evaluation of hydrologic response to climate variation.

• Establish basins for process-based studies and for estimates of future hydrologic conditions.

Although sea-level rise is an important climate-changerelated issue, it is not directly addressed by this proposed 

climate-response network, which focuses on inland hydrologic 

response. Much of the “Climate and Hydrology of New 

England” section of this report is updated text from Hodgkins 

and others (2009).

Climate and Hydrology of New England

The climate of New England is complex and variable; 

latitude, proximity to the Atlantic coast, and variations in landsurface elevation exert determinative effects on the climate 

(New England Regional Assessment Group, 2001). New 

England is about halfway between the equator and the North 

Pole and is affected by warm, moist air from the south and 

cold, dry air from the north. The Atlantic Ocean moderates air 

temperatures in both winter and summer. In winter, the ocean 

variably affects the location of snow/rain boundaries. Despite 

the substantial effect of the ocean, the prevailing air flow is not 

from the Atlantic Ocean but from the drier North American 

continent. The mountainous topography of northern and western New England affects precipitation and air temperatures. 
2 Framework for a Hydrologic Climate-Response Network in New England

Precipitation is higher on the windward side of mountains than 

on the leeward side; however, because storm-track directions 

through the mountains are highly variable, the windward and 

leeward areas differ for different storms. Air temperature generally decreases with increasing elevation.

Streamflows in New England typically are highest in 

the spring, when rain falls on a ripe snowpack or on saturated 

soils. Streamflows recede as snowmelt ends and as evapotranspiration increases. This recession is frequently interrupted by 

runoff from rainstorms. Warm-season streamflows are usually 

lowest in August and September. In the fall, after evapotranspiration decreases substantially, repeated rains often saturate 

the soil and lead to high streamflows. Also in the fall, large 

amounts of rain can fall as a result of hurricanes, tropical 

storms, or their remnants. Winter streamflows are generally 

low in northern New England, where winter precipitation 

typically falls as snow. Winter streamflows in southern New 

England can be more variable than streamflows in northern 

New England because of more winter rain.

The snowpack in New England typically accumulates 

throughout the winter and reaches its maximum depth and 

water equivalent (the amount of water stored in the snowpack) 

in northern New England (where the snowpack is more 

substantial than in southern New England) in March or April. 

The median seasonal maximum depth of the snowpack from 

1955 to 1992 varied from less than 8 inches (in.) in coastal 

Connecticut and Rhode Island to more than 32 in. in the 

mountains of western Maine and northern New Hampshire 

and in northern Maine (Cember and Wilks, 1993). Most 

historical field-based data for snow water equivalent in New 

England have been collected in Maine. The average water 

equivalent on or near March 1 ranged from 3 to 5 in. along 

the Maine coast to 7 to 9 in. in the western mountains and in 

northern Maine (Loiselle and Hodgkins, 2002). The 109 datacollection sites analyzed by Loiselle and Hodgkins (2002) 

had an average of 43 years of record through 2000. Almost 

all of the data-collection sites were lower than 2,000 feet (ft) 

in elevation and therefore do not represent the full range of 

average water equivalent in Maine, as many mountains have 

elevations higher than 2,000 ft.

Historical Climate and Hydrologic Changes in 

New England

Climate-related seasonal hydrologic changes have been 

documented in New England on the basis of data collected 

during the last 50 to 200 years. Many changes have been documented in winter and spring, whereas some changes have been 

found in summer and fall and for annual flow variables. Overall, there is strong regionally coherent evidence of changes 

consistent with increasing air temperatures in late winter and 

spring in the last 30 to 40 years in northern New England 

(Maine, New Hampshire, and Vermont).

Annual

Various changes in low to high annual streamflows in 

New England have been documented (Hodgkins and Dudley, 

2005). Annual low streamflows significantly increased 

(p < 0.1) at several streamflow-gaging stations in northern 

New England from the early to mid-1900s through 2002. 

Annual peak flows have increased significantly during the 

last 50 to 100 years at several streamflow-gaging stations 

across New England (Hodgkins and Dudley, 2005; Collins, 

2009; Hodgkins, 2010a; Armstrong and others, 2012). 

Annual maximum and minimum groundwater levels during 

the most recent 20 and 30 years have increased in northern 

New England (Dudley and Hodgkins, 2013); in general, 

increases in maximum levels have been greater than increases 

in minimum levels, resulting in trends toward an increasing 

annual range. Weider and Boutt (2010) found groundwater 

levels increasing overall in New England in the last decade. 

Precipitation has increased in New England across all seasons 

(Karl and Knight, 1998; Douglas and Fairbanks, 2011; 

Hodgkins and Dudley, 2011).

Sea level has been rising globally for the past 

20,000 years largely because of melting continental ice sheets 

that accumulated during the last ice age (Poore and others, 

2000). One of the projected effects of climate warming is a 

continued rise in sea level caused by a combination of melting 

glaciers and ice sheets (on land) and thermal expansion of 

the ocean, called eustatic sea-level rise (Frumhoff and others, 

2007). Historical rates of relative sea-level rise (eustatic 

sea-level rise combined with the effects of land subsidence) 

measured along the coast of New England during the last 

century (48 to 101 years of data through 2013) range from 

0.07 to 0.14 inches per year (in/yr; National Oceanic and 

Atmospheric Administration, 2014). Future estimated rates of 

eustatic sea-level rise range from 0.05 to 0.33 in/yr (Kirshen 

and others, 2008). The USGS, in cooperation with the 

National Park Service, recently conducted a study to estimate 

future inundation of salt marshes in response to sea-level rise 

in Acadia National Park, Maine, and the surrounding region 

(Nielsen and Dudley, 2013).

Winter and Spring

March mean streamflows increased significantly over 

time (p < 0.1) at 14 of 27 streamflow-gaging stations in New 

England; all of the significant increases were in northern 

New England. Flows increased 76 to 185 percent at the 

seven stations with the longest continuous records (1920s or 

1930s through 2002) in northern New England (Hodgkins 

and Dudley, 2005). There were no stations with significant 

decreases. The streamflow changes in northern New England 

are likely related to changes in snowpack melt, though 

changes in precipitation patterns and other factors could 

also contribute to the changes in streamflow (Hodgkins and 

Dudley, 2006b). Increased air temperatures cause increased 

late-winter flows through earlier snowmelt and more 
Climate and Hydrology of New England 3

precipitation falling as rain. Eighteen of 23 snow-measurement 

sites in northern New England with at least 50 years of records 

had a significant decrease (p < 0.1) in late-winter snowpack 

depth or an increase in snowpack density (Hodgkins and 

Dudley, 2006a). Increased snowpack density over time for a 

set late-winter date indicates that the snow has become more 

ready to melt by that date.

The ratio of December through March snowfall to total 

precipitation decreased significantly (p = 0.043) for the average of four U.S. Historical Climatology Network (USHCN) 

stations in northern New England from 1949 to 2000. The 

year-to-year ratio of snowfall to total precipitation in northern 

New England was correlated with air temperature (r = –0.45, 

p = 0.008) and total snowfall (r = 0.48, p = 0.0003) but not 

with total precipitation (r = –0.078, p = 0.59; Huntington and 

others, 2004). This supports the idea that winter snow and runoff in New England have been more sensitive to air temperature changes than to changes in precipitation amount.

Huntington and others (2003) found a significant 

decrease over time (p = 0.0021) in average ice thickness 

around February 28 on the Piscataquis River in central Maine. 

The ice thinned about 9 in. (45 percent) from 1912 to 2001. 

On average, for the nine rivers in northern New England 

with the longest records, river-ice occurrence (total number 

of winter days with ice-affected flow) decreased significantly 

(p = 0.0013) from 1936 to 2000 (Hodgkins, Dudley, and 

Huntington, 2005a). Most of the 20-day change in the total 

days of ice occurred from the 1960s to 2000. Year-to-year 

river-ice occurrence was highly correlated with winter air 

temperature (r = –0.70, p < 0.0001) and less highly correlated 

with winter precipitation (r = -0.52, p < 0.0001). More days of 

river ice were associated with colder temperatures and lower 

precipitation (Hodgkins, Dudley, and Huntington, 2005a).

Winter-spring streamflows became earlier at many 

rivers in New England during the 20th century; significant 

trends were mostly in northern New England. Most of the 

1- to 2-week change in northern New England occurred in 

the most recent three decades through 2002 (Dudley and 

Hodgkins, 2002; Hodgkins and others, 2003; Hodgkins and 

Dudley, 2006b). Winter-spring streamflow timing is based on 

the center-of-volume date—the date, each year, on which half 

of the winter-spring streamflow volume passes a streamflowgaging station. Historical winter-spring streamflow timing for 

the Piscataquis River in central Maine is shown in figure 1. 

80

85

90

95

100

105

110

115

120

125

130

1900 1920 1940 1960 1980 2000 2020

Julian date of center of volume of flow

Year

LOESS smooth trend line

Data point

EXPLANATION

Figure 1. Historical winter-spring streamflow timing for the Piscataquis River in central Maine. The Julian date in is the 

sequential number of days in a year, with January 1 being day 1. (Julian date 90, for example, corresponds to March 31 in a 

nonleap year.) A local regression (LOESS) smoothing line is shown in red.
4 Framework for a Hydrologic Climate-Response Network in New England

Year-to-year streamflow timing was highly correlated with 

March-through-April air temperature (r = –0.72, p < 0.0001; 

Hodgkins and others, 2003). Higher air temperatures were 

associated with earlier streamflows. The highest correlation 

coefficient between streamflow timing and precipitation was 

–0.37 (p = 0.0018) with January precipitation. May streamflows decreased significantly (p < 0.1) at 10 of 27 stations in 

New England; all of these decreases were in northern New 

England. Flows decreased 9 to 46 percent at the seven stations 

with the longest continuous records (Hodgkins and Dudley, 

2005). No stations showed significant increases. Higher winter 

(December through March) precipitation is associated with 

higher April streamflows at many streamflow-gaging stations 

in northern and central New England (Hodgkins and others, 

2012). This indicates that snowpack accumulation is an important mechanism for winter water storage and subsequently 

important for spring streamflows in this area. Higher March 

air temperatures are associated with lower April streamflows 

at many streamflow-gaging stations in central and southern 

New England, likely because the majority of snowmelt runoff 

occurs before April in warm years.

Dudley and Hodgkins (2013) documented increases 

in monthly groundwater levels in northern New England 

during the winter and spring during the past 30 years. The 

highest annual groundwater levels most commonly occur 

during spring or early summer (March through June), most 

frequently in April. April month-end levels correlate strongly 

with April mean streamflow and winter-spring runoff volume. 

While winter-spring streamflow timing in the Northeast has 

become earlier during the past century, this timing has not 

been observed to correlate with April groundwater levels 

or any other monthly groundwater levels (Dudley and 

Hodgkins, 2013).

On average, for the nine rivers in northern New England 

with the longest records, river-ice breakup dates (the annual 

last spring days of ice-affected flow) became significantly 

earlier (p = 0.0037) from 1936 to 2000. No appropriate riverice data were available in southern New England. Most of the 

11-day change in river-ice breakup in northern New England 

occurred from the 1960s to 2000 (Hodgkins, Dudley, and 

Huntington, 2005a). River-ice breakup was highly correlated 

with March-through-April air temperature (r = –0.73, 

p < 0.0001) and less highly correlated with precipitation 

(highest r = –0.37, p = 0.0027; Hodgkins, Dudley, and 

Huntington, 2005a).

Lake ice-out dates became significantly earlier at all five 

lakes in New England that had data from the mid-1800s to the 

early 2000s (Hodgkins and others, 2002; Benson and others, 

2012; Hodgkins, 2013). Ice-out dates between 1859 and 2008 

at representative lakes (Hodgkins and others, 2002), were 

8.4 days earlier in northern/mountainous areas of northern 

New England and 13.5 days earlier in more southern areas 

of northern New England (Hodgkins, 2013). No long-term 

ice-out data are known from lakes in rural areas of southern 

New England. Historical ice-out dates for Damariscotta Lake 

in midcoastal Maine are shown in figure 2. The magnitude 

of trends over time depends on the length of the historical 

period considered. Lake ice-out dates during the last 50 years 

became earlier by 1.8 days per decade, based on the median 

change for all lakes with adequate data. This rate of change 

is much higher than those observed over longer historical periods; ice-outs became earlier by 0.6 days per decade 

during the last 75 years, 0.4 days per decade during the last 

100 years, and 0.6 days per decade during the last 125 years 

(Hodgkins, 2013).

Summer and Fall

There is evidence of historical summer and fall 

hydrologic changes in New England. In summer, the lowest 

base flows increased from 1950 to 2006 at most streamflowgaging stations in western New England (Hodgkins and 

Dudley, 2011). Many increases were greater than 20 percent, 

and some increases were greater than 50 percent in and near 

New Hampshire and Vermont. In contrast, some decreases 

were greater than 20 percent in the lowest base flows in 

northern and coastal areas of Maine. Summer air temperature 

in New England increased on average by 2.0 degrees 

Fahrenheit (°F) from 1950 to 2006 and may have played a 

role in the decreased base flows for streams in northern and 

coastal Maine by increasing evapotranspiration in areas with 

substantial wetlands and open-water bodies. Small decreases 

in precipitation in parts of this area may also have contributed 

to the base-flow decreases (Hodgkins and Dudley, 2011).

The timing and magnitude of low flows (which typically 

occur in the late summer and early fall in New England) are 

much more highly correlated with summer precipitation than 

with air temperature (Hodgkins, Dudley, and Huntington, 

2005b). No strong relation was found between historical April 

streamflows and late-spring or summer streamflows in New 

England (Hodgkins and others, 2012). The lack of a strong 

relation implies that summer precipitation, rather than spring 

conditions, controls summer streamflows.

Dudley and Hodgkins (2013) documented increases in 

monthly groundwater levels in northern New England during the summer and fall during the past 30 years. The lowest 

groundwater levels most commonly occur during summer or 

fall (July through November), most frequently in September. 

September levels correlate strongly with August groundwater 

levels and August and September streamflows as well as with 

September base flow. Base flow from groundwater discharge 

typically supplies a large portion of streamflow during July, 

August, and September because of the relatively low amount 

of surface-water runoff in these months.

Summer stormflows increased from 1950 to 2006 by 

more than 50 percent at many stations in New England, 

particularly in and near New Hampshire and Vermont. 

Summer rainfall increased at most weather stations in New 

England from 1950 to 2006, with many increases of more 

than 20 percent in western New England (Hodgkins and 

Dudley, 2011).
Climate and Hydrology of New England 5

70

80

90

100

110

120

130

1820 1840 1860 1880 1900 1920 1940 1960 1980 2000 2020

Year

Julian date of lake ice-out

LOESS smooth trend line

Data point

EXPLANATION

Figure 2. Historical ice-out dates for Damariscotta Lake in midcoastal Maine. The Julian date in is the sequential number of 

days in a year, with January 1 being day 1. A local regression (LOESS) smoothing line is shown in red.

Some consistent hydrologic changes during the fall 

in New England have been observed. Four of 16 rivers in 

northern New England had significantly later (p < 0.1) first 

fall days of river ice from the first half of the twentieth 

century to 2000; no rivers had significantly earlier first fall 

days of ice (Hodgkins, Dudley, and Huntington, 2005a). 

Some significant changes in the timing or magnitude of fall 

high flows have been found (Hodgkins and others, 2003; 

Dudley and Hodgkins, 2005; Hodgkins and Dudley, 2005). 

October streamflows significantly increased at five rivers in 

western New England through 2002; no rivers had significant 

decreases (Hodgkins and Dudley, 2005).

Drivers of Climate-Response Network 

Hydrologic Variables

Precipitation and (or) temperature variability typically 

drive the variability of hydrologic response. These 

meteorological drivers can differ by season. Organizing 

New England hydrologic climate-response variables by their 

important drivers increases understanding of which parts of 

the hydrologic cycle are expected to be affected by future 

temperature or precipitation change and whether the changes 

are expected to be caused by annual or seasonal changes 

(table 1).

Table 1. Annual and seasonal climatic drivers of hydrologic variability in New England.

[--, no variables included]

Climatic driver Hydrologic climate-response variables

Annual Winter and spring Summer and fall

Temperature Annual peak flow Winter-spring runoff timing

Lake ice-out dates

--

Precipitation Annual peak flow -- Groundwater levels

Base-flow magnitude
6 Framework for a Hydrologic Climate-Response Network in New England

Future Hydrologic Changes in New England

Output from recent modeling using multiple atmosphereocean general circulation models (GCMs) provides a range 

of climate projections for the northeastern United States. The 

GCMs were regionally downscaled and were forced with the 

low (B1), mid-high (A2), and high (A1FI) greenhouse-gas 

emission scenarios as described by Nakićenović and others 

(2000). Hayhoe and others (2007) used climate projections 

as input to the variable infiltration capacity (VIC) hydrologic model to simulate future hydrologic responses. Spring 

streamflow timing is expected to become earlier by 5 to 

8 days, and annual 7-day low flows are expected to decrease 

by 1 to 4 percent between the periods 1961–90 and 2035–64 

(Hayhoe and others, 2007). Projected low-flow changes by 

midcentury are small under the low- and mid-high-emissions 

scenarios; however, under the high-emissions scenario, larger 

decreases (11 percent) are projected by the period 2070–99. 

The number of short-term and long-term droughts (based on 

soil moisture deficits) is expected to increase by the period 

2035–64. Total annual snow-water equivalent and the number 

of days with snow per month are expected to decrease. The 

central tendencies of general circulation model output indicate 

modest increases (about 10 percent) for New England annual 

precipitation and air temperature increases from about 1.8 to 

5.4 °F (1 to 3 degrees Celsius [°C]) by the end of the century 

(Markstrom and others, 2012).

Cathance Stream Basin in Maine (Mastin and others, 2011; Dudley and others, 2012) and Pomperaug River 

Basin in Connecticut (Bjerklie and others, 2012) were 2 of 

14 distributed-parameter Precipitation-Runoff Modeling 

System (PRMS) existing watershed models in the United 

States used to determine the sensitivity and potential effects 

of long-term climate change on freshwater resources across 

the United States (Markstrom and others, 2012). Regionally 

downscaled output from five GCMs and low (B1), medium 

(A1B), and mid-high (A2) greenhouse-gas emissions scenarios 

were used to estimate an ensemble of climate-change input 

scenarios for the basins. Projected increases in maximum 

and minimum daily air temperatures for all climate change 

scenarios for the 21st century result in projected decreases in 

the percentage of precipitation that falls as snow, snowpack 

water equivalent, and snowmelt. The projected changes in 

snowpack accumulation and melt would affect the seasonal 

amount and timing of streamflow. PRMS-modeled flows indicate that the projected changes in snowmelt timing will result 

in increases in streamflow for winter to early spring months 

(January through March) and decreases for spring months 

(April through June). The Cathance model indicates warmer 

winters will result in increased groundwater recharge during 

winter months (Pomperaug indicates future increases only for 

January) and decreases in recharge for all other times of the 

year. The Cathance and Pomperaug models indicate overall 

modest increases (about 10 percent) in precipitation over time, 

longer growing seasons, increases in evapotranspiration, and 

decreases in soil moisture (Markstrom and others, 2012).

Bjerklie and others (2011) estimated future changes 

in snowfall and groundwater recharge by using a regional 

watershed model for watersheds contributing to Long Island 

Sound, mostly from New England, including the Connecticut 

River Basin. GCM forecasted climate conditions were based 

on the B1 and A2 scenarios. Watershed model output for both 

scenarios for the end of the 21st century indicated increases in 

groundwater recharge over much of the region and substantial snowfall decreases across Massachusetts, Connecticut, 

southern Vermont, and southern New Hampshire relative to 

the beginning of the 21st century.

The USGS, in cooperation with the Maine Department of 

Transportation, studied changes in peak flows at four basins in 

coastal Maine on the basis of projected changes in air temperature and precipitation (Hodgkins and Dudley, 2013). The study 

used PRMS models to estimate future peak flows by way of 

a sensitivity analysis; a matrix of combinations that bracket 

probable future changes in precipitation and air temperature 

were applied to the historical meteorological input data for the 

models, and peak flows of specified annual exceedance probabilities (design flows) were computed from the PRMS model 

output for each basin. Air temperatures were adjusted by four 

different amounts, from –3.6 °F (–2 °C) to 10.8 °F (6 °C) of 

observed temperatures. Precipitation was adjusted by three 

different percentage values, from –15 percent to 30 percent of 

observed precipitation.

The study results indicated that increases in air temperature (with no changes in precipitation) lead to decreases in 

peak flows, a likely result of decreases in winter snowpack 

accumulation and thus decreases in snowmelt runoff. Increases 

in precipitation (with no changes in temperature) lead to 

increases in peak flows. For likely changes projected for the 

northeastern United States for the middle of the 21st century 

(combined temperature increase of 3.6 °F and precipitation 

increases of 0 to 15 percent), peak-flow changes at the four 

coastal Maine basins in this study were modeled to be evenly 

distributed between increases and decreases of less than 

25 percent (Hodgkins and Dudley, 2013). Peak-flow increases 

caused by precipitation increases are largely balanced by peakflow decreases caused by air temperature increases.

Potential Effects of Hydrologic Changes

Effects of climate change on hydrology could affect 

human water supply, hydroelectric power generation, transportation infrastructure, and stream and riparian ecology in 

the northeastern United States. Earlier snowmelt runoff could 

affect sensitive water systems by reducing water availability in 

the summer. Managers of storage reservoirs may need to modify operation schedules or increase reservoir storage earlier 

in the spring to allow for successful operation in a potentially 

longer summer low-flow season.

Changes in streamflow in the northeastern United States 

could also be important for other reasons; for example, 

increased winter flows can and have caused an increase in the 
Framework for a Hydrologic Climate-Response Network 7

frequency of midwinter ice jams (Beltaos, 2002). River ice 

jams can cause major flooding and damage river infrastructure. Ice jams played a major role in New England flooding in 

1936 and 1991 (Grover, 1937; Wuebben and others, 1995).

Changes in the timing or magnitude of future streamflows 

will likely affect ecosystems. The ecological implications of 

changes in winter-spring streamflow timing in New England 

are not well understood. One possible effect is a greater challenge for the survival of Atlantic salmon. If the peak spring 

migration of juvenile salmon from freshwater rivers (which 

is controlled by photoperiod, temperature, and flow) becomes 

out of phase with optimal environmental conditions in rivers, 

estuaries, or the ocean, this could present a greater challenge to salmon survivability (McCormick and others, 1998). 

Changes in the timing of high spring flow and recession to 

summer low flows may be related to the observed altered timing of migration of Atlantic salmon (Huntington and others, 

2003; Juanes and others, 2004).

Trends toward earlier snowmelt and increased summer 

evapotranspiration rates could shorten the annual periods of 

standing water used by amphibians for breeding in forested 

depressional wetlands (vernal pools; Brooks, 2009). Increases 

in summer evapotranspiration could decrease river base flows, 

which include surface water released naturally from storage 

in lakes, ponds, and wetlands (Hodgkins and Dudley, 2011). 

Lowered base flows could reduce available fish habitat during 

low-flow periods.

River ice causes many erosional and depositional features 

in river channels and on channel floodplains, especially in 

northern New England. Physical disturbances associated with 

ice-breakup scouring and flooding are important to nutrient 

and organic-matter dynamics, water chemistry, and the abundance and diversity of river biota (Prowse and Beltaos, 2002). 

The succession of riparian vegetation is directly linked to the 

scouring effects of ice (Prowse and Beltaos, 2002). River-ice 

breakup is likely to have important effects on primary producers, consumers, and food-web dynamics of river biota, 

although detailed information describing the magnitude of 

their effects is scarce (Scrimgeour and others, 1994). Mortality, emigration, or displacement of fishes at all life stages 

often results from severe ice conditions, through the actions 

of damming, scouring, associated flooding, or direct freezing 

(Power and others, 1993). Anchor ice, slush ice that adheres to 

streambeds, can have serious effects on fish eggs and embryos 

developing within gravel beds (Prowse, 1994). Anchor ice 

does not form when surface-ice cover is present, and therefore 

anchor ice could increase as surface-ice cover decreases.

Earlier lake ice-out dates are correlated with lower 

late-summer hypolimnion lake oxygen levels on the basis of 

limited data from northern New England (Hodgkins, 2013). 

Climatic warming has been shown in modeling studies to 

cause earlier lake ice-out dates, longer periods of summer 

stratification, and lower summer lake oxygen levels (Stefan 

and others, 1993; Elo and others, 1998). The lowering of 

hypolimnion oxygen levels could lead to enhancement 

of phosphorus release from sediments and increased lake 

eutrophication (Elo and others, 1998; Nõges and others, 

2009). Trends toward earlier ice-outs and thus increased light 

availability, lake circulation, and water temperatures could 

lead to changes in spring and summer phytoplankton and 

zooplankton dynamics and benthic invertebrate abundance 

(Jassby and others, 1990; Porter and others, 1996; Blenckner, 

Omstedt, and Rummukainen, 2002; Blenckner, Pettersson, 

and Padisák, 2002).

In summary, historical climate-related seasonal hydrologic changes have been documented in New England in 

recent decades. Winter-spring hydrologic changes are related 

more to changes in air temperatures than to changes in precipitation; in contrast, summer-fall hydrologic changes are related 

more to changes in precipitation. Annual peak flows are 

affected by changes in both air temperature and precipitation. 

Future climatic changes will likely affect human infrastructure 

and stream ecology in New England.

Framework for a Hydrologic ClimateResponse Network

The framework of a hydrologic climate-response network 

for New England has four major purposes:

• Identify specific hydrologic variables that are sensitive 

to climate change. This has been done in the “Climate 

and Hydrology of New England” section.

• Identify climate-response regions: geographic regions 

grouped by similar hydrologic responses.

• Propose a fixed-station monitoring network composed 

of existing streamflow, groundwater, lake ice, snowpack, and meteorological data-collection sites for 

evaluation of inland hydrologic response to climate 

variation.

• Establish basins for process-based studies and for estimates of future hydrologic conditions.

Climate-Response Regions

Hydrologic climate-response regions should have 

relatively homogeneous climates. New England’s climate, as 

described in the “Climate and Hydrology of New England” 

section, is complex, with large north-to-south, coastal-toinland, and sea-level-to-mountain-region gradients. New 

England would be divided into 14 regions (fig. 3, table 2) 

that follow major river-basin boundaries, have relatively 

homogeneous climates, and contain data-network sites with 

similar values or trends in key hydrologic variables. The 14 

lower tier regions would be grouped into 4 upper tier regions 

according to similarities that are most evident at a coarse 

geographic scale. The upper tier regions would each be 

identified by a four-digit sequence, and the lower tier regions 
8 Framework for a Hydrologic Climate-Response Network in New England

010101

010102

010103

010201

010202

010203

010301

010302

010303 010304

010305

010401

010402

010403

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EXPLANATION

Lower tier climate response

 regions

010101–Aroostook West

010102–Aroostook East

010103 –White Mountain

010201–Eastern Maine

010202–Central Maine

010203–Upper Connecticut

010301–Downeast

010302–Midcoast Maine

010303–Merrimack

010304–Middle Connecticut

010305–St. Lawrence

010401–Gulf of Maine

010402–Long Island Sound

010403–Lower Connecticut

46°

44°

42°

74° 72° 70° 68°

0 60 120 MILES

0 60 120 KILOMETERS

ATLANTIC

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Figure 3. Hydrologic climate-response regions in New England.
Framework for a Hydrologic Climate-Response Network 9

Table 2. Description of hydrologic climate-response regions in New England.

[See figure 3 for climate-response region locations. CRR, climate-response region; St., Saint; NH, New Hampshire]

CRR number CRR name Description

010101 Aroostook West Includes all of the American side of the St. John River Basin above the Fish River

010102 Aroostook East Includes all of the American side of the St. John River Basin below the Fish River

010103 White Mountain Includes the upper Penobscot, upper Kennebec, and upper Androscoggin River Basins

010201 Eastern Maine Includes the lower Penobscot River Basin and the American side of the St. Croix River Basin

010202 Central Maine Includes the middle Kennebec, middle Androscoggin, and upper Saco River Basins

010203 Upper Connecticut Includes all but one New Hampshire and Vermont basins emptying into the Connecticut River above 

Lebanon, NH

010301 Downeast Includes all small, coastal drainage basins in the Downeast area

010302 Midcoast Maine Includes the lower Kennebec, lower Androscoggin, and lower Saco River Basins

010303 Merrimack Includes all basins draining into the Gulf of Maine through the Merrimack River

010304 Middle Connecticut Includes all basins in New Hampshire, Vermont, and Massachusetts emptying into the Connecticut 

River between Lebanon and the lower Massachusetts border

010305 St. Lawrence Includes all basins in Vermont emptying into the St. Lawrence River or Hudson River drainages, as 

well as one emptying into Canada

010401 Gulf of Maine Includes all basins in New Hampshire and Vermont that empty into the Gulf of Maine except that of 

the Merrimack River

010402 Long Island Sound Includes all drainages in Massachusetts, Connecticut, and Rhode Island basins that empty into Long 

Island Sound except those of the Connecticut River

010403 Lower Connecticut Includes all Massachusetts and Connecticut basins emptying into the Connecticut River below the 

lower Massachusetts border

would be designated by the four-digit identifier of their parent 

higher tier region, followed by a two-digit suffix. Smoothed 

plots of winter-spring streamflow timing (fig. 4) and historical 

lake ice-out dates (fig. 5) in New England show that individual 

lakes and streams, for these variables, generally group well 

by upper tier climate-response region, particularly for winterspring streamflow timing.

Major river-basin boundaries were followed for hydrologic climate-response-region boundaries. The current 

proposed configuration of the climate-response regions is 

optimized to best fit the spatial patterns in key hydrologic 

variables that have already been identified, but results of additional analyses of hydrologic variations could inform changes 

to the boundaries and (or) number of hydrologic climateresponse regions in the future.

Primary Components and Associated Key 

Variables of a Hydrologic Climate-Response 

Network

Establishing a hydrologic climate-response network 

includes the identification of hydrologic components that 

include the major fluxes (such as streamflow) and storage 

compartments (such as groundwater storage) of the regional 

water cycle. Each component has one or more key variables 

that can be feasibly measured at data-collection sites. For 

example, streamflow has been identified as a component, with 

a key variable of streamflow being winter-spring streamflow 

timing. The key variables of components discussed in this 

section have been demonstrated to be responsive to climate 

change or are expected to be responsive to it in the next 

few decades, and are important for human water use or 

ecosystem function.

Three criteria were used to identify key variables to be 

included in a hydrologic climate-response data network: the 

existence of long-term historical data, the expectation that a 

variable will be responsive to changes in precipitation and (or) 

air temperature during the next few decades, and the human or 

ecological importance of the component variables. Long-term 

historical data allow a more complete perspective on future 

climate-related changes than short-term data because past 

decadal variability and longer term changes are better known. 

The “Climate and Hydrology of New England” section of this 

report lists known historical changes for variables of several 

hydrologic components and the known importance of these 

variables for humans and ecosystems. Many variables can 

be used to describe some of the components in a hydrologic 

climate-response data network. For example, streamflow 

variables could include annual peak flows, March mean flows, 

or many other measures. On the basis of extensive past work, 

some variables are more likely than others to be responsive to 
10 Framework for a Hydrologic Climate-Response Network in New England

70

80

90

100

110

120

130

140

1900 1920 1940 1960 1980 2000 2020

Julian date of center of volume of flow

Year

Upper tier climate response region 0101

Upper tier climate response region 0102

Upper tier climate response region 0103

Upper tier climate response region 0104

EXPLANATION

Figure 4. Winter-spring streamflow timing for streams in New England.

60

70

80

90

100

110

120

130

140

1800 1820 1840 1860 1880 1900 1920 1940 1960 1980 2000

Year

Julian date of lake ice-out

Upper tier climate response region 0101

Upper tier climate response region 0102

Upper tier climate response region 0103

Upper tier climate response region 0104

EXPLANATION

Figure 5. Historical lake ice-out dates in New England.
Framework for a Hydrologic Climate-Response Network 11

changes in precipitation and (or) air temperature (see “Climate 

and Hydrology of New England” section). Components 

proposed for inclusion in a hydrologic climate-response 

data network have at least one key variable with extensive 

historical data at multiple sites: streamflow, groundwater, lake 

ice, snowpack, and meteorological data. Other hydrologic 

components, such as water quality, are important to humans 

and (or) ecosystems but lack variables with extensive 

historical data. Key variables of primary components are listed 

in the following sections; additional components and (or) 

variables could be added as part of a larger network.

Streamflow

For the streamflow component, two key variables are 

proposed: winter-spring streamflow timing and the magnitude 

of the annual peak flow. Winter-spring streamflow timing is 

measured by the winter-spring center-of-volume (WSCV) date 

(Dudley and Hodgkins, 2002; Hodgkins and others, 2003; 

Hodgkins and Dudley, 2006b). The WSCV is a robust measure 

of streamflow timing. To compute the WSCV date, daily flow 

volumes from the start to the end of the annual winter-spring 

season are summed. The WSCV date is the date, in counting from the start of the season, by which half of the volume 

flows by a streamflow-gaging station. Another key variable 

derived from streamflow data—the magnitude of summer base 

flows—is discussed in the “Groundwater” section.

The USGS has been measuring and recording daily 

streamflow at some sites in New England for more than a 

century. More than 50 years of streamflow data are available for many rural, unregulated streams through the USGS 

National Water Information System (http://waterdata.usgs.gov/

usa/nwis/sw). The streamflow data at these sites have been 

collected by the USGS using consistent, well-documented, 

high-quality methods (Corbett and others, 1943; Rantz and 

others, 1982). Therefore, historical changes in the data can be 

determined with confidence.

Streamflow data proposed for New England are from 

USGS streamflow-gaging stations that have streamflows 

which are minimally affected by direct human watershed 

changes such as reservoir regulation and urbanization. The 

streamflow-gaging stations come from the Hydro-Climatic 

Data Network 2009 (HCDN–2009) subset of the USGS 

Geospatial Attributes of Gages for Evaluating Streamflow, 

version II (GAGES II), dataset (Falcone, 2011; Lins, 2012). 

The HCDN–2009 designation in GAGES II provides a determination of watersheds for potential study of climate-related 

streamflow trends; these watersheds represent hydrologic 

conditions least disturbed by human influences (relative to 

other watersheds within 12 major ecoregions in the United 

States) and have at least 20 years of complete and continuous 

data through 2009.

In some cases, stations that do not meet all of the criteria 

used for the HCDN–2009 network were added to the New 

England climate-response network. Some of the HCDN–2009 

criteria were related to water-quality criteria, and stations with 

Canadian drainage were not included because of the lack of 

basin data consistent with United States data. Active stations 

were added if they have had no known regular alteration of 

natural daily mean streamflow (high and low flows) from 

streamflow regulation, flow diversion or augmentation, surface-water or groundwater withdrawals, or known substantial 

changes in basin land use such as urbanization. Some stations 

with short records were added if they met this criteria and 

filled in gaps in spatial coverage or were important for specific 

reasons—for example, basins that contain important resources 

such as Atlantic salmon habitat and (or) Native American or 

U.S. Department of Interior or Agriculture lands.

Active stations in New England with 80-percent data 

completeness for each decade from 1960 to 2012 (11 of 

13 years for 2000 to 2012) would be used to examine longterm changes in streamflow variables. Thirty-one streamflowgaging stations in New England met the criteria for minimal 

disturbance and long-term completeness (fig. 6; table 3). 

Another 30 stations in New England met the criteria for 

minimal disturbance and have shorter or less complete 

records; these stations are included in the network for shortterm trend analysis (at least 30 years) and observation (less 

than 30 years) but are not used for long-term analysis until the 

criteria for long-term stations is met. It may be desirable for 

certain analyses to exclude nested watersheds in New England 

that have substantial shared watershed area. On the basis of 

minimally disturbed criteria, early years of data at two stations 

in Maine (Carrabassett River near North Anson prior to 1931 

and Little Androscoggin River near South Paris prior to 1924) 

are not appropriate for inclusion in low-flow analyses, nor are 

data for a few days with unusual regulation at one station in 

Maine (Narraguagus River at Cherryfield in 1978 and 1985). 

Although the majority of the streamflow-gaging stations 

proposed for the network (fig. 6) are in the three northern 

New England states, efforts are being made by the USGS 

in southern New England, in partnership with cooperating 

agencies, to initiate or reactivate additional streamflow-gaging 

stations in minimally altered basins for eventual inclusion in 

the hydrologic climate-response network.

Groundwater

Groundwater is an important source of domestic water 

in northern New England, where more than 60 percent of 

domestic water comes from groundwater and 40 percent of 

the population is self-supplied by private wells (Kenny and 

others, 2009). Groundwater-level data have been collected by 

the USGS in New England for several decades; levels directly 

measure the availability of groundwater for human use and 

aquatic ecosystems. In general, the records are not as long 

or complete as those of streamflow. Historical groundwater 

records often exhibit monthly or longer sampling frequencies 

with fragmentary periods of record. As a consequence, it is 

challenging to meet record-completeness criteria necessary for 

long-term trend testing.
12 Framework for a Hydrologic Climate-Response Network in New England

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46°

44°

42°

74° 72° 70° 68°

0 60 120 MILES

0 60 120 KILOMETERS

ATLANTIC

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01195100

01187300

01181000

01162500

01139000

01123000

01333000

01015800

01017290

01017550

01017960

01021480

01022840

01029200

01030350

01047200

01048220

01055500

01063310

01064500

01052500

01055000 01048000

01038000

01031500

01014000

01013500

01022500

01057000

01047000

01010000

01010500

01030500

01010070

01022294

01073000

01078000

01117468

01118300

01121000

01134500

01137500

01142500

01144000

01150900

01169000

01208990

04296000

01046000

01054200

01054300

01139800

01170100

01017060

01018035

01027200

01037380

01067950

01054114

01095220

01135300

EXPLANATION

Streamflow-gaging station, by 

 period-of-record classification

 and station number

Long-term trend

Short-term trend and observation

Figure 6. Streamflow-gaging stations in New England that drain relatively natural watersheds. Streamflow-gaging stations 

have at least 50 years of records for long-term trend testing, at least 30 years for short-term trend testing, and fewer than 

30 years for observations. See figure 3 for climate-response regions by color.
Framework for a Hydrologic Climate-Response Network 13

Table 3. Streamflow-gaging stations in New England that drain relatively natural watersheds.—Continued

[See figure 6 for station locations. Green fill highlights “True” values. mi2, square miles; ft, feet; HCDN-2009, Hydro-Climatic Data Network 2009; ME, 

Maine; NH, New Hampshire; MA, Massachusetts; RI, Rhode Island; CT, Connecticut; VT, Vermont]

Station 

number Station name

Drainage 

area

(mi2)

Elevation

(ft)

HCDN2009

Meets criteria of record length 

and completeness

30-

year

50-

year

70-

year

90-

year

01010000 St. John River at Ninemile Bridge, ME 1,341 931 No True True False False

01010070 Big Black River near Depot Mountain, ME 171 885 No False False False False

01010500 St. John River at Dickey, ME 2,680 590 No True True False False

01013500 Fish River near Fort Kent, ME 873 511 Yes True True True False

01014000 St. John River below Fish River at Fort Kent, ME 5,929 476 No True True True False

01015800 Aroostook River near Masardis, ME 892 530 No True True False False

01017060 Hardwood Brook below Glidden Brook near Caribou, ME 5.7 480 No False False False False

01017290 Little Madawaska River at Caribou, ME 234 420 No False False False False

01017550 Williams Brook at Phair, ME 3.82 580 No False False False False

01017960 Meduxnekeag River above South Branch Meduxnekeag 

River near Houlton, ME

88 355 No False False False False

01018035 Meduxnekeag River at Lowery Road near Houlton, ME 257 290 No False False False False

01021480 Old Stream near Wesley, ME 29.1 170 No False False False False

01022294 East Branch Bear Brook near Beddington, ME 0.042 907 No False False False False

01022500 Narraguagus River at Cherryfield, ME 227 44 Yes True True False False

01022840 Otter Creek near Bar Harbor, ME 1.35 90 No False False False False

01027200 North Branch Penobscot River near Pittston Farm, ME 232 1,086 No False False False False

01029200 Seboeis River near Shin Pond, ME 173 512 No False False False False

01030350 Wytopitlock Stream near Wytopitlock, ME 48.8 395 No False False False False

01030500 Mattawamkeag River near Mattawamkeag, ME 1,418 217 Yes True True True False

01031500 Piscataquis River near Dover-Foxcroft, ME 298 358 Yes True True True True

01037380 Ducktrap River near Lincolnville, ME 14.4 135 No False False False False

01038000 Sheepscot River at North Whitefield, ME 145 101 No True True True False

01046000 Austin Stream at Bingham, ME 90 350 No False False False False

01047000 Carrabassett River near North Anson, ME 353 303 Yes True True True False

01047200 Sandy River near Madrid, ME 25.3 930 No False False False False

01048000 Sandy River near Mercer, ME 516 197 No False False False False

01048220 East Branch Wesserunsett Stream near Athens, ME 19.5 500 No False False False False

01052500 Diamond River near Wentworth Location, NH 152 1,259 Yes True True True False

01054114 Peabody River at Gorham, NH 46.3 794 No False False False False

01054200 Wild River at Gilead, ME 69.6 683 Yes True False False False

01054300 Ellis River at South Andover, ME 130 620 No False False False False

01055000 Swift River near Roxbury, ME 96.9 616 Yes True True True False

01055500 Nezinscot River at Turner Center, ME 169 276 No False False False False

01057000 Little Androscoggin River near South Paris, ME 73.5 447 Yes True True True False

01063310 Stony Brook at East Sebago, ME 0.81 275 No False False False False

01064500 Saco River near Conway, NH 385 418 No True True True False

01067950 Kennebunk River near Kennebunk, ME 26.7 70 No False False False False

01073000 Oyster River near Durham, NH 12.1 65 Yes True True True False

01078000 Smith River near Bristol, NH 85.8 450 Yes True True True True
14 Framework for a Hydrologic Climate-Response Network in New England

Table 3. Streamflow-gaging stations in New England that drain relatively natural watersheds.—Continued

[See figure 6 for station locations. Green fill highlights “True” values. mi2, square miles; ft, feet; HCDN-2009, Hydro-Climatic Data Network 2009; ME, 

Maine; NH, New Hampshire; MA, Massachusetts; RI, Rhode Island; CT, Connecticut; VT, Vermont]

Station 

number Station name

Drainage 

area

(mi2

)

Elevation

(ft)

HCDN2009

Meets criteria of record length 

and completeness

30-

year

50-

year

70-

year

90-

year

01095220 Stillwater River near Sterling, MA 29.1 400 No False False False False

01117468 Beaver River near Usquepaug, RI 8.87 108 Yes True False False False

01118300 Pendleton Hill Brook near Clarks Falls, CT 4.02 153 Yes True True False False

01121000 Mount Hope River near Warrenville, CT 28.6 336 Yes True True True False

01123000 Little River near Hanover, CT 30 221 Yes True True False False

01135300 Sleepers River (Site W-5) near St. Johnsbury, VT 42.9 642 No False False False False

01134500 Moose River at Victory, VT 75.2 1,104 Yes True True False False

01137500 Ammonoosuc River at Bethlehem Junction, NH 87.6 1,181 Yes True True True False

01139000 Wells River at Wells River, VT 98.4 506 Yes True True True False

01139800 East Orange Branch at East Orange, VT 8.95 1,180 Yes True True False False

01142500 Ayers Brook at Randolph, VT 30.5 630 Yes True True True False

01144000 White River at West Hartford, VT 690 375 Yes True True True True

01150900 Ottauquechee River near West Bridgewater, VT 23.4 1,149 Yes False False False False

01162500 Priest Brook near Winchendon, MA 19.4 850 Yes True True True True

01169000 North River at Shattuckville, MA 89 458 Yes True True True False

01170100 Green River near Colrain, MA 41.4 435 Yes True False False False

01181000 West Branch Westfield River at Huntington, MA 94 389 Yes True True True False

01187300 Hubbard River near West Hartland, CT 19.9 595 Yes True True True False

01195100 Indian River near Clinton, CT 5.68 35 Yes True False False False

01208990 Saugatuck River near Redding, CT 21 285 Yes True False False False

01333000 Green River at Williamstown, MA 42.6 615 Yes True True False False

04296000 Black River at Coventry, VT 122 710 Yes True True False False

A recent USGS study of groundwater-level trends 

in northern New England (Dudley and Hodgkins, 2013) 

identified wells in Maine, New Hampshire, and Vermont that 

are minimally affected by human disturbance and thus suitable 

for a climate-response network. Screening criteria involved the 

review of well data (time-series plots) and analysis summaries 

published in annual USGS State Water-Data Reports for 

non-climate-related effects such as substantial water-use 

withdrawals or proximity to regulated surface-water bodies. 

Local USGS groundwater hydrologists were also consulted 

on the appropriateness of wells. Wells with levels deemed not 

to be predominantly natural were excluded. In a few cases, 

clusters of unaffected wells were built close to each other 

in the same aquifer and had highly correlated (R2 > 0.80) 

records; in these cases only the well with the longest and most 

complete record was included. Using a criterion of a minimum 

of 10 years of data (which could be nonconsecutive), Dudley 

and Hodgkins (2013) identified 77 wells in northern New 

England that would be suitable for a climate-response 

network. For the current report, USGS groundwater specialists 

in southern New England went through a similar process to 

identify appropriate wells. For New England groundwater 

wells, a completeness criterion of 80 percent per decade yields 

70 and 12 wells appropriate for short-term (30-year) and longterm (50-year) trend testing, respectively (fig. 7; table 4).

Dudley and Hodgkins (2013) examined correlations of 

groundwater levels with precipitation and streamflow data 

and found that groundwater levels in May through August 

correlate strongly with annual (water year) streamflow (fig. 8, 

for example, from Dudley and Hodgkins, 2013); correlations 

of groundwater levels with monthly precipitation are less 

frequent and weaker. Correlations of groundwater levels with 

streamflow data suggest methods for leveraging the richness 

of historical streamflow data to extend the record of historical 

groundwater levels.
Framework for a Hydrologic Climate-Response Network 15

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YW 807

KW 52

OW 400A

SMW 61 PEW 456

WW 796

PEW 594

ARW 906

KW 872A

OW 1214 KW 766

NAW 143

WSW 66

WBW 00101

WBW 00102

OW 400

NAW 218

PQW 1 MOW 36

MKW 22

KEW 2 MKW 85

GSW 75 HTW 5 DDW 46

CVW 4 CVW 2 CVW 3

CVW 1 CKW 1 WCW 1 BAW 10

NPW 3

NLW1

FKW 1 NFW 53 HLW 54

ENW 30 PFW 8 OXW 38

YW 1

CBW 34

RJW 1 WOW 1 CW 1383

CW 1382

ADW 14 OW 615A ANW 988C

WAW2 LLW 19

HW 137 MMW 2 KW 881

MHW 3 KW 882

OW 616

OW 616A

LCW 1

WOW 82

MJW 3

FW 901 GLW1

BIW 1

HW 1

BKW 1

FW 908

FW 893

PIW 2

ARW 891 ARW 895

ARW 1A

ADW 15

IBW 1

MGW 11

WW 797

GW 23 CL 223

D CO 335 117

FF 23 HM 445

HM 449

MB 36 SB 30

SB 41 SM 7

SSW 12

LTW 104 XOW 14 WAW 38

AJW 462 WPW 76

XNW 13

HLW 23

LIW 1

GW 22

NBW 107

NBW 313

NBW 228

NBW 44

NBW 46

NBW 198

BMW 22

OSW 22

EGW 36

WNW 17

WNW 34

WNW 108

PZW 78

XNW 13

BU 144 CV 51

EL 82

GR 328

GR 330 GR 329 GR 331

SC 19

SY 24

GLW6 GLW5

OTW 7 XJW 55 CMW 95

BEW 9 M7W 19 GMW 2 GKW 68

A3W 12

PDW HHW 1 23

CYW 13

PTW 51

PHW 16

HMW 8 ORW 63

TMW 3

CSW 8

WXW 20

DFW 44

EXPLANATION

Groundwater well, by period-of-

 record classification and number

Long-term trend

Short-term trend and observation

NSN 77

ENW 60

CNW 36

XEW 38

XEW 39

FSW 172

SDW 258

NGW 116

SDW 527 SDW 526

SDW 525

WFW 51

SHW F3W 23 275

PWW 494

LKW 14

MTW 82

ATW 83 TAW 337

N4W 37 HGW 76

XGW 2

CHW 587 CHW 586

RIW 785 RIW 417

SNW 1198

HOW 67

LTW 142

POW 551 EXW 475

EXW 6 EXW 158 WGW 206

WGW 181 WCW 59 COW 466

FOW 40 FOW 290

BUW 395 BUW 398

BUW 397 CUW 265

BUW 396

Map detail 

above right

Map detail right

Map detail 

above left

XOW 14

WAW 38

Figure 7. Groundwater wells in New England minimally affected by human disturbance. Wells have at least 50 years of 

records for long-term trend testing, at least 30 years for short-term trend testing, and fewer than 30 years for observations. 

See figure 3 for climate-response regions by color.
16 Framework for a Hydrologic Climate-Response Network in New England

climate-network criteria.

[See figure 7 for well locations. Years of record, number of years (through 

water year 2013) when at least one datum point is present. Green fill highlights “TRUE” values. CT, Connecticut; MA, Massachusetts; ME, Maine; 

NH, New Hampshire; RI, Rhode Island; VT, Vermont]

Table 4. Groundwater wells in northern New England that meet Table 4. Groundwater wells in northern New England that meet 

climate-network criteria.—Continued

[See figure 7 for well locations. Years of record, number of years (through 

water year 2013) when at least one datum point is present. Green fill highlights “TRUE” values. CT, Connecticut; MA, Massachusetts; ME, Maine; 

NH, New Hampshire; RI, Rhode Island; VT, Vermont]

Well number Well name

Years 

of 

record

Meets record 

completeness and 

length criteria

30-year 50-year

414704072580501 CT BU143 18 False False

414649072574401 CT BU144 17 False False

411832072325501 CT CL223 22 False False

413457072252201 CT CO335 28 False False

414833072190301 CT CV51 21 False False

412825072410501 CT D117 28 False False

415458072291901 CT EL82 21 False False

411256073153101 CT FF23 48 True False

415649072494801 CT GR328 31 False False

415647072495901 CT GR329 30 False False

415643072502201 CT GR330 30 False False

415653072501701 CT GR331 23 False False

410443073414101 CT GW22 12 False False

410515073415901 CT GW23 12 False False

412423072542801 CT HM445 22 False False

412417072541901 CT HM449 21 False False

413518072264501 CT MB36 21 False False

412931071514201 CT NSN77 22 False False

412954073125201 CT SB30 23 False False

412935073122701 CT SB41 22 False False

414243072040501 CT SC19 28 False False

412824072173301 CT SM7 35 True False

415956073241501 CT SY24 27 False False

421550073025101 MA A3W12 28 False False

423641071102501 MA AJW462 37 True False

415447071155301 MA ATW83 50 True False

421228072585301 MA BEW9 28 False False

414630070014901 MA BMW22 51 True False

421012072324501 MA CMW95 31 False False

412154070404701 MA CNW36 22 False False

423809072435601 MA CSW8 49 True False

422733072532601 MA CYW13 28 False False

423310072355801 MA DFW44 49 True False

415125069581501 MA EGW36 39 True False

412118070311001 MA ENW60 24 False False

414705071045301 MA F3W23 50 True False

413522070373601 MA FSW172 39 False False

421355072322001 MA GKW68 60 True True

420357072511601 MA GLW5 49 True False

420259072581701 MA GLW6 49 True False

Well number Well name

Years 

of 

record

Meets record 

completeness and 

length criteria

30-year 50-year

421316073212801 MA GMW2 63 True True

420353070520301 MA HGW76 50 True False

422058072085501 MA HHW1 49 True False

424841071004101 MA HLW23 54 True True

423339072524101 MA HMW8 28 False False

415228070554601 MA LKW14 50 True False

422627071154002 MA LTW104 49 True False

421240072490201 MA M7W19 28 False False

415433070583302 MA MTW82 49 True False

415812071111101 MA N4W37 50 True False

411536069591301 MA NBW107 32 False False

411712070022801 MA NBW198 33 False False

411555070021901 MA NBW228 38 True False

411542070023303 MA NBW313 32 False False

411620070113201 MA NBW44 32 False False

411645070104401 MA NBW46 35 True False

414025070572801 MA NGW116 50 True False

423441072170701 MA ORW63 29 False False

414726069581601 MA OSW22 39 True False

420912073043001 MA OTW7 49 True False

422103072241102 MA PDW23 32 True False

422103072241103 MA PDW24 31 False False

422906072124301 MA PHW16 30 False False

422745073112001 MA PTW51 51 True False

415217070393102 MA PWW494 28 False False

420355070112302 MA PZW78 39 True False

413958070281801 MA SDW258 39 True False

414219070313601 MA SDW525 12 False False

414139070311501 MA SDW526 12 False False

414124070311401 MA SDW527 12 False False

414714071175901 MA SHW275 50 True False

421851071312601 MA SSW12 25 False False

415457071060101 MA TAW337 50 True False

423717072043101 MA TMW3 56 True True

423115071032001 MA WAW38 49 True False

414518070435701 MA WFW51 55 True True

415732070000401 MA WNW108 36 True False

415353069585401 MA WNW17 51 True False

415722070010001 MA WNW34 39 True False

423505070491702 MA WPW76 49 True False
Framework for a Hydrologic Climate-Response Network 17

Table 4. Groundwater wells in northern New England that meet 

climate-network criteria.—Continued

[See figure 7 for well locations. Years of record, number of years (through 

water year 2013) when at least one datum point is present. Green fill highlights “TRUE” values. CT, Connecticut; MA, Massachusetts; ME, Maine; 

NH, New Hampshire; RI, Rhode Island; VT, Vermont]

Table 4. Groundwater wells in northern New England that meet 

climate-network criteria.—Continued

[See figure 7 for well locations. Years of record, number of years (through 

water year 2013) when at least one datum point is present. Green fill highlights “TRUE” values. CT, Connecticut; MA, Massachusetts; ME, Maine; 

NH, New Hampshire; RI, Rhode Island; VT, Vermont]

Well number Well name

Years 

of 

record

Meets record 

completeness and 

length criteria

30-year 50-year

421923072451001 MA WXW20 27 False False

412304070382001 MA XEW38 22 False False

412434070392601 MA XEW39 22 False False

420954070564501 MA XGW2 49 True False

420905072254001 MA XJW55 49 True False

424204072015201 MA XNW13 74 True True

424752071315202 MA XNW13 27 False False

424800071295301 MA XNW13 50 True False

424810073160401 MA XNW13 49 True False

422819071065701 MA XOW14 74 True True

440730070035304 ME ANW988C 14 False False

464807068284401 ME ARW1A 15 False False

463642069344601 ME ARW891 26 False False

464234068010401 ME ARW895 15 False False

464259067572901 ME ARW906 25 False False

435902070171301 ME CW1382 11 False False

435653070201801 ME CW1383 11 False False

451128070280301 ME FW893 15 False False

443831070002601 ME FW901 14 False False

450539070301301 ME FW908 12 False False

444950068220601 ME HW1 16 False False

441440068182701 ME HW137 20 False False

441849069442001 ME KW52 45 False False

440918069564001 ME KW766 37 True False

440810069553601 ME KW872A 35 True False

441533069452401 ME KW881 13 False False

442233069490701 ME KW882 11 False False

440823070291501 ME OW1214 34 True False

444637070552301 ME OW400 52 False False

443647070552302 ME OW400A 24 False False

440642070583402 ME OW615A 11 False False

442515070481001 ME OW616 14 False False

442515070481002 ME OW616A 11 False False

445319068560101 ME PEW456 36 True False

453629068531801 ME PEW594 21 False False

452829069322101 ME PIW2 13 False False

445148069513301 ME SMW61 24 False False

443407069020901 ME WOW82 11 False False

450713067162801 ME WW796 34 True False

445227067520101 ME WW797 28 False False

Well number Well name

Years 

of 

record

Meets record 

completeness and 

length criteria

30-year 50-year

434822070482501 ME YW1 23 False False

432310070393301 ME YW807 26 False False

435948071220301 NH ADW14 19 False False

435948071220302 NH ADW15 20 False False

431916071125901 NH BAW10 18 False False

434952071390901 NH CBW34 21 False False

431526071345501 NH CVW1 26 False False

431224071303601 NH CVW2 50 True False

431248071290201 NH CVW3 22 False False

431049071324301 NH CVW4 47 True False

430527071140101 NH DDW46 22 False False

433616072074001 NH ENW30 20 False False

432428071390701 NH FKW1 47 True False

425744071532001 NH GSW75 19 False False

430235071275501 NH HTW5 49 True False

425543072175801 NH KEW2 51 True False

442830071321001 NH LCW1 47 True False

430721071005001 NH LIW1 58 True True

441401071531501 NH LLW19 21 False False

425303071283701 NH MKW22 28 False False

425339071281501 NH MKW85 17 False False

425024071413001 NH MOW36 48 False False

432534071095601 NH NFW53 22 False False

432343071570901 NH NLW1 66 True True

432322072112401 NH NPW3 20 False False

434221071051501 NH OXW38 20 False False

431540071452801 NH WCW1 48 True False

435645071420520 NH WSW66 19 False False

415546071474701 RI BUW395 22 False False

415847071471401 RI BUW396 22 False False

415606071462201 RI BUW397 21 False False

415559071471201 RI BUW398 21 False False

412434071422401 RI CHW586 22 False False

412424071423601 RI CHW587 21 False False

414315071410701 RI COW466 22 False False

415626071254601 RI CUW265 68 True True

413505071452801 RI EXW158 30 False False

413358071433801 RI EXW475 33 True False

413423071431901 RI EXW6 66 True True

414357071405101 RI FOW290 22 False False
18 Framework for a Hydrologic Climate-Response Network in New England

Table 4. Groundwater wells in northern New England that meet 

climate-network criteria.—Continued

[See figure 7 for well locations. Years of record, number of years (through 

water year 2013) when at least one datum point is present. Green fill highlights “TRUE” values. CT, Connecticut; MA, Massachusetts; ME, Maine; 

NH, New Hampshire; RI, Rhode Island; VT, Vermont]

Well number Well name

Years 

of 

record

Meets record 

completeness and 

length criteria

30-year 50-year

414420071422301 RI FOW40 30 False False

413126071455501 RI HOW67 30 False False

413220071115501 RI LTW142 21 False False

413325071152401 RI POW551 22 False False

412932071374302 RI RIW417 38 True False

412718071415201 RI RIW785 24 False False

412935071355701 RI SNW1198 21 False False

414106071223901 RI WCW59 31 False False

413907071465001 RI WGW181 46 True False

413645071332901 RI WGW206 31 False False

444731071514701 VT BIW1 47 True False

445603072422901 VT BKW1 42 False False

431551072350601 VT CKW1 47 True False

443952072114001 VT GLW1 46 True False

433240072242901 VT HLW54 44 True False

445158072155001 VT IBW1 13 False False

440016073070901 VT MGW11 33 True False

441829072413901 VT MHW3 25 False False

443646073124901 VT MJW3 52 False False

441552072341901 VT MMW2 29 False False

434217073010601 VT PFW8 55 True True

435129072483301 VT RJW1 42 False False

441215072483101 VT WAW2 35 False False

442939072093701 VT WBW00101 18 False False

442939072093702 VT WBW00102 18 False False

435343072151801 VT WOW1 46 True False

Key variables for a groundwater network include the 

annual highest and lowest levels. The annual maximum 

groundwater level (most common in April) is a measure of 

recharge to the groundwater system and correlates strongly 

with April mean streamflow and winter-spring runoff volume (WSV); April mean streamflow and WSV are measures 

of water available for aquifer recharge in the spring from 

snowpack melt and rain. Dudley and Hodgkins (2013) used 

monthly data and did not observe a correlation between 

winter-spring runoff timing (WSCV date) and annual peak 

groundwater level. However, it is possible that analysis of 

groundwater-level data with a finer temporal resolution (for 

example, daily data) would show that the timing of the annual 

peak groundwater level correlates with the winter-spring 

runoff timing.

During the lowest groundwater conditions of the year, 

municipalities, individuals, and industries can encounter 

groundwater-supply challenges. The annual minimum 

groundwater level (most common in September) correlates 

strongly with August levels and August and September 

streamflows as well as with September base flow (Dudley 

and Hodgkins, 2013). These are all related metrics, as base 

flow from groundwater discharge typically composes a large 

portion of streamflow during July, August, and September.

The base-flow component of streamflow comes from 

groundwater and other delayed sources. Base flow is important 

to fish and other aquatic species. The USGS streamflowgaging stations identified for potential inclusion in a 

hydrologic climate-response data network and appropriate for 

the analysis of low flows (table 3) would be appropriate to use 

as input to an automated technique, such as HYSEP (Sloto and 

Crouse, 1996), for separating base flow from total streamflow.

Lake Ice

The key historical measure of lake ice (and the only 

commonly available measure of lake ice in New England) is 

lake ice-out date—the annual date in spring when winter ice 

cover leaves a lake (Hodgkins and others, 2002; Hodgkins, 

2013). This is normally defined as the date at which 

substantial ice is no longer visible for a lake or the date at 

which a boat can traverse between set points. In Northern 

Hemisphere mid-latitude areas such as New England, ice-out 

dates can serve as useful indicators of late-winter and earlyspring climate change. A remarkable amount of lake ice-out 

data has been recorded and saved in New England during 

the past two centuries, mostly in northern New England. 

Lake ice-out dates for many lakes in New England have been 

compiled (Hodgkins and James, 2002; Hodgkins, 2010b) and 

analyzed (Hodgkins and others, 2002; Hodgkins, 2013); data 

from additional lakes have been recently compiled. There are 

37 lakes that have at least 80-percent data completeness for 

each decade from 1960 to 2013 (11 of 13 years for 2000 to 

2012). As of 2012, 5 lakes have 165 years or more of data, and 

another 14 have more than 110 years of data. Long-term lake 

ice-out data for many lakes in New England represent a unique 
Framework for a Hydrologic Climate-Response Network 19

12.0

12.5

13.0

13.5

14.0

14.5

15.0

15.5

16.0

16.5

0.0 17.0

2.0

4.0

6.0

8.0

10.0

12.0

14.0

1930 1940 1950 1960 1970 1980 1990 2000 2010

Depth to water, in meters

Streamflow, in cubic meters per second

Years

U.S. Geological Survey streamflow-gaging station 01038000,

 Sheepscot River at North Whitefield, Maine

U.S. Geological Survey well 440918069564001 ME-KW766,

 Litchfield, Maine

EXPLANATION

Figure 8. Relation of August groundwater levels and annual mean streamflows; modified from Dudley and Hodgkins (2013, 

fig. 7). Curves are 7-year moving averages.

hydroclimatic dataset that is useful for continued monitoring 

of hydrologic response to regional climate change. These lakes 

would be used in a hydrologic climate-response data network. 

An additional seven lakes with 30 to 50 years of record would 

augment the network for short-term trend analysis (fig. 9; 

table 5). These lakes are appropriate for inclusion in the 

network on the basis of 80-percent data completeness for each 

decade from 1980 to 2013 (11 of 13 years for 2000–2012). 

Many more lakes in northern New England have short records 

or records with large gaps. These lakes could also be included 

in the network when their records approach useful lengths 

(and meet completeness criteria).

Most of the lakes in this study are in rural areas 

(Hodgkins and others, 2002). Lakes in the northern parts 

of Maine, New Hampshire, and Vermont generally drain 

remote, undeveloped forests. Lakes in more southerly areas 

of northern New England generally drain rural areas with 

forests, some low-density residential development, and small 

towns. Lake Auburn is near a relatively small urban area 

(Auburn, Maine); Houghtons and Ponkapoag Ponds outside 

Boston, Massachusetts, are near a large urban area. There are 

no lakes currently known with substantial amounts (more than 

10 years) of ice-out data from nonurban lakes in southern New 

England. The ice-out dates for lakes near urban areas could be 

affected by urban heat-island temperature effects.

Ice-out definitions for individual lakes can vary over 

time and among observers (Hodgkins and others, 2002). 

Twenty years or more of overlapping data from independent 

observers were available for six lakes. On the basis of this 

limited dataset, Hodgkins and others (2002) concluded that 

observer biases (different people on the same lake recording 

different ice-out dates for the same year) of more than 1 day 

are unlikely on relatively round lakes. In contrast, 3- to 4-day 

biases can occur on long, narrow lakes if the observation 

locations are on opposite ends of the lake. On two long, 

narrow lakes with north-south axes, the observer of later iceout dates was located at the northern end of the lakes. These 

observational biases could result in large biases in ice-out 

trends over time at individual lakes. At a large number of 

lakes, however, it is unlikely that observer-location biases 

would tend to bias trend tests in any one direction. For 

example, for a large number of lakes there is no reason to 

expect that people observed less recent ice-outs at the southern 

end of lakes and more recent ice-outs at the northern end 

of lakes.

Snowpack

Long-term snowpack data are mostly limited to 

Maine, but given its importance in New England hydrology, 

snowpack is included as a variable in the New England 

hydrologic climate-response network. The following text is 

from Hodgkins and others (2009, p. 13):

“Key snowpack variables are the magnitude of 

late-winter water equivalent, depth, and density 

for selected dates. Emergency management and 

response agencies, flood-forecasting agencies, 
20 Framework for a Hydrologic Climate-Response Network in New England

NEW YORK

NEW

JERSEY

NEW

QUEBEC BRUNSWICK

Base from U.S. Geological Survey digital data 1:24,000

Universal Transverse Mercator projection, zone 19

46°

44°

42°

74° 72° 70° 68°

0 60 120 MILES

0 60 120 KILOMETERS

ATLANTIC

OCEAN

EXPLANATION

Lake, by period-of-record classification

Long-term trend

Short-term trend and observation

Stinson

Spofford

Auburn

China

Cobbosseecontee

Damariscotta

Embden

Kezar

Maranacook

Moosehead

Mooselookmeguntic

Pennesseewassee

Portage

Rangeley

Richardson

Sebago

Sebec

Swan

Umbagog

West Grand

Sunapee

Winnipesaukee

Ponkapoag

Houghtons

Togus

Big Wood

First Connecticut

Wesserunsett

Cold Stream

Crystal

Green Porter

Nickerson

Sabattus

Harvey

Squam

Bomoseen

Echo

Fairlee

Maidstone

Sunset

Laurel

Mirror

Aziscohos

Figure 9. Lakes in New England with substantial amounts of ice-out data. Sites have at least 50 years of records for long-term 

trend testing, at least 30 years for short-term trend testing, and fewer than 30 years for observations. See figure 3 for climateresponse regions by color. See table 5 for full lake names.
Framework for a Hydrologic Climate-Response Network 21

Table 5. Lakes in New England with substantial amounts of ice-out data.

[See figure 9 for lake locations. ft, feet; MA, Massachusetts; ME, Maine; NH, New Hampshire; VT, Vermont]

Lake name and location Elevation

(ft)

Period of record

(years)

Houghton’s Pond near Ponkapoag, MA 161 126

Ponkapoag Pond at Ponkapoag, MA 161 126

Aziscohos Lake at Aziscohos Dam, ME 1,513 97

Big Wood Pond at Jackman, ME 1,161 92

China Lake at East Vassalboro, ME 194 86

Cobbosseecontee Lake near Winthrop Center, ME 164 171

Cold Stream Pond near Enfield, ME 190 67

Crystal Lake at Dry Mills, ME 308 53

Damariscotta Lake at Damariscotta Mills, ME 46 175

Embden Pond near North Anson, ME 413 88

Green Lake at Lakewood, ME 167 78

Kezar Lake near Lovell, ME 374 112

Lake Auburn at East Auburn, ME 259 170

Lake Wesserunsett at East Madison, ME 335 125

Maranacook Lake at Winthrop, ME 210 88

Moosehead Lake at Moosehead, ME 1,011 165

Mooselookmeguntic Lake at Upper Dam, ME 1,453 111

Nickerson Lake near Carys Mills, ME 377 64

Pennesseewassee Lake at Norway, ME 394 137

Portage Lake near Portage, ME 610 87

Porter Lake near New Vineyard, ME 633 74

Rangeley Lake at Oquossoc, ME 1,519 133

Richardson Lakes at Middle Dam, ME 1,444 131

Sabattus Pond at Sabattus, ME 236 87

Sebago Lake near North Windham, ME 266 172

Sebec Lake at Sebec, ME 305 130

Swan Lake at Swanville, ME 203 122

Togus Pond near West Windsor, ME 180 71

Umbagog Lake near Upton, ME 1,240 122

West Grand Lake at Grand Lake Stream, ME 303 135

First Connecticut Lake near Pittsburg, NH 1,636 92

Lake Winnipesaukee at Interlaken Park, NH 515 126

Laurel Lake near Fitzwilliam Depot, NH 1,099 50

Mirror Lake at Hubbard Brook Experimental Forest at West Thornton, NH 705 41

Spofford Lake at Spofford, NH 748 70

Squam Lake at Holderness, NH 597 35

Stinson Lake at Stinson Lake, NH 1,355 76

Sunapee Lake at Sunapee, NH 1,090 144

Echo Lake at East Charleston, VT 1,253 43

Harvey Lake at West Barnet, VT 892 62

Lake Bomoseen near Fair Haven, VT 427 54

Lake Fairlee near West Fairlee, VT 705 37

Maidstone Lake at Bullthroat, VT 1,302 39

Sunset Lake near Hortonia, VT 508 37
22 Framework for a Hydrologic Climate-Response Network in New England

people who live near streams, and many waterdependent industries need to know how much water 

to expect each year from snowmelt. Primarily for 

this reason, the Maine Cooperative Snow Survey 

Program, run jointly by the Maine Geological 

Survey (MGS) and the USGS, compiles snowpack 

data collected by the USGS, the MGS, the National 

Weather Service, electric-power utilities, waterpower companies, pulp and paper companies, 

and others on a regular basis (currently weekly, 

historically biweekly) in late winter and spring 

(Hodgkins and Dudley, 2006a).

“The depth and water equivalent (the depth of water 

that would result if the snowpack were melted) of 

the snowpack have been measured at selected sites 

in Maine since the early part of the 20th century 

[Hodgkins, Dudley, and Loiselle, 2005]. Most of 

the sites are in flat or gently sloping areas of mixed 

hardwood and conifer forest. Measurements are 

not made near conifers. Most data are collected at 

locations with an elevation of less than 2,000 ft. 

Historical site information for the sites in this 

report is extremely limited. Some sites have been 

moved away from the local effects of development, 

extensive logging, or unacceptable amounts of 

conifer growth.

“Snowpack depth and water-equivalent data were 

analyzed for those sites with data spanning at least 

50 years through 2004 (Hodgkins and Dudley, 

2006a). The exact date of sampling at a site varies 

from year to year. Data for a site commonly are 

not available for every year for a given sampling 

window. Sampling windows were defined as 

15-day windows centered on February 15, March 1, 

March 15, April 1, April 15, and May 1. To be 

included for analysis, the sites were required to 

have at least 50-percent complete data for the first 

and second halves of their record for at least one 

sampling window. Thirty-seven sites in and near 

Maine met the described criteria. Historical snow 

depth and water-equivalent data for these sites are 

reported in [Hodgkins, Dudley, and Loiselle (2005)] 

as follows:

“Because sampling windows were used, it is possible to have biased sampling over time at sites 

(Hodgkins and Dudley, 2006a). If sampling tends to 

be earlier or later over time, any significant trends 

in the snowpack data could be the result of sampling bias. All data sets (individual sites for each 

applicable sampling window) that met the criteria 

for inclusion were tested for significant changes 

over time in the date of sampling. Data from many 

sites sampled during the March 1 sampling window 

were found to be biased, with many sampling dates 

prior to March 1 early in the record and many dates 

after March 1 later in the record. Fourteen sites were 

eliminated because of significant bias in the date of 

sampling. Data from 23 sites with data for at least 

one sampling window did not show significant sampling bias and were considered appropriate for use in 

computing climate-related trends over time [fig. 10; 

table 6]. These sites would be the starting point for 

sites to be included in a hydrologic climate-response 

data network.”

It would be desirable to add shorter-term snowpack sites, but 

this requires an amount of analysis beyond the scope of this 

report. It would also be desirable to have additional snowpack 

sites outside of Maine, particularly in areas of regular substantial snowpack.

Meteorological Stations

Precipitation and air temperature trends and variability 

are important to streamflow, groundwater, lake ice-out, and 

snowpack trends and variability. The relative influence of 

precipitation and air temperature varies by season. Many 

recent climate-change-related studies have made use of the 

U.S. Historical Climatology Network (USHCN) monthly 

dataset to analyze meteorological trends; the most recent 

dataset available is version 2 (Quinlan and others, 1987; 

Menne and others, 2009). The USHCN data are qualityassured and evaluated on the basis of record length and 

completeness; data are subject to time-of-observation bias 

adjustments (Karl and others 1986; Vose and others, 2003), 

homogeneity testing, and adjustment procedures to account for 

non-climate-related changes in the record such as instrument 

and station location changes (Menne and Williams, 2009). 

Missing data are estimated by using weighted averages of 

highly correlated neighboring data. The 44 USHCN stations 

in New England are shown in table 7 and figure 11; stations 

have a minimum of 99 years of record through 2012 and are 

appropriate for the analysis of long-term trends.

Process-Based Studies

An important part of establishing a hydrologic climateresponse network in New England would be to identify basins 

that are appropriate for use in process-based studies designed 

to improve understanding of and predict hydrologic and 

ecosystem change. The combination of extensive historical 

hydrologic data, ecological data, and deterministic watershed modeling would greatly increase our understanding of 

the effects of climate change on hydrologic components and 

ecosystem health.

For each of the 14 lower tier regions in the proposed 

hydrologic climate-response network, a representative basin 

(in geology, land cover, and other characteristics) that has 

extensive historical data for multiple hydrologic components 

would be identified; potential sites are indicated in table 8 and 
Framework for a Hydrologic Climate-Response Network 23

NEW YORK

NEW

JERSEY

NEW

QUEBEC BRUNSWICK

Base from U.S. Geological Survey digital data 1:24,000

Universal Transverse Mercator projection, zone 19

46°

44°

42°

74° 72° 70° 68°

0 60 120 MILES

0 60 120 KILOMETERS

ATLANTIC

OCEAN

The Forks

Grindstone

Mercer

Amherst

Dover-Foxcroft

Ft. Kent

N. Anson

Errol

Aziscohos Dam

Middle Dam

Upper Dam

Pinkham

S. Paris

Pittsfield

Gorham

Guerette

Mayfield

Eustis

Stratton Carrabassett

Dallas

Chain of Ponds

Kokadjo

EXPLANATION

Snowpack site, by period-of-record

 classification

Long-term trend

Short-term trend and observation

Figure 10. Location of long-term snowpack sites in New England. Sites have at least 50 years of records for long-term trend 

testing, at least 30 years for short-term trend testing, and fewer than 30 years for observations. See figure 3 for climateresponse regions by color. See table 6 for full site names.
24 Framework for a Hydrologic Climate-Response Network in New England

Table 6. Long-term snowpack sites in New England.

[See figure 10 for site locations. Abbreviations in site name are part of the official name. All sites are in Maine, unless 

otherwise noted. A sampling window is defined as a 15-day period centered on the date shown. NH, New Hampshire]

Site number Site name Map name

(in fig. 10) Sampling window

1002 The Forks The Forks 1-Mar

1004 Grindstone Grindstone 1-Mar

1015 Mercer Mercer 1-Mar

1020 Dover-Foxcroft (B) Dover-Foxcroft 1-Mar

1024 North Anson N. Anson 1-Mar

1044 Pinkham Notch (UWP), NH Pinkham 1-Mar

1050 Pittsfield (B) Pittsfield 1-Mar

1053 Gorham, NH Gorham 1-Mar

1066 Mayfield (Bingham Upper) Mayfield 1-Mar

1292 Kokadjo (KWP) Kokadjo 1-Mar

1002 The Forks The Forks 15-Mar

1018 Amherst (BH) Amherst 15-Mar

1022 Fort Kent Ft. Kent 15-Mar

1024 North Anson N. Anson 15-Mar

1027 Errol/Errol Dam (UWP), NH Errol 15-Mar

1028 Aziscohos/Aziscohos Dam (UWP) Aziscohos 15-Mar

1030 Middle Dam (UWP) Middle Dam 15-Mar

1031 Upper Dam (UWP) Upper Dam 15-Mar

1046 South Paris S. Paris 15-Mar

1061 Guerrette Guerrette 15-Mar

1100 Eustis (KWP) Eustis 15-Mar

1246 Stratton (KWP) Stratton 15-Mar

1288 Carrabassett (KWP) Carrabassett 15-Mar

1289 Dallas (KWP) Dallas 15-Mar

1290 Chain of Ponds (KWP) Chain of Ponds 15-Mar

1027 Errol/Errol Dam (UWP), NH Errol 1-Apr

1028 Aziscohos/Aziscohos Dam (UWP) Aziscohos 1-Apr

1030 Middle Dam (UWP) Middle Dam 1-Apr

1031 Upper Dam (UWP) Upper Dam 1-Apr
Framework for a Hydrologic Climate-Response Network 25

Table 7. Long-term meteorological stations in New England.

[See figure 11 for station locations. Location of meteorological stations shown in figure 8. Abbreviations in site name are part of the 

official name. ft, feet; PPOR, years of precipitation record through 2012; TPOR, years of air temperature record through 2012; CT, Connecticut; ME, Maine; MA, Massachusetts; NH, New Hampshire; RI, Rhode Island; VT, Vermont]

Meteorological station Elevation

(ft)

PPOR

(years)

TPOR

Number Name (years)

062658 CT 062658 FALLS VILLAGE 550 117 117

063207 CT 063207 GROTON 40 117 117

067970 CT 067970 STAMFORD 5 N 190 107 117

068138 CT 068138 STORRS 650 117 117

170100 ME 170100 ACADIA NP 470 117 117

170814 ME 170814 BRASSUA DAM 1,060 113 115

171628 ME 171628 CORINNA 297 117 117

172426 ME 172426 EASTPORT 85 117 117

172765 ME 172765 FARMINGTON 420 117 117

173046 ME 173046 GARDINER 140 117 117

173944 ME 173944 HOULTON 5N 390 109 117

174566 ME 174566 LEWISTON 180 117 117

175304 ME 175304 MILLINOCKET 360 117 117

176905 ME 176905 PORTLAND JETPORT 45 117 117

176937 ME 176937 PRESQUE ISLE 599 117 114

179891 ME 179891 WOODLAND 140 117 117

190120 MA 190120 AMHERST 150 117 117

190535 MA 190535 BEDFORD 160 117 117

190736 MA 190736 BLUE HILL 630 117 117

193213 MA 193213 GREAT BARRINGTON 5 SW 817 99 117

194105 MA 194105 LAWRENCE 50 117 117

195246 MA 195246 NEW BEDFORD 70 117 117

196486 MA 196486 PLYMOUTH-KINGSTON 45 117 117

196681 MA 196681 PROVINCETOWN 20 117 117

196783 MA 196783 READING 90 117 117

198367 MA 198367 TAUNTON 20 117 117

198757 MA 198757 WALPOLE 2 165 117 117

199316 MA 199316 WEST MEDWAY 210 117 117

270706 NH 270706 BETHLEHEM 2 1,180 117 117

272174 NH 272174 DURHAM 80 117 117

272999 NH 272999 FIRST CONNECTICUT LAKE 1,660 117 110

273850 NH 273850 HANOVER 603 117 117

274399 NH 274399 KEENE 520 117 117

370896 RI 370896 BLOCK ISLAND STATE AP 110 117 117

374266 RI 374266 KINGSTON 114 117 117

376698 RI 376698 PROVIDENCE WSO AP 51 117 117

431081 VT 431081 BURLINGTON WSO AP 330 117 117

431243 VT 431243 CAVENDISH 842 117 117

431360 VT 431360 CHELSEA 800 117 117

431580 VT 431580 CORNWALL 345 117 117

432769 VT 432769 ENOSBURG FALLS 420 117 117

437054 VT 437054 SAINT JOHNSBURY 700 117 117

437607 VT 437607 SOUTH HERO 110 117 117

437612 VT 437612 SOUTH LINCOLN 1,341 117 117
26 Framework for a Hydrologic Climate-Response Network in New England

NEW YORK

NEW

JERSEY

NEW

QUEBEC BRUNSWICK

Base from U.S. Geological Survey digital data 1:24,000

Universal Transverse Mercator projection, zone 19

46°

44°

42°

74° 72° 70° 68°

0 60 120 MILES

0 60 120 KILOMETERS

ATLANTIC

OCEAN

EXPLANATION

Meteorological station, by

 period-of-record classification

Long-term trend

Falls Village

Groton

Stamford

Storrs

Acadia

Eastport

Farmington

Gardiner

Houlton

Lewiston

Millinocket

Corinna

Portland

Presque Isle

Brassua

Woodland

Amherst Bedford

Blue Hill

Reading

West Medway

Walpole Great Barrington

Lawrence

New Bedford

Plymouth-Kingston

Provincetown

Taunton

Bethlehem

Durham

First Connecticut

Hanover

Keene

Block Island

Kingston

Providence

Burlington

Cavendish

Chelsea

Cornwall

Enosburg Falls

South Lincoln

St. Johnsbury

South Hero

Figure 11. U.S. Historical Climatology Network meteorological stations in New England. Stations have at least 50 years of 

records for long-term trend testing. See figure 3 for climate-response regions by color. See table 7 for full station names.
Framework for a Hydrologic Climate-Response Network 27

Table 8. Basin sites appropriate for process-based studies.

[See figure 12 for basin locations. ME, Maine; NH, New Hampshire; MA, 

Massachusetts; RI, Rhode Island; CT, Connecticut; VT, Vermont]

Station 

number Station name

01010000 St. John River at Ninemile Bridge, ME

01013500 Fish River near Fort Kent, ME

01017060 Hardwood Brook below Glidden Brook near 

Caribou, ME

01018035 Meduxnekeag River at Lowery Road near 

Houlton, ME

01022500 Narraguagus River at Cherryfield, ME

01027200 North Branch Penobscot River near Pittston Farm, ME

01030500 Mattawamkeag River near Mattawamkeag, ME

01031500 Piscataquis River near Dover-Foxcroft, ME

01037380 Ducktrap River near Lincolnville, ME

01038000 Sheepscot River at North Whitefield, ME

01047000 Carrabassett River near North Anson, ME

01052500 Diamond River near Wentworth Location, NH

01054200 Wild River at Gilead, ME

01064500 Saco River near Conway, NH

01067950 Kennebunk River near Kennebunk, ME

01073000 Oyster River near Durham, NH

01078000 Smith River near Bristol, NH

01095220 Stillwater River near Sterling, MA

01117468 Beaver River near Usquepaug, RI

01121000 Mount Hope River near Warrenville, CT

01135300 Sleepers River (Site W-5) near St. Johnsbury, VT

01137500 Ammonoosuc River at Bethlehem Junction, NH

01142500 Ayers Brook at Randolph, VT

01150900 Ottauquechee River near West Bridgewater, VT

01162500 Priest Brook near Winchendon, MA

01181000 West Branch Westfield River at Huntington, MA

01208990 Saugatuck River near Redding, CT

01333000 Green River at Williamstown, MA

04296000 Black River at Coventry, VT

figure 12. Specific effort would be made to select candidate 

basins that have existing watershed models and ones that 

contain important resources such as Atlantic salmon habitat 

and (or) Native American and U.S. Department of Interior or 

Agriculture lands. A deterministic watershed model would 

then be developed for each of these basins (if not already 

completed) to improve understanding of basin hydrologic 

processes. The watershed models would use numerical 

methods to describe the physical processes that control the 

movement of water throughout a basin. Runoff processes 

simulated by the models would include overland flow, shallow 

subsurface flow, and groundwater flow.

The watershed models would be constructed by using 

the USGS Precipitation-Runoff Modeling System (PRMS; 

Leavesley and others, 1983; Markstrom and others, 2008). 

PRMS is well suited for simulating runoff from rural basins 

and has been applied to many basins in the United States. 

PRMS is a deterministic, distributed-parameter modeling 

system. The model is deterministic in that it computationally 

incorporates multiple components of the hydrologic cycle 

as understood through known physical laws or empirical 

relations in hydrologic science. The modeled hydrologic 

relations are typically governed by quantifiable physical 

characteristics of the basin. Parameters describing the physical 

basin characteristics are assigned in a distributed fashion, 

representing the spatial variation (heterogeneity) in basin 

characteristics. In this manner, the model is designed to 

simulate the hydrologic system as realistically as possible.

The models would be calibrated to historical records. 

Calibrated watershed models provide simulated time series of 

daily streamflow for many locations throughout a basin. The 

models leverage limited streamflow-gaging-station data and 

provide a method for characterizing subbasin hydrology. An 

example of rainfall-runoff-model subareas for two basins in 

eastern coastal Maine (Dudley, 2008) is shown in figure 13. 

The model explicitly simulates the physical processes of 

surface runoff, subsurface flow, and groundwater flow and 

processes affecting soil moisture, snowpack accumulation and 

melt, and evapotranspiration. This information would enable 

natural-resource managers to characterize the timing and 

quantity of water moving through the basin to support many 

endeavors, including geochemical calculations, water-use 

assessment, river biota population dynamics modeling, and 

habitat modeling and assessment. It would also allow scenario 

testing for interactions between climate change and changes in 

water use and land use.

Additional research would be conducted to improve 

understanding of processes such as soil moisture dynamics, 

groundwater/surface-water interactions, ice dynamics, and 

hydrologic/ecological interactions that are important to 

habitats and species. For example, with improved availability 

of groundwater data, PRMS could be integrated with the 

USGS groundwater model MODFLOW in an application 

called GSFLOW (Markstrom and others, 2008) to support 

investigations of basin-scale groundwater and surfacewater resources. Using models to characterize the relative 

contributions of surface water and groundwater to streamflow 

throughout the basin would lead to an improved understanding 

of water quantity and quality and the effects of future 

hydrologic changes on ecosystems in the basin.
28 Framework for a Hydrologic Climate-Response Network in New England

NEW YORK

NEW

JERSEY

NEW

QUEBEC BRUNSWICK

Base from U.S. Geological Survey digital data 1:24,000

Universal Transverse Mercator projection, zone 19 

46°

44°

42°

74° 72° 70° 68°

0 60 120 MILES

0 60 120 KILOMETERS

ATLANTIC

OCEAN

EXPLANATION

Basin site appropriate for process-based 

 studies and number

01181000

01162500

01333000

01064500

01052500

01038000

01031500

01013500

01022500

01047000

01010000

01030500

01073000

01078000

01117468

01121000

01137500

01142500

01150900

01208990

04296000

01054200

01017060

01018035

01027200

01037380

01067950

01095220

01135300

01117468

Figure 12. Basin sites appropriate for process-based studies. See figure 3 for climate-response regions by color.
Framework for a Hydrologic Climate-Response Network 29

01021230

01021200

EXPLANATION

Wetlands 

Base from U.S. Geological Survey and Maine Office of GIS digital data

Universal Transverse Mercator projection, zone 19

Lakes and ponds

Streamgaging-station site

Geographic point of interest 

Watershed model basin drainage network

Dennys River

Cathance Stream

Dennys River

Cathance Stream

Model response unit (MRU)

67°18'0"W

67°28'30"W 67°18'0"W

45°7'0"N

45°7'0"N

45°1'30"N

45°1'30"N

44°56'0"N

44°56'0"N

44°50'30"N

Dead Stream

Curry Brook

Dennys River

Meddybemps Lake

Pleasant Lake

Bearce Lake

Cathance Stream

Great

Works

Pond

Lake Cathance

Little

Cathance

Lake

Meddybemps

Heath

Mill Stream

Cobscook

Bay

S t ony Brook

Venture Br ook

Dead Stream

Curry Brook

Dennys River

Meddybemps Lake

Pleasant Lake

Bearce Lake

Cathance Stream

Great

Works

Pond

Lake Cathance

Little

Cathance

Lake

Meddybemps

Heath

Mill Stream

Kendall Mountain

Breakneck Mountain

Cooper

Hill

Cobscook

Bay

0 3 6 MILES

0 3 6 KILOMETERS

S t ony Brook

Venture Br ook

Figure 13. An example of rainfall-runoff-model subareas for two basins in eastern coastal Maine; modified from Dudley (2008, fig. 5).
30 Framework for a Hydrologic Climate-Response Network in New England

Summary

Seasonal, annual, and longer term variations in 

precipitation and air temperature can affect the timing and 

magnitudes of numerous hydrologic processes that, in 

turn, can affect human water supply, hydroelectric power 

generation, transportation infrastructure, and stream and 

riparian ecology. Recent investigations conclude that many 

different hydrologic processes in New England are sensitive 

to variations in precipitation and air temperature. Hydrologic 

variables such as peak flows, the timing of winter-spring 

flows, lake ice-out dates, snowpack, and groundwater levels 

have changed during the last century and are expected to 

change in the future. Many changes in winter and spring have 

been documented, and some changes in summer and fall and 

for annual flow variables have also been found. Observed 

trends during winter and spring are largely related to changes 

in air temperature because of the sensitivity of snowpack to air 

temperature changes in New England. Trends during summer 

and fall are largely related to changes in precipitation.

The framework for the New England climate-response 

network described in this report identifies specific inland 

hydrologic variables that are sensitive to climate variation; identifies geographic regions with similar hydrologic 

responses; proposes a fixed-station monitoring network that 

includes existing streamflow, groundwater, lake ice, snowpack, 

and meteorological data-collection networks for evaluation 

of hydrologic response to climate variation; and establishes 

potential streamflow basins for intensive process-based studies 

and for estimates of future hydrologic conditions.

The framework proposes that New England be divided 

into 14 regions that follow major river-basin boundaries, have 

relatively homogeneous climates, and contain network sites 

with similar values or trends in key hydrologic variables. 

Establishing the proposed network would require the 

identification of hydrologic components of interest (fluxes 

and storage compartments), the key variables that characterize 

each component, and a set of data-collection sites. Three 

criteria were used to identify key variables: the existence 

of long-term historical data, the expectation that a variable 

will be responsive to changes in precipitation and (or) air 

temperature during the next several decades, and the human or 

ecological importance of the component variables.

For the streamflow component, two key variables are 

proposed: winter-spring streamflow timing and the magnitude 

of the annual peak flow. Streamflow data proposed for New 

England are from rivers, monitored by U.S. Geological Survey 

streamflow-gaging stations, with streamflows minimally 

affected by direct changes to the watershed from human 

activities such as reservoir regulation and urbanization. Thirtyone streamflow-gaging stations in New England meet the 

criteria for minimal disturbance and long-term completeness 

(at least 80-percent data completeness for each decade from 

1960 to 2013 (11 of 13 years for 2000 to 2012). Another 

30 stations in New England meet the criteria for minimal 

disturbance and have shorter or less complete records.

Key variables for a groundwater network include the 

annual highest and lowest levels. For New England groundwater wells, a completeness criterion of 80 percent per decade 

yields 70 and 12 wells appropriate for short-term (30-year) 

and long-term (50-year) trend testing, respectively.

The key (and only commonly available in New England) 

historical measure of lake ice is lake ice-out date—the annual 

date in spring when winter ice cover leaves a lake. There are 

37 lakes that meet long-term-completeness criteria (as defined 

in the previous paragraph). As of 2012, 5 lakes have 165 years 

or more of data, and another 14 have more than 110 years 

of data.

Key snowpack variables are the magnitude of latewinter water equivalent, depth, and density for selected 

dates. Twenty-three sites with long-term data for at least one 

late-winter sampling window were considered appropriate 

for a New England hydrologic climate-response network; 

data from these sites did not show significant sampling bias 

over time. It would be desirable to have additional snowpack 

sites outside of Maine, particularly in areas of regular 

substantial snowpack.

Precipitation and air temperature trends and variability 

are important to streamflow, groundwater, lake ice-out, and 

snowpack trends and variability. The relative influence of 

precipitation and air temperature varies by season. A network 

of 44 meteorological stations have a minimum of 99 years of 

record through 2012 and are appropriate for analyzing longterm trends.

An important part of establishing a hydrologic climateresponse network in New England is identifying basins that 

are appropriate for use in process-based studies designed 

to improve understanding of and predict hydrologic and 

ecosystem change. For each region in the proposed hydrologic 

climate-response network, a representative basin (in geology, 

land cover, and other characteristics) that has extensive 

historical data for multiple hydrologic components would 

be identified. A deterministic watershed model would 

then be developed for each of these basins (if not already 

completed). The models would then be used to improve 

understanding of hydrologic processes in basins (fluxes and 

storages), make streamflow projections, and provide input to 

ecological models.

This proposed framework for a New England climateresponse network lays a foundation for the organization of 

data-collection networks and climate-response regions and for 

the identification of key climate-related hydrologic variables. 

Ongoing and future analyses of hydrologic data are expected 

to inform improvements to the proposed framework.
References Cited 31

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For more information concerning this report, contact:

Director, New England Water Science Center

U.S. Geological Survey 

196 Whitten Road 

Augusta, ME 04330 

dc_nweng@usgs.gov

or visit our Web site at:

http://me.water.usgs.gov

Publishing support by: 

The Pembroke Publishing Service Center.
Lent and others—Framework for a Hydrologic Climate-Response Network in New England—Open-File Report 2015–1062

ISSN 2331-1258 (online)

http://dx.doi.org/10.3133/ofr20151062