AN EVOLVING STREAMFLOW-GAGING NETWORK

From its beginning, the USGS streamflow-gaging network 

has evolved in response to the needs of the public. In the late 

19th century, streamflow-gaging activities in Massachusetts 

and Rhode Island began at the behest of industries that used the 

power of flowing water. Many of these industries were mills 

along the swiftly flowing rivers of Massachusetts and Rhode 

Island. At that time, a mill employee or local resident measured 

the stream stage, the height of the water surface with respect to 

a reference elevation. Discharge, the volume of water flowing 

past a point during a unit of time, was measured by the USGS 

when the office hydrographer (now called a hydrologist or a 

hydrologic technician) traveled to the site. Usually discharge 

was measured at least once a month, but could be less frequent 

if travel was difficult. Measurement intervals and the types 

of data differed from site to site. At some sites, the stage was 

measured each day if the river was free of ice; and at others, the 

stage was measured sporadically and a monthly mean for stage 

was calculated from the measurements. The entire data-collection effort was overseen by USGS personnel, and the stage and 

monthly mean discharge values were published in the USGS 

Water-Supply and Irrigation Paper series (Barrows and 

Hoyt, 1905). 

The first streamflow-gaging station in Massachusetts with the 

longest continuous record of data was installed on the Connecticut River at Sunderland in March 1904. In 1929, it was moved 

9 miles north to Montague City, where it still operates today. 

The second such station was established in August 1909 on 

the Quaboag River in West Brimfield, and the third in August 

1912 on the Ware River at Gibbs Crossing (Socolow and others, 

The U.S. Geological Survey (USGS) has been collecting streamflow data in Massachusetts and Rhode Island 

for over 100 years. Since the first streamflow measurements were made in the late 19th century, the isolated 

sites where streamflow data were collected have evolved into a monitoring network of 112 streamflow-gaging 

stations. Today, nearly three-quarters of the stations have satellite telemetry equipment to make streamflow data 

available to the public on the World Wide Web within 4 hours of collection. Data from this network are used 

by Federal, State, and local government agencies, water-resources managers, National Weather Service river 

forecasters, watershed associations, university scientists, recreational enthusiasts, and citizens with an interest 

in their local rivers. 

From its inception in the 19th century, the USGS streamflow-gaging network has served the public interest. 

From providing information about streamflow to mill owners to providing data to river forecasters, data from 

this network have helped water-resource managers make sound decisions in managing water resources in 

Massachusetts and Rhode Island. This fact sheet summarizes the history and development of this network and 

demonstrates how data are collected from it. It discusses how the network has historically served the public 

interest, continues to do so today after a century of continuous data collection, and how it will do so in the future.

2003). By 1930, 17 stations were operating in Massachusetts, 

all but 2 of which were in western Massachusetts. In Rhode 

Island, the oldest currently operating streamflow-gaging station 

was built in 1929 on the Blackstone River at Woonsocket in an 

area also heavily industrialized with mills. 

Over the years, the network has grown in response to floods 

and droughts. Severe flooding in the 1930s provided an impetus 

for additional flow-monitoring stations. The number of stations 

increased from a total of 15 in Massachusetts and Rhode Island 

before the floods to about 60 during the late 1930s and early 

1940s. Six of Rhode Island’s 22 continuous streamflow-gaging 

stations were installed shortly after the devastating hurricane of 

U.S. Department of the Interior

U.S. Geological Survey

USGS Fact Sheet FS–2004-3056

April 2004

Streamflow-gaging station Little River at Oxford, Massachusetts. This 

1940 photo shows the gage house, cable car, and cableway.

1

ONE HUNDRED YEARS OF STREAMFLOW MEASUREMENTS IN 

MASSACHUSETTS AND RHODE ISLAND 
1938. After the extended drought of the 1960s, 25 new stations 

were installed in the two states. 

Today (2004) 90 stations in Massachusetts and 22 in Rhode 

Island provide continuous streamflow data (fig. 1). The total 

number of stations in both states reached a maximum of 114 in 

1973, at which time some stations were discontinued because 

of changes in water-resource-management needs (Zarriello and 

Socolow, 2003). The total number of stations from 1973 until 

the present has fluctuated around 100, and now stands at 112. In 

both states, stations are cooperatively funded by the USGS and 

by other Federal, State, and local government agencies, with the 

USGS maintaining and operating the stations and publishing 

the streamflow data annually. 

Data from these networks serve the dual purpose of meeting 

site-specific and regional needs. Examples of site-specific 

needs include the regulation of dam storage and release, and 

monitoring the magnitude and frequency of flooding and low 

flows. Examples of regional needs include flood forecasting 

in cooperation with the National Weather Service, developing 

regionalized flow estimates for use at sites where there are 

no streamflow data, and determining long-term changes in 

streamflow. Streamflow data are also used to study patterns of 

contamination in river water and sediments and to determine 

how land use affects streamflows. 

In addition to the continuously operating streamflow-gaging 

network, the USGS installs and operates temporary stations, 

usually for 1 or 2 years, to collect data for specific investigations. These short-term stations may be installed in such diverse 

settings as the outlets of ponds, inside culverted waterways in 

urban areas, or in wetlands. Some short-term stations record 

stage only. When the data have been collected or the investigation ends, the station is usually discontinued. For example, 

MA-RI office personnel recently installed temporary stations to 

collect streamflow and water-quality data for several tributaries 

to the Charles River. 

HOW STREAMFLOW DATA ARE COLLECTED AND 

PROCESSED

The technology for measuring and transmitting stage data 

has changed greatly during the past 100 years from manual field 

observations to automated acquisition, processing, and dissemination. From the 1920s to the 1950s, stage recorders used a 

float that moved up and down with the water surface. Through 

a cable and pulley, the float’s movements were transferred to a 

pen, which traced the stage record onto graph paper taped to a 

revolving drum. The graphs were manually read and interpreted.

Electronic storage and processing of streamflow data began 

in the early 1960s, when recorders were developed that punched 

stage readings into paper tapes. These tapes were then read by 

a computer and the data were stored in electronic files. During 

the 1970s, data recorders with satellite-telemetry equipment 

were introduced. Within the past 14 years, the percentage of 

telemetered stations in Massachusetts and Rhode Island has 

increased from 20 percent to 72 percent. At 4-hour intervals, 

the data are transmitted to a satellite, which relays them to a 

central USGS computer. The data are then sent from the central 

Figure 1. Locations and periods of record for the 112 streamflow-gaging stations currently operating in Massachusetts and Rhode Island. 

2

MASSACHUSETTS

RHODE 

ISLAND

CONNECTICUT

NEW 

YORK

VERMONT NEW HAMPSHIRE

EXPLANATION

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ATLANTIC OCEAN

Massachusetts Bay

Cape Cod Bay

Nantucket Sound

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Block Island Sound

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USGS computer to the computer in the local USGS office 

in Massachusetts. By the mid-1990s, all streamflow-gaging 

stations in Massachusetts and Rhode Island were equipped with 

digital data recorders. 

In contrast, techniques for measuring discharge have changed 

little during the past 100 years. Discharge measurements and 

stream-channel surveys are still made by USGS personnel who 

visit the stations about every 2 months. Because erosion and 

deposition of bed and bank material can change the shape of 

the channel at the station site, the stage and discharge data for 

each station must be periodically remeasured. A current meter is 

still used to measure the water velocity at predetermined points 

along a marked tagline (fig. 2), a suspended cableway, or a 

bridge across the river. The depth of the water is also measured 

at each point. These depth and velocity measurements are used 

to compute the total volume of water flowing past the tagline 

during a specific interval of time.

Once six to eight paired measurements of stage and discharge 

have been collected for a station, these values are plotted on a 

graph. A line of best fit, called a rating curve, is drawn through 

the plotted points (fig. 3). A rating curve is a graphical tool 

that relates stage to discharge over the entire range of a river’s 

flow, from extremely low to extremely high flows. Today, 

the mathematical function represented by the rating curve 

is programmed and stored in USGS computers to compute 

discharge from measurements of stage. 

Stage and discharge data are usually available to the public 

on the World Wide Web within 4 hours of the time measurements were taken (Zarriello and Socolow, 2003). Data on the 

World Wide Web also include all historical records of daily 

mean streamflow. Streamflow data collected during each water 

year (October through the following September) are published 

in an annual data report, which in recent years has also become 

available on the World Wide Web. Other USGS reports 

document streamflow measurements made at temporary stations 

installed for specific investigations. 

NEW TECHNOLOGY

Advances in streamflow-gaging technology are expected to 

improve the accuracy and reliability of streamflow measurements under a wide range of hydrologic conditions. Two goals 

in Massachusetts and Rhode Island are to equip all stations with 

telemetry and to increase the frequency of transmission at all 

stations from every 4 hours to every hour. Most of the recent 

advances, however, consist of the development of equipment 

to measure water velocity indirectly. Flow sensors, such as 

the acoustic Doppler current profiler, can make thousands of 

velocity and depth measurements in rapid succession as they 

are towed across a river. Such equipment makes the collection 

of streamflow data safer and cheaper, particularly during floods, 

on large rivers with rapid flows, or in confined spaces such as 

culverted waterways and storm drains. Satellite technology 

is also improving; in the future, it might be possible to make 

streamflow measurements from space. Such observations would 

be especially important for floods on rivers in remote areas. 

FUTURE DIRECTIONS

As demands on water resources increase, so do the demands 

for streamflow data. Specifically, the link between surfacewater and ground-water resources is receiving an increasing 

amount of attention. Because streams and ground water may be 

hydraulically connected with one another, they constitute a single 

resource. Withdrawals at wells near streams can greatly reduce 

streamflow, and in some cases, can cause streams to run dry. To 

address this concern, the USGS has used data from both surfaceand ground-water sources to determine how best to allocate 

water supplies, particularly during the summertime when flows 

are low. Computer models can simulate the effects of alternative 

water-management scenarios on the availability of water. In 

addition, the USGS has developed regional relations to estimate 

streamflow data for ungaged sites (Zarriello and Socolow, 2003). 

Such relations have been refined and expanded to many ungaged 

areas to provide complete regional sets of streamflow data to 

the public. Finally, long-term streamflow records show trends 

that can be correlated with changes in human activities or with 

climate change. 

The collection of streamflow data for Massachusetts and 

Rhode Island is a vital aspect of water-resources planning and 

hydrologic research. The streamflow-gaging network provides 

the information needed by water-resource managers to make 

informed decisions about using and protecting surface-water 

resources to prevent the loss of life and property, to protect 

public health, and to ensure a continuing source of water to meet 

society’s needs. Maintaining the streamflow-gaging network will 

ensure that reliable streamflow data will remain available to 

the public. 

3

Figure 3. The rating curve for the Connecticut River at Montague City 

streamflow-gaging station, Massachusetts (the oldest continuously 

operating station in Massachusetts).

Figure 2. The USGS measures discharge on the Connecticut River at 

Montague City, Massachusetts, 2001.

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FLOODS AND DROUGHTS

Intense rain, snowmelt, and storm surges are major causes of 

floods. Although damage from floods can be severe, most floods 

are restricted to small areas around rivers. Drought is a moisture 

deficit that has an adverse effect on vegetation, animals, and people 

over a sizeable area. Streamflows can become depleted during a 

drought if water is withdrawn too rapidly from nearby wells. Whereas 

the duration of a flood is typically a few days, droughts can last 

for several years, or even decades. Near-real-time records from 

USGS streamflow-gaging stations are used by Federal, State, local 

emergency-management agencies, and the National Weather Service 

to warn the public in advance of floods to reduce the loss of life and 

damage to property, and to manage water levels in streams during 

droughts so that the depletion of streamflow can be minimized. 

The worst flood on record in Massachusetts and Rhode Island 

was the result of intense rain and a storm surge before and during 

the hurricane of September 21, 1938. In early April 2004, intense rains 

caused flooding in Massachusetts (fig. 4). The longest and most 

severe drought on record lasted from 1961 to 1969 in Massachusetts 

and from 1963 to 1967 in Rhode Island. The most recent drought 

affecting Massachusetts and Rhode Island occurred in the spring and 

summer of 1999.

Visit the USGS national water-watch Web site at 

http://water.usgs.gov/waterwatch for more information about floods 

and droughts. Go to http://ma.water.usgs.gov/water/water_floods.htm 

for more information about floods and high flows, and to 

http://ma.water.usgs.gov/drought/drought_index.htm for more 

information about droughts and low flows in Massachusetts and 

Rhode Island.

REFERENCES CITED

Barrows, H.K., and Hoyt, J.C., 1905, Report of the progress of stream measurements for the calendar year 1904, 

Part I: U.S. Geological Survey Water-Supply and 

Irrigation Paper No. 124; Series P, Hydrographic 

Progress Reports, 29, p. 1-157. 

Socolow, R.S., Girouard, G.G., and Ramsbey, L.R., 2003, 

Water Resources Data––Massachusetts and Rhode 

Island––Water Year 2002: U.S. Geological Survey 

Water-Data Report MA-RI-02-1, 339 p. 

Zarriello, P.J., and Socolow, R.S., 2003, The U.S. 

Geological Survey streamflow and observation-well 

network in Massachusetts and Rhode Island: U.S. 

Geological Survey Open-File Report 03-277, 114 p.

CONTACTS

For more information about USGS streamflow gaging and 

other USGS activities in Massachusetts and Rhode Island, 

contact the USGS offices in Northborough, MA, 

1-508-490-5000, and Providence, RI, 1-401-331-9050, 

or visit http://ma.water.usgs.gov/ for online data and links.

Prepared by Mary S. Ashman, Roy S. Socolow, and Joseph L. 

Zanca. Graphic design by Mark V. Bonito.

4

Figure 4. Recent hydrograph from the Massachusetts-Rhode Island 

office’s Web page for the Montague City station, Connecticut River, 

with the flood peak of April 2, 2004. A flood of this magnitude has a 

probability of occurring about once every 2 years.

Cows drowned probably during the 1927 Connecticut River flood.

The dry bed of the Ipswich River during the drought of 1999.