Cover photo:

The Abbott Run Reservoir, photo taken November 25, 2003.
U.S. Department of the Interior

U.S. Geological Survey

Estimated Water Use and Availability in the

Lower Blackstone River Basin, Northern

Rhode Island and South-Central

Massachusetts, 1995–99

By LORA K. BARLOW

Water-Resources Investigations Report 03-4190

In cooperation with the

RHODE ISLAND WATER RESOURCES BOARD

Providence, Rhode Island

2003
For additional information write to:

Subdistrict Chief

Massachusetts–Rhode Island District

U.S. Geological Survey

275 Promenade, Suite 150

Providence, RI 02908

or visit our Web site at

http://ri.water.usgs.gov

Copies of this report can be purchased from:

U.S. Geological Survey

Branch of Information Services

Box 25286

Denver, CO 80225-0286

Any use of trade, product, or firm names in this publication is for descriptive purposes only and does 

not imply endorsement by the U.S. Government.

U.S. DEPARTMENT OF THE INTERIOR

GALE A. NORTON, Secretary

U.S. GEOLOGICAL SURVEY

Charles G. Groat, Director
Contents III

CONTENTS

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

Introduction......................................................................................................................................................................... 2

Purpose and Scope.................................................................................................................................................... 2

Previous Investigations............................................................................................................................................. 3

Description of the Study Area.................................................................................................................................. 3

Sand and Gravel Aquifers and Ground-Water Reservoirs........................................................................... 3

Surface Water.................................................................................................................................................. 6

Climate ............................................................................................................................................................ 7

Population ....................................................................................................................................................... 7

Land Use and Land Cover.............................................................................................................................. 7

Acknowledgments.................................................................................................................................................... 13

Water Use............................................................................................................................................................................ 13

Water Supply ............................................................................................................................................................ 13

Public Supply.................................................................................................................................................. 15

Self-Supply...................................................................................................................................................... 20

Aggregate Water Use by Category.......................................................................................................................... 21

Domestic ......................................................................................................................................................... 21

Public Supply........................................................................................................................................ 23

Self-Supply............................................................................................................................................ 23

Commercial..................................................................................................................................................... 23

Public Supply........................................................................................................................................ 25

Self-Supply............................................................................................................................................ 25

Industrial.......................................................................................................................................................... 25

Public Supply........................................................................................................................................ 25

Self-Supply............................................................................................................................................ 25

Agricultural and Golf-Course Irrigation........................................................................................................ 25

Consumptive and Non-Account Use............................................................................................................. 26

Electric Power Generation ............................................................................................................................. 27

Wastewater-Return Flows........................................................................................................................................ 27

Public Disposal ............................................................................................................................................... 27

Wastewater Imports and Exports................................................................................................................... 33

Infiltration and Inflow Estimates ................................................................................................................... 33

Self-Disposal................................................................................................................................................... 35

Total Return Flows......................................................................................................................................... 35

Water-Use Summary...................................................................................................................................... 35

Water Availability .............................................................................................................................................................. 38

Streamflow-Gaging Stations Used in Analysis....................................................................................................... 38

Method Used to Estimate Base-Flow Volume ....................................................................................................... 39

Safe-Yield Analysis for Public-Supply Reservoirs................................................................................................. 39

Evaluation of Water Availability and Basin Stress................................................................................................. 41

Streamflow Depletion by Ground-Water Withdrawals.......................................................................................... 47

Water Budget...................................................................................................................................................................... 52

Inflow ........................................................................................................................................................................ 52

Outflow ..................................................................................................................................................................... 53
IV Contents

Summary and Conclusions ................................................................................................................................................ 54

References Cited................................................................................................................................................................. 55

Glossary .............................................................................................................................................................................. 57

Appendix 1. SIC code estimates by minor civil division................................................................................................. 61

Appendix 2. Water-Use Case Study—Cumberland, Rhode Island................................................................................. 65

FIGURES

1-6. Maps showing:

1. Blackstone River basin and study area, northern Rhode Island and south-central Massachusetts.... 4

2. Distribution of sand and gravel and till deposits, and ground-water reservoirs as named by 

the Rhode Island Water Resources Board (Rhode Island portion only) in the lower 

Blackstone River basin........................................................................................................................... 5

3. Streamflow-gaging stations and public-supply reservoirs within the lower Blackstone 

River basin.............................................................................................................................................. 6

4. Estimated population by town and subbasin in the lower Blackstone River basin, 1995–99............ 9

5. Land use in 1995 in the lower Blackstone River basin........................................................................ 12

6. Public-supply wells and surface-water-intake locations within the lower Blackstone River basin... 18

7. Graph showing public- and self-supply water use by category in the lower Blackstone River 

basin for the period 1995–99: (A) domestic, (B) commercial, (C) industrial, and (D) agricultural........... 24

8–10. Maps showing:

8. Power-generation facilities within the lower Blackstone River basin................................................. 28

9. Outfall locations for wastewater-treatment facilities serving towns within the lower 

Blackstone River basin........................................................................................................................... 30

10. National Pollution Discharge Elimination System outfalls for commercial and industrial 

facilities within the lower Blackstone River basin ............................................................................... 32

11. Diagram showing water withdrawals (supply), use, and return flow (disposal) for the lower 

Blackstone River basin................................................................................................................................... 37

12. Graph showing available base flow calculated as base flow minus minimum streamflow 

according to two criteria, the 7-day, 10-year low flow (7Q10) and Aquatic Base Flow (ABF), 

for June, July, August, and September for the period 1957–99 at the streamflow-gaging station 

at the Branch River at Forestdale, Rhode Island (U.S. Geological Survey station number 01111500).... 40

13. Map showing subbasin stress indicated by the ratio of water withdrawals, 1995–99, to estimated 

water availability, 1957–99, during August; and graphs of water availability for June, July, 

August, and September for the six subbasins within the lower Blackstone River basin............................ 44

14–15. Graphs showing:

14. Specified daily pumping rates at Cumberland Water Department Manville well no.1, 

Rhode Island, 1995–99, and calculated streamflow depletion in the nearby Blackstone River........ 50

15. Streamflow depletion as a percentage of well pumping rate (Qs/Qw * 100) for six 

public-supply wells with different aquifer properties and distances to the stream in the 

lower Blackstone River basin. Qs is the rate of streamflow depletion (cubic foot per second) 

and Qw is the pumping rate of the well (cubic foot per second).......................................................... 52
Contents V

TABLES

1. Land area and 5-year average population for each minor civil division within the lower 

Blackstone River basin, northern Rhode Island and south-central Massachusetts, 1995–99..................... 8

2. Land area and population for minor civil divisions, water suppliers (major and minor), and 

wastewater-treatment facilities serving those municipalities within the lower Blackstone 

River basin, 1995–99...................................................................................................................................... 10

3. Total 5-year average population and population served by public-water systems and publicwastewater systems by minor civil division in the lower Blackstone River basin, 1995–99..................... 14

4. Water withdrawals for public-supply wells and surface-water intakes by subbasin in the lower 

Blackstone River basin, 1995–99 .................................................................................................................. 16

5. Public-supply withdrawals, public-supply imports, public-supply exports, public-supply use, 

self-supply use, and total estimated withdrawals by minor civil division and subbasin in the 

lower Blackstone River basin, 1995–99........................................................................................................ 19

6. Agricultural, commercial, and industrial land-use area by subbasin as a percentage of total land 

area for the category in each minor civil division for the lower Blackstone River basin........................... 21

7. Total water use, public and self-supply, by category in the lower Blackstone River basin, 1995–99....... 22

8. Agricultural coefficients used to estimate livestock water use in the lower Blackstone River basin ........ 26

9. Average return flow for wastewater-treatment facilities serving communities of the lower 

Blackstone River basin, 1995–99 .................................................................................................................. 29

10. Average return flow for National Pollution Discharge Elimination System outfall locations for 

the lower Blackstone River basin, 1995–99.................................................................................................. 31

11. Public disposal (estimated and metered) of wastewater, including imports, exports, and 

infiltration and inflow, self-disposal (onsite septic estimates and metered), and total return 

flows for the lower Blackstone River basin, 1995–99.................................................................................. 34

12. Summary of estimated water withdrawals, imports, exports, use, non-account use, 

consumptive use, and return flow in the lower Blackstone River basin, 1995–99 ..................................... 36

13. U. S. Geological Survey streamflow-gaging stations in the lower Blackstone River basin....................... 38

14. Available base-flow volumes calculated at the 50th percentile by the PART program minus 

minimum streamflows determined by two criteria, the 7-day, 10-year low flow and the 

Aquatic Base Flow, for the Branch River at Forestdale (01111500) for June, July, August, 

and September for the period 1957–99 ......................................................................................................... 40

15. Safe-yield estimates and 5-year average demand for surface-water reservoirs of three 

municipal water suppliers in the lower Blackstone River basin, 1995–99.................................................. 41

16. Area of sand and gravel and till deposits and percent of sand and gravel deposits within the 

lower Blackstone River basin ........................................................................................................................ 42

17. Summary of water availability, defined as base flow plus safe-yield estimates, for June through 

September in the lower Blackstone River basin, 1957–99........................................................................... 43

18. Summary of water availability, defined as base flow by aquifer type plus safe yield, for June 

through September in the lower Blackstone River basin, 1957–99............................................................. 45

19. Average water withdrawal rates for the low-flow period in the lower Blackstone River basin, 

1995–99........................................................................................................................................................... 47

20. Summary of basin-stress ratios for June through September in the lower Blackstone River 

basin, 1957–99................................................................................................................................................ 48

21. Selected public-supply wells, parameters used to calculate streamflow depletion with the 

program STRMDEPL, and streamflow depletion as a percentage of the well pumping rate at 

10, 20, and 30 days after the start of pumping.............................................................................................. 49

22. Long-term average annual hydrologic water budget by subbasin for the lower Blackstone 

River basin, 1957–99...................................................................................................................................... 53
VI Contents

CONVERSION FACTORS, VERTICAL AND HORIZONTAL DATUM, 

ABBREVIATIONS, AND ACRONYMS

CONVERSION FACTORS

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

°C = (°F-32)/1.8

Transmissivity: The standard unit for transmissivity is cubic foot per day per square foot times foot of aquifer thickness [(ft3/d)/ft2]ft. In this report, 

the mathematically reduced form, foot squared per day (ft2/d), is used for convenience.

Electric power: The kilowatt (KW) is the standard unit for measuring electric-power generation and is used in this report.

VERTICAL AND HORIZONTAL DATUM

In this report, vertical coordinate information is referenced to the North American Vertical Datum of 1988 (NAVD 88), and horizontal coordinate 

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

Multiply By To obtain

cubic foot per second (ft3/s) 0.0283 cubic meter per second (m3/s)

cubic foot per second per square mile [(ft3/s)/mi2] 0.0109 cubic meter per second per square kilometer (m3/s/km2)

foot (ft) 0.3048 meter (m)

foot per day (ft/d) 0.3048 meter per day (m/d)

gallons per day (gal/d) 0.00378 cubic meter per day (m3/d)

inch (in.) 2.54 centimeter (cm)

inch per acre per week [(in/acre)/wk] 6.274 centimeter per hectare per week [(cm/ha)/wk]

inch per month (in/mo) 2.54 centimeter per year (cm/yr)

inch per year (in/yr) 2.54 centimeter per year (cm/yr)

mile (mi) 1.609 kilometer (km)

million gallons (Mgal) 3,785 cubic meter (m3)

million gallons per day (Mgal/d) 3,785 cubic meters per day (m3/d)

million gallons per day per square mile (Mgal/d/mi2) 1,462.1 cubic meter per day per square kilometer (m3/d/km2)

million gallons per day per yard [(Mgal/d)/yd] 0.00414 million cubic meters per day per meter (Mm3/d/m)

million cubic feet (Mft3) 0.0283 million cubic meters (Mm3)

square foot per day (ft2/d) 0.0929 square meters per day (m2/d)

square mile (mi2) 2.59 square kilometer (km2)
Contents VII

ABBREVIATIONS AND ACRONYMS

7Q10 7-day, 10-year low flow

ABF Aquatic Base Flow

ADAPS Automated Data Processing System

DPW Department of Public Works

FD Fire District

HUC Hydrologic Unit Code

I/I Infiltration and Inflow

MassGIS Massachusetts Geographic Information System

MCD Minor Civil Division

NBC Narragansett Bay Commission

NEWUDS New England Water Use Database System

NPDES National Pollution Discharge Elimination System

NRCS National Resource Conservation Service

NWS National Weather Service

PCD Pollution Control District

PCS Permit Compliance System

RIDEM Rhode Island Department of Environmental 

Management

RIDOA Rhode Island Department of AdministrationDivision of Planning

RIGIS Rhode Island Geographic Information System

RIWRB Rhode Island Water Resources Board

SIC Standard Industrial Classification

STF3 Summary Tape File 3

T/S diffusivity

USGS U.S. Geological Survey

WC Water Commission

WD Water Department

WDI Water District

WDIV Water Division

WSB Water Supply Board

WSD Water and Sewer Department

WWTF Wastewater Treatment Facility

Abstract 1

Estimated Water Use and Availability in the 

Lower Blackstone River Basin, Northern 

Rhode Island and South-Central 

Massachusetts, 1995–99

By Lora K. Barlow 

Abstract

The Blackstone River basin includes 

approximately 475 square miles in northern Rhode 

Island and south-central Massachusetts. The study 

area (198 square miles) comprises six subbasins of 

the lower Blackstone River basin. The estimated 

population for the study period 1995–99 was 149,651 

persons. Water-use data including withdrawals, use, 

and return flows for the study area were collected. 

Withdrawals averaged 29.869 million gallons per 

day (Mgal/d) with an estimated 12.327 Mgal/d 

exported and an estimated 2.852 Mgal/d imported; 

this resulted in a net export of 9.475 Mgal/d. Publicsupply withdrawals were 22.694 Mgal/d and selfsupply withdrawals were 7.170 Mgal/d, which is 

about 24 percent of total withdrawals. Two users 

withdrew 4.418 Mgal/d of the 7.170 Mgal/d of selfsupply withdrawals. Total water use averaged 

20.388 Mgal/d. The largest aggregate water use was 

for domestic supply (10.113 Mgal/d, 50 percent of 

total water use), followed by industrial water use 

(4.127 Mgal/d, 20 percent), commercial water use 

(4.026 Mgal/d, 20 percent), non-account water use 

(1.866 Mgal/d, 9 percent) and agricultural water use 

(0.252 Mgal/d, 1 percent). Wastewater disposal 

averaged 15.219 Mgal/d with 10.395 Mgal/d or 68 

percent disposed at National Pollution Discharge 

Elimination System (NPDES) outfalls for municipal 

wastewater-treatment facilities. The remaining 

4.824 Mgal/d or 32 percent was self-disposed, 

1.164 Mgal/d of which was disposed through 

commercial and industrial NPDES outfalls.

Water availability (base flow plus safe-yield 

estimates minus streamflow criteria) was estimated 

for the low-flow period, which included June, July, 

August, and September. The median base flow 

for the low-flow period from 1957 to 1999 was 

estimated at 0.62 Mgal/d per square mile for sand and 

gravel deposits and 0.19 Mgal/d per square mile for 

till deposits. Safe-yield estimates for public-supply 

reservoirs totaled 20.2 Mgal/d. When the 7-day, 10-

year low flow (7Q10) was subtracted from base flow, 

an estimated median rate of 50.5 Mgal/d of water was 

available for the basin during August, the lowest 

base-flow month. In addition, basin-wide wateravailability estimates were calculated with and 

without streamflow criteria for each month of the 

low-flow period at the 75th, 50th, and 25th percentiles 

of base flow. These water availability estimates 

ranged from 42.3 to 181.7 Mgal/d in June; 20.2 to 

96.7 Mgal/d in July; 20.2 to 85.4 Mgal/d in August, 

and 20.2 to 97.5 Mgal/d in September. Base flow was 

less than the Aquatic Base Flow (ABF), minimum 

flow considered adequate to protect aquatic fauna, 

from July through September at the 25th percentile 

and in August and September at the 50th percentile. 

A basin-stress ratio, which is equal to total 

withdrawals divided by water availability, was also 

calculated. The basin-stress ratio for August at the 
2 Estimated Water Use and Availability in the Lower Blackstone River Basin, Northern Rhode Island and South-Central Massachusetts, 1995–99

50th percentile of base flow minus the 7Q10 was 

0.68 for the study area. For individual subbasins, 

the ratio ranged from 0.13 in the Chepachet River 

subbasin to 0.95 in the Abbot Run subbasin. In 

addition, basin-stress ratios with and without 

streamflow criteria for all four months of the 

low-flow period were calculated at the 75th, 50th, and 

25th percentiles of base flow. These values ranged 

from 0.19 to 0.83 in June, 0.36 to 1.50 in July, 0.40 to 

1.14 in August, and 0.31 to 0.78 in September. Ratios 

could not be calculated by using the ABF at the 50th 

and 25th percentiles in August and September 

because the estimated base flow was less than the 

ABF.

The depletion of the Blackstone River flows by 

Cumberland Water Department Manville well 

no. 1 in Rhode Island was estimated with the 

computer program STRMDEPL and specified daily 

pumping rates. STRMDEPL uses analytical solutions 

to calculate time-varying rates of streamflow 

depletion caused by pumping at wells. Results show 

that streamflow depletions were about 97 percent of 

average daily pumping rates for 1995 through 1999. 

Relative streamflow depletions for six public-supply 

wells with different aquifer properties and distances 

to a stream—Cumberland Water Department 

Manville wells no. 1 and no. 2; Pawtucket wells no. 2, 

3, and 4; and Lincoln Lonsdale well no. 4— were 

simulated with a constant pumping rate to illustrate 

the effect different aquifer properties and distance 

have on depletion. After 30 days of simulated 

pumping, relative streamflow depletions for the six 

wells were 90, 91, 65, 71, 59, and 82 percent of 

withdrawals, respectively.

A long-term hydrologic budget was calculated 

for the period 1957–99. Water-withdrawal and 

wastewater-return-flow data used in the hydrologic 

budget were from 1995 through 1999. Total inflows 

and outflows for the entire study area were 

815.83 Mgal/d. Precipitation, streamflow from 

upstream subbasins, and wastewater-return flow 

constituted 55, 43, and 2 percent of the total inflow, 

respectively. Evapotranspiration, streamflow out of 

the basin, and withdrawals constituted 24, 72, and 4 

percent of the total outflow, respectively.

INTRODUCTION

The Rhode Island Water Resources Board 

(RIWRB), a state government board charged with 

managing the proper development, utilization, and 

conservation of water resources, faces increased and 

competing demands for the water resources of Rhode 

Island. The primary responsibility of the RIWRB is to 

ensure that sufficient water supply is available for present 

and future generations by apportioning water to all areas 

of the state, if necessary (Rhode Island Water Resources 

Board, 2002). Accurate information on water-use patterns 

and their effects on water availability is needed for an 

optimal allocation of the State’s water resources. For these 

reasons, the RIWRB decided to evaluate water use and 

availability within each of the State’s major basins. In 

2000, the U.S. Geological Survey (USGS) began a study 

in cooperation with the RIWRB to collect, organize, and 

analyze water-use and water-availability data for the 

Blackstone River basin.

Purpose and Scope

This report discusses water-use data for six 

subbasins of the Blackstone River basin in northern 

Rhode Island and south-central Massachusetts from 1995 

through 1999. The water-use data presented includes 

withdrawals for public- and self-supply use, aggregate 

water-use by category (domestic, commercial, industrial, 

agricultural, consumptive, and non-account, and electric 

power generation), and wastewater-return flows [at 

National Pollution Discharge Elimination System 

(NPDES) surface-water-discharge sites and onsite septic]. 

Imports and exports of water and wastewater were 

calculated for each of the six subbasins and the study area 

as a whole from metered withdrawals, estimated use, and 

return flows. Base flow was calculated for the period 

1957–99 by the computer program PART (Rutledge, 

1998) on the basis of long-term streamflow-gaging data 

from the Branch River at Forestdale (01111500). Baseflow estimates at the 75th, 50th, and 25th percentiles for 

the low-flow period (June, July, August, and September) 

were combined with safe-yield estimates to calculate 

water availability for each subbasin and the study area as a 

whole. Withdrawals were then divided by availability 

estimates to calculate basin stress for each subbasin and 

the study area for the low-flow period. In addition, streamdepletion effects were simulated for six public-supply 
Introduction 3

wells by using the computer program STRMDEPL 

(Barlow, 2000). A long-term hydrologic budget for the 

study area was also calculated for the period 1957–99. In 

addition, a water-use analysis for one minor civil division, 

Cumberland, Rhode Island, is appended to illustrate the 

types of information retrievals that can be made from the 

New England Water Use Data System (NEWUDS).

Previous Investigations

Several previous water-use studies have been 

conducted by the USGS to evaluate water use in Rhode 

Island and the Blackstone River basin. These reports 

contain information on water withdrawals and use for 

major basins in Rhode Island (Craft and others, 1990), and 

water use within the town of Cumberland, Rhode Island 

(Horn and others, 1994). 

In addition, reports published by the Rhode 

Island Department of Administration-—Division of 

Planning (RIDOA) document total water use by type. 

Water use for Rhode Island by public-supply, self-supply, 

and irrigation is reported in Rhode Island Department of 

Administration-—Division of Planning (1988). Total 

freshwater withdrawals, water use, and management of 

supply and demand are described in Rhode Island 

Department of Administration—Division of Planning 

(1991).

Several studies have analyzed ground-water 

resources in the Blackstone River basin in Rhode Island 

(Frimpter, 1974; Johnston and Dickerman, 1974a and 

1974b, and Lang, 1961). These reports provide 

information on precipitation, streamflows, recharge, and 

aquifer yield within the basin. The studies by Johnston 

and Dickerman split the Blackstone River basin into two 

sections, the Branch River basin (1974a), and the 

Blackstone River drainage area (1974b). In the Branch 

River basin report Johnston and Dickerman (1974a) 

calculated sustained yields for four different aquifer areas 

by mathematically simulating pumping from wells in a 

model of the aquifer area. Results indicated that sustained 

yields of 5.5, 3.4, 1.6, and 1.3 Mgal/d might be obtained 

from the sand and gravel aquifers near Slatersville, 

Oakland, Harrisville, and Chepachet, Rhode Island, 

respectively. In the Blackstone River report Johnston and 

Dickerman (1974b) modeled and simulated sustained 

yields from five separate areas within the basin. Total 

sustained yield for the five areas was 30 Mgal/d including 

sections of the Moshassuck and Ten Mile basins. 

Description of the Study Area

The Blackstone River basin in northern Rhode 

Island and south-central Massachusetts includes an area of 

approximately 475 mi2. The study area for this report, 

herein referred to as the lower Blackstone River basin, is 

198 mi2 and includes six subbasins, five of which span the 

Rhode Island–Massachusetts border. These subbasins 

include: the Clear River subbasin, the Chepachet River 

subbasin, the Branch River subbasin, the West River 

subbasin, the Peters River subbasin, and the Abbott Run 

subbasin (fig. 1). 

The lower Blackstone River basin in Rhode Island 

encompasses several communities: Cumberland, 

Woonsocket, and sections of Burrillville, Central Falls, 

Glocester, Lincoln, North Smithfield, Pawtucket, and 

Smithfield. In Massachusetts, the lower Blackstone River 

basin includes sections of Attleboro, Bellingham, 

Blackstone, Douglas, Franklin, Millville, North Attleboro, 

Plainville, Uxbridge, and Wrentham. The towns of 

Cumberland, Woonsocket, Blackstone, Millville, and 

Uxbridge are entirely within the Blackstone River basin; 

however, only Cumberland is completely within the lower 

Blackstone River basin. 

Sand and Gravel Aquifers and 

Ground-Water Reservoirs

Sand and gravel aquifers in Rhode Island are 

irregularly shaped deposits that occur primarily in stream 

valleys (fig. 2). There are six ground-water reservoirs 

within the lower Blackstone River basin in Rhode Island; 

these ground-water reservoirs have been defined by the 

RIWRB as areas underlain by sand and gravel with 

transmissivity equal to or greater than 4,000 ft2/d and a 

saturated thickness equal to or greater than 40 ft (W.B. 

Allen, Rhode Island Water Resources Board, written 

commun., 1978). The six ground-water reservoirs are: the 

Lower Blackstone, Slatersville, Blackstone, Abbott Run, 

Upper Branch, and Lower Branch Blackstone. Johnston 

and Dickerman (1974a and 1974b) reported that the 

stratified thickness of the sand and gravel aquifer in the 

lower Blackstone River basin in Rhode Island ranged 

from 10 to greater than 120 ft, and transmissivity ranged 

from 5,000 to 40,000 ft2/d.
4 Estimated Water Use and Availability in the Lower Blackstone River Basin, Northern Rhode Island and South-Central Massachusetts, 1995–99

0 10 20 30 40 50 KILOMETERS

0 10 20 30 40 50 MILES BLACKSTONE

42o00'

41o

30'

70o

00'

73o

30' 73o

00' 72o

30' 72o

00' 71o

30'

71o

00' 70o

30'

42o

30'

SUBBASIN BOUNDARY

RIVERS

EXPLANATION

STUDY AREA

PONDS, LAKES, 

 AND RESERVOIRS

BLACKSTONE RIVER 

 BASIN BOUNDARY

STATE BOUNDARY

Clear River 

Subbasin

Chepachet 

River 

Subbasin

Branch River 

Subbasin

West River Subbasin

Peters 

River

Subbasin

Abbott

Run 

Subbasin

B LACKSTONE

RIVE R

BLACKSTONE

RIVER

BL ACKSTONE

RIVER

MASSACHUSETTS

RHODE ISLAND

WORCESTER

OXFORD

WOONSOCKET

BURRILLVILLE

GLOCESTER

SMITHFIELD

NORTH SMITHFIELD

LINCOLN

CUMBERLAND

CENTRAL FALLS

PAWTUCKET

ATTLEBORO

NORTH

ATTLEBORO

PLAINVILLE

WRENTHAM

FRANKLIN

BELLINGHAM

BLACKSTONE

MILLVILLE

UXBRIDGE

WEBSTER

DOUGLAS

SUTTON NORTHBRIDGE

MENDON

HOPEDALE

MILFORD

UPTON

HOPKINTON

GRAFTON

MILLBURY

WESTBOROUGH

AUBURN

SHREWSBURY

PAXTON

HOLDEN

BOYLSTON

WEST

BOYLSTON

LEICESTER

MASSACHUSETTS

RHODE ISLAND

MILES

71o

48' 71o

36' 71o

24'

42o

24'

42o

12'

42o

00'

0 5 10

0 5 10 KILOMETERS

41o

48'

Base from the National Resource Conservation Service

12-digit HUC base map, 1:24,000, 2001

Projection: Rhode Island State Plane

Figure 1. Blackstone River basin and study area, northern Rhode Island and south-central Massachusetts.
Introduction 5

0 5 10 KILOMETERS

0 5 10 MILES

71o48' 71o

42' 71o

36' 71o

30' 71o

24'

42o

06'

42o

00'

41o54'

EXPLANATION

LAKES, PONDS, AND RESERVOIRS

TILL

GROUND-WATER RESERVOIRS AND NAMES

SAND AND GRAVEL DEPOSITS

Upper Branch Upper Branch

Slatersville Slatersville

Lower Blackstone Lower Blackstone

Blackstone Blackstone

Upper Branch

Slatersville

Lower Blackstone

BLACKSTONE RIVER

Lower Branch Lower Branch

Blackstone Blackstone

Lower Branch

Blackstone

Abbott Run Abbott Run bbott Run

RIVERS AND STREAMS

LOWER BLACKSTONE BASIN BOUNDARY

Glacial geology base map from the Rhode Island 

Geographic Information System, 1:24,000, (1989);

Surficial geology base map from the Massachusetts 

Geographic Information System, 1:125,000, (1999);

Projection: Rhode Island State Plane

Blackstone

Figure 2. Distribution of sand and gravel and till deposits, and ground-water reservoirs as named by the Rhode Island Water Resources Board (Rhode Island 

portion only) in the lower Blackstone River basin, northern Rhode Island and south-central Massachusetts.
6 Estimated Water Use and Availability in the Lower Blackstone River Basin, Northern Rhode Island and South-Central Massachusetts, 1995–99

Surface Water

The 14-digit Hydrologic Unit Code (HUC) data 

layer from the Natural Resource Conservation Service 

(NRCS) (Reed Simms, GIS specialist U.S. Department of 

Agriculture-—Natural Resource Conservation Service, 

written commun., 2001) was used to define the subbasin 

boundaries used in this report. Streamflow-gaging stations 

in the lower Blackstone River basin (fig. 3) include the 

Nipmuc River near Harrisville, RI (01111300), the 

Branch River at Forestdale (01111500), and the 

Blackstone River at Woonsocket (01112500). Ungaged 

sections of the lower Blackstone River basin include the 

Peters River subbasin south of the Woonsocket 

streamflow-gaging station, and the Abbott Run subbasin.

71o48' 71o

42' 71o

36' 71o

30' 71o

24'

42o

06'

42o

00'

41o

54'

0 5 10 MILES

0 5 10 KILOMETERS

Diamond Hill

Reservoir

Abbott Run

Reservoir

Crookfall Brook

Reservoir #3

 Sneech

 Pond

Clear River 

Subbasin

Chepachet 

River 

Subbasin

Branch River 

Subbasin

West River Subbasin Peters 

River 

Subbasin

Abbott

Run 

Subbasin

01111300

01111500

01112500

Base from the National Resource Conservation Service

12-digit HUC base map, 1:24,000, (2001)

Projection: Rhode Island State Plane

Crookfall Brook

Reservoir #1

EXPLANATION

LAKES, PONDS, AND RESERVOIRS

RIVERS AND STREAMS

SUBBASIN BOUNDARIES

STREAMFLOW-GAGING STATION AND NUMBER

Harris

 Pond

01111500

Robin 

Hollow

Reservoir

Happy 

Hollow

Reservoir

Clear Rive r

Chepachet River Branch

River

Abbo t Run

Blackstone River

Clear Rive r

Chepachet River Branch

River

Abbo t Run

Blackstone River

Nipmuc Ri verNip

muc Ri ver

Figure 3. Streamflow-gaging stations and public-supply reservoirs within the lower Blackstone River basin, northern Rhode Island and south-central 

Massachusetts.
Introduction 7

The largest tributary to the main stem of the 

Blackstone River in Rhode Island is the Branch River. The 

Branch River flows in a northeastern direction to its 

confluence with the Blackstone River in the West River 

subbasin (fig. 3). The two tributaries to the Branch are the 

Clear River and the Chepachet River. The Clear River 

flows east to its confluence with the Branch, and the 

Chepachet River flows in a northeastern direction. Abbott 

Run in the Abbott Run subbasin flows in a southern 

direction east of the Blackstone River and joins with the 

main stem of the Blackstone just north of its confluence 

with the Providence and Seekonk Rivers. 

Four surface-water reservoirs and one pond in the 

lower Blackstone River basin are used for public supply 

(fig. 3). These include the Diamond Hill and Abbott Run 

Reservoirs of the Pawtucket Water Supply Board (WSB); 

Crookfall Brook Reservoirs no. 1 and no. 3 of the 

Woonsocket Water Division (WDIV); and Sneech Pond 

of the Cumberland Water Department (WD). 

Climate

Rainfall records from the National Weather Service 

(NWS) rain gage in Woonsocket, Rhode Island, indicate 

that the average annual rainfall for the lower Blackstone 

River basin was 47.9 in/yr for the period 1957–99 (Carol 

LaRiviere, Assistant Superintendent for the Woonsocket 

Water Division, written commun., 2002). Long-term 

average monthly rainfall for this 42-year period ranged 

from 3.5 to 4.6 in/mo with the low in June and the high in 

November. The lowest measured monthly rainfall was 

0.4 in., in October 1994. The highest measured monthly 

rainfall was 12.12 in., in June 1982. For the 5-year period 

of study, 1995–99, the average annual rainfall at the 

Woonsocket gage was 51.5 in/yr, which is 3.6 in/yr greater 

than the average annual rainfall for the period 1957–99. 

For the 5-year study period, average monthly rainfall at 

the Woonsocket gage ranged from 3.1 to 6.0 in/mo, with 

the low in August and the high in January. The lowest 

measured rainfall for this period was 0.5 in. in June 1999 

and the highest measured monthly rainfall was 12.1 in. in 

June 1998. 

A climatological station operated by the NWS 

at T. F. Green Airport in Warwick, RI, is about 5 mi from 

the mouth of the lower Blackstone River basin. This 

station collects temperature and rainfall data, but the 

Woonsocket rain gage within the lower Blackstone River 

basin does not collect temperature data. The Northeast 

Regional Climate Center at Cornell University publishes 

long-term climate data on their web site in 30-year 

increments (Cornell University, 2001); the latest available 

record is from 1961–90. Mean monthly temperatures at 

Warwick for this period ranged from 27.9°F in January to 

72.7°F in July, with an annual mean of 50.4°F. Mean 

monthly precipitation at Warwick ranged from 3.18 in. in 

July to 4.11 in. in April, with an annual total of 45.53 in. 

During the same period, 1961–90, mean monthly 

precipitation at Woonsocket ranged from 3.42 in. in July 

to 4.19 in. in April, with an annual total of 47.4 in. Mean 

annual precipitation at Warwick was 96 percent of mean 

annual precipitation at Woonsocket.

Population

The 5-year average population for the lower 

Blackstone River basin was estimated to be 149,651 

persons (table 1). The population within the lower 

Blackstone River basin generally decreases from east to 

west. The most highly populated subbasin is the Peters 

River subbasin with an estimated population of 70,641 

persons, or 47.2 percent of the study-area population 

(table 1 and fig. 4). The next most populated subbasin is 

the West River subbasin with 31,862 persons or 21.3 

percent, followed by the Abbott Run subbasin with 21,750 

persons or 14.5 percent, the Clear River subbasin with 

12,316 persons or 8.2 percent, the Branch River subbasin 

with 8,392 persons or 5.6 percent, and the Chepachet 

River subbasin with 4,689 persons or 3.1 percent. The 

lower Blackstone River basin includes the cities of 

Woonsocket and Pawtucket, with 5-year average 

populations of about 41,800 and 68,300, respectively 

(table 2). These cities and other suburban towns in the 

eastern subbasins of the lower Blackstone River basin 

have higher populations than towns in the western 

subbasins (fig. 4).

Land Use and Land Cover

Land within the lower Blackstone River basin is 

predominately forested (55.8 percent). The next largest 

land-use category is residential (18.4 percent), followed 

by wetlands (7.4 percent), agricultural (5.4 percent), water 

(3.3 percent), commercial (1.5 percent), industrial (1.0 

percent), and transportation (1.0 percent). Other land-use 

categories compose the remaining 6.2 percent of the lower 

Blackstone River basin.
8 Estimated Water Use and Availability in the Lower Blackstone River Basin, Northern Rhode Island and South-Central Massachusetts, 1995–99

Table 1. Land area and 5-year average population for each minor civil division within the lower Blackstone River basin, northern Rhode Island and southcentral Massachusetts, 1995–99 

[Data sources: area and population estimates for subbasins were made by using Rhode Island Geographic Information System and Massachusetts Geographic 

Information System town datalayers, National Resource Conservation Service 14-digit Hydrologic Unit Code datalayer for New England, and U.S. Census 

Bureau census blocks and statistics updated for the period 1995–99 by using population figures from University of Massachusetts (2000) and Rhode Island 

Economic Development Corporation (2000). mi2, square mile]

Minor civil division Land area

(mi2)

5-year average

population

Chepachet River subbasin

Burrillville 5.03 1,774

Glocester 16.24 2,915

Subtotal ..................... 21.27 4,689

Clear River subbasin

Burrillville 29.02 9,518

Glocester 5.06 758

Douglas 9.70 1,692

Uxbridge 1.68 348

Subtotal ..................... 45.46 12,316

Branch River subbasin

Burrillville 12.67 3,624

Glocester 3.37 403

North Smithfield 9.43 4,131

Smithfield .21 38

Millville .19 95

Uxbridge .48 101

Subtotal ..................... 26.35 8,392

West River subbasin

Burrillville 1.77 479

North Smithfield 5.62 3,920

Woonsocket 2.73 18,703

Blackstone 4.37 3,234

Douglas 2.02 351

Millville 4.21 2,095

Uxbridge 13.92 3,080

Subtotal ..................... 34.64 31,862

Peters River subbasin

Central Falls .75 8,338

Cumberland 12.38 15,848

Lincoln 7.02 9,950

North Smithfield 5.27 1,117

Pawtucket .55 5,667

Smithfield 1.43 497

Woonsocket 4.60 18,889

Attleboro .91 1,864

Peters River subbasin—Continued

Bellingham 7.22 6,303

Blackstone .09 63

Franklin 1.75 1,614

Wrentham 1.14 491

Subtotal ..................... 43.11 70,641

Abbott Run subbasin

Cumberland 15.78 13,877

Attleboro .30 613

Franklin .75 660

N. Attleboro 3.91 3,431

Plainville 1.60 1,020

Wrentham 4.98 2,149

Subtotal ..................... 27.32 21,750

Lower Blackstone River basin

Burrillville 48.5 15,396

Central Falls .8 8,338

Cumberland 28.2 29,725

Glocester 24.7 4,076

Lincoln 7.0 9,950

North Smithfield 20.3 9,168

Pawtucket .6 5,667

Smithfield 1.6 535

Woonsocket 7.3 37,592

Attleboro 1.21 2,477

Bellingham 7.2 6,303

Blackstone 4.5 3,297

Douglas 11.7 2,043

Franklin 2.5 2,274

Millville 4.4 2,190

N. Attleboro 3.9 3,431

Plainville 1.6 1,020

Uxbridge 16.1 3,529

Wrentham 6.1 2,640

Total ......................... 198.2 149,651

Minor civil division Land area

(mi2)

5-year average

population
Introduction 9

71o42' 71o

36' 71o

30' 71o

24' 71o

18'

42o

06'

42o

00'

41o

54'

0 5 10 MILES

0 5 10 KILOMETERS

less than 5,000

5,001 to 10,000

10,001 to 20,000

20,001 to 35,000

35,001 to 70,000

EXPLANATION

POPULATION BY TOWN POPULATION BY SUBBASIN

4,690 Chepachet River

8,390 Branch River

12,320 Clear River

21,750 Abbott Run

31,860 West River

70,640 Peters River

TOWN BOUNDARIES SUBBASIN BOUNDARIES

Base from the National Resource Conservation Service

12-digit HUC base map, 1:24,000, (2001)

Projection: Rhode Island State Plane 

TOWN NAMES SUBBASIN NAMES

Clear River Subbasin Clear River Subbasin

Chepachet River Chepachet River 

Subbasin Subbasin

Branch River Subbasin Branch River Subbasin

West River Subbasin West River Subbasin

Peters River Peters River

Subbasin Subbasin

Abbott Run Abbott Run 

Subbasin Subbasin

Clear River Subbasin

Chepachet River 

Subbasin

Branch River Subbasin

West River Subbasin

Peters River

Subbasin

Abbott Run 

Subbasin

Branch River Subbasin

DOUGLAS DOUGLAS

UXBRIDGE UXBRIDGE

MILLVILLE MILLVILLE

BLACKSTONE BLACKSTONE

BELLINGHAM BELLINGHAM FRANKLIN FRANKLIN

WRENTHAM WRENTHAM

PLAINVILLE PLAINVILLE

NORTH 

ATTLEBORO ATTLEBORO

ATTLEBORO ATTLEBORO

WOONSOCKET WOONSOCKET

CUMBERLAND CUMBERLAND

SMITHFIELD SMITHFIELD LINCOLN LINCOLN

NORTH 

SMITHFIELD SMITHFIELD

GLOCESTER GLOCESTER

BURRILLVILLE BURRILLVILLE

CENTRAL CENTRAL

FALLS

PAWTUCKET PAWTUCKET

DOUGLAS

UXBRIDGE

MILLVILLE

BLACKSTONE

BELLINGHAM FRANKLIN

WRENTHAM

PLAINVILLE

NORTH 

ATTLEBORO

ATTLEBORO

WOONSOCKET

CUMBERLAND

SMITHFIELD LINCOLN

NORTH 

SMITHFIELD

GLOCESTER

BURRILLVILLE

CENTRAL

FALLS

PAWTUCKET

SMITHFIELD

MASSACHUSETTS

RHODE ISLAND

Figure 4. Estimated population by town and subbasin in the lower Blackstone River basin, northern Rhode Island and south-central Massachusetts, 1995–99.
10 Estimated Water Use and Availability in the Lower Blackstone River Basin, Northern Rhode Island and South-Central Massachusetts, 1995–99 Table 2. Land area and population for minor civil divisions, water suppliers (major and minor), and wastewater-treatment facilities serving those municipalities within the lower Blackstone River basin, northern Rhode Island and south-central Massachusetts, 1995–99—Continued Minor civil division Total land area of MCD (mi2

)

Land area

within

study area

(mi2)

5-year average 

population of 

MCD (1995–99)

Population of 

MCD within 

study area

Major/minor supplier

Population

on public 

supply

Wastewater-treatment facility

Population

on public 

disposal

Burrillville 57.1 48.5 15,900 15,400 Pascoag FD 3,300 Burrillville WWTF 7,000

Harrisville FD 2,700Mohegan Water Association 50Glendale Water Association 120Oakland Water Association 250Maplehill Mobile Home Park 530Nasonville WDI 130

MCD total ................................................................................................................................................................ 7,100 7,000

Central Falls, RI 1.3 0.8 16,600 8,300 Pawtucket WSB 16,600 NBC–Bucklin Point WWTF 16,100

MCD total ................................................................................................................................................................ 16,600 16,100

Cumberland, RI 28.2 28.2 29,700 29,700 Cumberland WD 20,500 NBC–Bucklin Point 14,200

Pawtucket WSB 8,500

MCD total ................................................................................................................................................................ 29,000 14,200

Glocester, RI 56.8 24.7 9,300 4,100 Hemlock Estates 200 0

Davis Mobile Home Park 150Brandy Acres 150Laurel Crest Housing 40

MCD total ................................................................................................................................................................ 540 -- 0

Lincoln, RI 19 7 18,700 9,900 Lincoln WC1 17,800 NBC–Bucklin Point WWTF 12,700

MCD total ................................................................................................................................................................ 17,800 12,700

North Smithfield, RI 24.7 20.3 10,000 9,200 Woonsocket WDIV 20 Woonsocket WWTF 2,900

Slatersville Public Supply 1,440Deerfield Commons 90

MCD total ................................................................................................................................................................ 1,550 2,900

Pawtucket, RI 8.9 0.6 68,300 5,700 Pawtucket WSB 68,300 NBC–Bucklin Point 67,200

MCD total ................................................................................................................................................................ 68,300 67,200

Smithfield, RI 27.8 1.6 18,900 500 Smithfield WSB2 8,200 Smithfield WWTF 13,300

East Smithfield WDI3 7,500Greenville WDI3 7,900

MCD total ................................................................................................................................................................ 23,6004 13,300

Table 2. Land area and population for minor civil divisions, water suppliers (major and minor), and wastewater-treatment facilities serving those municipalities within the lower Blackstone River basin, 

northern Rhode Island and south-central Massachusetts, 1995–99

[5-year average population of MCD (1995–99): The 5-year average population for towns in the Blackstone River basin in Rhode Island and Massachusetts were made from population projections 

available from the Rhode Island Economic Development Corporation (2000) and the University of Massachusetts (2000). Major/minor supplier: Major suppliers are in bold. Note: Service populations 

for suppliers and wastewater-treatment facilities are the total for the minor civil division/municipality. Populations: are rounded to the nearest 100 persons (except for minor suppliers); DPW, Department 

of Public Works; FD, Fire District; MCD, minor civil division; NBC, Narragansett Bay Commission; PCD, Pollution Control District; WC, Water Commission; WD, Water Department; WDI, Water 

District; WDIV, Water Division; WSB, Water Supply Board; WSD, Water and Sewer Department; WWTF, Wastewater-Treatment Facility; mi2, square miles; --, no public disposal]
Introduction 11

1About 95, 2, and 3 percent of the water distributed by the Lincoln Water Department for the study period was from the Providence Water Supply Board, the Woonsocket Water Division, and 

Lincoln Lonsdale well no. 4.

2Only the Smithfield Water Supply Board serves residents within the Blackstone River basin; the other two suppliers serve residents outside the lower Blackstone River basin.3The East Smithfield and Greenville Water Districts do not serve people within the lower Blackstone River basin.4Population on public supply is greater than the population of town because the three public-supply populations include people outside of the town of Smithfield.

Woonsocket, RI 7.9 7.3 41,800 37,600 Woonsocket WDIV 41,800 Woonsocket WWTF 40,300

MCD total ................................................................................................................................................................ 41,800 40,300

Attleboro, MA 28.3 1.2 39,300 2,500 Attleboro WD 38,800 Attleboro WWTF 26,700

MCD total ................................................................................................................................................................ 38,800 26,700

Bellingham, MA 18.9 7.2 15,700 6,300 Bellingham DPW 14,600 Woonsocket WWTF 500

Charles River PCD 1,900

MCD total ................................................................................................................................................................ 14,600 2,400

Blackstone, MA 11.3 4.5 8,300 3,300 Blackstone WD 7,300 Woonsocket WWTF 2,600

MCD total ................................................................................................................................................................ 7,300 2,600

Douglas, MA 38.1 11.7 6,600 2,000 Douglas WSD 3,100 Douglas WWTF 2,000

MCD total ................................................................................................................................................................ 3,100 2,000

Franklin, MA 27 2.5 27,600 2,300 Franklin DPW 24,900 Charles River PCD 19,200

MCD total ................................................................................................................................................................ 24,900 19,200

Millville, MA 5 4.4 2,500 2,200 Uxbridge WD 100 0

MCD total ................................................................................................................................................................ 100 -- 0

North Attleboro, MA 19 3.9 25,500 3,400 North Attleboro WD 24,100 North Attleboro WWTF 16,600

MCD total ................................................................................................................................................................ 24,100 16,600

Plainville, MA 11.6 1.6 7,400 1,000 Plainville WD 7,000 North Attleboro WWTF 3,600

MCD total ................................................................................................................................................................ 7,000 3,600

Uxbridge, MA 30.1 16.1 11,200 3,500 Uxbridge WD 9,100 Uxbridge WWTF 6,500

MCD total ................................................................................................................................................................ 9,100 6,500

Wrentham, MA 22.9 6.1 10,100 2,600 Wrentham WDIV 8,100 0

MCD total ................................................................................................................................................................ 8,100 -- 0

Table 2. Land area and population for minor civil divisions, water suppliers (major and minor), and wastewater-treatment facilities serving those municipalities within the lower Blackstone River basin, 

northern Rhode Island and south-central Massachusetts, 1995–99—Continued

Minor civil division

Total land 

area of MCD

(mi2)

Land area

within

study area

(mi2)

5-year average 

population of 

MCD (1995–99)

Population of 

MCD within 

study area

Major/minor supplier

Population

on public 

supply

Wastewater-treatment facility

Population

on public 

disposal
12 Estimated Water Use and Availability in the Lower Blackstone River Basin, Northern Rhode Island and South-Central Massachusetts, 1995–99

Land use within the lower Blackstone River basin 

differs from east to west (fig. 5). As of 1995, the western 

subbasins (the Chepachet, Branch, Clear, and West River 

subbasins) had lower percentages of residential land 

use (ranging from 10.3 to 19.8 percent) and higher 

percentages of forested land use (ranging from 57.6 to 

72.3 percent). In contrast, the eastern subbasins (the 

Peters River and Abbott Run subbasins) had higher 

percentages of residential land use (26.0 and 25.1 percent, 

respectively), and lower percentages of forested land use 

(38.1 and 45.5 percent, respectively).

EXPLANATION

FOREST

RESIDENTIAL

WETLAND

AGRICULTURAL

WATER

COMMERCIAL

INDUSTRIAL

TRANSPORTATION

OTHER

SUBBASIN BOUNDARY

Base from the Rhode Island Geographic Information System and

the Massachusetts Geographic Information System

Land use base map, 1:24,000, (1995) and 

Land use base map, 1:25,000, (1995)

Projection: Rhode Island State Plane

0 5 10 MILES

0 5 10 KILOMETERS

71o48' 71o

42' 71o

36' 71o

30' 71o

24'

42o

00'

41o

54'

Clear River 

Subbasin

Chepachet 

River 

Subbasin

Branch River 

Subbasin

West River Subbasin

Peters 

River 

Subbasin

Abbott

Run 

Subbasin

Figure 5. Land use in 1995 in the lower Blackstone River basin, northern Rhode Island and south-central Massachusetts.
Water Use 13

The percentages of commercial, industrial, and 

agricultural land use did not vary greatly from the western 

to eastern subbasins. For the six subbasins, commercial 

land use ranged from 0.3 to 4.0 percent, industrial land use 

ranged from 0.1 to 2.7 percent, and agricultural land use 

ranged from 3.2 to 10.0 percent.

Acknowledgments

The author thanks the numerous municipal, State, 

and Federal agencies that provided data or assisted in the 

collection of data for this report: the Cumberland Water 

Department, the Pawtucket Water Supply Board, the 

Lincoln Water Department, the Woonsocket Water 

Division, the Slatersville Public Supply, the Smithfield 

Water Supply Board, the East Smithfield Water District, 

the Greenville Water District, the Harrisville Fire District, 

the Pascoag Fire District, the Massachusetts Department 

of Environmental Protection, the RIWRB, the Rhode 

Island Department of Health, the Rhode Island 

Department of Environmental Management (RIDEM), 

the RIDOA, and the U.S. Environmental Protection 

Agency. The author thanks the following U.S. Geological 

Survey employees: Paul M. Barlow for assistance with the 

computer program STRMDEPL, James B. Campbell for 

coordinating meetings and presentations, Kathryn M. 

Hess for reviewing the methods used in calculating 

ground-water availability, Stephen P. Garabedian for 

technical guidance and review, Albert T. Rutledge for 

assistance with the computer programs RECESS and 

PART, and Timothy P. Thies and Emily C. Wild for data 

collection.

WATER USE

The database used to store and retrieve water-use 

data for this report was NEWUDS, which is a Microsoft 

Access database developed by the U.S. Geological Survey 

for the storage of water-use information for New England. 

The NEWUDS database design and instructions for use 

are explained in Tessler (2002) and Horn (2002), 

respectively. The NEWUDS database gives waterresource managers access to accurate, comprehensive, and 

comparable water-use data. Withdrawals, use, and return 

flows tracked within the NEWUDS database can be used 

to determine current supply and demand, facilitate 

prediction of future demands, develop plans to ensure 

sufficient supplies for future use, and monitor the 

effectiveness of conservation measures (Horn and others, 

1994). 

Data for the following water-use processes 

were collected for the period 1995-99 and entered 

into NEWUDS at the town and subbasin levels: 

(1) withdrawals for public and self-supply, (2) treatment, 

(3) distribution and conveyance, (4) consumptive use, 

(5) non-consumptive water use, and (6) return flow. All 

six processes are represented as sites within the database: 

(1) wells and intakes, (2) potable-water and wastewater 

treatment plants, (3) local and regional distribution, (4) 

consumptive use, (5) aggregate and site-specific uses, and 

(6) local and regional wastewater collection; aggregate 

self-disposal (on-site septic); and NPDES permitted sites 

(including municipal wastewater-treatment facilities and 

commercial and industrial sites). 

To represent the connections among the water-use 

processes, the NEWUDS database links sites to one 

another through a conveyance table. The quantity of water 

conveyed from site to site is entered into the Rate and 

Transactions tables within the database. The information 

stored within this database can be retrieved according to 

several variables, including water supplier, specific well or 

intake, and aggregate use. 

Water Supply

The political subdivisions within the lower 

Blackstone River basin provide the basic unit by 

which water-use data for the study were initially 

collected and analyzed. The Minor Civil Division (MCD) 

is the smallest unit for which water use data were 

available for collection. Data were collected from the 

water suppliers and wastewater-collection agencies 

serving each MCD (table 2). Geographic distribution of 

total population and population served by public water 

and wastewater were estimated from data gathered from 

census block groups and the 1990 Census Summary Tape 

File 3 (STF3) available from the U.S. Census Bureau 

(U.S. Census Bureau, 2001a and 2001b) and town 

population estimates from 1995 through 1999 (Rhode 

Island Economic Development Corporation, 2000a and 

University of Massachusetts, Amherst, 2000) (table 3). 
14 Estimated Water Use and Availability in the Lower Blackstone River Basin, Northern Rhode Island and South-Central Massachusetts, 1995–99

Table 3. Total 5-year average population and population served by public-water systems and public-wastewater systems by minor civil division in the lower 

Blackstone River basin, northern Rhode Island and south-central Massachusetts, 1995–99—Continued

Minor civil division Estimated total 

population

Public supply Public disposal

Number of

individuals

Percent of total 

population

Number of 

individuals

Percent of total 

population

Lower Blackstone River basin

Chepachet River subbasin

Burrillville 1,774 710 -- 713 --

Glocester 2,915 202 -- 0 --

Subtotal ............................................. 4,689 912 19.4 713 15.1

Clear River subbasin

Burrillville 9,518 5,879 -- 5,905 --

Glocester 758 51 -- 0 --

Douglas 1,692 796 -- 508 --

Uxbridge 348 194 -- 122 --

Subtotal ............................................. 12,316 6,920 56.2 6,535 53.1

Branch River subbasin

Burrillville 3,624 444 -- 352 --

Glocester 403 0 -- 0 --

North Smithfield 4,131 251 -- 750 --

Smithfield 38 20 -- 13 --

Millville 95 0 -- 0 --

Uxbridge 101 55 -- 35 --

Subtotal ............................................. 8,392 770 9.2 1,150 13.7

West River subbasin

Burrillville 479 51 -- 22 --

North Smithfield 3,920 365 -- 2,036 --

Woonsocket 18,703 18,703 -- 18,131 --

Blackstone 3,234 2,843 -- 1,003 --

Douglas 351 166 -- 105 --

Millville 2,095 0 -- 0 --

Uxbridge 3,080 1,824 -- 1,169 --

Subtotal ............................................. 31,8602 23,952 75.2 22,466 70.5

Peters River subbasin

Central Falls 8,338 8,338 -- 7,991 --

Cumberland 15,848 14,879 -- 9,826 --

Lincoln 9,950 9,937 -- 7,838 --

North Smithfield 1,117 15 -- 122 --

Pawtucket 5,667 5,667 -- 5,654 --

Smithfield 497 336 -- 224 --

Woonsocket 18,889 18,839 -- 18,005 --

Attleboro 1,864 1,830 -- 1,299 --

Bellingham 6,303 5,697 -- 4801 --

Blackstone 63 56 -- 20 --

Franklin 1,614 1,442 -- 1,209 --

Wrentham 491 418 -- 0 --

Subtotal ............................................. 70,641 68,562 97.1 52,695 74.6

Table 3. Total 5-year average population and population served by public-water systems and public-wastewater systems by minor civil division in the lower 

Blackstone River basin, northern Rhode Island and south-central Massachusetts, 1995–99

[Data sources: Population estimates for total, public-supply, and public-disposal for subbasins were made using the Rhode Island Geographic Information 

System and Massachusetts Geographic Information System town datalayers, the Natural Resource Conservation Service 14-digit Hydrologic Uunit Code 

datalayer for New England, and the U.S. Census Bureau census blocks and statistics updated for the period 1995–99 by using total town population figures 

from University of Massachusetts (2000) and Rhode Island Economic Development Corporation (2000). --, not applicable]
Water Use 15

Abbott Run subbasin

Cumberland 13,877 12,117 -- 4,353 --

Attleboro 613 601 -- 427 --

Franklin 660 563 -- 453 --

North Attleboro 3,431 3,105 -- 1,150 --

Plainville 1,020 965 -- 496 --

Wrentham 2,149 1,829 -- 0 --

Subtotal ............................................. 21,750 20,062 92.2 7,239 33.3

Total of the lower Blackstone 

River basin ........................................ 149,651 119,206 79.7 90,828 60.7

Table 3. Total 5-year average population and population served by public-water systems and public-wastewater systems by minor civil division in the lower 

Blackstone River basin, northern Rhode Island and south-central Massachusetts, 1995–99—Continued

Minor civil division Estimated total 

population

Public supply Public disposal

Number of

individuals

Percent of total 

population

Number of 

individuals

Percent of total 

population

Site-specific withdrawals were collected for community 

and non-community wells. Site-specific return flows 

were collected for NPDES permitted discharges, 

including those from industrial and commercial users 

and wastewater-treatment facilities. Water-use 

data were collected for 19 MCDs in Rhode Island and 

Massachusetts and later disaggregated to the subbasin 

level on the basis of three data layers: the 14-digit HUCs, 

Census Blocks, and land use. The 14-digit HUCs were 

obtained from the NRCS (Reed Simms, GIS specialist 

U.S. Department of Agriculture—Natural Resource 

Conservation Service, written commun., 2001), the 

Census Blocks were obtained from the U.S. Census 

Bureau (U.S. Census Bureau, 2001a), and land-use 

data was obtained from the RIGIS and the MassGIS 

(Rhode Island Geographic Information System, 2001b, 

and Massachusetts Geographic Information System, 

2001).

Public Supply

Population information from the 1990 STF3 by 

block group was attributed to the digital census blocks and 

combined with the basin boundaries from the NRCS 14-

digit HUC datalayer to estimate the 1990 population on 

public water and public sewer. The 5-year averages of 

total population, population on public water, and 

population on public sewer in each subbasin were then 

estimated by adjusting the 1990 population estimates to 

reflect changes in population from 1995 through 1999 

(table 3). Population estimates for 1995 through 1999 for 

Rhode Island and Massachusetts were available over the 

Internet (Rhode Island Economic Development 

Corporation, 2000a; University of Massachusetts, 

Amherst, 2000).

The percentage of population receiving publicsupply water ranged from 97.1 percent in the Peters River 

subbasin to 9.2 percent in the Branch River subbasin 

(table 3). The percentage of the total population receiving 

public-supply water within the lower Blackstone River 

basin was 79.7 percent. The lowest populations, and 

percentage of individuals on public supply, occurred in the 

three westernmost subbasins—the Clear, Chepachet, and 

Branch River subbasins.

There are six major public-water suppliers in 

Rhode Island and two major public-water suppliers in 

Massachusetts that withdraw water from the lower 

Blackstone River basin: Harrisville Fire District (FD), 

Pascoag FD, Lincoln Water Commission (WC), 

Cumberland Water Department (WD), Pawtucket Water 

Supply Board (WSB), the Woonsocket Water Division 

(WDIV) and the Bellingham and North Attleboro WDs 

(table 4). "Major water suppliers" is a term often used 

for public suppliers who withdraw or deliver more 

than 50 Mgal/yr, or 0.114 Mgal/d (State of Rhode Island 

General Assembly, 2003; Rhode Island Water Resources 

Board, 2003). The 5-year average withdrawals for 

these public suppliers ranged from 0.116 Mgal/d to 

13.17 Mgal/d. In addition to the 8 major suppliers who 

withdraw water from the lower Blackstone River basin, 

11 minor water suppliers (10 in Rhode Island and 1 in 

Massachusetts) also withdraw water from the area. 
16 Estimated Water Use and Availability in the Lower Blackstone River Basin, Northern Rhode Island and South-Central Massachusetts, 1995–99

Table 4. Water withdrawals for public-supply wells and surface-water intakes by subbasin in the lower Blackstone River basin, northern Rhode Island and 

south-central Massachusetts, 1995–99—Continued

Water Supplier Map ID(s) Town/city 

(locality)

Well/wellfield

description

Average water 

withdrawals

(Mgal/d)

Percentage of 

public-supply 

withdrawals in 

study area

Lower Blackstone River basin

Chepachet River subbasin

Davis Mobile Home Park 1,2 Glocester Well Nos. 1 and 2 0.01 <0.1

Hemlock Estates 3, 4, 16 Glocester Well Nos. 7, 8, and 6 .014 .1

Maplehill Mobile Home Park 5, 6, 7 Burrillville Well Nos. 1, 2, and 3 .06 .3

Subtotal ....................................................................................................................................................... 0.084 .4

Clear River subbasin

Harrisville Fire District 8 Burrillville Well No. 1 (emergency use only) 0 0

9 Burrillville Well No. 2 .108 .5

10 Burrillville Well No. 3 .112 .5

Pascoag Fire District 11 Burrillville Well No. 1 (abandoned) 0 0

12, 13 Burrillville Well Nos. 2 and 3 1.307 1.3

Subtotal ....................................................................................................................................................... 0.527 2.3

Branch River subbasin

Brandy Acres 14 Glocester Well .014 .1

Glendale Water Association 15 Burrillville Wells .007 <.1

Mohegan Water Association 17, 18 Burrillville Well Nos. 1 and 4 .003 <.1

Nasonville Water District 19, 20 Burrillville Well fields A and B .009 <.1

Oakland Water Association 21 Burrillville Wells .017 .1

Slatersville Public Supply 22 North Smithfield Driven well field 2.060 .3

23 North Smithfield Pacheco Park well No. 3 -- --

24 North Smithfield Well No. 1 -- --

25 North Smithfield Well No. 6 -- --

Subtotal ....................................................................................................................................................... 0.11 0.5

West River subbasin

Deerfield Commons 

(North Smithfield Properties)

28, 29, 30 North Smithfield Well Nos. 1,2, and 5 .006 <.1

Subtotal ....................................................................................................................................................... 0.006 <0.1

Peters River subbasin

Bellingham Water Department 31 Bellingham Well No. 1 .238 1

32 Bellingham Well No. 12 .103 .5

33–39, 41 Bellingham Well Nos. 13, 14, 15, 16, 17, 

18, 19, and 20

0 0

40 Bellingham Well No. 2 .046 .2

42 Bellingham Well No. 3 .067 .3

43 Bellingham Well No. 4 .377 1.7

Lincoln Water Commission 46, 49, 50 Lincoln Lonsdale well No. 10, and 

Manville well Nos. 3 and 5

0 0

47 Lincoln Lonsdale well No. 11 0 0

48 Lincoln Lonsdale well No. 4 .166 .7

Table 4. Water withdrawals for public-supply wells and surface-water intakes by subbasin in the lower Blackstone River basin, northern Rhode Island and 

south-central Massachusetts, 1995–99

[Water supplier: Major suppliers in bold. Map ID: Label used in figure 6. ID, identifier; No., number; Mgal/d, million gallons per day; <, actual value is less 

than value shown; --, information not available]
Water Use 17

1Pascoag Fire District well Nos. 2 and 3 are metered at one location on a quarterly basis. 2Slatersville Public Supply does not meter its withdrawals. A rate of 0.060 Mgal/d was estimated based on information provided by the supplier. 

Peters River subbasin—Continued

Cumberland Water Department 51 Cumberland Manville well No. 1 .179 .8

52 Cumberland Manville well No. 2 .16 .7

53 Cumberland Sneech Pond intake .838 3.7

Woonsocket Water Division 54 North Smithfield Crookfall Brook Reservoir No. 1 

intake

4.759 21

Subtotal ....................................................................................................................................................... 6.933 30.6

Abbott Run subbasin

Cumberland Water Department 55, 56 Cumberland Abbott Run well Nos. 2 and 3 0 0

Pawtucket Water Supply Board 57 Cumberland Happy Hollow intake 12.018 53

64, 65, 69 Cumberland Well Nos. 10, 11, and 5 0 0

66 Cumberland Well No. 2 .156 .7

67 Cumberland Well No. 3 .273 1.2

68 Cumberland Well No. 4 .065 .3

70 Cumberland Well No. 6 .13 .6

71 Cumberland Well No. 7 .169 .7

72 Cumberland Well No. 8 .179 .8

73 Cumberland Well No. 9 .183 .8

North Attleboro Water 

Department

59 North Attleboro Adamsdale well .155 .7

60 North Attleboro Hillman well .859 3.8

61 North Attleboro Plainville well No. 1 .815 3.6

62, 63 North Attleboro Plainville well Nos. 2 and 3 0 0

Kings Grant Water Company 58 North Attleboro Well No. 1 .032 .1

Subtotal ....................................................................................................................................................... 15.034 66.3

Total of the lower Blackstone River basin ...................................................................................................... 22.694 100

Table 4. Water withdrawals for public-supply wells and surface-water intakes by subbasin in the lower Blackstone River basin, northern Rhode Island and 

south-central Massachusetts, 1995–99—Continued

Water Supplier Map ID(s) Town/city 

(locality)

Well/wellfield

description

Average water 

withdrawals

(Mgal/d)

Percentage of 

public-supply 

withdrawals in 

study area

Withdrawals for public supply in the lower 

Blackstone River basin are from ground and surface water 

(fig. 6). The Woonsocket WDIV uses surface water as the 

sole source, whereas the Pawtucket WSB and the 

Cumberland WD use a combination of surface water and 

ground water. The Harrisville and Pascoag FDs use 

ground water as the sole source. The Lincoln WC and the 

Smithfield WSB receive interbasin transfers of surface 

water through the Providence WSB from the Scituate 

Reservoir in the Pawtuxet River basin; these interbasin 

transfers are the primary source of water for the Lincoln 

WC and the sole source of water for the Smithfield WSB. 

Public-supply withdrawal rates ranged from 0.084 Mgal/d 

in the Chepachet River subbasin to 15.034 Mgal/d in the 

Abbott Run subbasin (table 4). Public-supply withdrawal 

rates for the lower Blackstone River basin averaged 

22.694 Mgal/d. 

Six potable-water treatment plants serve water to 

residents within the lower Blackstone River basin: the 

Cumberland WD treatment plant, the Pawtucket WSB 

treatment plant, the Providence WSB J.P. Holton 

treatment plant, the Woonsocket WDIV Charles Hammen 

treatment plant, the Attleboro WD treatment plant, and the 

Plainville WD pressure-filtration plant. The remaining 

water departments do not have centralized treatment of 

their water supplies because the source is ground water. 
18 Estimated Water Use and Availability in the Lower Blackstone River Basin, Northern Rhode Island and South-Central Massachusetts, 1995–99

71o48' 71o

42' 71o

36' 71o

30' 71o

24'

42o

06'

42o

00'

41o

54'

EXPLANATION

STUDY AREA

LAKES, PONDS, AND RESERVOIRS

RIVERS AND STREAMS

PUBLIC-SUPPLY INTAKES AND IDENTIFIERS—Numbers shown in table 4

SUBBASIN BOUNDARIES

STATE BOUNDARIES

PUBLIC-SUPPLY WELLS AND IDENTIFIERS—Numbers shown in table 4

0 10 KILOMETERS 5

0 5 10 MILES

8 9

5-7

3,4

1,2

59 70-73

66-69

57

65

64

58

61-63

60

51,52 46,49,50

47,48

42,43

33-39&41

40

32

31

28-30

24

23 25

22

21

19,20

17,18

15

14,16

12,13 11

10

55-56

54 53

59

54

RHODE ISLAND

MASSACHUSETTS

CONNECTICUT

GLOCESTER

SMITHFIELD

LINCOLN

CUMBERLAND

WOONSOCKET

NORTH SMITHFIELD

BURRILLVILLE

DOUGLAS

UXBRIDGE

MILLVILLE

BLACKSTONE

BELLINGHAM FRANKLIN

WRENTHAM

PLAINVILLE

NORTH 

ATTLEBORO

ATTLEBORO

PAWTUCKET

CENTRAL 

FALLS

Base from the National Resource Conservation Service 

12-digit HUC base map, 1:24,000, (2001)

Projection: Rhode Island State Plane

Figure 6. Public-supply wells and surface-water-intake locations within the lower Blackstone River basin, northern Rhode Island and south-central 

Massachusetts.
Water Use 19

In general, the water supply from ground water is treated 

through pH adjustment and chlorination at booster 

stations within the distribution system and does not 

require a centralized water-treatment facility. 

Public-supply imports and exports for the lower 

Blackstone River basin and each subbasin were estimated 

for the period 1995–99 by subtracting public-supply 

withdrawals from public-supply use. In the case where use 

is greater than withdrawals, an import of water has 

occurred and in the case where withdrawals are greater 

than use, an export of water has occurred. Average 

estimated public-supply imports for the six subbasins 

of the lower Blackstone River basin ranged from 

0.005 Mgal/d in the Chepachet River subbasin to 

3.951 Mgal/d in the Peters River subbasin (table 5). 

Public-supply imports for the entire lower Blackstone 

River basin were 2.852 Mgal/d. Water imported into the 

lower Blackstone River basin, as a whole, is less than the 

sum of the imports into each individual subbasin because 

some water is imported between subbasins within 

lower Blackstone River basin (table 5). Public-supply 

exports for 1995 through 1999 on average ranged 

from 0.000 Mgal/d in the West River subbasin to 

13.240 Mgal/d in the Abbott Run subbasin (table 5). 

Public-supply exports for the lower Blackstone River 

basin totaled 12.327 Mgal/d.

Table 5. Public-supply withdrawals, public-supply imports, public-supply exports, public-supply use, self-supply use, and total estimated withdrawals by 

minor civil division and subbasin in the lower Blackstone River basin, northern Rhode Island and south-central Massachusetts, 1995–99—Continued

Minor civil division

5-year average estimates

Public-supply 

withdrawals 

Public-supply 

imports

Public-supply 

exports

Public-supply 

use 

Self-supply 

withdrawals

Self-supply 

use

Total 

withdrawals

Lower Blackstone River basin

Chepachet River subbasin

Burrillville 0.06 0.005 0 0.065 0.101 0.101 0.161

Glocester .024 0 .003 .021 .229 .229 .253

Subtotal ................................... 0.084 0.005 0.003 0.086 0.33 0.33 0.414

Clear River subbasin

Burrillville .527 0 .049 .478 .435 12.814 .961

Glocester 0 .004 0 .004 .055 .055 .055

Douglas 0 .058 0 .058 .065 .065 .065

Uxbridge 0 .022 0 .022 .012 .012 .012

Subtotal ................................... 0.527 0.085 0.049 0.562 0.568 2.947 1.093

Branch River subbasin

Burrillville .036 .035 0 .071 .274 .274 .31

Glocester .014 0 .014 0 .033 .033 .047

North Smithfield .06 0 .034 .026 .436 .436 .496

Smithfield 0 .003 0 .003 .001 .001 .001

Millville 0 .001 0 <.001 .006 .006 .006

Uxbridge 0 .009 0 .008 .004 .004 .004

Subtotal ................................... 0.11 0.046 0.048 0.108 0.755 0.755 0.864

West River subbasin

Burrillville 0 .006 0 .006 .037 .037 .037

North Smithfield .006 .026 0 .032 .299 .299 .305

Woonsocket 0 1.833 0 1.833 4.42 22.041 34.420

Blackstone 0 .29 0 .29 .029 .029 .029

Douglas 0 .015 0 .015 .013 .013 .013

Millville 0 .007 0 .007 .143 .143 .143

Uxbridge 0 .243 0 .243 .104 .104 .104

Subtotal ................................... 0.006 2.421 0 2.427 5.045 2.666 5.049

Table 5. Public-supply withdrawals, public-supply imports, public-supply exports, public-supply use, self-supply use, and total estimated withdrawals by 

minor civil division and subbasin in the lower Blackstone River basin, northern Rhode Island and south-central Massachusetts, 1995–99 

[Numbers may not sum correctly due to rounding. All values in million gallons per day. <, actual value is less than value shown]
20 Estimated Water Use and Availability in the Lower Blackstone River Basin, Northern Rhode Island and South-Central Massachusetts, 1995–99

1Includes 2.379 million gallons per day withdrawn by Ocean State Power in the West River subbasin. The withdrawn water is then piped to Ocean State 

Power’s thermoelectric facility in Burrillville, Rhode Island, which is located within the Clear River subbasin. 2Estimated self-supply withdrawal/use for Seville/Dorado, Company, Inc., a textile mill, 2.039 million gallons per day. 3Includes self-supply withdrawal from Ocean State Power.

Peters River subbasin

Central Falls 0 0.906 0 0.906 0 0 0

Cumberland 1.177 .732 0 1.909 .015 .015 1.192

Lincoln .166 1.08 0 1.246 .058 .058 .224

North Smithfield .002 .005 0 .007 .106 .106 .108

Pawtucket 0 .672 0 .672 0 0 0

Smithfield 0 .087 0 .087 .011 .011 .011

Woonsocket 4.759 0 2.799 1.96 .007 .007 4.766

Attleboro 0 .277 0 .277 .003 .003 .003

Bellingham .831 0 .25 .58 .066 .066 .897

Blackstone 0 .011 0 .011 .006 .006 .006

Franklin 0 .13 0 .13 .013 .013 .013

Wrentham 0 .051 0 .051 .006 .006 .006

Subtotal ................................... 6.935 3.951 3.049 7.837 0.285 0.285 7.226

Abbott Run subbasin

Cumberland 13.173 0 11.704 1.469 0.105 0.105 13.278

Attleboro 0 .054 0 .054 .002 .002 .002

Franklin 0 .051 0 .051 .008 .008 .008

North Attleboro 1.861 0 1.537 .324 .036 .036 1.897

Plainville 0 .074 0 .074 .013 .013 .013

Wrentham 0 .222 0 .222 .023 .023 .023

Subtotal ................................... 15.034 0.401 13.24 2.195 0.187 0.187 15.221

Total of the lower Blackstone 

River basin .............................. 22.694 2.852 12.327 13.215 7.17 7.17 29.869

Table 5. Public-supply withdrawals, public-supply imports, public-supply exports, public-supply use, self-supply use, and total estimated withdrawals by 

minor civil division and subbasin in the lower Blackstone River basin, northern Rhode Island and south-central Massachusetts, 1995–99—Continued

Minor civil division

5-year average estimates

Public-supply 

withdrawals 

Public-supply 

imports

Public-supply 

exports

Public-supply 

use 

Self-supply 

withdrawals

Self-supply 

use

Total 

withdrawals

Estimated public-supply use from 1995 through 

1999 on average ranged from 0.086 Mgal/d in the 

Chepachet River subbasin to 7.837 Mgal/d in the Peters 

River subbasin (table 5). Total public-supply use for the 

lower Blackstone River basin was 13.215 Mgal/d.

Self-Supply

A list of self-supplied users within the lower 

Blackstone River basin was compiled from several 

sources (Rhode Island Department of Administration—

Division of Planning, 1993; U.S. Environmental 

Protection Agency, 2000; Rhode Island Geographic 

Information System, 2001a; and Massachusetts 

Department of Environmental Protection, written 

commun., 2000). Non-community or self-supplied users 

serve both transient and non-transient populations; 

transient populations do not remain the same (for 

example, at rest stops, campgrounds, and gas stations), 

whereas a non-transient population remains the same, but 

does not use water year-round (for example, at schools). 

Withdrawal information for some campgrounds and 

private commercial users within the lower Blackstone 

River basin was not available; however, these uses often 

amount to less than 0.01 Mgal/d. In addition to sitespecific self-supply use, aggregate self-supply use was 

estimated for domestic, industrial, commercial, and 

agricultural use. 

Self-supply use in the lower Blackstone River 

basin ranged from 0.187 Mgal/d in the Abbott Run 

subbasin to 2.947 Mgal/d in the Clear River subbasin 

(table 5; 2.379 Mgal/d is the estimated self-supply use at 
Water Use 21

the Ocean State Power thermoelectric facility). Selfsupply use for the lower Blackstone River basin totaled 

7.170 Mgal/d. 

Aggregate Water Use by Category

To categorize water use by subbasin for each town 

as agricultural, commercial, industrial, and domestic, an 

estimate was made by subbasin of the land area within the 

various land-use categories or census-block-derived 

populations. The RIGIS 1995 and MassGIS 1999 updated 

land-use digital datalayers were intersected with subbasin 

boundaries to determine the distribution of three land-use 

categories—agricultural, commercial, and industrial—

among subbasins (table 6). The numbers in table 6 are the 

percentages of land in a particular land-use category for 

towns within each subbasin. For example, 15.6 percent of 

the agricultural land in the town of Burrillville is in the 

Chepachet River basin, the remaining 84.4 percent of the 

agricultural land use in Burrillville is in other subbasins or 

outside the Blackstone River basin. Domestic water use 

for each subbasin was determined on the basis of 1990 

census blocks and their associated statistics combined 

with the subbasin coverage (U.S. Census, 2001a; U.S. 

Census, 2001b). The resulting 1990 population in each 

subbasin was then updated with population estimates for 

1995 through 1999 for total, public-supply, and publicdisposal water use.

The land-use and population estimates for each 

subbasin were combined with data for aggregate water use 

gathered from public suppliers and towns to apportion 

aggregate water use for each category (agricultural, 

commercial, industrial, and domestic) by subbasin. In the 

case of site-specific use, withdrawal sites were intersected 

with the subbasin coverage. The 5-year average estimated 

withdrawal for the site was then assigned to the subbasin.

Domestic

Domestic water use was the largest aggregate 

water-use category for the lower Blackstone River basin. 

The 5-year average total domestic water use (public- and 

self-supply) for the lower Blackstone River basin was 

10.113 Mgal/d. Domestic use by subbasin ranged from 

0.347 Mgal/d or 3 percent of the total in the Chepachet 

River subbasin to 4.753 Mgal/d or 47 percent in the Peters 

River subbasin (table 7). 

Table 6. Agricultural, commercial, and industrial land-use area by 

subbasin as a percentage of total land area for the category in each minor 

civil division for the lower Blackstone River basin, northern Rhode Island 

and south-central Massachusetts

[--, no land use in category within subbasin]

Minor civil division

Percentage of land-use category by town 

within subbasin

Agricultural Commercial Industrial

Chepachet River subbasin

Burrillville 15.6 2.9 37.8

Glocester 33.8 45.1 --

Clear River subbasin

Burrillville 42.2 60.8 32.3

Glocester 2.5 1.5 --

Douglas 24.8 -- --

Uxbridge 3.5 -- --

Branch River subbasin

Burrillville 34.1 36.3 29.9

Glocester 5.4 -- --

North Smithfield 16.8 38.9 78.3

Smithfield

Millville -- 15.8 --

Uxbridge 1.2 3.2 --

West River subbasin

Burrillville 5.9 -- --

North Smithfield 28.1 28.2 13.9

Woonsocket 27.1 31.2 48.8

Blackstone 33.4 84.7 100

Douglas 6.6 16.7 --

Millville 87.9 84.2 100

Uxbridge 36.2 64.4 1.1

Peters River subbasin

Central Falls -- 76.5 63.1

Cumberland 39.7 85.6 69.5

Lincoln 22.1 75.5 33.3

North Smithfield 26.6 26.9 3.5

Pawtucket -- 12.6 5.8

Smithfield 0.4 .4 21.1

Woonsocket 72.9 46.5 41.9

Attleboro 0.6 5 7.4

Bellingham 52.1 25.1 19.1

Blackstone -- 15.3 --

Franklin 7 -- --

Wrentham 8.5 -- --

Abbott Run subbasin

Cumberland 60.3 14.4 30.5

Attleboro 1.8 -- --

Franklin 6.1 -- --

North Attleboro 37.3 -- 1.3

Plainville 43.4 -- --

Wrentham -- 1.3 --
22 Estimated Water Use and Availability in the Lower Blackstone River Basin, Northern Rhode Island and South-Central Massachusetts, 1995–99

Table 7. Total water use, public and self-supply, by category in the lower Blackstone River basin, northern Rhode Island and south-central Massachusetts, 

1995–99—Continued

Minor civil division

5-year average water use

Domestic Commercial Industrial Agricultural Non-account Total

Lower Blackstone River basin

Chepachet River subbasin

Burrillville 0.128 0.001 0.016 0.013 0.007 0.166

Glocester .219 .014 0 .018 0 .25

Subtotal ............................ 0.347 0.015 0.016 0.031 0.007 0.416

Clear River subbasin

Burrillville .672 12.527 .014 .036 .043 3.292

Glocester .057 <.001 0 .001 0 .059

Douglas .115 0 0 .001 .007 .123

Uxbridge .025 0 0 .001 .009 .035

Subtotal ............................ 0.869 2.527 0.014 0.04 0.058 3.509

Branch River subbasin

Burrillville .266 .018 .013 .029 .019 .345

Glocester .03 0 0 .003 0 .033

North Smithfield .293 .031 .133 .004 0 .462

Smithfield .003 0 0 0 .001 .004

Millville .007 0 0 0 0 .007

Uxbridge .007 .002 0 <.001 .002 .012

Subtotal ............................ 0.607 0.051 0.146 0.036 0.022 0.863

West River subbasin

Burrillville .035 0 0 .005 .003 .043

North Smithfield .278 .023 .024 .006 0 .331

Woonsocket 1.016 .211 22.519 .002 .125 3.875

Blackstone .229 .033 .005 .002 .051 .32

Douglas .024 .003 0 <.001 .001 .029

Millville .148 <.001 .001 .001 0 .15

Uxbridge .219 .041 <.001 .015 .072 .347

Subtotal ............................ 1.9502 0.311 2.549 0.033 0.252 5.095

Peters River subbasin

Central Falls .593 .028 .249 0 .035 .906

Cumberland 1.122 .302 .174 .015 .311 1.924

Lincoln .792 .256 .145 .008 .102 1.304

North Smithfield .079 .021 .006 .006 0 .113

Pawtucket .403 .095 .159 0 .016 .672

Smithfield .038 .003 .05 <.001 .008 .099

Woonsocket 1.022 .314 .413 .007 .211 1.967

Attleboro .149 .019 .092 <.001 .02 .28

Bellingham .389 .025 .002 .024 .205 .646

Blackstone .004 .006 0 0 .001 .011

Franklin .125 0 0 .002 .015 .142

Wrentham .036 0 0 .002 .019 .057

Subtotal ............................ 4.753 1.07 1.291 0.064 0.944 8.122

Table 7. Total water use, public and self-supply, by category in the lower Blackstone River basin, northern Rhode Island and south-central Massachusetts, 

1995–99

[Numbers may not sum correctly due to rounding. All values in million gallons per day. MCD, minor civil division; <, actual value is less than value shown]
Water Use 23

1Includes 2.379 million gallons per day used by the Ocean State Power thermoelectric facility. 2Includes an estimated 2.039 million gallons per day used by the Seville/Dorado Company, textile mill.

Abbott Run subbasin

Cumberland 0.995 0.051 0.109 0.023 0.396 1.574

Attleboro .049 0 0 .001 .006 .056

Franklin .051 0 0 .002 .007 .059

North Attleboro .269 0 .002 .013 .077 .36

Plainville .064 0 0 .009 .013 .087

Wrentham .16 .002 0 0 .084 .245

Subtotal ............................ 1.587 0.052 0.111 0.048 0.583 2.382

Total of the lower Blackstone 

River basin ....................... 10.113 4.026 4.127 0.252 1.866 20.388

Table 7. Total water use, public and self-supply, by category in the lower Blackstone River basin, northern Rhode Island and south-central Massachusetts, 

1995–99—Continued

Minor civil division

5-year average water use

Domestic Commercial Industrial Agricultural Non-account Total

Public Supply

Public-supply domestic water use for the 

municipalities within the lower Blackstone River basin 

was estimated with information provided in the Water 

Supply Management Plans in Rhode Island and Annual 

Statistical Reports in Massachusetts (Archer, 1994; Camp, 

Dresser, and McKee, 1994; Dufresne-Henry, Inc., 1997, 

1999; Pare Engineering, Corp., 1992, 1998, 2000; 

Pawtucket Water Supply Board, 1998, 2000; Water Works 

Engineering and Associates, Inc., 1994; Massachusetts 

Department of Environmental Protection, written 

commun., 2000). Several plans provided a percentage 

estimate for domestic use in relation to total distribution, 

or reported the domestic use in million gallons per month. 

The towns of Central Falls, Pawtucket, and 

Woonsocket rely entirely on public supply for domestic 

water use. The public-supply populations for the other 

towns within the lower Blackstone River basin were 

estimated from 1990 census data adjusted for changes in 

population from 1995 to 1999. Several minor water 

suppliers do not meter withdrawals. In these cases, an 

estimate of the domestic water use was calculated by 

multiplying the estimated population by 67 gal/d/person, 

which is a coefficient calculated by dividing domestic 

water use by the population served (Korzendorfer and 

Horn, 1995).

Total public-supply domestic use for the lower 

Blackstone River basin was 8.032 Mgal/d. Public-supply 

domestic use ranged from 0.054 Mgal/d in the Branch 

River subbasin to 4.600 Mgal/d in the Peters River 

subbasin (fig. 7). 

Self-Supply

Self-supply domestic water use by town was 

estimated on the basis of the difference between the town 

population and the estimated public-supply population; 

this difference was then multiplied by a coefficient of 

71 gal/d/person (Korzendorfer and Horn, 1995). The selfsupplied populations were estimated from information 

provided in the 1990 census blocks updated for population 

changes for 1995 through 1999 or data on self-supplied 

populations provided in the Water Supply Management 

Plans. Total self-supply domestic use for the lower 

Blackstone River basin was 2.081 Mgal/d. Self-supply 

domestic use ranged from 0.138 Mgal/d in the Abbott 

Run subbasin to 0.555 Mgal/d in the West River subbasins 

(fig. 7). 

Commercial

An estimate of commercial water use for the 

communities within the lower Blackstone River basin was 

calculated from the RI Major Employers List (Rhode 

Island Economic Development Corporation, 2000b) and 

the Massachusetts Division of Employment and Training 

(2001). This information was combined with water-use 

coefficients by Standard Industrial Classification (SIC) 

code and the numbers of employees for each SIC code to 

estimate aggregate commercial water use by town (Horn, 

1999). The SIC code estimates (Appendix 1) were 

supplemented with estimates obtained either from the 

water supplier (in the case of public-supply commercial 

use) or from an individual facility (in the case of selfsupply commercial use).
24 Estimated Water Use and Availability in the Lower Blackstone River Basin, Northern Rhode Island and South-Central Massachusetts, 1995–99 WATER USE, IN MILLION GALLONS PER DAY

SUBBASINS

A.

C. D.

B.

EXPLANATION

SELF-SUPPLY

PUBLIC-SUPPLY

0.001

0.010

0.100

1.000

10.000

CHEPACHET

CLEAR

BRANCH

WEST

PETERS

ABBOTT RUN

CHEPACHET

CLEAR

BRANCH

WEST

PETERS

ABBOTT RUN

CHEPACHET

CLEAR

BRANCH

WEST

PETERS

ABBOTT RUN

CHEPACHET

CLEAR

BRANCH

WEST

PETERS

ABBOTT RUN

0.001

0.010

0.100

1.000

10.000

.284

.063

.398 .471 .553

.054

.555

1.395

.153

4.600

.138

1.449

.007 .008

2.501

.026 .026 .026

.017

.294

.016

1.054

.052

.009.008 .007 .006

.140

.006

2.063

.486

.055

1.236

.111

.031 .040 .036 .033

.062

.003

.048 

Figure 7. Public- and self-supply water use by category in the lower Blackstone River basin, northern Rhode Island and south-central Massachusetts, for the 

period 1995–99: (A) domestic, (B) commercial, (C) industrial, and (D) agricultural.
Water Use 25

The 5-year average total commercial water use 

(public- and self-supply) for the lower Blackstone River 

basin was 4.026 Mgal/d. Commercial water use ranged 

from 0.015 Mgal/d in the Chepachet River subbasin to 

2.527 Mgal/d in the Clear River subbasin (table 7). 

Public Supply

Public-supply commercial water use was estimated 

either by subtracting the known self-supply commercial 

use from the total commercial water-use estimate by 

community, or was estimated directly from the Water 

Supply Management Plans. Several public suppliers listed 

either the flow amount by use type or gave a percentage 

estimate of the total distribution by use type.

Total public-supply commercial use for the lower 

Blackstone River basin was 1.460 Mgal/d. Public-supply 

commercial use ranged from 0.008 Mgal/d in the 

Chepachet River subbasin to 1.054 Mgal/d in the Peters 

River subbasin (fig. 7). 

Self-Supply

Total self-supply commercial use for the lower 

Blackstone River basin was 2.567 Mgal/d. Self-supply 

commercial use ranged from 0.000 Mgal/d in the Abbott 

Run subbasin to 2.501 Mgal/d in the Clear River subbasin 

(fig. 7; 2.379 Mgal/d is from the Ocean State Power 

thermoelectric facility in the Clear River subbasin). 

Industrial

An estimate of industrial water use for the 

communities within the lower Blackstone River basin was 

calculated from the RI Major Employers List (Rhode 

Island Economic Development Corporation, 2000b) and 

the Massachusetts Division of Employment and Training 

(2001). This information was combined with water-use 

coefficients by SIC code and the numbers of employees 

for each SIC code to estimate aggregate industrial water 

use by town (Horn, 1999). The SIC code estimates 

(Appendix 1) were supplemented with estimates obtained 

either from the water supplier (in the case of public-supply 

industrial use) or from an individual facility (in the case of 

self-supply industrial use). 

The 5-year average total industrial water use 

(public- and self-supply) for the lower Blackstone River 

basin was 4.127 Mgal/d. Total industrial water use 

ranged from 0.014 Mgal/d in the Clear River subbasin to 

2.549 Mgal/d in the West River subbasin (table 7).

Public Supply

Public-supply industrial water use was estimated 

either by subtracting the known self-supplied industrial 

users from the total industrial water-use estimate by 

community, or was estimated directly from the Water 

Supply Management Plans. Several public suppliers listed 

either the flow amount by use type or gave a percentage 

estimate of the total distribution by use type.

Total public-supply industrial use for the lower 

Blackstone River basin was 1.852 Mgal/d. Public-supply 

industrial use ranged from 0.006 Mgal/d in the Branch 

and Clear River subbasins to 1.236 Mgal/d in the Peters 

River subbasin (fig. 7). 

Self-Supply

Total self-supply industrial use for the lower 

Blackstone River basin was 2.275 Mgal/d. Self-supply 

industrial use ranged from 0.000 Mgal/d in the Abbott 

Run subbasin to 2.063 Mgal/d in the West River subbasin 

(fig. 7). 

Agricultural and Golf-Course Irrigation

Estimates of agricultural water use by town in 

Rhode Island were based on a combination of the Farms 

List by town for Rhode Island (Rhode Island Department 

of Environmental Management, 2002) and the 1997 

Census of Agriculture publication by county (U.S. 

Department of Agriculture, 1999a). The number and type 

of farms by town was determined for each type of 

livestock: beef cattle, poultry, and so forth. This value was 
26 Estimated Water Use and Availability in the Lower Blackstone River Basin, Northern Rhode Island and South-Central Massachusetts, 1995–99

then divided into the population total for each type of 

livestock in each county. From this information, the 

number of livestock per town was estimated and then 

multiplied by the respective water-use coefficient in 

gal/d/head (table 8). 

The acreage of cropland requiring irrigation was 

determined by multiplying an estimate of agricultural 

land area by town (RIGIS land-use datalayer) by the 

percentage of agricultural land within the entire lower 

Blackstone River basin. Rainfall data available from the 

Woonsocket rain gage were compared to the irrigation 

requirement of 1 in/acre/week (Laura Medalie, U.S. 

Geological Survey, written commun., 1995) to estimate 

how much irrigation was required over the summer 

months during the study period. An average rainfall deficit 

of 0.19 in/week was estimated for the summer months 

from 1995 to 1999.

Determinations for agricultural water use for towns 

within the lower Blackstone River basin in Massachusetts 

were made by first determining the agricultural land area 

(in acres of cropland and pasture) within each town and 

then dividing this figure by the number of acres of 

agricultural land within the county (U.S. Department of 

Agriculture, 1999b). The acres of cropland were used to 

estimate the amount of irrigation required and the acres of 

pasture were used to estimate the number of head of 

livestock per town.

The rate of water used by golf courses for 

irrigation was estimated by multiplying the number of 

linear yards per course by a water-use coefficient of 

0.0116 Mgal/d/1,000 yards (Laura Medalie, U.S. 

Geological Survey, written commun., 1995). This 

coefficient was included in the agricultural water-use 

estimate.

The 5-year average total agricultural water use 

(public- and self-supply) for the lower Blackstone River 

basin from 1995 to 1999 was 0.252 Mgal/d. Agricultural 

water use ranged from 0.031 Mgal/d in the Chepachet 

River subbasin to 0.064 Mgal/d in the Peters River 

subbasin (table 7, fig. 7). The only public-supply 

agricultural water use in the lower Blackstone River basin 

was in the Peters River subbasin in Massachusetts and 

amounted to 0.003 Mgal/d.

Consumptive and Non-Account Use

Consumptive use is that part of withdrawn water 

that is evaporated, transpired, incorporated into products 

or crops, consumed by humans or livestock, or otherwise 

removed from the immediate environment (Horn, 1999). 

Rates of consumptive use were estimated to be 15 percent 

for domestic use and 10 percent for commercial and 

industrial use; these percentages are consistent with 

traditional consumptive-use rates in New England. 

Nationally, conveyance losses and consumptive use 

during irrigation can account for 76 percent of irrigation 

withdrawals (Solley and others, 1993). 

In addition to consumptive use for each aggregateuse type, non-account-use data from the major public 

suppliers were gathered from either the Water Supply 

Management Plans in Rhode Island provided by the 

RIWRB or the Annual Statistical Reports in 

Massachusetts provided by the Massachusetts Department 

of Environmental Protection (MADEP). Non-account 

water use often includes firefighting, inaccurate meters, 

flushing, major breaks, recreation, illegal connections, 

street washing, and leakage (exfiltration). The 5-year 

average non-account use for public suppliers serving 

people within the lower Blackstone River basin ranged 

from 0.027 Mgal/d for the Douglas WD to 0.683 Mgal/d 

for the Cumberland WD. A report prepared for the 

Cumberland WD by Pare Engineering (2000) gave 

estimates for each non-account use by type. Leakage or 

exfiltration was estimated as the highest at 62.0 percent of 

all types of non-account use. Other categories that account 

for more than 5 percent of non-account use were 

firefighting (12.0 percent) and major breaks (6.4 percent). 

Non-account use for the lower Blackstone River basin was 

estimated to be 1.866 Mgal/d (table 7). The estimates by 

subbasin ranged from 0.007 Mgal/d in the Chepachet 

River subbasin to 0.944 Mgal/d in the Peters River 

subbasin.

1Coefficent is from the 1990 Rhode Island Water Use Compilation. 2Coefficent is from the 1995 Rhode Island Water Use Compilation. 3Coefficent is from the 1995 Vermont Water Use Compilation.

Table 8. Agricultural coefficients used to estimate livestock water use in 

the lower Blackstone River basin, northern Rhode Island and south-central 

Massachusetts

Livestock type Gallons/day/head

Beef cattle 116

Dairy cows 135

Heifers 23.5

Hogs and pigs 14

Pullets older than 3 months 3.05

Turkeys 2.07

Sheep and lambs 22

Horses and ponies 312.5

Goats 22
Water Use 27

Electric Power Generation

There are four hydroelectric power-generation 

facilities in the lower Blackstone River basin and one 

thermoelectric power-generation facility: Thundermist, 

Synergics, Elizabeth Webbing, and Central Falls, and 

Ocean State Power (fig. 8). All the water that is withdrawn 

by the four hydroelectric facilities is returned to the river, 

whereas the Ocean State Power thermoelectric facility 

withdrawals are 100-percent consumed (evaporated). The 

four instream-use facilities are considered “run of river” 

facilities; that is, inflow and outflow are kept as nearly 

equal as possible on an instantaneous basis to maintain 

habitat and water quality (Melissa Grader, Fish and 

Wildlife Biologist, U.S. Fish and Wildlife Service, oral 

commun., 2002).

The Thundermist hydroelectric facility in 

Woonsocket can generate up to 1200 KW. The facility is 

just downstream of the Woonsocket Falls Dam in 

Woonsocket. The operating range for flow through the 

facility is between 250 and 850 ft3/s. The intake for the 

facility is just upstream of the Woonsocket Falls Dam. A 

minimum of 0.10 in. of flow depth is maintained over the 

200-ft-wide dam. Withdrawals are not metered; therefore, 

the actual amount withdrawn is unknown. Withdrawal 

amounts are dependent on several factors: streamflow, 

accumulated debris on the intake trash rack, and the 

mechanical efficiency at the facility (M.F. Debroisse, 

Thundermist, oral commun., 2002).

Ocean State Power withdrew an average of 

2.379 Mgal/d from the Blackstone River in Woonsocket 

from 1995 through 1999. The Ocean State Power intake is 

located in the West River subbasin. Withdrawals are piped 

to the thermoelectric facility, which is in Clear River 

subbasin. The thermoelectric facility is permitted to 

withdraw as much as 4.4 Mgal/d. However, when flows in 

the Blackstone River are less than 102 ft3/s, Ocean State 

Power must truck water to their thermoelectric facility to 

maintain operations. During the study period, water was 

trucked to the facility in September 1997; July, August, 

and September 1999; and November 1999 (Gary Couture, 

EHS Engineer, Ocean State Power, written commun., 

2000). Water at this site is primarily used to cool turbines. 

Ocean State Power is a zero-liquid-discharge facility, and, 

as such, the water used at the facility is completely 

consumed by evaporation (Gary Couture, EHS Engineer, 

Ocean State Power, oral commun., 2000).

Synergics can generate up to 1724 KW. This 

facility is in Blackstone, Massachusetts, near the border of 

Rhode Island and Massachusetts. The operating range for 

the facility is between 40 and 1,000 ft3/s. The Synergics 

facility has a 5,200-ft-long bypass channel. There is no 

flow requirement for the bypass; however, 10–20 ft3/s is 

voluntarily released. 

The Elizabeth Webbing hydroelectric facility can 

generate up to 700 KW. The facility is located in Central 

Falls, RI, and operates between 270 and 1,060 ft3/s. The 

Central Falls hydroelectric facility, also in Central Falls, 

can generate up to 700 KW. The maximum withdrawal 

capacity for the facility is 920 ft3/s. The Central Falls 

facility has a 1,500-ft-long bypass channel, which is 

required to maintain a minimum flow of 108 ft3/s. 

Wastewater-Return Flows

Wastewater-return flow is an important component 

in the water-use cycle. Public disposal of wastewater often 

results in the transfer of water from one basin or subbasin 

to another by means of local or regional collection. For 

example, the Narragansett Bay Commission (NBC) 

Bucklin Point wastewater-treatment facility (WWTF) 

collects wastewater through their regional collection 

system from communities within the lower Blackstone 

River basin. The collected wastewater is then discharged 

to the Seekonk River, which is outside the Blackstone 

River basin. Self-disposal of wastewater usually occurs at 

the same site where the water was used either through 

septic systems or discharge of the wastewater after 

treatment through surface-water discharge pipes, also 

known as outfalls. 

Public Disposal

Discharge data for NPDES sites were collected 

from the RIDEM in Rhode Island and from the 

Environmental Protection Agency’s Permit Compliance 

System (PCS) database in Massachusetts. NPDES sites 

include municipal wastewater-treatment facilities and 

private commercial and industrial facilities. Nine 

wastewater-treatment facilities serve the communities 

within the lower Blackstone River basin (table 9 and 

fig. 9). However, only three facilities are within the lower 

Blackstone River basin: the Burrillville, RI, WWTF; the 

Woonsocket, RI, WWTF; and the Uxbridge, MA, 

WWTF. The remaining WWTFs are outside the lower 

Blackstone River basin. These facilities discharge 

wastewater to the Mumford River (in the Blackstone 

River basin but outside the lower Blackstone River basin), 

the Seekonk River, the Woonasquatucket River, the Ten 

Mile River, and the Charles River (table 9). 
28 Estimated Water Use and Availability in the Lower Blackstone River Basin, Northern Rhode Island and South-Central Massachusetts, 1995–99

71o48' 71o

42' 71o

36' 71o

30' 71o

24'

42o

06'

42o00'

41o

54'

EXPLANATION

STUDY AREA

LAKES, PONDS, AND RESERVOIRS

RIVERS AND STREAMS

INTAKE FOR OCEAN STATE POWER

SUBBASIN BOUNDARIES

STATE BOUNDARIES

HYDROELECTRIC POWER-GENERATION FACILITY AND NAME

0 10 KILOMETERS 5

0 5 10 MILES

OCEAN STATE POWER THERMOELECTRIC POWER-GENERATION FACILITY

RHODE ISLAND

MASSACHUSETTS

CONNECTICUT

GLOCESTER

SMITHFIELD

LINCOLN

CUMBERLAND

WOONSOCKET

NORTH SMITHFIELD

BURRILLVILLE

DOUGLAS

UXBRIDGE

MILLVILLE

BLACKSTONE

BELLINGHAM FRANKLIN

WRENTHAM

PLAINVILLE

NORTH 

ATTLEBORO

ATTLEBORO

PAWTUCKET

CENTRAL 

FALLS

Base from the National Resource Conservation Service 

12-digit HUC base map, 1:24,000, (2001)

Projection: Rhode Island State Plane

Synergics Synergics ynergics

Thundermist Thundermist hundermist

Central Falls Central Falls entral Falls

Elizabeth lizabeth 

Webbing Webbing

Elizabeth 

Webbing

Figure 8. Power-generation facilities within the lower Blackstone River basin, northern Rhode Island and south-central Massachusetts
Water Use 29

1Bellingham is sewered by both the Woonsocket WWTF and the Charles River Pollution Control Facility. 21995 wastewater return flows for Douglas are currently unavailable; for this reason, average return flow only includes 1996–99. 3A small portion of the town of Smithfield is sewered by the Narragansett Bay Commission-Bucklin Point facility. 4NPDES discharge location is downstream of Populatic Pond.

Table 9. Average return flow for wastewater-treatment facilities serving communities of the lower Blackstone River basin, northern Rhode Island and 

south-central Massachusetts, 1995–99

[NPDES, National Pollution Discharge Elimination System; WWTF, wastewater-treatment facility; Mgal/d, million gallons per day; --, data not collected for 

this study]

Wastewater-treatment facility Municipalities served NPDES permit 

number Receiving water

Average return 

flow

(Mgal/d)

Municipal WWTFs within the Lower Blackstone River basin

Clear River subbasin

Burrillville WWTF Burrillville, RI RI0100455 Clear River 0.812

Peters River subbasin

Woonsocket WWTF Bellingham, MA1 RI0100111 Blackstone River .049

Blackstone, MA .149

North Smithfield, RI .585

Woonsocket, RI 8.081

Total discharge for facility ................................................................................................................................................... 8.86

West River subbasin

Uxbridge WWTF Uxbridge, MA MA0102440 Blackstone River 0.723

Total discharge of the municipal WWTFs within the lower Blackstone River basin .............................................................. 10.395

Municipal WWTFs Outside the Lower Blackstone River basin

Douglas WWTF Douglas, MA MA0101095 Mumford River 20.188

Narragansett Bay Commission–Bucklin Point Central Falls, RI RI0100072 Seekonk River 2.284

Cumberland, RI 2.543

East Providence, RI --

Lincoln, RI 2.327

Pawtucket, RI 15.064

Smithfield, RI3 .047

Total discharge for facility ................................................................................................................................................... 23.916

Smithfield Sewer Authority WWTF Smithfield, RI RI010025 Woonasquatucket River

1.723

Attleboro WWTF Attleboro, MA MA0100595 Ten Mile River 4.416

North Attleboro WWTF North Attleboro, MA MA0101036 Ten Mile River 3.017

Plainville, MA .354

Total discharge for facility ................................................................................................................................................... 3.371

Charles River Pollution Control Facility Bellingham, MA2 MA0102598 Charles River4 .194

Franklin, MA 3.231

Medway, MA --

Millis, MA --

Total discharge for facility ................................................................................................................................................... 4.354

Total discharge of the municipal WWTFs outside the lower Blackstone River basin............................................................. 37.965

Total discharge for all facilities................................................................................................................................................ 48.363
30 Estimated Water Use and Availability in the Lower Blackstone River Basin, Northern Rhode Island and South-Central Massachusetts, 1995–99

71o48' 71o

36' 71o

24'

42o

12'

42o

00'

41o

48'

Douglas

WWTF

Burrillville

WWTF

Woonsocket

WWTF

Smithfield

WWTF

Uxbridge

WWTF

North Attleboro

WWTF

Attleboro

WWTF

NBC-BUCKLIN POINT

WWTF

Charles River

Pollution Control

District WWTF

BURRILLVILLE

SMITHFIELD LINCOLN

GLOCESTER

NORTH

SMITHFIELD

DOUGLAS

UXBRIDGE

MILLVILLE

BLACKSTONE

BELLINGHAM

FRANKLIN

WRENTHAM

PLAINVILLE

NORTH

ATTLEBORO

ATTLEBORO

EAST 

PROVIDENCE

PAWTUCKET

CENTRAL

FALLS

MEDWAY

MILLIS

CUMBERLAND

BURRILLVILLE WWTF

NBC-BUCKLIN POINT WWTF

SMITHFIELD WWTF

WOONSOCKET WWTF

ATTLEBORO WWTF

CHARLES RIVER 

POLLUTION CONTROL

DISTRICT WWTF

DOUGLAS WWTF

NORTH ATTLEBORO WWTF

UXBRIDGE WWTF

TOWN BOUNDARY 

STATE BOUNDARY

BLACKSTONE BASIN BOUNDARY

SUBBASIN BOUNDARIES

OUTFALL OF WASTEWATERTREATMENT FACILITY

MASSACHUSETTS

RHODE ISLAND

CONNECTICUT

RHODE ISLAND

Base from the Rhode Island Geographic Information System and

the Massachusetts Geographic Information System

Municipalities base map, 1:24,000, (1989) and Town base map, 1:25,000, (2001)

Projection: Rhode Island State Plane feet

AREAS SERVED BY NAMED WASTEWATER-TREATMENT FACILITY (WWTF)

0 5 10 MILES

0 5 10 KILOMETERS

EXPLANATION

Clear River 

Subbasin

Chepachet 

River 

Subbasin

Branch River 

Subbasin

West River 

Subbasin

Peters 

River 

to mouth 

Subbasin

Abbott

Run 

Subbasin

Figure 9. Outfall locations for wastewater-treatment facilities serving towns within the lower Blackstone River basin, northern Rhode Island and southcentral Massachusetts.
Water Use 31

Average annual return flow for the nine wastewatertreatment facilities serving communities within the lower 

Blackstone River basin ranged from 0.188 Mgal/d to 

23.916 Mgal/d for 1995 through 1999 (table 9). Total 

average return flows for this period were 48.363 Mgal/d 

(table 9). Most of the wastewater flows received at these 

facilities are collected from outside the lower Blackstone 

River basin (fig. 9). Total average return flows for the 

three municipal wastewater-treatment facilities within the 

lower Blackstone River basin were 10.395 Mgal/d. In 

addition, 1.164 Mgal/d was discharged via NPDES sites 

to the lower Blackstone River basin by commercial and 

industrial facilities (table 10 and fig. 10). 

Table 10. Average return flow for National Pollution Discharge Elimination System outfall locations for the lower Blackstone River basin, northern Rhode 

Island and south-central Massachusetts, 1995–99

[ID, identifier; NPDES, National Pollution Discharge Elimination System; WWTF, wastewater-treatment facility; Mgal/d, million gallons per day]

Commercial/industrial facility Map ID Town/city NPDES permit

number

Average

return flow

(Mgal/d)

Lower Blackstone River basin

Clear River subbasin

Eleanor Slater Hospital/ Zambarano Unit 1 Burrillville, RI RI0100129 0.105

Subtotal ............................................................................................................................................................................. 0.105

Branch River subbasin

Turex, Incorporated 2 Burrillville, RI RI0000116 .006

Atlantic Thermoplastics 3 North Smithfield, RI RI0000566 .001

Phillips Components 4 North Smithfield, RI RI0000019 .003

Subtotal ............................................................................................................................................................................. 0.010

Peters River subbasin

Osram Sylvania 5 Central Falls, RI RI0001180 .247

Air Products and Chemicals 6 Cumberland, RI RI0021865 .157

A.T. Cross 7 Lincoln, RI RI0000124 .006

Blackstone Valley Electric Company 8 Lincoln, RI RI0023132 .008

Fleet National Bank 9 Lincoln, RI RI0021865 0

Okonite Company 10 Lincoln, RI RI0020141 .159

Deblois Oil Company 11 North Smithfield, RI RI0021971 .013

ACS Industries, Incorporated 12 Woonsocket, RI RI0021393 .186

Subtotal ............................................................................................................................................................................. 0.776

West River subbasin

Blackstone Smithfield Corporation 13 North Smithfield, RI RI0000485 .004

Subtotal ............................................................................................................................................................................. 0.004

Abbott Run subbasin

Pawtucket WSB potable treatment plant 14 Cumberland, RI RI0001589 .269

Subtotal ............................................................................................................................................................................. 0.269

Total of the lower Blackstone River basin ............................................................................................................................ 1.164
32 Estimated Water Use and Availability in the Lower Blackstone River Basin, Northern Rhode Island and South-Central Massachusetts, 1995–99

71o48' 71o

42' 71o

36' 71o

30' 71o

24'

42o06'

42o

00'

41o

54'

Clear Rive r

Chepachet River Branch

River

Abbo t Run

Blackstone River

0 5 10 MILES

0 5 10 KILOMETERS

5

14

10

6 7 8 9

11

12

1

2

4 3

13

5

EXPLANATION

STUDY AREA

LAKES, PONDS, AND RESERVOIRS

RIVERS

NATIONAL POLLUTION DISCHARGE ELIMINATION 

 SYSTEM OUTFALL LOCATION—Numbers shown on table 10

Base from the National Resource Conservation Service

12-digit HUC base map, 1:24,000, (2001)

Projection: Rhode Island State Plane

SUBBASIN BOUNDARIES

MASSACHUSETTS

RHODE ISLAND

Clear Rive r

Chepachet River Branch

River

Abbo t Run

Blackstone River

Pet ers Riv er

B la ck stone Ri ver

GLOCESTER

SMITHFIELD

LINCOLN

CUMBERLAND WOONSOCKET

NORTH SMITHFIELD

BURRILLVILLE

DOUGLAS

UXBRIDGE

MILLVILLE

BLACKSTONE

BELLINGHAM

FRANKLIN

WRENTHAM

PLAINVILLE

NORTH 

ATTLEBORO

ATTLEBORO

PAWTUCKET

CENTRAL 

FALLS

Figure 10. National Pollution Discharge Elimination System outfalls for commercial and industrial facilities within the lower Blackstone River 

basin, northern Rhode Island and south-central Massachusetts.
Water Use 33

Public-disposal of domestic wastewater was 

calculated for the lower Blackstone River basin from 

estimated populations on public disposal for each town 

(Medalie, 1995) adjusted for population changes from 

1995 through 1999, multiplied by water use per capita 

minus consumptive use (eq. 1). Public disposal of 

commercial wastewater was calculated from the total 

commercial-use rates for the town minus the estimated 

consumptive-use rates and NPDES return flows for 

commercial facilities (eq. 2). Public disposal of industrial 

wastewater was calculated in the same manner as public 

disposal of commercial wastewater (eq. 3). Infiltration 

and inflow was estimated by subtracting the sum of all 

public-disposal wastewater estimates from the reported 

discharge rates at the municipal wastewater-treatment 

facilities (eq. 4).:

PDWWDom

= PDpop * (WUper capita – (0.15WUper capita)), (1)

PDWWCom = WUCom

– 0.10WUCom – NPDESCom, (2)

PDWWInd = WUInd – 0.10WUInd – NPDESInd, (3)

and

I/I = NPDESMun

– (PDWWDom + PDWWCom + PDWWInd), (4)

where

PDWWCom = public-disposal wastewater commercial,

PDWWDom = public-disposal wastewater domestic,

PDWWInd = public-disposal wastewater industrial,

PDpop = population on public-disposal,

WUper capita = water use per capita (per person),

WUCom = commercial water use,

WUInd = industrial water use,

NPDESCom = metered National Pollution Discharge

Elimination System return flows for 

commercial sites,

NPDESInd = metered National Pollution Discharge 

Elimination System return flows for 

industrial sites,

NPDESMun = metered National Pollution Discharge 

Elimination System return flows for 

municipal wastewater-treatment 

facilities, and

I/I = infiltration and inflow.

Wastewater Imports and Exports

The estimated amount of public wastewater 

collected from the lower Blackstone River basin was 

10.121 Mgal/d (table 11). When a municipal wastewatertreatment facility collects wastewater from outside 

of the subbasin, this wastewater is considered imported. 

Average wastewater imports ranged from 0.000 Mgal/d 

in the Chepachet, Branch, and Abbott Run subbasins to 

4.734 Mgal/d in the Peters River subbasin. Average 

wastewater imports for the lower Blackstone River basin 

were estimated at 1.818 Mgal/d (table 11).

When a municipal wastewater-treatment facility 

discharges wastewater outside of a subbasin but serves 

sections of town(s) within that subbasin, these discharges 

are considered wastewater exports. That is, they 

will be exported from the subbasin and treated at a 

wastewater-treatment facility outside the subbasin. 

Average wastewater exports ranged from 0.038 Mgal/d in 

the Clear River subbasin to 3.467 Mgal/d in the Peters 

River subbasin. Average total wastewater exports for the 

lower Blackstone River basin were 4.086 Mgal/d.

Infiltration and Inflow Estimates

Infiltration and Inflow (I/I) is water that enters the 

sewer system through indirect and direct means. 

Infiltration is extraneous water that enters the sewer 

system through leaking joints, cracks and breaks, or 

porous walls. Inflow is stormwater that enters the sewer 

system from storm-drain connections (catch basins), roof 

leaders, foundation and basement drains, or through 

manhole covers (Metcalf and Eddy, 1991).

The Burrillville WWTF in the Clear River 

subbasin provided wastewater-flow data by use type 

(John E. Martin, III, Superintendent, Burrillville WWTF, 

written commun., 2000) and was estimated to receive 

0.000 Mgal/d of infiltration and inflow. The Uxbridge 

WWTF in the West River subbasin was estimated to 

receive 0.268 Mgal/d of infiltration and inflow, 

which was about 37 percent of total metered NPDES 

discharge from the municipal wastewater-treatment 

facility. The Woonsocket WWTF in the Peters River 

subbasin was estimated to receive 2.639 Mgal/d of 

infiltration and inflow, which is about 30 percent of the 

total metered NPDES discharged from the municipal 

wastewater-treatment plant (table 11).
34 Estimated Water Use and Availability in the Lower Blackstone River Basin, Northern Rhode Island and South-Central Massachusetts, 1995–99

Table 11. Public disposal (estimated and metered) of wastewater, including imports, exports, and infiltration and inflow, self-disposal (onsite septic 

estimates and metered), and total return flows for the lower Blackstone River basin, northern Rhode Island and south-central Massachusetts, 1995–99—

Continued

Minor civil

division

Estimated Public-disposal Metered 

NPDES 

municipal 

WWTF 

discharge

Self-disposal 

Total 

wastewater 

return flow

Wastewater 

collected

within

subbasin

Imports Exports Infiltration/

Inflow

Onsite 

septic

Metered

NPDES (COM 

and IND)

Lower Blackstone River basin

Chepachet River subbasin

Burrillville 0.076 -- 0.076 -- -- 0.067 0 0.067

Glocester -- -- -- -- -- .198 0 .198

Subtotal ............ 0.076 -- 0.076 -- -- .266 0 .266

Clear River subbasin

Burrillville .656 0.231 0 0 0.812 .224 .105 1.141

Glocester -- -- -- -- -- .049 0 .049

Douglas .031 -- .031 -- -- .067 0 .067

Uxbridge .007 -- .007 -- -- .014 0 .014

Subtotal ............ 0.694 0.231 .038 0 0.812 0.354 0.105 1.271

Branch River subbasin

Burrillville .063 -- .063 -- -- .201 .006 .207

Glocester -- -- -- -- -- .206 0 .026

North Smithfield .182 -- .182 -- -- .204 .004 .208

Smithfield .001 -- .001 -- -- .002 0 .002

Millville -- -- -- -- -- .006 0 .006

Uxbridge .004 -- .004 -- -- .004 0 .004

Subtotal ............ 0.249 -- 0.249 -- -- 0.443 0.01 0.453

West River subbasin

Burrillville .002 -- .002 -- -- .027 0 .027

North Smithfield .16 -- .16 -- -- .114 .004 .114

Woonsocket 3.1935 -- 3.1935 -- -- .145 0 .145

Blackstone .077 -- .077 -- -- .152 0 .152

Douglas .009 -- .009 -- -- .014 0 .014

Millville -- -- -- -- -- .128 0 .128

Uxbridge .108 1.347 -- .268 .723 .116 0 .839

Subtotal ............ 3.55 0.347 3.442 0.268 0.723 0.696 0.004 1.419

Peters River subbasin

Central Falls .771 -- .771 -- -- .022 .247 .269

Cumberland 1.084 -- 1.084 -- -- .279 .157 .436

Lincoln .795 -- .795 -- -- .168 .173 .341

North Smithfield .028 .353 -- .204 .585 .06 .013 2.073

Pawtucket .55 -- .55 -- -- 0 0 0

Smithfield .061 -- .061 -- -- .023 0 .023

Woonsocket 1.417 3 4 54.229 -- 2.435 8.081 .046 .186 9.096

Attleboro .127 -- .127 -- -- .155 0 .155

Bellingham .054 0 -- 0 .049 .296 0 2.296

Table 11. Public disposal (estimated and metered) of wastewater, including imports, exports, and infiltration and inflow, self-disposal (on-site septic 

estimates and metered), and total return flows for the lower Blackstone River basin, northern Rhode Island and south-central Massachusetts, 1995–99

[Numbers may not sum correctly due to rounding errors. All values in million gallons per day. Italicized values indicate an import or export out of the study 

area. Wastewater collected within subbasin: Public-disposal estimates were made by equations 1-3 in the “Public disposal” section of this report. 

Infiltration/Inflow: Infiltration and inflow was estimated by equation 4 in the “Public disposal” section of this report. Total wastewater return flow:

Wastewater return flow is the sum of self-disposal (onsite septic and NPDES commercial and industrial sites) and NPDES metered discharge for municipal 

WWTFs. COM, commercial; IND, industrial; NPDES, National Pollution Discharge Elimination System; WWTF, wastewater-treatment facility; <, actual 

value is less than value shown; --, not applicable]
Water Use 35

10.336 Mgal/d of the 0.347 Mgal/d imported for public-disposal is from outside the study area. 2Wastewater is conveyed to the Woonsocket WWTF therefore, publicly collected wastewater return flow is reported on the Woonsocket line 

 under wastewater return flow.

3Includes an estimated 1.854 Mgal/d of wastewater collected from the Seville/Dorado Company, textile mill (Adel Banoub, Woonsocket WWTF, 

written commun., 2003). 4Includes an estimated 0.294 Mgal/d of wastewater imported to the subbasin from the dewatering process of a sludge merchant, Synagro, (Adel Banoub, 

Woonsocket WWTF, written commun., 2003). 51.036 Mgal/d of the 4.229 Mgal/d imported for public-disposal is from outside the study area.

Peters River subbasin—Continued

Blackstone 0.006 0.152 -- 0 0.149 0.003 0 20.003

Franklin .073 -- 0.073 -- -- .032 0 .032

Wrentham -- -- -- -- -- .031 0 .031

Subtotal ............ 4.968 4.734 3.467 2.639 8.86 1.114 0.776 10.782

Abbott Run subbasin

Cumberland .407 -- .407 -- -- .439 .269 .439

Attleboro .026 -- .026 -- -- .016 0 .016

Franklin .027 -- .027 -- -- .016 0 .016

North Attleboro .093 -- .093 -- -- .156 0 .156

Plainville .03 -- .03 -- -- .025 0 .025

Wrentham -- -- -- -- -- .135 0 .135

Subtotal ............ 0.583 -- 0.583 -- -- 0.787 0.269 1.429

Total of the lower 

Blackstone 

River basin ....... 10.121 1.818 4.086 2.907 10.395 3.66 1.164 15.219

Table 11. Public disposal (estimated and metered) of wastewater, including imports, exports, and infiltration and inflow, self-disposal (onsite septic 

estimates and metered), and total return flows for the lower Blackstone River basin, northern Rhode Island and south-central Massachusetts, 1995–99—

Continued

Minor civil

division

Estimated Public-disposal Metered 

NPDES 

municipal 

WWTF 

discharge

Self-disposal 

Total 

wastewater 

return flow

Wastewater 

collected

within

subbasin

Imports Exports Infiltration/

Inflow

Onsite 

septic

Metered

NPDES (COM 

and IND)

Wastewater discharge from municipal wastewatertreatment facilities in the lower Blackstone River basin 

ranged from 0.723 Mgal/d in the West River subbasin to 

8.860 Mgal/d in the Peters River subbasin. There 

are no municipal wastewater-treatment facilities in the 

Chepachet, Branch, and Abbott Run subbasins (table 11). 

Self-Disposal

Of the 19 municipalities included in this study, only 

Glocester, RI, and Wrentham and Millville, MA, entirely 

self-dispose of their wastewater. The 5-year average rate 

of self-disposal for the lower Blackstone River basin, 

including disposal from commercial and industrial 

NPDES discharge sites was 4.824 Mgal/d. An estimated 

3.660 Mgal/d, or 76 percent, was self-disposed through 

on-site septic and the remaining 1.164 Mgal/d, or 24 

percent, was discharged by commercial and industrial 

NPDES facilities (tables 10 and 11).

Total Return Flows

Wastewater-return flows by subbasin, including 

self-disposal and public disposal, indicate that the Clear 

River and Peters River subbasins have a net gain of 

wastewater. The remaining subbasins in the lower 

Blackstone River basin have a net loss of wastewater 

(imports minus exports). Total return flow of wastewater 

(public and self-disposal) ranged from 0.266 Mgal/d in 

the Chepachet River subbasin to 10.782 Mgal/d in the 

Peters River subbasin (table 11).

Water-Use Summary

Total withdrawals for the lower Blackstone 

River basin for the period 1995-99 were 29.869 Mgal/d 

(table 12). The 5-year average withdrawal rates ranged 

from 0.414 Mgal/d in the Chepachet River subbasin to 

15.221 Mgal/d in the Abbott Run subbasin. A net export 
36 Estimated Water Use and Availability in the Lower Blackstone River Basin, Northern Rhode Island and South-Central Massachusetts, 1995–99

1Includes 2.379 Mgal/d imported from the West River subbasin for use at the Ocean State Power thermoelectric facility. 2Includes 2.379 Mgal/d consumed at the Ocean State Power thermoelectric facility. 3Includes 2.379 Mgal/d withdrawn by Ocean State Power and 2.039 Mgal/d withdrawn by Seville/Dorado.

Table 12. Summary of estimated water withdrawals, imports, exports, use, non-account use, consumptive use, and return flow in the lower Blackstone 

River basin, northern Rhode Island and south-central Massachusetts, 1995–99

[Numbers may not sum correctly due to rounding. All values in million gallons per day. Net import or export: +, imports to subbasin and basin; -, exports 

from subbasin and basin. AG, agricultural; COM, commercial; DOM, domestic; IND, industrial; Mgal/d, --, million gallons per day; water use not applicable]

Subbasin

Water 

withdrawals

(public

and self)

Net import (+)

or export (-) of

potable water

Water use (public and self) Return Flow Net import (+)

or export (-) of 

wastewater

DOM, COM,

IND, AG

Non-account

(public use)

Consumptive useSurface 

water

Ground 

water

Chepachet River 0.414 0.002 0.409 0.007 0.079 0.000 0.266 -0.086

Clear River 1.093 2.4151 3.451 .058 2.5572 .917 .354 0.193

Branch River .864 -.002 .841 .022 .111 .010 .443 -0.249

West River to Peters River 5.0493 .042 4.843 .252 .582 .727 .696 -3.095

Peters River to mouth 7.226 .902 7.178 .944 .949 9.636 0.787 -1.267

Abbott Run 15.221 -12.839 1.799 .583 .254 .269 1.160 -0.583

Total of the study area.................. 29.869 -9.475 18.522 1.867 4.532 11.559 3.660 -2.268

of 9.475 Mgal/d of potable water for the lower Blackstone 

River basin was calculated. Net exports ranged 

from 0.002 Mgal/d in the Branch River subbasin to 

12.839 Mgal/d in the Abbott Run Subbassin. Net imports 

of water ranged from 0.002 Mgal/d in the Chepachet 

River subbasin to 2.415 Mgal/d in the Clear River 

subbasin (2.379 Mgal/d was imported into the Clear River 

subbasin for use at the Ocean State Power thermoelectric 

facility). 

Water use, including public and self-supply, 

for the lower Blackstone River basin was estimated at 

18.522 Mgal/d (not including non-account use). 

Water use ranged from 0.409 Mgal/d in the Chepachet 

River subbasin to 7.178 in the Peters River subbasin. Nonaccount water use totaled 1.867 Mgal/d for the lower 

Blackstone River basin and ranged from 0.007 Mgal/d in 

the Chepachet River subbasin to 0.944 Mgal/d in the 

Peters River subbasin. Consumptive use for the lower 

Blackstone River basin was estimated at 4.532 Mgal/d 

and ranged from 0.079 Mgal/d in the Chepachet River 

subbasin to 2.557 Mgal/d in the Clear River subbasin 

(2.379 Mgal/d was consumed at the Ocean State Power 

thermoelectric facility).

Surface-water return flow consisted of wastewater 

discharged at NPDES outfall locations. The total 

for the lower Blackstone River basin was 11.559 Mgal/d 

and ranged from 0.000 Mgal/d in the Chepachet River 

subbasin to 9.636 Mgal/d in the Peters River subbasin. 

Ground-water return flow for the lower Blackstone River 

basin was estimated at 3.660 Mgal/d and ranged from 

0.266 Mgal/d in the Chepachet River subbasin to 

1.160 Mgal/d in the Abbott Run subbasin. Overall, 

wastewater was exported from the lower Blackstone River 

basin. Net exports of wastewater for the lower Blackstone 

River basin were estimated at 2.268 Mgal/d and ranged 

from 0.086 Mgal/d in the Chepachet River subbasin to 

3.095 Mgal/d in the West River subbasin. The Clear River 

subbasin had a net import of wastewater at 0.193 Mgal/d. 

Withdrawals, use, and return flows for the lower 

Blackstone River basin are shown in figure 11.
Water Use 37

Domestic

Industrial

Commercial

Agricultural

 INCOMING TOTAL OUT- GOING

EXPLANATION

Mgal/d

% Percent

Million gallons per dayPublic supply and public disposalSelf-supply and self-disposalConsumptive use

Net export for use

Unaccounted-for use Unmetered wastewater 

(inflow and infiltration)

WATER USE

7.71Mgal/d

22.15Mgal/d

9.48Mgal/d

22.69Mgal/d

1.87Mgal/d

2.91Mgal/d

10.11Mgal/d

4.13Mgal/d

4.03Mgal/d

0.25Mgal/d

12.66Mgal/d

4.53Mgal/d

11.56Mgal/d

3.66 Mgal/d

2.27Mgal/d

 2.85 imported,12.33 exported

34.2%

65.8%

20.5%

79.5%

22.4%

77.6%

44.6%

8.2%

6.4%

<0.1%

8.2%

41.8%

20.6%

79.4%

65.6%

34.4%

63.7%

36.3%

99.0%

1.0%

33.7%

51.3%

15.0%

24.2%

65.8%

10.0%

10.3%26.3%

63.4%

24.0%

76.0%

32.1%

 8.7%

54.1%

4.0%

36.7%

63.3%

29.0%

31.7%

35.8%

3.5%

69.8% 24.1%

75.9%

7.17Mgal/d

4.88Mgal/d 10.1%

89.9%

1.82 imported,4.09 exported

82.1%17.9%

100%

20.5%

 8.5%

1.2%

43.7%

24.8%

 8.5%

23.0%

Public Disposal

Self Disposal

DISPOSAL

Net export for treatment

Ground-water

return flow

Surface-water

return flow

Consumptive use

Self Supply

Ground-water  withdrawal

Public Supply

Surface-water  withdrawal

SUPPLY

Figure 11. Water withdrawals (supply), use, and return flow (disposal) for the lower Blackstone River basin, northern Rhode Island and south-central Massachusetts.
38 Estimated Water Use and Availability in the Lower Blackstone River Basin, Northern Rhode Island and South-Central Massachusetts, 1995–99

WATER AVAILABILITY

This section describes the methods used to estimate 

water availability within the lower Blackstone River basin. 

The availability of ground-water discharge (base flow) for 

the lower Blackstone River basin was determined for four 

months: June, July, August, and September (referred to as 

the low-flow period). This determination was made from 

U.S. Geological Survey long-term streamflow-gaging 

stations. 

Base flow during the low-flow period was 

estimated for a reference site by the PART program 

developed by Rutledge (1998, 2000). Water-availability 

determinations described in this report include base-flow 

volumes determined by PART and safe-yield estimates for 

public-supply reservoirs within the lower Blackstone 

River basin. The safe-yield estimates for the Cumberland 

WD’s Sneech Pond, the Pawtucket Water Supply Board’s 

reservoir system, and the Woonsocket Water Division’s 

Crookfall Brook Reservoirs no. 1 and no. 3 and Harris 

Pond were obtained from the respective municipal water 

departments’ Water Supply Management Plans (Pare 

Engineering, 2000; Pawtucket Water Supply Board, 2000; 

and Camp, Dresser, and McKee, 1994). Harris Pond is 

outside the lower Blackstone River basin but supplies 

water to communities within the lower Blackstone River 

basin.

In addition, water availability was evaluated relative 

to withdrawals. Public- and self-supply withdrawals were 

divided by water-availability determinations for ground 

and surface water. The ratio of withdrawals to availability 

gives an indication of relative subbasin stress within the 

lower Blackstone River basin.

Streamflow depletions by ground-water 

withdrawals for six supply wells within the lower 

Blackstone River basin were analyzed with STRMDEPL, 

a program developed by Barlow (2000). These wells are 

in aquifers with different properties and are at different 

distances from nearby streams.

Streamflow-Gaging Stations 

Used in Analysis

The USGS has collected data for decades at three 

streamflow-gaging stations in the Blackstone River basin 

in Rhode Island (Socolow and others, 2000). These 

stations include the Nipmuc River near Harrisville, RI 

(01111300); the Branch River at Forestdale, RI 

(01111500); and the Blackstone River at Woonsocket, RI 

(01112500) (fig. 3, table 13). Each station was examined 

for possible use as a reference gaging station to estimate 

base flow for each of the six subbasins within the lower 

Blackstone River basin. From this group of stations, the 

Branch River at Forestdale, RI (01111500), was selected 

as the best reference station for the base-flow calculations. 

The overall saturated thickness of sand and gravel 

deposits within the drainage area associated with this 

station is representative of the other deposits in the 

lower Blackstone River basin. In addition, discharge 

records at this site are rated as fair. Currently, flows at the 

Forestdale station have occasional minor regulation from 

an upstream pond. Prior to 1957, there was greater 

regulation (Socolow and others, 2000); for this reason, 

only discharge records from the calendar years 1957–99 

were used for analysis.

To normalize flows between the different subbasins 

in the lower Blackstone River basin, the areal extent of 

sand and gravel deposits upstream of the Forestdale 

station was determined with the MassGIS basin tools and 

a coverage of sand and gravel deposits.

Table 13. U.S. Geological Survey streamflow-gaging stations in the lower Blackstone River basin, northern Rhode Island and south-central Massachusetts

[Latitude and longitude: In degrees, minutes, and seconds. No., number; USGS, U.S. Geological Survey; mi2, square mile]

USGS station No. Name Latitude

° ′ ′′

Longitude

° ′ ′′

Period of record 

(years)

Drainage area

(mi2)

1111300 Nipmuc River near Harrisville, RI 41 58 52 71 41 11 33 16

1111500 Branch River at Forestdale, RI 41 59 47 71 33 47 59 91.2

1112500 Blackstone River at Woonsocket, RI 42 00 22 71 30 13 70 416
Water Availability 39

Method Used to Estimate 

Base-Flow Volumes

This section describes the method (Rutledge, 

1998 and 2000) used to calculate base flow in the lower 

Blackstone River basin. On the basis of this method and 

two minimum streamflow criteria (the 7-day, 10-year low 

flow [7Q10, Socolow and others, (2000)] and Aquatic 

Base Flow [ABF, U.S. Fish and Wildlife Service, (1981)], 

available base-flow volumes for the low-flow period were 

calculated. 

The computer programs RECESS and PART 

(Rutledge, 1998) were used to estimate ground-water 

discharge (base flow) for the Branch River at Forestdale 

during the low-flow period. RECESS uses input data 

generated from long-term streamflow-gaging records 

stored in the USGS Automated Data Processing System 

(ADAPS) to calculate the master recession constant (K). 

The K value calculated by the RECESS program at the 

Branch River at Forestdale was 30.9 days per log cycle for 

calendar years 1957–99. 

The K value is input into the PART program, which 

calculates base flow. Output from PART is given as daily, 

monthly, and quarterly streamflow and base flow in 

inches. Base flow from PART was then converted to a 

flow rate by using the drainage area for the Forestdale 

station. To estimate available base flow, the 7Q10 and 

ABF were subtracted from the monthly base-flow 

volumes calculated for the period 1957-99. The 7Q10 is 

the discharge at the 10-year recurrence interval taken from 

a frequency curve of annual values of the lowest mean 

discharge for 7 consecutive days (Socolow and others, 

2000). The 7Q10 is commonly used to assess the capacity 

of a river to carry pollutants (Kliever, 1996). The 7Q10 

calculated for the Forestdale streamflow-gaging station 

was 11.9 ft3/s (7.9 Mgal/d), which corresponds to the 

99.5-percent flow duration. Aquatic Base Flow, an 

alternative minimum streamflow criterion, is often set at 

0.5 ft3/s/mi2 of drainage area when no discharge records 

are available; however, when discharge records are 

available, it can be calculated as the median of the August 

daily means or the median of the August monthly means 

(Ries, 1997). The ABF is considered the minimum 

streamflow necessary to protect indigenous aquatic fauna 

throughout the year (U.S. Fish and Wildlife, 1981). The 

ABF for the Forestdale station was calculated as the 

median of the August monthly means for 1957 through 

1999. The ABF was 38.8 ft3/s (25.1 Mgal/d), which 

corresponds to the 83.6-percent flow duration. 

All values of available base flow for the 42 years of 

interest were plotted by month and minimum streamflow 

criterion (fig. 12). On the basis of the ABF criterion, the 

base flow at the Branch River at Forestdale was below the 

ABF about 66 percent of the time in August, 55 percent of 

the time in September, 46 percent of the time in July, and 

6 percent of the time in June for the period 1957–99 

(fig. 12). Water-availability estimates made from baseflow calculations are conservative estimates because 

actual streamflows are generally greater than base flow 

except for periods of no recharge. 

Available base-flow volumes at the Branch River at 

Forestdale station decrease from June to August and then 

increase slightly in September (fig. 12). In addition, the 

range in available base-flow volumes decreases as the 

summer progresses. This may be due to the larger 

variability in precipitation volumes in June compared to 

the other months of the low-flow period. Available baseflow volumes calculated at the 50th percentile with 

the 7Q10 criterion ranged from 1,180 Mgal (about 

39.3 Mgal/d) in June to 428 Mgal (about 13.8 Mgal/d) in 

August. The available base-flow volume calculated 

with the ABF criterion ranged from 658 Mgal (about 

21.9 Mgal/d) in June to 0 Mgal in August and September. 

This means that base flow at the 50th percentile was 

below the ABF in August and September (table 14).

Safe-Yield Analysis for 

Public-Supply Reservoirs

Safe-yield analyses for the surface-water reservoirs 

within the lower Blackstone River basin have been done 

by consulting firms and reported in the municipal water 

departments’ Water Supply Management Plans (Pare 

Engineering Corporation, 2000; Pawtucket Water Supply 

Board, 2000; Camp, Dresser, and McKee, 1994). Safeyield analyses for the Pawtucket WSB and the 

Woonsocket WD were based on the drought of record for 

Rhode Island during 1964–66. The drought used to 

calculate the Cumberland WD safe-yield estimate for 

Sneech Pond was not identified in the Water Supply 

Management Plan (Pare Engineering Corporation, 2000); 

however, safe-yield determinations are often based on the 

routing of streamflows for the selected period through the 

water-supply system (Camp, Dresser, and McKee, 1994).
40 Estimated Water Use and Availability in the Lower Blackstone River Basin, Northern Rhode Island and South-Central Massachusetts, 1995–99

500

400

300

200

100

-100

0

JUNE JULY AUGUST SEPTEMBER

WATER AVAILABLE (BASE FLOW MINUS MINIMUM STREAMFLOW),

 IN MILLION CUBIC FEET

-750

750

1,500

2,240

3,740

2,990

0

90th percentile

75th percentile

50th percentile

25th percentile

10th percentile

Mean

MONTH AND MINIMUM STREAMFLOW CRITERIA 

WATER AVAILABLE (BASE FLOW MINUS MINIMUM STREAMFLOW),

 IN MILLION GALLONS

7Q10

ABF

7-day, 10-year low flow

Aquatic Base Flow

Figure 12. Available base flow calculated as base flow minus minimum streamflow determined by two criteria, the 7-day, 10-year low flow (7Q10) and 

Aquatic Base Flow (ABF), for June, July, August, and September for the period 1957–99 at the streamflow-gaging station at the Branch River at Forestdale, 

Rhode Island (U.S. Geological Survey station number 01111500). 

Table 14. Available base-flow volumes calculated at the 50th percentile by the PART program minus minimum streamflows determined by two criteria, 

the 7-day 10-year low flow and the Aquatic Base Flow, for the Branch River at Forestdale (01111500) for June, July, August, and September for the period 

1957–99

[7Q10, 7-day 10-year low flow; ABF, Aquatic Base Flow; Mgal, million gallons; Mft3, million cubic feet]

Minimum

flow criteria

Available base flow in Mgal (Mft3) Minimum

flow criteria

Available base flow in Mgal (Mft3)

June July August September June July August September

7Q10 1,180 (158) 586 (78) 428 (57) 483 (65) ABF 658 (88) 47 (6) 0 (0) 0 (0)
Water Availability 41

Safe-yield estimates for the three municipal water 

suppliers with surface-water reservoirs range from 0.75 to 

16 Mgal/d (table 15). The safe yield of the Cumberland 

WD’s Sneech Pond was estimated at 0.75 Mgal/d. The 

combined safe yield of the Woonsocket WD’s Crookfall 

Brook Reservoirs was estimated at 3.5 Mgal/d, and 

the Harris Pond Reservoir safe yield was estimated 

at 4.4 Mgal/d. The largest surface-water safe yield was 

within the Pawtucket WSB’s reservoir system and was 

estimated at 16 Mgal/d. These safe-yield estimates were 

compared to the 5-year average demand. The results show 

that 5-year average withdrawals from Sneech Pond and 

the Crookfall Brook Reservoirs are greater than the 

safe-yield estimates. In contrast, withdrawals from the 

Pawtucket WSB’s reservoir system and the Woonsocket 

WD’s Harris Pond are 75.1 and 6.7 percent of their safeyield estimates, respectively (table 15). 

Evaluation of Water Availability and 

Basin Stress

Water availability in the six subbasins of the lower 

Blackstone River basin was evaluated for the low-flow 

period. Water availability as described in this report is the 

sum of available base-flow and safe-yield estimates.

A regression equation relating the percent area of 

sand and gravel deposits to the percent contribution of 

base flow from sand and gravel was developed for six 

streamflow-gaging stations in the Pawcatuck River basin 

in Rhode Island (P.J. Zarriello, U.S. Geological Survey, 

written commun., 2003). Based on this equation, 60 

percent of base flow at the Forestdale station in Rhode 

Island would be from sand and gravel deposits and the 

remaining 40 percent would be from till deposits. 

Johnston and Dickerman (1974a) reported that, on 

average, about 78 percent of the base flow in the Branch 

River subbasin was assumed to be from sand and gravel 

deposits and the remaining 22 percent from till. Based 

on these two sources of information, the median base 

flow during the low-flow period ranges from 0.958 to 

1.242 ft3/s/mi2 (0.619 to 0.803 Mgal/d/mi2) for sand and 

gravel deposits and 0.163 to 0.293 ft3/s/mi2 (0.105 to 

0.189 Mgal/d/mi2) for till deposits. 

The analysis presented in this report is 

based on the results of the regression equation and 

estimates that 60 percent of base flow is from sand and 

gravel (0.619 Mgal/d/mi2) and 40 percent is from till 

(0.189 Mgal/d/mi2). Although the Johnston and 

Dickerman (1974a) results may be attributable to the

thinner till deposits in the Branch River basin as compared 

to those in the Pawcatuck River basin, methods for 

estimating flow from till have evolved over the years and 

therefore the regression equation developed for the 

streamflow-gaging stations in the Pawcatuck River basin 

was used to estimate the contribution from each aquifer 

type.

To estimate available base flow by subbasin, the 

available base flow calculated at the Forestdale 

streamflow-gaging station per square mile of sand and 

gravel deposits and till deposits was multiplied by the area 

of the respective deposits in each subbasin (table 16). 

The drainage area for the Forestdale station is composed 

of about 28.7 mi2 of sand and gravel deposits and about 

62.5 mi2 of till deposits. Upstream subbasins were not 

considered in the available base-flow calculations used in 

the relative-stress ratios, because withdrawal data were 

not available for all upstream areas. 

Water withdrawals and return flows for the 

Chepachet, Clear, and Branch River subbasins, which 

compose about 98 percent of the drainage area to the 

Branch River station at Forestdale, were evaluated for any 

Table 15. Safe-yield estimates and 5-year average demand for surfacewater reservoirs of three municipal water suppliers in the lower Blackstone 

River basin, northern Rhode Island and south-central Massachusetts, 

1995–99

[WD, water department; WDIV, water division; WSB, water supply board; 

Mgal/d, million gallons per day]

Municipal 

water supplier Source

Safe

yield

(Mgal/d)

5-year 

average 

demand

(Mgal/d)

Percent

of safe

yield

Lower Blackstone River Basin

Peters River subbasin

Cumberland 

WD

Sneech Pond 0.75 0.837 111.6

Woonsocket 

WDIV

Crookfall Brook 

Reservoirs No. 1 

and 3

3.5 4.759 136

Abbott Run subbasin

Pawtucket 

WSB

Diamond Hill, 

Arnolds Mills, 

Robin Hollow Pond, 

and Happy Hollow 

Reservoirs

16 12.017 75.1

Outside the lower Blackstone River basin

Mill River subbasin

Woonsocket 

WDIV

Harris Pond 4.4 0.293 6.7
42 Estimated Water Use and Availability in the Lower Blackstone River Basin, Northern Rhode Island and South-Central Massachusetts, 1995–99

anthropogenic factors that might influence base flow at 

the station. During the study period 2.371 Mgal/d of water 

was withdrawn (table 5) and 1.990 Mgal/d returned 

through on-site septic and the municipal wastewatertreatment facilities (table 11) during 1995–99; these 

values represent a net loss of 0.381 Mgal/d. This net loss 

is less than 3 percent of the median base flow at the station 

for August. For this reason, anthropogenic factors were 

considered to have a negligible affect on base flow. 

Median water availability for each subbasin was 

calculated for the low-flow period by subtracting the 

7Q10 and ABF from base-flow estimates and adding safeyield estimates for public-supply reservoirs (table 17 and 

fig. 13). These estimates indicate that Abbott Run 

subbasin has the largest volume of available water and the 

Chepachet River subbasin had the smallest volume of 

available water (table 17). Water-availability estimates 

were calculated at the 14-digit HUC level; interpolation of 

this data to smaller areas may overestimate or 

underestimate availability.

The medians of the available water volumes 

estimated for June were larger than for any other summer 

month: 106.8 Mgal/d (7Q10) and 68.5 Mgal/d (ABF). The 

median based on the ABF criterion was about 64 percent 

of the available volume based on the 7Q10 criterion. The 

medians based on the 7Q10 criterion for July, August, and 

September were about 58, 47, and 52 percent of the 

corresponding volume estimated for June. The median 

based on the ABF criterion for July was about 34 percent 

of the volume estimated in June. In August and 

September, median base flow calculated by PART was 

less than the ABF; however, estimates indicated that water 

was available from surface-water safe yield. 

In addition to the medians of available water 

estimates, the 75th and 25th percentiles for available water 

estimates for each subbasin and the lower Blackstone 

River basin were calculated (table 17) to provide a range 

of values over the low-flow period to aid in management 

of water resources within the basin. Because the month of 

August has the lowest base flow, median results for 

August are highlighted to illustrate the stresses that the 

basin is likely to undergo in a typical year. Due to the fact 

that the ABF criterion is higher than the calculated base 

flow at the 50th percentile in August, results presented use 

the 7Q10 as the minimum streamflow criterion.

Overall, water availability for the lower Blackstone 

River basin ranges from 42.4 Mgal/d to 181.8 Mgal/d in 

June, 20.2 Mgal/d to 96.7 Mgal/d in July, 20.2 Mgal/d to 

85.5 Mgal/d in August, and 20.2 Mgal/d to 97.5 Mgal/d in 

September (table 17). Estimated yields from sand and 

gravel deposits and till deposits are presented in table 18.

To evaluate basin stress by subbasin, the average 

monthly withdrawal volumes from surface- and groundwater by subbasin for the period 1995–99 (table 19) were 

divided by estimates of available water (table 17): 

, (5)

where

R = basin-stress ratio (when ratio equals 1, 

withdrawals equal available water), 

W (G + S) = the sum of the 5-year average monthly 

withdrawals (W) from ground (G) and 

surface (S) water for the low-flow period 

within the subbasin,

BF = base-flow estimates based on the Branch 

River at Forestdale streamflow-gaging 

station, and

ΣS = the sum of safe-yield estimates for all the 

surface-water systems in the subbasin.

Table 16. Area of sand and gravel and till deposits and percent of sand 

and gravel deposits within the lower Blackstone River basin, northern 

Rhode Island and south-central Massachusetts

[SGD, sand and gravel deposits; mi2, square miles]

Subbasin

Area (mi2)

Subbasin SGD in 

subbasin

Till in 

subbasin

Percent of sand 

and gravel 

deposits in 

subbasin

Chepachet 21.3 8.6 12.7 40.4

Clear 45.5 10.4 35.1 22.8

Branch 26.3 10.2 16.2 38.8

West River to 

Peters River

34.6 12.5 22.1 36.1

Peters River to 

mouth

43.1 15.5 27.6 36

Abbott Run 27.3 7 20.3 25.6

Study area 198.1 64.2 133.9 32.4

R WG S ( ) +

BF + ΣS = -----------------------
Water Availability 43

1Water-availability estimates for the basin include safe-yield estimates of 4.2 Mgal/d in the Peters River subbasin and 16.0 Mgal/d in the Abbott Run 

subbasin.

Table 17. Summary of water availability, defined as base flow plus safe-yield estimates, for June through September in the lower Blackstone River basin, 

northern Rhode Island and south-central Massachusetts, 1957–99

[All values in million gallons per day. 7Q10, 7-day 10-year low flow; ABF, Aquatic Base Flow; Mgal/d, million gallons per day]

 Subbasin

Percentile of base flow Percentile of base flow minus the 7Q10 Percentile of base flow minus the ABF

75th 50th 25th 75th 50th 25th 75th 50th 25th

June

Chepachet River 19.2 12.3 9.2 17.2 10.3 7.2 12.6 5.7 2.6

Clear River 32.4 20.8 15.57 29 17.4 12.1 21.3 9.7 4.4

Branch River 23.3 14.9 11.1 20.8 12.5 8.7 15.3 6.9 3.2

West River 29.7 19 14.2 26.6 15.9 11.1 19.5 8.9 4.1

Peters River 36.7 23.5 17.6 32.9 19.7 13.7 24.2 11 5

Abbott Run 20.3 13 9.7 18.2 10.9 7.6 13.3 6.1 2.8

Basin total1............... 181.8 123.7 97.5 164.9 106.8 80.6 126.6 68.5 42.4

July

Chepachet River 9.1 6.9 4.5 7.1 4.9 2.5 2.5 0.4 0

Clear River 15.3 11.7 7.7 12 8.3 4.3 4.3 0.7 0

Branch River 11 8.4 5.5 8.6 6 3.1 3.1 0.5 0

West River 14 10.7 7 10.9 7.6 3.9 3.9 0.6 0

Peters River 17.4 13.3 8.7 13.6 9.5 4.9 4.8 0.8 0

Abbott Run 9.6 7.3 4.8 7.5 5.2 2.7 2.7 0.4 0

Basin total1............... 96.7 78.7 58.5 79.8 61.8 41.6 41.6 23.6 20.2

August

Chepachet River 7.7 5.6 3.5 5.7 3.6 1.5 1.2 0 0

Clear River 13.1 9.5 5.9 9.7 6.1 2.5 2 0 0

Branch River 9.4 6.8 4.2 7 4.4 1.8 1.4 0 0

West River 12 8.7 5.4 8.9 5.6 2.3 1.8 0 0

Peters River 14.8 10.7 6.7 11 6.9 2.8 2.3 0 0

Abbott Run 8.2 5.9 3.7 6.1 3.8 1.5 1.3 0 0

Basin total1............... 85.5 67.5 49.5 68.6 50.6 32.6 30.3 20.2 20.2

September

Chepachet River 9.2 6.2 4.2 7.2 4.2 2.2 2.6 0 0

Clear River 15.5 10.5 7.1 12.1 7.1 3.7 4.4 0 0

Branch River 11.1 7.5 5.1 8.7 5.1 2.7 3.2 0 0

West River 14.2 9.6 6.5 11.1 6.5 3.4 4.1 0 0

Peters River 17.6 11.9 8.1 13.7 8.1 4.2 5 0 0

Abbott Run 9.7 6.6 4.4 7.6 4.4 2.3 2.8 0 0

Basin total1............... 97.5 72.6 55.7 80.6 55.7 38.8 42.4 20.2 20.2
44 Estimated Water Use and Availability in the Lower Blackstone River Basin, Northern Rhode Island and South-Central Massachusetts, 1995–99 5 Mi 0 5 Km 0 —Ratio includes 16.0 Mgal/d of available water from Pawtucket Water Supply Board Reservoir system safe-yield estimate. —Ratio includes 4.25 Mgal/d of available water from Sneech Pond and Crookfall Brook Reservoirs no. 1 and 3 safe-yield estimates. 7-DAY, 10-YEAR LOW FLOW AQUATIC BASE FLOW JUNE JULY AUG. SEPT. MONTH 0.1

1

10

100

AVAILABLE WATER, IN MILLION 

GALLONS PER DAY

7Q10ABF

7Q10ABF

7Q10ABF

7Q10ABF

7Q10ABF

7Q10ABF

JUNE JULY AUG. SEPT.

MONTH

JUNE JULY AUG. SEPT.

MONTH

JUNE JULY AUG. SEPT.

MONTH

JUNE JULY AUG. SEPT.

MONTH

JUNE JULY AUG. SEPT.

MONTH

0.1

1

10

100

AVAILABLE WATER, IN MILLION 

GALLONS PER DAY

0.1

1

10

100

AVAILABLE WATER, IN MILLION 

GALLONS PER DAY

0.1

1

10

100

AVAILABLE WATER, IN MILLION 

GALLONS PER DAY

0.1

1

10

100

AVAILABLE WATER, IN MILLION 

GALLONS PER DAY

0.1

1

10

100

AVAILABLE WATER, IN MILLION 

GALLONS PER DAY

West River Peters River

Abbott Run

Branch River Chepachet River

Clear River

7Q10

ABF

42o

41o55'

42o05'

71o45' 71o40'

MASSACHUSETTS

RHODE ISLAND

West River Subbasin

Abbott Run 

Subbasin Clear River Subbasin Branch River Subbasin Peters River

Subbasin

Chepachet

River 

Subbasin

71o35' 71o30' 71o25'

EXPLANATION

RATIO OF ALL GROUND- AND SURFACE-WATER WITHDRAWALS TO WATER AVAILABILITY—The base-flow portion of the water availability estimates used in the ratio calculation are from the sand and gravel deposits within the subbasin only.

0.13

0.95

0.74

0.85

0.13

0.21

0.21

0.95

0.85

0.74

0.21

Figure 13. Subbasin stress indicated by the ratio of water withdrawals, 1995–99, to estimated water availability, 1957–99, during August; and graphs of water availability for June, July, August, and 

September for the six subbasins within the lower Blackstone River basin, northern Rhode Island and south-central Massachusetts.
Water Availability 45

Table 18. Summary of water availability, defined as base flow by aquifer type plus safe-yield, for June through September in the lower Blackstone River 

basin, northern Rhode Island and south-central Massachusetts, 1957–99—Continued

 Subbasin

Percentile of base flow Percentile of base flow minus the 7Q10 Percentile of base flow minus the ABF

75th 50th 25th 75th 50th 25th 75th 50th 25th

June

Estimated Yields from Sand and Gravel Deposits

Chepachet River 13.2 8.5 6.3 11.9 7.1 4.9 8.7 4 1.8

Clear River 15.9 10.2 7.6 14.3 8.5 6 10.5 4.8 2.2

Branch River 15.7 10 7.5 14 8.4 5.9 10.3 4.7 2.1

West River 19.3 12.3 9.2 17.3 10.3 7.2 12.7 5.8 2.6

Peters River 23.8 15.2 11.4 21.3 12.7 8.9 15.7 7.1 3.3

Abbott Run 10.7 6.9 5.1 9.6 5.8 4 7.1 3.2 1.5

Subtotal .................... 98.6 63.2 47.2 88.3 52.8 36.9 64.9 29.5 13.5

Estimated Yields from Till Deposits

Chepachet River 6 3.8 2.8 5.3 3.2 2.2 3.9 1.8 .8

Clear River 16.5 10.6 7.9 14.8 8.8 6.2 10.9 4.9 2.3

Branch River 7.6 4.9 3.6 6.8 4.1 2.8 5 2.3 1

West River 10.4 6.7 5 9.3 5.6 3.9 6.8 3.1 1.4

Peters River 13 8.3 6.2 11.6 6.9 4.8 8.5 3.9 1.8

Abbott Run 9.5 6.1 4.6 8.5 5.1 3.6 6.3 2.8 1.3

Subtotal .................... 62.9 40.3 30.1 56.3 33.7 23.5 41.4 18.8 8.6

Basin total1........... 181.7 123.7 97.5 164.8 106.7 80.6 126.5 68.5 42.3

July

Estimated Yields from Sand and Gravel Deposits

Chepachet River 6.3 4.8 3.1 4.9 3.4 1.7 1.7 0.3 0

Clear River 7.5 5.8 3.8 5.9 4.1 2.1 2.1 .3 0

Branch River 7.4 5.7 3.7 5.8 4 2.1 2.1 .3 0

West River 9.1 7 4.6 7.1 5 2.5 2.5 .4 0

Peters River 11.3 8.6 5.6 8.8 6.1 3.1 3.1 .5 0

Abbott Run 5.1 3.9 2.5 4 2.8 1.4 1.4 .2 0

Subtotal .................... 46.7 35.7 23.3 36.4 25.4 13 13 2 0

Estimated Yields from Till Deposits

Chepachet River 2.8 2.2 1.4 2.2 1.5 .8 .8 .1 0

Clear River 7.8 6 3.9 6.1 4.2 2.2 2.2 .3 0

Branch River 3.6 2.8 1.8 2.8 2 1 1 .2 0

West River 4.9 3.8 2.5 3.8 2.7 1.4 1.4 .2 0

Peters River 6.1 4.7 3.1 4.8 3.3 1.7 1.7 .3 0

Abbott Run 4.5 3.4 2.3 3.5 2.5 1.3 1.3 .2 0

Subtotal .................... 29.8 22.8 14.9 23.2 16.2 8.3 8.3 1.3 0

Basin total1........... 96.7 78.7 58.4 79.8 61.8 41.5 41.5 23.5 20.2

Table 18. Summary of water availability, defined as base flow by aquifer type plus safe yield, for June through September in the lower Blackstone River 

basin, northern Rhode Island and south-central Massachusetts, 1957–99

[All values in million gallons per day. 7Q10, 7-day 10-year low flow; ABF, Aquatic Base Flow; Mgal/d, million gallons per day]
46 Estimated Water Use and Availability in the Lower Blackstone River Basin, Northern Rhode Island and South-Central Massachusetts, 1995–99

1Water-availability estimates for the basin include safe-yield estimates of 4.2 Mgal/d in the Peters River subbasin and 16.0 Mgal/d in the Abbott Run 

subbasin.

August

Estimated Yields from Sand and Gravel Deposits

Chepachet River 5.3 3.9 2.4 4 2.5 1 0.8 0 0

Clear River 6.4 4.7 2.9 4.8 3 1.2 1 0 0

Branch River 6.3 4.6 2.8 4.7 2.9 1.2 1 0 0

West River 7.8 5.6 3.5 5.8 3.6 1.5 1.2 0 0

Peters River 9.6 7 4.3 7.1 4.5 1.8 1.5 0 0

Abbott Run 4.3 3.1 1.9 3.2 2 .8 .7 0 0

Subtotal .................... 39.8 28.8 17.9 29.5 18.5 7.5 6.1 0 0

Estimated Yields from Till Deposits

Chepachet River 2.4 1.7 1.1 1.8 1.1 .5 .4 0 0

Clear River 6.7 4.8 3 4.9 3.1 1.3 1 0 0

Branch River 3.1 2.2 1.4 2.3 1.4 .6 .5 0 0

West River 4.2 3 1.9 3.1 2 .8 .6 0 0

Peters River 5.2 3.8 2.3 3.9 2.4 1 .8 0 0

Abbott Run 3.8 2.8 1.7 2.8 1.8 .7 .6 0 0

Subtotal .................... 25.4 18.4 11.4 18.8 11.8 4.8 3.9 0 0

Basin total1........... 85.4 67.4 49.5 68.5 50.5 32.5 30.2 20.2 20.2

September

Estimated Yields from Sand and Gravel Deposits

Chepachet River 6.3 4.3 2.9 4.9 2.9 1.5 1.8 0 0

Clear River 7.6 5.2 3.5 6 3.5 1.8 2.2 0 0

Branch River 7.5 5.1 3.4 5.9 3.4 1.8 2.1 0 0

West River 9.2 6.2 4.2 7.2 4.2 2.2 2.6 0 0

Peters River 11.4 7.7 5.2 8.9 5.2 2.7 3.3 0 0

Abbott Run 5.1 3.5 2.4 4 2.4 1.2 1.5 0 0

Subtotal .................... 47.2 31.9 21.6 36.9 21.6 11.3 13.5 0 0

Estimated Yields from Till Deposits

Chepachet River 2.8 1.9 1.3 2.2 1.3 .7 .8 0 0

Clear River 7.9 5.3 3.6 6.2 3.6 1.9 2.3 0 0

Branch River 3.6 2.5 1.7 2.8 1.7 .9 1 0 0

West River 5 3.4 2.3 3.9 2.3 1.2 1.4 0 0

Peters River 6.2 4.2 2.8 4.8 2.8 1.5 1.8 0 0

Abbott Run 4.6 3.1 2.1 3.6 2.1 1.1 1.3 0 0

Subtotal .................... 30.1 20.4 13.8 23.5 13.8 7.2 8.6 0 0

Basin total1........... 97.5 72.5 55.6 80.6 55.6 38.7 42.3 20.2 20.2

Table 18. Summary of water availability, defined as base flow by aquifer type plus safe-yield, for June through September in the lower Blackstone River 

basin, northern Rhode Island and south-central Massachusetts, 1957–99—Continued

 Subbasin

Percentile of base flow Percentile of base flow minus the 7Q10 Percentile of base flow minus the ABF

75th 50th 25th 75th 50th 25th 75th 50th 25th
Water Availability 47

The basin-stress ratio gives an indication of how 

much of a water resource is currently utilized in relation to 

its long-term availability. This ratio, calculated for the 

month of August at the 50th percentile minus the 7Q10 

minimum flow, ranged from 0.13 in the Chepachet River 

subbasin to 0.95 in the Abbott Run subbasin (table 20 and 

fig. 13). Water-availability estimates and basin-stress 

ratios were calculated from subbasin to subbasin, which 

does not reflect the cumulative demand from upstream 

subbasins. Overall availability and basin stress for the 

lower Blackstone River basin as a whole is presented in 

tables 18 and 20. The Abbott Run subbasin had the 

highest level of subbasin stress. Water withdrawals in this 

subbasin provide water to two major suppliers: the 

Pawtucket WSB in Rhode Island and the North Attleboro 

WD in Massachusetts. The basin-stress ratio calculated 

for August for the entire lower Blackstone River basin at 

the 50th percentile minus the 7Q10 minimum flow was 

0.68. That is, 68 percent of the available water calculated 

for a typical year is withdrawn from the lower Blackstone 

River basin in August, while the 7Q10 streamflow is 

maintained. 

Overall, the basin-stress ratio for the lower 

Blackstone River basin ranges from 0.19 to 0.83 in June, 

0.36 to 1.50 in July, 0.40 to 1.14 in August, and 0.31 to 

0.78 in September (table 20). Basin-stress ratios based on 

the ABF minimum flow could not be calculated at the 

25th percentile from July to September and at the 50th and 

25th percentiles in August and September because base 

flow at these percentiles is less than the ABF minimum 

flow.

Streamflow Depletion by 

Ground-Water Withdrawals

The computer program STRMDEPL developed by 

Barlow (2000) was used to evaluate the effects of groundwater withdrawals on streamflow depletion. STRMDEPL 

calculates streamflow depletion caused by time-varying 

pumping at a well. The program is based on analytical 

solutions to the ground-water-flow equations developed 

by Jenkins (1968) and Hantush (1965). The solution of 

Jenkins (1968) assumes unimpeded connection between 

the stream and the aquifer, whereas that of Hantush (1965) 

accounts for resistance to flow at the boundary between 

the stream and aquifer caused by semipervious streambed 

and streambank materials. The following simplifying 

assumptions must be made in the application of the 

analytical solutions (Barlow, 2000):

1. The aquifer is isotropic, homogeneous, and 

semi-infinite in areal extent;

2. The transmissivity of the aquifer does not change 

with time. Thus, for a water-table aquifer, drawdown 

is considered to be negligible when compared to the 

initial saturated thickness of the aquifer;

3. The stream that forms a boundary to the aquifer is 

straight, fully penetrates the aquifer, and is in direct 

hydraulic connection with the aquifer;

4. The stage of the stream (and the ground-water head 

at the stream boundary) remains constant with time;

5. Water is released instantaneously from storage;

6. The well is open to the full saturated thickness of the 

aquifer; and

7. The pumping rate is steady during any period of 

pumping.

Two separate analyses were done for public-supply 

wells in the lower Blackstone River basin. In the first 

analysis, specified daily pumping rates were used to 

calculate streamflow depletion caused by the Cumberland 

WD’s Manville well no. 1 during the 5-year period of 

study, 1995–99, on the basis of the Jenkins equation. In 

the second analysis, streamflow depletion caused by a 

constant pumping rate was calculated at six public-supply 

wells during 10-, 20-, and 30-day periods (table 21). The 

second analysis was done to simulate relative streamflow 

depletions during one month at wells in aquifers with 

different properties and at different distances to a nearby 

stream. Streamflow depletion caused by pumping at the 

six public-supply wells was calculated on the basis of the 

Jenkins equation for two of the wells and the Hantush 

equation for four of the wells.

Table 19. Average water-withdrawal rates for the low-flow period in the 

lower Blackstone River basin, northern Rhode Island and south-central 

Massachusetts, 1995–99

[All values in million gallons per day]

Subbasin

5-year average withdrawal rates for low-flow 

period

June July August September

Chepachet River 0.487 0.508 0.462 0.372

Clear River 1.344 1.402 1.289 1.379

Branch River .952 .981 .916 .817

West River 5.303 4.435 4.758 4.577

Peters River 8.638 8.763 8.245 7.349

Abbott Run 18.305 19.211 18.89 15.622

Basin total ................... 35.029 35.3 34.56 30.116
48 Estimated Water Use and Availability in the Lower Blackstone River Basin, Northern Rhode Island and South-Central Massachusetts, 1995–99

Table 20. Summary of basin-stress ratios for June through September in the lower Blackstone River basin, northern Rhode Island and south-central 

Massachusetts, 1957–99

[7Q10, 7-day 10-year low flow; ABF, Aquatic Base Flow; --, not applicable]

 Subbasin

Percentile of available water Percentile of available water

minus the 7Q10

Percentile of available water

minus the ABF

75th 50th 25th 75th 50th 25th 75th 50th 25th

June

Chepachet River 0.03 0.04 0.05 0.03 0.05 0.07 0.04 0.08 0.19

Clear River .04 .06 .09 .05 .08 .11 .06 .14 .3

Branch River .04 .06 .09 .05 .08 .11 .06 .14 .3

West River .18 .28 .37 .2 .33 .48 .27 .6 1.31

Peters River .21 .31 .4 .23 .36 .48 .3 .57 .93

Abbott Run .51 .63 .71 .54 .68 .78 .62 .83 .97

Basin total ................ 0.19 0.28 0.36 0.21 0.33 0.43 0.28 0.51 0.83

July

Chepachet River .06 .07 .11 .07 .1 .2 .2 1.29 --

Clear River .09 .12 .18 .12 .17 .33 .33 2.11 --

Branch River .09 .12 .18 .11 .16 .32 .32 2.05 --

West River .32 .41 .63 .41 .58 1.13 1.13 7.28 --

Peters River .4 .5 .68 .49 .64 .96 .96 1.75 --

Abbott Run .75 .82 .92 .82 .91 1.03 1.03 1.17 --

Basin total ................ 0.36 0.45 0.6 0.44 0.57 0.85 0.85 1.5 --

August

Chepachet River .06 .08 .13 .08 .13 .31 .39 -- --

Clear River .1 .14 .22 .13 .21 .52 .64 -- --

Branch River .1 .13 .22 .13 .21 .52 .63 -- --

West River .4 .55 .89 .54 .85 2.1 2.57 -- --

Peters River .43 .55 .76 .54 .74 1.17 1.26 -- --

Abbott Run .78 .86 .96 .86 .95 1.08 1.09 -- --

Basin total ................ 0.4 0.51 0.7 0.5 0.68 1.06 1.14 -- --

September

Chepachet River .04 .06 .09 .05 .09 .17 .14 -- --

Clear River .09 .13 .19 .11 .19 .37 .31 -- --

Branch River .07 .11 .16 .09 .16 .31 .26 -- --

West River .32 .48 .7 .41 .7 1.34 1.13 -- --

Peters River .34 .46 .6 .41 .6 .87 .79 -- --

Abbott Run .61 .69 .76 .66 .76 .85 .83 -- --

Basin total ................ 0.31 0.42 0.54 0.37 0.54 0.78 0.71 -- --

Depletion in the Blackstone River caused by 

pumping at the Cumberland WD’s Manville well no. 1 

was analyzed with STRMDEPL on the basis of specified 

daily pumping rates for the period 1995-99 (1,826 days). 

The well is about 200 ft from the Blackstone River. The 

diffusivity of the aquifer is determined by dividing the 

transmissivity of the aquifer by the storativity or specific 

yield. The transmissivity of the aquifer near the Manville 

well was estimated as 12,000 ft2/d and the specific yield 

was set at 0.28. The diffusivity (T/ S) of the aquifer near 

the well was estimated to be 42,850 ft2/d (0.50 ft2/s) on 

the basis of the hydraulic properties of the aquifer in the 

lower Blackstone River basin given in Johnston and 

Dickerman (1974b). The streambed materials are coarse 

in the vicinity of the well (D.C. Dickerman, U.S. 

Geological Survey, oral commun., 2000); therefore, it was 

assumed that there would be no resistance to flow at the 

streambank caused by semipervious materials. As a result, 

the Jenkins equation was used to calculate streamflow 

depletion at the well.
Water Availability 49

Table 21. Selected public-supply wells, parameters used to calculate streamflow depletion with the program STRMDEPL, and streamflow depletion as a percentage 

of the well pumping rate at 10, 20, and 30 days after the start of pumping

[CWD, Cumberland Water Department; LWC, Lincoln Water Commission; WSB, Water Supply Board; ft, foot; ft2/s, square feet per second]

Well name

 Distance of supply

well to stream

(ft)

Diffusivity

(ft2/s)

Semipervious 

streambank 

material

Streambank 

leakance term

(ft)

Streamflow depletion as a

percentage of pumping rate 

10 days 20 days 30 days

Not simulated

CWD Manville well No.1 200 0.5 0 -- 83 88 90

CWD Manville well No. 2 180 .5 0 -- 85 89 91

Simulated

LWC Lonsdale well No. 4 250 .87 1 225 70 79 82

Pawtucket WSB well No. 2 250 .54 1 557 47 59 65

Pawtucket WSB well No. 3 100 .54 1 557 56 66 71

Pawtucket WSB well No. 4 400 .54 1 557 39 52 59

The analytical solution presented in Jenkins (1968) 

is

Qs = Qwerfc (U), (6)

where

erfc is the complementary error function,

, (7)

and

Qs is the rate of streamflow depletion (ft3/s),

Qw is the pumping rate of the well (ft3/s),

d is the perpendicular distance from the well to the 

stream (ft),

S is the storativity (or specific yield) of the aquifer 

(dimensionless),

T is the transmissivity of the aquifer (ft2/s), and

t is time (s).

As noted in Barlow (2000), immediately after 

withdrawals begin, the source of water to the supply well 

is ground water released from storage in the aquifer, and 

there is little or no streamflow depletion. As time 

increases, the proportion of water released from storage 

that contributes to the discharge from the well decreases, 

whereas the amount of streamflow depletion that 

contributes to the discharge from the well increases. 

Streamflow depletion consists of two components: 

captured ground-water discharge and induced infiltration. 

Ultimately, as steady-state conditions are reached, all of 

the discharge from the well will consist of streamflow 

depletion. STRMDEPL, which does not differentiate 

between captured ground-water discharge and induced 

infiltration, provides a calculation of total streamflow 

depletion (Barlow, 2000). 

Manville well no. 1 was pumped intermittently 

during January 1995. The first day of pumping was 

January 4, 1995, at a rate of 0.06 ft3/s. For this reason, an 

initial pumping rate of 0.06 ft3/s (0.04 Mgal/d) was 

specified in the input file. This initial rate was used for 

10,000 days prior to the beginning of the simulation to 

obtain an initial streamflow depletion that accounts for the 

effects of pumping prior to the start of the analysis. This 

rate caused an initial streamflow depletion of 0.0597 ft3/s. 

Specified daily pumping rates at the well and 

calculated streamflow depletions in the river for the period 

1995–99 are shown in figure 14. As seen in the figure, 

daily pumping rates indicate that the well was used 

intermittently throughout the period of analysis and that 

there were large variations in the rates of withdrawal, 

ranging from 0.00 to 1.03 ft3/s (0.00 to 0.67 Mgal/d). 

There were 483 days during the period of analysis during 

which the well was inactive. The well was inactive in 

April, May, June, and July of 1995. In addition, pumping 

at the well showed a trend of decreasing use in the second 

half of 1996. The years 1997, 1998, and 1999 include 

days during which the well was inactive; however, these 

periods were usually less than a week.

Average daily pumping rates at Manville well no. 1 

for each year of the 5-year period, 1995–99, were 0.05, 

0.20, 0.37, 0.38, and 0.40 ft3/s, respectively. Streamflow 

depletions for Manville well no. 1 were about 97 percent 

of average daily pumping rates for 1995 through 1999. 

U d

2 = S ⁄ 4Tt
50 Estimated Water Use and Availability in the Lower Blackstone River Basin, Northern Rhode Island and South-Central Massachusetts, 1995–99

0

0.2

0.4

0.6

0.8

1

1.2

YEAR

STREAMFLOW DEPLETION

PUMPING RATE

PUMPING RATE AND STREAMFLOW DEPLETION,

IN CUBIC FEET PER SECOND

1995 1997 1998 1999 1996

Figure 14. Specified daily pumping rates at Cumberland Water Department Manville well no.1, Rhode Island, 1995-99, and calculated streamflow depletion in 

the nearby Blackstone River.

The range and variability of calculated streamflow 

depletions, however, is much less than the range and 

variability of the daily pumping rates. Variability of the 

daily pumping rates is effectively damped by the 

diffusivity of the aquifer and distance of the well to the 

stream. The streamflow depletions exhibit the same 

general trend as the withdrawals during the period of 

analysis.

In addition to calculating streamflow depletion for 

the Cumberland WD Manville well no. 1, relative 

streamflow depletions (Qs/Qw) were calculated for 

Manville well no. 1 and five other public-supply wells in 

the lower Blackstone River basin (table 21). A constant 

pumping rate of 0.4 ft3/s was simulated for a period of 

180 days at the six supply wells to illustrate the effects that 

different aquifer properties and various well distances to 

streams have on relative streamflow depletion.

The Cumberland WD wells, Manville well no. 1 

and no. 2, were determined to be in direct hydraulic 

connection with the stream (Johnston and Dickerman, 

1974b, D.C. Dickerman, oral commun., 2000). Therefore, 

the Jenkins (1968) equation was used in the STRMDEPL 

program. However, the Pawtucket and Lincoln supply 

wells selected for analysis are near ponded areas 

where the Abbott Run and Blackstone Rivers were 

determined to have fine-grained semipervious streambed 
Water Availability 51

and streambank materials (Johnston and Dickerman, 

1974b; and D. C. Dickerman, oral communication, 

September, 2000). For this reason, the Hantush (1965) 

equation was used in the STREMDEPL program for 

these four wells and the streambank-leakance term was 

estimated for each well. The analytical solution presented 

by Hantush is

Qs = Qw {erfc(U) – exp[-U2 + (U + w)

2]erfc(U +w)}, (8)

where Exp is = the exponential function, , 

where a is the streambank leakance term (ft), 

and is defined by a = Kb′/K′, where K is the hydraulic 

conductivity of the aquifer (ft/d), K′ is the hydraulic 

conductivity of the streambank (ft/d), and b′ is the 

thickness of the streambank (ft).

The hydraulic conductivity of the aquifer (K) is 

determined by dividing the transmissivity of the aquifer by 

its saturated thickness. Hydraulic conductivities of the 

aquifer estimated for the six wells range from 131 to 

325 ft/d. 

The hydraulic conductivity of the streambank (K′) 

is unknown at the Lincoln Water Commission and 

Pawtucket WSB sites along the Blackstone River. Field 

measurements of the vertical hydraulic conductivity of 

streambed sediments at 11 sites in the Hunt River basin by 

Rosenshein and others (1968) ranged from 0.1 ft/d for 

organically rich, fine sand and silt to 15.2 ft/d for medium 

to coarse sand. Hunt River streambed sediments on 

average are 2 ft thick, but can be as much as 10 ft locally 

(Rosenshein and others, 1968). Hydraulic properties of 

the Blackstone River basin stream-aquifer system in 

South Grafton, MA, were estimated using analytical 

modeling techniques by Desimone and Barlow (1998). 

Because vertical hydraulic conductivities and streambank 

thicknesses were not available for the four wells simulated 

by the Hantush equation, the calibrated values from the 

Grafton site were used (K′ = 1.4 ft/d and b′ = 2.4 ft) 

(DeSimone and Barlow, 1998). Based on a combination 

of these calibrated values and the hydraulic conductivities 

at the well locations, the streambank leakance term was 

225 ft for the Lincoln Lonsdale well no. 4 and 557 ft for 

the Pawtucket WSB wells 2, 3, and 4 (table 21).

The STRMDEPL simulation results for the six 

public-supply wells (table 21, fig. 15) show that the 

greatest relative streamflow depletion occurred at the 

Cumberland WD Manville well no. 2, which is 

about 180 ft from the streambank. This well likely has 

unimpeded connection with the stream. As well distances 

increase, relative streamflow depletions decrease. 

However, Pawtucket well no. 3, which is closer to the 

stream (100 ft) and at whose location the aquifer has a 

higher diffusivity than the aquifer at Manville well no. 2, 

has lower relative streamflow depletions due to 

impedance from streambed and streambank materials. 

Relative streamflow depletions at 10, 20, and 30 days 

after simulation were tabulated to show the variation in 

relative streamflow depletion over a one-month period 

due to varying aquifer properties and distances to a nearby 

stream (table 21). Changes in the relative streamflow 

depletion after the 30-day period have a smaller rate 

of increase than those occurring within the first 30 days 

(fig. 15).

w

Tt S⁄

a = -----------
52 Estimated Water Use and Availability in the Lower Blackstone River Basin, Northern Rhode Island and South-Central Massachusetts, 1995–99

0

20

40

60

80

100

0 3 0 6 0 9 0 120 150 180

CWD Manville well no. 1

CWD Manville well no. 2

Pawtucket WSB well no. 2

Pawtucket WSB well no. 3

Pawtucket WSB well no. 4

LWC Lonsdale well no. 4

TIME, IN DAYS

STREAMFLOW DEPLETION AS A PERCENTAGE OF

WELL PUMPING RATE (Qs/Q

w*100) 

Figure 15. Streamflow depletion as a percentage of well pumping rate (Qs/Qw * 100) for six public-supply wells with different aquifer 

properties and distances to the stream in the lower Blackstone River basin, northern Rhode Island and south-central Massachusetts. Qs

is the rate of streamflow depletion (cubic feet per second) and Qw is the pumping rate of the well (cubic feet per second).

WATER BUDGET

A long-term water budget was developed for the 

lower Blackstone River basin and for each of the six 

subbasins within the lower Blackstone River basin. The 

14-digit HUC subbasins used to report withdrawals, use, 

and return flow in this report served as units for the budget 

calculation. A simple water budget can be stated as the 

mass-balance equation: inflow minus outflow equals 

change in storage. A long-term average annual water 

budget was used. Therefore, change in storage could be 

assumed to be zero and inflow equals outflow. The 

components of inflow and outflow are defined separately 

in the long-term budget equation:

PT + SFI + GWI + WWRFI = ET + SFO + W + GWU, (9)

where 

PT = average annual precipitation over the 

subbasin or basin,

SFI = streamflow from upstream subbasins,

GWI = ground-water inflow,

WWRFI = wastewater-return flow from septic and 

NPDES (commercial, industrial, and 

municipal wastewater facilities),

ET = estimated evapotranspiration,

SFO = streamflow out of the subbasin or basin,

W = withdrawals (public-supply and self-supply), 

and

GWU = ground-water underflow.

Inflow

Three terms in the water-budget equation were 

used to quantify the inflow to each subbasin and to the 

whole lower Blackstone River basin: precipitation (PT), 

streamflow entering the basin boundary from upstream 

(SFI), and wastewater-return flow (WWRFI) (table 22). 

A fourth term, ground-water inflow (GWI), was not 

estimated for the lower Blackstone River basin hydrologic 

budget because the information was unavailable. 
Water Budget 53

Table 22. Long-term average annual hydrologic budget by subbasin for the lower Blackstone River basin, northern Rhode Island and south-central 

Massachusetts, 1957–99

[NPDES, National Pollution Discharge Elimination System; Mgal/d, million gallons per day; Mgal/d/mi2, million gallons per day per square mile; mi2, square 

miles; --, not applicable]

Water-budget component

Areal extent

Chepachet

River

subbasin

Clear

River

subbasin

Branch River 

subbasin

West

River 

subbasin

Peters

River 

subbasin

Abbott

Run

subbasin

Lower 

Blackstone 

River basin

Total drainage area at outlet (mi2) 21.3 45.5 93.1 242.3 447.2 27.3 474.5

Estimated inflow (Mgal/d)

Precipitation (PT) 48.55 103.72 60.13 79.06 98.38 62.33 452.17

Streamflow from upstream (SFI) 0 0 85.54 261.57 509.07 0 348.04

Ground-water inflow (GWI) -- -- -- -- -- -- --

Return flow (WWRFI) 0.27 1.27 0.45 1.42 10.78 1.43 15.62

Total inflow ....................................... 48.82 104.99 146.12 342.05 618.23 63.76 815.83

Estimated outflow (Mgal/d)

Evapotranspiration (ET) 21.28 45.45 26.35 35.38 44.03 27.32 199.8

Streamflow (SFO) 27.13 58.45 118.91 301.62 566.97 21.22 586.16

Water withdrawals (W) 0.41 1.09 0.86 5.05 7.23 15.22 29.87

Ground-water underflow (GWU) -- -- -- -- -- -- --

Total outflow ..................................... 48.82 104.99 146.12 342.05 618.23 63.76 815.83

Streamflow (SFO) in (Mgal/d/mi2) 1.27 1.28 1.28 1.25 1.27 0.78 1.24

Total monthly precipitation (PT) values in 

inches for the National Weather Service rain gage in 

Woonsocket, RI, were obtained from the Woonsocket 

WDIV for the period 1957–99 (Carol LaRiviere, Assistant 

Superintendent for the Woonsocket Water Division, 

written commun., 2002). Monthly precipitation for the 

rain gage averaged 47.9 in/yr. Total monthly precipitation 

accounts only for the precipitation over the subbasin; 

any precipitation in upstream subbasins is included 

in estimates of streamflow from upstream subbasins. 

Average monthly precipitation in Mgal/d ranged from 

48.55 Mgal/d in the Chepachet River subbasin to 

103.72 Mgal/d in the Clear River subbasin. Average 

precipitation for the lower Blackstone River basin was 

452.17 Mgal/d (table 22).

Streamflow from upstream subbasins (SFI) was 

calculated for each subbasin and the lower Blackstone 

River basin on the basis of streamflow at one of two 

USGS streamflow-gaging stations. Streamflow into the 

Branch River subbasin was estimated from mean monthly 

discharge records at the Branch River at Forestdale 

streamflow-gaging station (01111500) for the period 

1957–99. The long-term mean flow for the period 1957–

99 at the Forestdale station was 180.8 ft3/s (1.98 ft3/s/mi2, 

1.28 Mgal/d/mi2). Streamflows into the West River and 

Peters River subbasins were estimated from mean 

monthly discharge records at the Blackstone River at 

Woonsocket streamflow-gaging station (01112500) for 

the period 1957–99. The long-term mean flow for the 

period 1957–99 at the Woonsocket station was 810.9 ft3/s 

(1.95 ft3/s/mi2, 1.26 Mgal/d/mi2). The Chepachet, Clear, 

and Abbott Run subbasins have zero inflow due to 

streamflow from upstream subbasins. The largest inflow 

from upstream flow was in the Peters River subbasin, 

509.07 Mgal/d. Long-term average inflows to the lower 

Blackstone River basin for the period 1957–99 totaled 

348.04 Mgal/d (table 22).

Outflow

Three terms in the water budget equation are used 

to quantify outflows: evapotranspiration (ET), streamflow 

out of the subbasin (SFO), and water withdrawals (W) 

(table 22). A fourth term, ground-water underflow (GWU), 

was not estimated for the hydrologic budget because the 

information was unavailable. 
54 Estimated Water Use and Availability in the Lower Blackstone River Basin, Northern Rhode Island and South-Central Massachusetts, 1995–99

Evapotranspiration (ET) was estimated by 

subtracting estimated long-term streamflow within each 

subbasin from long-term average annual precipitation for 

the period 1957–99. Evapotranspiration was estimated at 

21.3 in/yr for the lower Blackstone River basin, which 

agrees with evapotranspiration estimates made for the area 

by Randall (1996). Estimated evapotranspiration rates 

ranged from 21.28 Mgal/d in the Chepachet River 

subbasin to 45.45 Mgal/d in the Clear River subbasin. 

Evapotranspiration for the entire lower Blackstone River 

basin was estimated at 199.8 Mgal/d.

Streamflow out of the subbasin (SFO) was 

estimated from the water-budget equation and equals the 

difference between the sum of inflows and the sum of 

evapotranspiration and withdrawals. Average streamflow 

out of the six subbasins ranged from 21.22 Mgal/d in the 

Abbott Run subbasin to 566.97 Mgal/d in the Peters River 

subbasin. Long-term outflow from the lower Blackstone 

River basin was estimated to be 586.16 Mgal/d (table 22).

SUMMARY AND CONCLUSIONS

This report discusses water use, availability, 

streamflow depletion at six public-supply wells and a 

long-term hydrologic budget for the lower Blackstone 

River basin in Rhode Island. This study was conducted by 

the U.S. Geological Survey, in cooperation with the 

Rhode Island Water Resources Board (RIWRB), to 

examine the pattern of water use within the basin and its 

effect on water availability. 

Water-use data, including withdrawals, uses, and 

return flows, were collected for six subbasins of the 

Blackstone River basin for the period 1995–99. Total 

withdrawals for the lower Blackstone River basin 

were 29.869 Mgal/d; public-supply withdrawals were 

22.694 Mgal/d, and self-supply withdrawals were 

7.170 Mgal/d. Total withdrawals by subbasin ranged 

from 0.414 Mgal/d in the Chepachet River subbasin to 

15.221 Mgal/d in the Abbott Run subbasin. Total water 

use for the lower Blackstone River basin was estimated 

at 20.388 Mgal/d; public-supply use was estimated at 

13.215 Mgal/d and self-supply use was estimated at 

7.170 Mgal/d. Water use ranged from 0.416 Mgal/d in the 

Chepachet River subbasin to 8.122 Mgal/d in the Peters 

River subbasin. The largest aggregate users in the lower 

Blackstone River basin were the domestic water users 

(10.113 Mgal/d, 50 percent), followed by industrial 

water users (4.127 Mgal/d, 20 percent), commercial water 

users (4.026 Mgal/d, 20 percent), non-account water use 

(1.866 Mgal/d, 9 percent), and agricultural water users 

(0.252 Mgal/d, 1 percent). Public-supply imports and 

exports for the basin totaled 2.852 and 12.327 Mgal/d, 

respectively.

Total wastewater disposal to the lower 

Blackstone River basin was 15.219 Mgal/d. Publicdisposal of wastewater at National Pollution Discharge 

Elimination System (NPDES) outfalls was 10.395 

Mgal/d, including imports from outside the lower 

Blackstone River basin, and self-disposal of wastewater 

was estimated at 4.824 Mgal/d. Of this amount, 

3.660 Mgal/d was disposed through on-site septic and 

1.164 Mgal/d was disposed through commercial and 

industrial NPDES surface-water discharge sites. Publicdisposal wastewater imports and exports for the basin 

totaled 1.818 and 4.086 Mgal/d, respectively. 

The computer program PART was used to estimate 

base flow at the Branch River at Forestdale, Rhode Island. 

Two minimum streamflows, the 7-day, 10-year low flow 

(7Q10) (11.9 ft3/s) and the Aquatic Base Flow (ABF) 

(38.8 ft3/s), were subtracted from the base-flow values 

calculated from PART for the low-flow period, which 

included June, July, August, and September. 

Available base flows estimated by PART at the 50th 

percentile minus the 7Q10 minimum flow were 180, 586, 

428, and 483 Mgal for the Branch River at Forestdale 

streamflow-gaging station drainage area, in June, July, 

August, and September, respectively. Available base flows 

estimated by PART at the 50th percentile minus the ABF 

minimum flow were about 658 Mgal in June and 47 Mgal 

in July for the station's drainage area. Base flows 

estimated by PART at the 50th percentile for August and 

September, however, were less than the ABF minimum 

flow. 

Water availability (base-flow estimates plus safeyield estimates) was 50.5 Mgal/d for the lower Blackstone 

River basin in August at the 50th percentile minus the 

7Q10. Water availability with and without taking 

minimum streamflow into account was calculated at the 

75th, 50th, and 25th percentiles for all four months of 

the low-flow period. These values ranged from 42.3 to 

181.7 Mgal/d in June, 20.2 to 96.7 Mgal/d in July, 20.2 to 

85.4 Mgal/d in August, and 20.2 to 97.5 Mgal/d in 

September. Water-availability estimates were done 

at the 14-digit HUC level; therefore, interpolation of this 

data to smaller areas may overestimate or underestimate 

availability. In addition, water-availability estimates 
References Cited 55

calculated from base flow are conservative estimates 

because actual streamflows are generally greater than base 

flow except for periods of no recharge.

A basin-stress ratio for the six subbasins of the 

lower Blackstone River basin was calculated by dividing 

total withdrawals by water availability for the low-flow 

period during 1995–99. The lowest base-flow rate was in 

August. The basin-stress ratio for August at the 50th 

percentile minus the 7Q10 minimum flow ranged from 

0.13 in the Chepachet River subbasin to 0.95 in the Abbott 

Run subbasin. The ratios for other subbasins in the lower 

Blackstone River basin were 0.21, 0.21, 0.74, and 0.85 for 

the Branch River, Clear River, Peters River, and West 

River subbasins, respectively. The ratio for the lower 

Blackstone River basin was 0.68. Basin-stress ratios with 

and without taking minimum streamflow into account 

were calculated at the 75th, 50th, and 25th percentiles for 

all four months of the low-flow period. These values 

ranged from 0.19 to 0.83 in June, 0.36 to 1.50 in July, 0.40 

to 1.14 in August, and 0.31 to 0.78 in September. Ratios 

calculated on the basis of the ABF criterion could not be 

calculated at the 25th percentile from July through 

September and at the 50th percentile in August and 

September because the estimated base flow at these 

percentiles was less than the ABF. Water availability 

estimates and basin-stress ratios were calculated from 

subbasin to subbasin, which does not reflect the 

cumulative demand from upstream subbasins.

Streamflow depletions resulting from ground-water 

withdrawals at six public-supply wells within the lower 

Blackstone River basin were quantified based on 

calculations from the program STRMDEPL developed by 

Barlow (2000). Streamflow depletions were about 97 

percent of average daily pumping rates for 1995 through 

1999 for the Cumberland Water District (WD) Manville 

well no. 1. In addition, relative streamflow depletions 

resulting from a simulated constant pumping rate were 

calculated for the Cumberland WD Manville wells no. 1 

and no. 2, Pawtucket wells no. 2, 3, and 4, and Lincoln 

Lonsdale well no. 4. The aquifers at these wells had 

different properties and the wells were at different 

distances from the streambank. Simulated relative 

streamflow depletions for these wells were 90, 91, 65, 71, 

59, and 82 percent, respectively.

A long-term hydrologic budget was calculated 

for the period 1957 through 1999. Water-withdrawal 

and wastewater-return-flow data were used in the 

hydrologic budget. Precipitation, surface-water inflow, 

and wastewater-return flow in the six subbasins ranged 

from 48.82 Mgal/d in the Chepachet River subbasin to 

618.23 Mgal/d in the Peters River subbasin. Inflow 

volumes were 104.99 Mgal/d, 146.12 Mgal/d, 

342.05 Mgal/d, and 63.76 Mgal/d for the Clear River, 

Branch River, West River, and the Abbott Run subbasins, 

respectively. Outflow volumes, which consisted of 

evapotranspiration, streamflow out of the basin, and 

withdrawals, were set equal to inflows. 

Inflow to the lower Blackstone River basin was 

815.83 Mgal/d. Inflows from precipitation, streamflow 

from upstream subbasins, and wastewater-return flow 

were 55, 43, and 2 percent of total inflows, respectively. 

Outflows from evapotranspiration, streamflow out of the 

basin, and withdrawals were 24, 72, and 4 percent of total 

outflows, respectively.

REFERENCES CITED

Archer, W.J., P.E., 1994, Lincoln Water Commission Water 

Management Plan: February 1994, variously paged.

Barlow, P.M., 2000, Documentation of computer program 

STRMDEPL—A program to calculate streamflow 

depletion by wells using analytical solutions, in Zarriello, 

P.J., and Ries, K.G., III, A precipitation-runoff model for 

analysis of the effects of water withdrawals on streamflow, 

Ipswich River Basin, Massachusetts: U.S. Geological 

Survey Water-Resources Investigations Report 00-4029, 

99 p.

Camp, Dresser, and McKee, 1994, City of Woonsocket, Rhode 

Island—Water supply management plan: Cambridge, MA, 

83 p., 3 pls.

Cornell University, 2001, Northeast Regional Climate Center, 

Climate data and products: accessed September 2001 at 

URL: http://met-www.cit.cornell.edu

Craft, P.A., Horn, M.A., and Medalie, Laura, 1990, Estimated 

withdrawals and use of freshwater in Rhode Island, 1990: 

U.S. Geological Survey Water-Resources Investigations 

Report 93-4150., 1 pl. 

Desimone, L.A., and Barlow, P.M., 1998, Use of computer 

programs STLK1 and STWT1 for analysis of streamaquifer hydraulic interaction: U.S. Geological Survey 

Water-Resources Investigations Report 98-4212, p. 61.

Dufresne-Henry, Inc., 1997, Report on water supply 

management plan—Pascoag Fire District, Pascoag Rhode 

Island: Westford, Massachusetts, 32 p., 2 pls.

_____1999, Report on water supply management plan—

Harrisville Fire District, Harrisville Rhode Island: 

Westford, MA, 33 p., 2 pls.

Frimpter, M.H., 1974, Ground-water Management Blackstone, 

Moshassuck, and Woonasquatucket River basins, 

Massachusetts and Rhode Island, Section 3.03: U.S. 

Geological Survey Open-File Report, 39 p.
56 Estimated Water Use and Availability in the Lower Blackstone River Basin, Northern Rhode Island and South-Central Massachusetts, 1995–99

Hantush, M.S., 1965, Wells near streams with semi-pervious 

beds: Journal of Geophysical Research, v. 70, no. 12, 

p. 2829–2838.

Horn, M.A., 1999, Method for estimating water use and 

interbasin transfers of freshwater and wastewater in an 

urbanized basin: U.S. Geological Survey Water-Resources 

Investigations Report 99-4287, 34 p.

_____2002, User's manual for the New England water-use 

database system: U.S. Geological Survey Open-File 

Report 01-328, 392 p.

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water withdrawal and distribution, water use, and 

wastewater collection and return flow in Cumberland, 

Rhode Island, 1988: U.S. Geological Survey WaterResources Investigations Report 93-4023, 54 p.

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depletion by wells: U.S. Geological Survey Techniques of 

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ground water in the Branch River basin, Providence 

County, Rhode Island: U.S. Geological Survey WaterResources Investigations 18-74, 39 p.

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ground water in the Blackstone River area, Rhode Island 

and Massachusetts: U.S. Geological Survey WaterResources Investigations Report 4-74, 1 pl.

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streams in northern Rhode Island: U.S. Geological Survey 

Water-Resources Investigations Report 95-4299, 11 p.

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water in the New England states, 1990: U.S. Geological 

Survey Water-Resources Investigations Report 94-4252, 

21 p. 

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Glossary 57

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GLOSSARY

7-day, 10-year low flow: The discharge at the 10-year 

recurrence interval taken from a frequency curve of annual 

values of the lowest mean discharge for 7 consecutive days 

(the 7-day low flow). The 7-day, 10-year low flow is 

commonly used to assess the capacity of a river to carry 

pollutants.

Aggregate water use: Water used within a defined area (town, 

basin, or water district).

Aquatic Base Flow: Median flow during the month of August 

considered adequate flow to protect indigenous aquatic 

fauna throughout the year established by the U.S. Fish and 

Wildlife Service. Can be calculated as long as there is U.S. 

Geological Survey streamflow-gaging data for at least 25 

years of unregulated flow, and the drainage area at the 

streamflow-gaging station is at least 50 square miles.

Base Flow: is flow in a channel sustained by ground-water 

discharge in the absence of direct runoff.

Base flow in inches (in.): shows the depth to which the 

drainage area would be covered if all the base flow for a 

given time period were uniformly distributed on it.

Commercial water use: Water used for motels, restaurants, 

office buildings, ski resorts, water parks, and other 

commercial facilities and institutions, including fish 

hatcheries. The water may be obtained from a public water 

supply or may be self-supplied. See also institutional water 

use.

Consumptive use: That part of withdrawn water that is 

evaporated, transpired, incorporated into products or crops, 

consumed by humans or livestock, or otherwise removed 

from the immediate water environment.

Conveyance: The systematic and intentional flow or transfer of 

water from one point to another. Conveyance types include 

water distribution and wastewater collection.
58 Estimated Water Use and Availability in the Lower Blackstone River Basin, Northern Rhode Island and South-Central Massachusetts, 1995–99

Distribution: The process of conveying water from a water 

supplier’s point of withdrawal or treatment through the 

distribution system to the user or another water supplier. 

Domestic water use: Water for household purposes, such as 

drinking, food preparation, bathing, washing clothes and 

dishes, flushing toilets, and watering lawns and gardens. 

Households include single and multi-family dwellings. 

Also called residential water use. The water may be 

obtained from public-supply or may be self-supplied.

Exfiltration: Leakage from a conveyance system or storage 

area into the surrounding and underlying materials.

Flow duration: is a cumulative frequency curve that shows the 

percent of time specified discharges were equaled or 

exceeded during a given period.

Industrial water use: Water used for industrial purposes, such 

as fabrication, processing, washing, and cooling, and 

includes such industries as steel, chemicals, paper, and 

petroleum refining. The water may be obtained from a 

public water supply or may be self-supplied. 

Infiltration: water entering a sewer system, including sewer 

service connections, from the ground through such means 

as defective pipes, pipe joints, connections, or manhole 

walls.

Inflow: consists of two types, steady inflow and direct inflow. 

Steady inflow is water discharged from cellar and 

foundation drains, cooling water discharges, and drains 

from springs and swampy areas. This type of inflow is 

steady and is identified and measured along with 

infiltration. Direct inflow is composed of those types of 

inflow that have a direct stormwater-runoff connection to 

the sanitary sewer and cause an almost immediate increase 

in wastewater flows. Possible sources are roof leaders, 

yard and areaway drains, manhole covers, cross 

connections from storm drains and catch basins, and 

combined sewers (Metcalf and Eddy, 1991).

Instream use: Water that is used, but not withdrawn, from a 

surface-water source, or a ground-water source, for 

hydroelectric-power generation, navigation, water-quality 

improvement or waste assimilation, fish propagation, 

wildlife preservation, recreation, and ecosystem 

maintenance, which includes freshwater circulation to the 

estuaries and maintenance of riparian vegetation and 

floodplain wetlands. Also referred to as non-withdrawal 

use or in-channel use.

Intake: Point of withdrawal from a surface water body such as 

a reservoir or a stream.

Interbasin transfer: Conveyance of water across a drainage- or 

river-basin divide.

Irrigation water use: The artificial application of water on 

lands to assist in the growth of crops or pasture including 

greenhouses. Irrigation water use may also include 

application of water to maintain vegetative growth in 

recreation lands such as parks and golf courses, including 

water used for frost and freeze protection of crops.

Local wastewater collection: collection of wastewater from 

domestic, industrial, and commercial users within a city or 

town (minor civil division) to be processed at a local 

wastewater-treatment facility.

Minor water supplier: a supplier who withdraws, distributes, 

or uses water for a public population, such as in nursing 

homes, condominium complexes, and mobile home parks.

Major water supplier: a supplier who withdraws, distributes, 

or uses more than 50 Mgal/yr as defined by the Rhode 

Island Water Resources Board.

Million gallons per day per square mile [(Mgal/d)/mi2]: is 

the average number of million gallons of water flowing per 

day from each square mile of area drained, the flow is 

assumed to be distributed uniformly in time and area.

Minor Civil Division: A term used by the U.S. Census Bureau, 

generally equivalent to a city or town.
Glossary 59

Non-account water use: Water within a public-water supply 

system that is unaccounted for in the suppliers’ billing 

records because it was lost through firefighting, inaccurate 

meters, flushing, major breaks, recreation, illegal 

connections, street washing and leakage (exfiltration).

NPDES discharge site: A National Pollution Discharge 

Elimination System (NPDES) discharge location at which 

effluent is released after use into a receiving stream. In 

Rhode Island these sites are named Rhode Island Pollution 

Discharge Elimination System (RIPDES) discharge sites. 

Also referred to as an outfall.

Outfall: Refers to the outlet or structure through which effluent 

is finally discharged.

Per capita water use: The average volume of water used per 

person (or other unit) during a standard time period, 

generally per day. (Other units may include various types 

of livestock, hospital beds, etc.).

Public-disposal wastewater: Wastewater collected through the 

public wastewater-collection system.

Public wastewater-collection system: Wastewater collected 

from users or groups of users, conveyed to a wastewater 

treatment plant, and released as return flow into the 

hydrologic environment or sent back to users as reclaimed 

wastewater.

Public water-supply system: Water withdrawn by public and 

private water systems and delivered to users or groups of 

users. Public water systems provide water for a variety of 

uses, such as domestic, commercial, industrial, and 

thermoelectric power.

Public-supply use: Water supplied from a public water system 

and used for domestic, commercial, industrial, and 

agricultural purposes.

Regional wastewater collection: Collection of wastewater 

from several cities and/or towns to be processed at a 

regional wastewater-treatment facility.

Return Flow: Water that is returned to surface or ground water 

after use or wastewater treatment.

Self-disposal wastewater: Wastewater that is returned to the 

ground through septic systems or returned to surface water 

through NPDES discharge sites by a user or group of users 

that are not on a public wastewater-collection system.

Self-supply water: Water withdrawn from a ground- or 

surface-water source by a user or group of users that are 

not on a public water-supply system.

Standard Industrial Classification (SIC) code: Four-digit 

codes established by the U.S. Office of Management and 

Budget and used in the classification of establishments by 

type of activity in which they are engaged.

Streamflow-gaging station: is a particular site on a stream, 

canal, lake, or reservoir where systematic observations of 

hydrologic data are obtained.

Wastewater: Water that carries wastes from domestic, 

industrial, and commercial users; a mixture of water and 

dissolved or suspended solids.

Wastewater treatment: The processing of wastewater to 

remove or reduce solids or other undesirable constituents.

Water supply: All of the processes involved in obtaining and 

distributing water prior to use. Includes withdrawal, 

treatment, and distribution.

Water treatment: The processing of potable water to meet safe 

drinking water standards. The processing may include: 

coagulation, flocculation, sedimentation, filtration, and 

disinfection.

Water use: Water that is used for public supply, industry, 

commercial, domestic, irrigation, livestock, and 

hydroelectric and thermoelectric power generation.

Withdrawal: The removal of surface water or ground water 

from the natural hydrologic system for use by humans.

Appendix 1:

SIC Code Estimates by Minor Civil Division

Appendix 1 63

Appendix 1. SIC code estimates by minor civil division[Water-use coefficient: Units are in gallons per employee per day. Mgal/d, million gallons per day; --, not applicable]

Category and two digit SIC code Water-use coefficient Attleboro (Mgal/d) Bellingham (Mgal/d) Blackstone (Mgal/d) Burrillville (Mgal/d) Central Falls (Mgal/d) Cumberland (Mgal/d) Douglas (Mgal/d) Franklin (Mgal/d) Glocester (Mgal/d) Lincoln (Mgal/d)

Construction 35 0.0188 0.0075 0.0016 -- -- 0.0001 0.0020 0.0112 -- 0.0042Industrial [20-39] 116 -- -- -- -- -- -- -- -- -- --

Food [20] 469 -- -- -- 0.0328 -- -- -- -- -- .0469Tobacco [21] 217 -- -- -- -- -- -- -- -- -- --Textile mill products [22] 315 -- -- -- .0473 0.2914 .1575 -- -- -- .0296Finished apparel [23] 13 -- -- -- -- -- .0000 -- -- -- .0004Wood, lumber [24] 78 .0019 -- -- -- -- .0098 -- .0015 -- --Furniture [25] 30 -- -- -- -- -- -- -- -- -- --Paper products [26] 863 -- -- -- -- .1752 -- -- -- -- --Printing, publishing [27] 42 .0096 -- -- -- -- .0013 -- .0027 -- .0006Chemical products [28] 289 .0629 -- -- -- .0038 -- -- .0083 -- .0260Petroleum [29] 1,045 -- -- -- -- -- -- -- -- -- --Rubber [30] 119 -- -- -- .0075 -- .0167 -- .0101 -- .0035Leather [31] 148 -- -- -- -- -- -- -- -- -- --Stone, clay, glass, and concrete [32] 202 -- -- -- -- .1010 -- -- -- -- --Primary metals [33] 178 .1101 -- -- -- -- .0134 -- .0485 -- .0890Fabricated metals [34] 95 .0947 .014497 -- .0114 .0128 .0193 -- .0154 -- .0670Machinery [35] 58 .0289 .0068556 -- -- .0024 -- .0041 .0164 0.0001 .0102Electronic equipment [36] 71 -- -- -- -- -- .0001 -- .0166 -- .0045Transportation equipment [37] 63 -- -- -- -- -- .0006 -- -- -- --Instruments [38] 66 .0074 -- -- -- -- .0009 -- .0314 -- .0070Jewelry, precious metals [39] 36 .0991 -- -- -- .0104 .0030 -- -- -- .0511Miscellaneous industrial -- -- -- -- -- -- -- -- -- --

Total industrial .433 .029 .002 .099 .597 .222 .006 .162 .000 .340

Commercial [40-97] 94 -- -- -- -- -- -- -- -- -- --

Transportation, communication, 

utilities [40-49]

51 .0066 .0009 -- -- -- .0103 .0005 .0172 -- .0189

Wholesale trade [50-51] 58 .0316 .0159 .0014 .0070 -- .0560 -- --Retail trade [52-59] 58 .2257 .0670 .0093 .0067 -- .0450 .0026 .1394 -- .0073Finance, insurance, and real 

estate [60-67]

71 .0194 .0042 -- -- -- -- .0016 .0181 -- .0391

Services [70-89] 106 .5347 .0362 .0077 .0377 .0339 .1514 .0024 .1528 .0307 .2663Public administration 

(Government) [91-97]

71 .0242 -- -- -- -- -- .0008 .0000 -- --

Total commercial .842 .124 .018 .051 .034 .207 .008 .383 .031 .331

Domestic 71 -- -- -- -- -- -- -- -- -- --
64 Estimated Water Use and Availability in the Lower Blackstone River Basin, Northern Rhode Island and South-Central Massachusetts, 1995–99 Appendix 1. SIC code estimates by minor civil division—Continued Category and two digit SIC code Water-use coefficient Millville (Mgal/d) North Attleboro (Mgal/d) Plainville (Mgal/d) North Smithfield (Mgal/d) Pawtucket (Mgal/d) Smithfield (Mgal/d) Uxbridge (Mgal/d) Woonsocket (Mgal/d) Wrentham (Mgal/d) Construction 35 0.0008 0.0065 0.0103 0.0053 0.0044 0.0034 0.0058 Industrial [20-39] 116 Food [20] 469 .2101 .0774 Tobacco [21] 217 Textile mill products [22] 315 .6426 0.3963 Finished apparel [23] 13 .0003 .0016 Wood, lumber [24] 78 .0012 .0016 Furniture [25] 30 .0224 .0030 Paper products [26] 863 .5264 .0155 Printing, publishing [27] 42 .0030 0.0001 .0252 .0003 .0061 Chemical products [28] 289 .0072 .0188 .0127 Petroleum [29] 1,045 Rubber [30] 119 .0029 .0155 .1939 .0129 Leather [31] 148 Stone, clay, glass, and concrete [32] 202 .1414 .0026 .0061 .1010 Primary metals [33] 178 .0466 .1899 .0107 .1139 Fabricated metals [34] 95 .0473 .0061 .0486 .0010 .0863 .0237 Machinery [35] 58 .0073 .0044 .0135 .0048 .0044 .0046 .0028 Electronic equipment [36] 71 .0060 .0089 .0256 .0026 .0163 Transportation equipment [37] 63 .0025 Instruments [38] 66 .0044 .0192 .0015 .0983 .0497 .0122 Jewelry, precious metals [39] 36 .0424 .0024 .1075 .0186 .0050 Miscellaneous industrial Total industrial .0008 .168 .042 .175 2.131 .181 .008 .786 .032 Commercial [40-97] 94 Transportation, communication, utilities [40-49] 51 .0020 .0003 .0158 .0030 .006833 Wholesale trade [50-51] 58 .0300 .0065 .0096 .0029 .0084 .0041412 Retail trade [52-59] 58 .2902 .0280 .0162 .0484 .0305 .0293 .2437 .03132 Finance, insurance, and real estate [60-67] 71 .0127 .0004 .0359 .0763 .0027 .0071 .0035784 Services [70-89] 106 .0001 .1496 .0366 .0519 .5060 .1514 .0117 .2780 .0689424 Public administration (Government) [91-97] 71 .0023 .0087

Total commercial .0001 .487 .071 .078 .609 .258 .064 .529 0.115

Domestic 71
Appendix 2:

Water-Use Case Study—Cumberland, Rhode Island

Appendix 2 67

CONTENTS

Retrievals ............................................................................................................................................................................ 69

Withdrawals........................................................................................................................................................................ 71

Cumberland Water Department............................................................................................................................... 72

Pawtucket Water Supply Board............................................................................................................................... 72

Water Use............................................................................................................................................................................ 74

Wastewater Return Flows.................................................................................................................................................. 75

References Cited................................................................................................................................................................. 75

FIGURES

2.1. Graph showing total withdrawals in million gallons per day within the town of 

Cumberland, Rhode Island, 1995–99............................................................................................................ 72

2.2. Map showing public-supply withdrawal locations in the town of Cumberland, Rhode Island ................. 73

2.3. Graph showing Cumberland Water Department monthly withdrawal volumes and wholesale 

purchases by source, 1995–99 ....................................................................................................................... 74

TABLES

2.1. New England Water Use Database System (NEWUDS) retrievals for the town of 

Cumberland, Rhode Island............................................................................................................................. 70

2.2. Water-use summary by category for the town of Cumberland, Rhode Island............................................ 75

Appendix 2 69

WATER-USE CASE STUDY—CUMBERLAND, 

RHODE ISLAND

In this appendix, a case study for the town of 

Cumberland is presented to illustrate the types of 

retrievals that can be made from the New England Water 

Use Database System [NEWUDS; Tessler (2002) and 

Horn (2002)]. Two water suppliers withdraw water for 

public supply within Cumberland: the Cumberland Water 

Department (WD) and Pawtucket Water Supply Board 

(WSB). The Cumberland WD received about 55 percent 

of its water supply from the Pawtucket WSB during the 5-

year period of study (1995-99). In addition, the southern 

portion of Cumberland known as Valley Falls receives its 

public-supply water directly from the Pawtucket WSB; 

therefore, water use for the Valley Falls section of 

Cumberland is presented separately from water use for the 

section of Cumberland that is supplied by the Cumberland 

WD.

RETRIEVALS

To retrieve the information described within this 

section from the NEWUDS database, a parameter query 

was created (table 2.1). A parameter query requires input 

from the user. In this example, the user is prompted to 

enter a system name. The query links together four tables 

in the database: tdxSystem, tblSite, tblConveyance, and 

tblTransaction. An explanation of naming conventions for 

tables in the NEWUDS database can be found in Tessler 

(2002). To retrieve the 5-year average, the summary 

option "average" was chosen. In addition, the minimum 

and maximum rates were selected within the summary 

option. 

The tasSystemSite table ties each site within the 

database to a particular system. The withdrawals, use, and 

return-flow sites for the town of Cumberland were 

attached to five different systems within the tasSystemSite 

table. For the town of Cumberland these systems 

included: the Cumberland WD, the Pawtucket WSB, 

Cumberland Aggregate, Cumberland Site Specific, and 

the Narragansett Bay Commission-Bucklin Point. These 

five system names were entered to retrieve data.

Because the Pawtucket WSB system serves the 

Valley Falls section of Cumberland, Pawtucket, and 

Central Falls, two statements were specified within the 

SiteName field to restrict the query to wells and intakes 

and the Valley Falls section of Cumberland (for example, 

"*Wells*", "*Intakes"; and "*Valley Falls"). An asterisk 

before or after the specified site name will retrieve all 

records that include those characters without the user 

having to specify the entire site name. 

The Cumberland Aggregate system includes all 

public-supply, self-supply, public-disposal, and selfdisposal uses for the town of Cumberland including the 

Valley Falls section. Because public supply for northern 

Cumberland is contained within the Cumberland WD 

system and public supply for Valley Falls is contained 

within the Pawtucket WSB system, a statement was used 

to restrict the retrieval to self-supply aggregate use (for 

example, "*self-supply"). Public-supply aggregate uses 

are within the public-supply system (for example, the 

Cumberland Water Department) and also within the 

Aggregate system because the user may want to compile 

the data in either system.

Because the system Cumberland Site Specific 

includes only two National Pollution Discharge 

Elimination System (NPDES) outfall locations, a 

statement was not needed to restrict the query. The 

Narraganset Bay Commission-Bucklin Point system 

includes the towns of Central Falls, Cumberland, East 

Providence, Lincoln, and Pawtucket. Because only the 

flow information for the town of Cumberland was needed, 

a statement was used to restrict the query (for example, 

"*Cumberland").
70 Estimated Water Use and Availability in the Lower Blackstone River Basin, Northern Rhode Island and South-Central Massachusetts, 1995–99

Table 2.1. New England Water Use Database System (NEWUDS) retrievals for the town of Cumberland, Rhode Island—Continued

System name Query restriction Conveyance name

Rate (Mgal/d)

Average Minimum Maximum

Cumberland WD None Sneech Pond intake to Cumberland Treatment Plant 0.837 0.237 1.016

Manville well No. 1 to Cumberland Treatment Plant .179 0 .293

Manville well No. 2 to Cumberland Treatment Plant .16 0 .263

Abbott Run well No. 2 to Cumberland Treatment Plant 0 0 0

Abbott Run well No. 3 to Cumberland Treatment Plant 0 0 0

Backwash discharge to Sneech Pond -- -- --

Pawtucket/Cumberland Interconnection to Cumberland 

local distribution

1.43 .198 3.725

Lincoln/Cumberland Interconnection to Cumberland local 

distribution (emergency use only)

0 0 0

Cumberland Treatment Plant to local distribution 1.176 .255 1.53

Cumberland local distribution to public-supply 

agricultural water use

0 0 0

Cumberland local distribution to public-supply 

commercial water use

.253 .143 .472

Cumberland local distribution to public-supply industrial 

water use

.248 .081 .634

Cumberland local distribution to public-supply domestic 

water use

1.431 .921 2.798

Cumberland local distribution to non-account water use .682 .46 1.352

Pawtucket WSB “*well” or “*intake” Happy Hollow intake to Pawtucket Treatment Plant 12.017 7.097 16.334

Pawtucket well No. 2 to Pawtucket Treatment Plant .156 0 .52

Pawtucket well No. 3 to Pawtucket Treatment Plant .273 0 .803

Pawtucket well No. 4 to Pawtucket Treatment Plant .065 0 .736

Pawtucket well No. 5 to Pawtucket Water Supply Board 

regional distribution

0 0 0

Pawtucket well No. 6 to Pawtucket Water Supply Board 

regional distribution

.129 0 .595

Pawtucket well No. 7 to Pawtucket Treatment Plant .169 0 .595

Pawtucket well No. 8 to Pawtucket Treatment Plant .179 0 .595

Pawtucket well No. 9 to Pawtucket Treatment Plant .183 0 .595

“*Valley Falls” Pawtucket Water Supply Board regional distribution to 

Valley Falls local distribution

.832 .681 1.117

Valley Falls local distribution to public-supply agricultural 

water use

0 0 0

Valley Falls local distribution to public-supply 

commercial water use

.081 .066 .097

Valley Falls local distribution to public-supply industrial 

water use

.089 .071 .107

Valley Falls local distribution to public-supply domestic 

water use

.603 .6 .61

Valley Falls local distribution to public-supply nonaccount water use.025 .025 .025

Table 2.1. New England Water Use Database System (NEWUDS) retrievals for the town of Cumberland, Rhode Island

[Query restriction: *, an asterisk before or after the specified site name will retrieve all records that include those characters without the user having to specify 

the entire site name. No., number; Mgal/d, million gallons per day; --, information not available]
Appendix 2 71

Cumberland Aggregate “*self-supplied” Cumberland self-supplied agricultural water use 0.038 0.011 0.157

Cumberland self-supplied commercial water use 0 0 0

Cumberland self-supplied industrial water use 0 0 0

Cumberland self-supplied domestic water use .081 .081 .081

Cumberland Site 

Specific

none Cumberland industrial water use to NPDES surface water 

discharge for Okonite, Company

.159 .067 .246

Cumberland public-supply industrial use to NPDES 

surface water discharge for Air Products and Chemicals

.157 .019 .33

NBC-–Bucklin Point “*Cumberland” Cumberland public-disposal agricultural water use to local 

wastewater collection

0 0 0

Cumberland public-disposal commercial water use to 

local wastewater collection

.223 .223 .223

Cumberland public-disposal domestic water use to local 

wastewater collection

.586 .586 .586

Cumberland local wastewater collection to Narragansett 

Bay Commission regional collection- Bucklin Point

2.543 .064 5.608

Valley Falls public-disposal agricultural water use to local 

wastewater collection

0 0 0

Valley Falls public-disposal domestic water use to local 

wastewater collection

.497 .495 503

Valley Falls public-disposal commercial water use to local 

wastewater collection

.088 .088 .088

Valley Falls public-disposal industrial water use to local 

wastewater collection

.096 .096 .096

Cumberland Aggregate “*self-disposal” Cumberland self-disposal of domestic water use to ground 

water return flow

.7 .7 .7

Cumberland self-disposal of commercial water use to 

ground water return flow

0 0 0

Cumberland self-disposal of industrial water use to ground 

water return flow

.232 .232 .232

Table 2.1. New England Water Use Database System (NEWUDS) retrievals for the town of Cumberland, Rhode Island—Continued

System name Query restriction Conveyance name

Rate (Mgal/d)

Average Minimum Maximum

WITHDRAWALS

Average monthly withdrawals for the town of 

Cumberland, which include self-supply withdrawals and 

public-supply withdrawals, for both the Cumberland WD 

and the Pawtucket WSB, ranged from about 11.7 Mgal/d 

in March 1996 to about 20.4 Mgal/d in June 1999, 

averaging 14.5 Mgal/d for the period 1995-99 (fig. 2.1). 

Of the 14.5 Mgal/d withdrawn, an average of 3.5 Mgal/d 

(24 percent) is used in the town of Cumberland (northern 

and southern Cumberland), an additional 0.3 Mgal/d is 

filter backwash at the Pawtucket WSB potable-water 

treatment facility, and the remaining 10.7 Mgal/d is 

exported out of Cumberland for use in Pawtucket 

(8.6 Mgal/d), Central Falls (2.0 Mgal/d), and Seekonk 

(< 0.1 Mgal/d). Withdrawals within the town of 

Cumberland follow a cyclical pattern; the largest volumes 

of water were withdrawn during the summer and the 

smallest in the winter and spring.
72 Estimated Water Use and Availability in the Lower Blackstone River Basin, Northern Rhode Island and South-Central Massachusetts, 1995–99

0

5

10

15

20

25

Jan.

1995

July

1995

Jan.

1996

July

1996

Jan.

1997

July

1997

Jan.

1998

July

1998

Jan.

1999

July

1999

WITHDRAWALS, IN MILLION GALLONS PER DAY

DATE

Figure 2.1. Total withdrawals in million gallons per day within the town of Cumberland, Rhode 

Island, 1995–99.

Cumberland Water Department

The Cumberland WD withdrew water from three 

separate sources during the study period: Sneech Pond 

and Manville wells no. 1 and no. 2. (figs. 2.2 and 2.3) 

These withdrawals averaged 0.837 Mgal/d, 0.179 Mgal/d, 

and 0.160 Mgal/d from 1995–99 (table 2.1 and fig. 2.3). 

Two Cumberland WD wells were inactive during the 

study period: Abbot Run wells no. 2 and no. 3 (fig. 2.2, 

table 2.1). In addition to the 1.176 Mgal/d supplied from 

the Cumberland WD’s own sources, an average of 

1.430 Mgal/d (Cumberland Water Department, written 

commun., 2002) was purchased from Pawtucket WSB. 

Pawtucket Water Supply Board

The Pawtucket WSB withdrew water from eight 

separate sources within the town of Cumberland during 

the study period, including the Happy Hollow Pond intake 

and Pawtucket wells no. 2, 3, 4, 6, 7, 8, and 9 (fig. 2.2). 

These withdrawals averaged 12.017, 0.156, 0.273, 0.065, 

0.129, 0.169, 0.179, and 0.183 Mgal/d, respectively 

(table 2.1). Three Pawtucket WSB wells (nos. 5, 10, and 

11) were inactive during the study period (fig. 2.2). The 

Pawtucket WSB withdrew an average of 13.171 Mgal/d 

during 1995–99. Of this amount, 91 percent came from 

the Happy Hollow Pond intake. The remaining 9 percent 
Appendix 2 73

71o48' 71o

42' 71o

36' 71o

30' 71o

24'

42o

06'

42o

00'

41o

54'

EXPLANATION

CUMBERLAND

LAKES, PONDS, AND RESERVOIRS

RIVERS AND STREAMS

PUBLIC-SUPPLY INTAKES AND 

 IDENTIFIERS—Well names and numbers shown in table 4

SUBBASIN BOUNDARIES

STATE BOUNDARIES

PUBLIC-SUPPLY WELLS AND 

 IDENTIFIERS—Well names and numbers shown in table 4

0 10 KILOMETERS 5

0 5 10 MILES

70-73

66-69

57

64 51,52

55-56

53 65

53

51

RHODE ISLAND

MASSACHUSETTS

CONNECTICUT

GLOCESTER

SMITHFIELD

LINCOLN

CUMBERLAND

WOONSOCKET

NORTH SMITHFIELD

BURRILLVILLE

DOUGLAS

UXBRIDGE

MILLVILLE

BLACKSTONE

BELLINGHAM FRANKLIN

WRENTHAM

PLAINVILLE

NORTH 

ATTLEBORO

ATTLEBORO

PAWTUCKET

CENTRAL 

FALLS

Base from the National Resource Conservation Service 

12-digit HUC base map, 1:24,000, (2001)

Projection: Rhode Island State Plane

Figure 2.2. Public-supply withdrawal locations in the town of Cumberland, Rhode Island.

came from the Pawtucket wells. The wells were used 

primarily in the summer months for all five years, with use 

extending into the spring or fall in 1996, 1998, and 1999. 

The maximum volume withdrawn from Happy Hollow 

Pond was 490 million gallons in June 1999, at an average 

rate of about 16.3 Mgal/d.
74 Estimated Water Use and Availability in the Lower Blackstone River Basin, Northern Rhode Island and South-Central Massachusetts, 1995–99

0.0

0.5

1.0

1.5

2.0

2.5

3.0

3.5

4.0

Jan.

1995

July

1995

Jan.

1996

July

1996

Jan.

1997

July

1997

Jan.

1998

July

1998

Jan.

1999

July

1999

DATE

WITHDRAWALS, IN MILLION GALLONS PER DAY

Sneech Pond Intake

Manville well no. 1

Manville well no. 2

CWD/Pawtucket WSB 

interconnection

Figure 2.3. Cumberland Water Department monthly withdrawal volumes and wholesale purchases 

by source, 1995–99.

WATER USE

The 5-year average water use for the town of 

Cumberland was 3.574 Mgal/d (table 2.2). Non-account 

water use for the Cumberland WD was reported as 26.1 

percent of distribution, and the Pawtucket WSB reported 

non-account water use at 3.0 percent. The Cumberland 

WD supplied 73.3 percent of the town’s water (including 

wholesale purchases from the Pawtucket WSB) and the 

Pawtucket WSB supplied 23.3 percent of the town’s water 

to the Valley Falls section of Cumberland. Averaging 

these percentages of non-account use relative to 

distribution for use in the town of Cumberland gives an 

estimated non-account use for the entire town of 19.8 

percent. Self-supply use accounted for about 3.3 percent 

of the total water use in Cumberland. Monthly water-use 

values for public-supply users in the Cumberland WD 

service area were based on yearly percentage values 

reported in the water-supply-management plan (Water 

Works Engineering and Associates, 1994). Only 1-year 

and 5-year estimates of water-use values were available 

for the Valley Falls section of Cumberland. 
Appendix 2 75

1The Pawtucket Water Supply Board service area includes the southern portion of Cumberland known as Valley Falls. Water use values reported here 

are for Valley Falls only. The Pawtucket Water Supply Board also serves Pawtucket and Central Falls.

Table 2.2. Water-use summary by category for the town of Cumberland, Rhode Island

[All values in million gallons per day. na, not applicable; --, none known]

Source

Water-use rate

Agricultural Commercial Industrial Domestic Non-account Total

Self-supply 0.038 -- -- 0.082 na 0.12

Cumberland Water Department 0 0.255 0.251 1.432 0.683 2.621

Pawtucket Water Supply Board1 0 .098 .107 .603 .025 .833

Total .................................................... 0.038 0.353 0.358 2.117 0.708 3.574

WASTEWATER RETURN FLOWS

The Narragansett Bay Commission’s Bucklin Point 

Facility in East Providence, Rhode Island received an 

estimated 2.543 Mgal/d of wastewater from the town of 

Cumberland. Public disposal of wastewater for 

Cumberland was estimated at about 1.490 Mgal/d, of 

which 1.083 Mgal/d was from domestic, 0.311 Mgal/d 

from commercial, and 0.096 Mgal/d from industrial 

wastewater. These estimates indicate that 1.053 Mgal/d or 

about 41.4 percent of the flow received at the Bucklin 

Point facility from the town of Cumberland may be 

attributed to infiltration and inflow. Self-disposal of 

wastewater for the town of Cumberland was estimated at 

about 0.932 Mgal/d, of which 0.700 Mgal/d was from 

domestic and 0.232 Mgal/d from industrial wastewater. 

REFERENCES CITED

Horn, M.A., 2002, User's manual for the New England wateruse database system: U.S. Geological Survey Open-File 

Report 01-328, 392 p.

Tessler, Steven, 2002, Data model and relational database 

design for the New England water-use data system 

(NEWUDS): U.S. Geological Survey Open-File Report 

01-359, 70 p., 1 pl.

Water Works Engineering and Associates, Inc., 1994, Town of 

Cumberland Department of Public Works Water 

Department Water Supply Management Plan: Prepared for 

State of Rhode Island Department of Environmental 

Management, Division of Water Supply Management; v. I, 

variously paged.