Summary and Conclusions 117

Summary and Conclusions

The Pawcatuck River Basin includes 303 mi2 in 

southwestern Rhode Island and southeastern Connecticut. 

The streams, ponds, and groundwater aquifers in the basin are 

valuable high-quality water resources that provide water for 

domestic and public supplies, irrigation, and a rich aquatic 

ecosystem. Streamflow records for several rivers for the 

summer irrigation season indicate that water withdrawals may 

be affecting aquatic habitat and diversity, water quality, and 

the value of the rivers as a scenic and recreational resource. 

Concerns over the effects of water withdrawals on streamflow, 

pond levels, groundwater levels, and aquatic habitat prompted 

the development of a surface-water model, groundwater 

models, and conjunctive-management models for the basin 

by the U.S. Geological Survey (USGS) in cooperation with 

the U.S. Department of Agriculture–Natural Resources 

Conservation Service (NRCS) and the Rhode Island Water 

Resources Board (RIWRB). The results of this study can be 

used to assist Federal, State, and local officials, environmental 

organizations, and private citizens in evaluating the water 

resources, water management, water-management alternatives, 

and land-use changes in the basin.

Climate, streamflow, groundwater-level, pond-level, 

and water-use data were collected throughout the Pawcatuck 

River Basin during 2000–04, the study period, to support 

development of the three models. Additionally, hydrogeologic 

data were compiled for the modeling efforts from previous 

studies throughout the basin. The surface-water (precipitationrunoff) model for the entire basin was developed by using the 

Hydrologic Simulation Program-FORTRAN (HSPF) model. 

The groundwater-flow models for the lower Wood River and 

eastern Pawcatuck River areas in the basin were developed by 

using MODFLOW. Conjunctive-management models were 

also developed for smaller areas within the groundwatermodel areas of the basin. These hydrologic models were 

used to evaluate current (2000–04) conditions, long-term 

conditions, effects of water withdrawals on streamflow 

and levels, water-management alternatives, and land-use 

changes in the basin. Additionally, the streamflow-depletion 

results from MODFLOW were compared to the results of a 

streamflow-depletion algorithm in the HSPF model for the two 

groundwater-model areas.

Part 1. Water Resources in the Pawcatuck 

River Basin

Climatic data were collected at two stations installed 

for the study and compiled from four National Oceanic and 

Atmospheric Administration (NOAA) stations in and near 

the Pawcatuck River Basin. Precipitation during the study 

period was similar to the long-term normal, although from 

August 2001 through 2002 precipitation was about 

17.3 in. below normal. Streamflow data were collected at nine 

long-term streamflow-gaging stations and at nine additional 

stations installed for the study. During the entire study period 

streamflows were close to the long-term average for the basin, 

but the period of below-normal precipitation from August 

2001 through 2002 resulted in below-normal streamflows 

from September 2001 through October 2002, except for May 

and June 2002. Additional streamflow data in the basin were 

collected through monthly streamflow measurements at 36 

partial-record stations during 2002–04. To help calibrate the 

models, daily streamflows were estimated by applying the 

mathematical procedure Maintenance of Variance Extension 

(MOVE.1) to the 36 partial-record stations for the entire 

study period. Climatic and streamflow data (measured 

and estimated) were used to calibrate the HSPF and 

MODFLOW models.

Groundwater-level data were collected from 19 wells that 

are part of the USGS long-term groundwater-monitoring network. Continuous records were collected at 4 of the 19 wells 

during the entire study period and at another 4 wells during 

2002–04. Data from the two model areas (lower Wood River 

and eastern Pawcatuck River) were used in calibrating the 

MODFLOW groundwater-flow models. Monthly pond-level 

data were collected at 23 sites during 2003–04. 

Water-withdrawal data for 16 wells were compiled from 

five major municipal suppliers in the basin. During the study 

period, the average withdrawal rate for these 16 wells was 

7.18 Mgal/d. Four of the five water suppliers increased withdrawals noticeably each year during May through September 

and especially during July and August. The one exception was 

water withdrawals by a school; these withdrawals decreased 

during the summer months when most of the students were not 

at the school. 

Water-withdrawal data were collected at 11 turf-farm 

sites for the period of 2002–04 or 2000–04. During the entire 

study period (2000–04), these turf farms averaged 3,399 gal/d/

acre during days of irrigation. The number of days of irrigation 

per year during the irrigation season (May 1 through October 

31) averaged about 31, but ranged from 0 days (one farm in 

2003) to 75 days (one farm in 2001). Water-withdrawal data 

were collected for three golf courses (one with a surfacewater supply and two with groundwater supplies) in the basin 

for 2002–04 or 2000–04. During the study period, these golf 

courses averaged 1,752 gals/d/acre during days of irrigation. 

The average number of days of irrigation during the irrigation 

season (April 16 through November 15) ranged from 75 days 

at the golf course with surface-water withdrawals to 131 days 

at the two golf courses with groundwater withdrawals. The 

number of days of irrigation per year ranged from 62 days at 

the golf course with surface-water withdrawals to 208 days at 

one of the two golf courses with groundwater withdrawals.

The water-withdrawal data collected at the turf farms 

and golf courses were then used to develop logistic-regression 

equations to estimate the probability of irrigation on specific 

days during the respective irrigation seasons for turf farms and 

golf courses. The equations were based on total precipitation 

and potential evapotranspiration during the previous 2 to 

20 days, depending on the equation, proceeding each day 
118 Effects of Water Withdrawals and Land-Use Changes on Streamflows and Groundwater Levels in Pawcatuck River Basin

of estimation. One equation was developed for turf farms 

and two equations were developed for golf courses, one 

for surface-water withdrawals and one for groundwater 

withdrawals. Once the days of irrigation for 2000–04 were 

estimated by the appropriate equations, the average hourly 

irrigation patterns determined for the turf farms or golf courses 

were then applied to the acreage of the unmetered sites. For 

the pre-study period of 1960–99, irrigation withdrawals had 

to be estimated for all turf farms and golf courses by using the 

appropriate logistic-regression equations, climate data during 

1960–99, the acreage from 2000–04, and the hourly irrigation 

pattern from 2000–04.

Part 2. Simulation of Water-Use and Land-Use 

Changes on Streamflow with a PrecipitationRunoff Model (HSPF)

Simulations of the effects of withdrawal practices and 

land-use changes on streamflow were developed in conjunction with the Pawcatuck Watershed Partnership (WUSG) and 

were made with the calibrated HSPF model for the period 

1960–2004. Simulations included the following scenarios: 

no withdrawals, current withdrawal, conversion of selected 

surface-water irrigation withdrawals to groundwater withdrawals, future water-supply demands, and land-use change. 

The first four scenarios focused on withdrawal alternatives in 

12 subbasins in 3 regions of the Pawcatuck River Basin—the 

Usquepaug-Queen River and Beaver River area, the eastern 

Pawcatuck River area, and the lower Wood River area. For 

each subbasin, the effects of withdrawal alternatives were 

evaluated by examining changes in the daily mean flow-duration curves simulated for the 1960–2004 period and the hourly 

flow hydrographs for August 2002, the month of lowest flow 

during the calibration period. The analysis was limited to 13 

selected sites that were of most interest to the WUSG, but any 

of the 84 model reaches defined could be used in the analysis. 

In general, the largest differences between current 

withdrawals and no withdrawals in the simulations were in 

four subbasins in the eastern Pawcatuck River area—the 

Chipuxet River (two locations), the Chickasheen River, and 

the headwaters of the Pawcatuck River. Currently municipal 

water-supply and agricultural withdrawals are substantial in 

this part of the basin, including the largest municipal watersupply withdrawal, which is in the Mink Brook area (part of 

the headwaters of the Pawcatuck River subbasin). Simulated 

flow-duration curves indicate that current withdrawals 

decreased the lowest flows in comparison to simulations with 

no withdrawals by about 40 percent in the upper Chickasheen 

Brook and by about an order of magnitude (up to 80 percent) 

in the lower Chipuxet River and the headwaters of the 

Pawcatuck River. A marked departure between simulated 

flow-duration curves with and without withdrawals begins at 

about the 50-percent duration in each of the eastern Pawcatuck 

River reaches examined, indicating withdrawals appreciably 

alter median to low streamflow in these reaches. The only 

other subbasin that showed a substantial difference between 

low flows with and without withdrawals was the Beaver River 

subbasin; at the 99.8-percent flow duration, streamflow under 

no withdrawals was about two times greater than under 

current demands. 

The effects of moving withdrawals from surface water 

to groundwater at selected sites were most pronounced in the 

daily mean flow-duration curves for the Beaver and Chipuxet 

River subbasins, where irrigation withdrew the largest percentage of streamflow during low-flow periods. Hourly flow fluctuations in the August 2002 hydrograph were greatly reduced 

or eliminated entirely by moving irrigation withdrawals from 

surface water to groundwater in subbasins with irrigation 

demands, even if the switch to groundwater did not result in 

appreciable differences in the daily flow-duration curves. 

Potential future water withdrawals were simulated at 

well sites selected by the RIWRB. Simulations included 

moving selected irrigation withdrawals from surface water 

to groundwater. Results indicate that hypothetical water 

withdrawals of 1 Mgal/d in the eastern Pawcatuck River 

subbasins could result in zero flow in the upper Chipuxet 

River and decrease the lowest flows by as much as an order 

of magnitude. A hypothetical 1 Mgal/d withdrawal from the 

Meadow Brook subbasin decreased the lowest flows by about 

half. Flows in other reaches affected by simulated future 

withdrawals generally did not show much change because the 

cumulative future withdrawals from those reaches were small 

relative to the streamflow. 

Simulations of land-use change (build-out analysis) 

evaluated the effects of land-use change only, change in water 

withdrawals only, and the combined effects of land- and 

water-use change. Land-use change was mostly determined on 

the basis of a statewide future land-use map compiled under 

the provisions of the Rhode Island Comprehensive Planning 

and Regulation Act of 1988. Developable lands were further 

restricted on the basis of steep bedrock, extremely rocky areas, 

and protected areas and buffers around water bodies and wetlands. Overall, about 10 percent of the basin was classified as 

developed in 1995, but about 50 percent of the basin could be 

developed under the restrictions described above. The largest 

change, which affected about a third of the basin, was from 

forest to low-to-medium-density residential development. 

The change in developed land use in the subbasins ranged 

from zero to about 75 percent of subbasin area, with a median 

change of about 40 percent.

The effects of water-use change associated with landuse change (build-out analysis) were simulated on the basis 

of housing density, an occupancy rate of 2.5 people per unit, 

and a water-use factor of 70 gal/d/person. Water use ranged 

from 44 to 1,400 gal/d/acre for low- to high-density residential development, respectively. In most areas of the basin it 

was assumed that 20 percent of the water use was consumptive (lost from the basin), and that the remaining 80 percent 

was returned through onsite septic systems. The exception to 

this was in the eastern (South Kingstown) and southwestern 

(Westerly and Stonington) parts of the basin where the entire 
Summary and Conclusions 119

water demand is considered lost from the basin because these 

areas are served by municipal water suppliers and sewers that 

return wastewater outside the basin. The domestic water use in 

the basin at buildout was estimated as 21.8 Mgal/d or about 4 

times the current domestic water use. 

Water use for new commercial and industrial development was estimated per unit area by using reported values for 

1995–99 (1.22 Mgal/d) and distributing this demand over the 

total area at buildout (8,414 acres). Results indicate that at 

buildout, commercial and industrial water use would be about 

7.47 Mgal/d for the basin or about a 5-fold increase over the 

reported 1995–99 commercial and industrial water use. In 

the buildout analysis irrigated land, other than land used by 

golf courses, was assumed to be replaced by developable land 

unless otherwise protected.

Buildout was simulated for the upper Chipuxet River, 

lower Beaver River, lower Wood River, and lower Pawcatuck 

River subbasins. The buildout plans for these areas reflect 

changes in water demand, land use, or both. Withdrawals 

in the upper Chipuxet River subbasin currently are minor, 

but about 54 percent of the subbasin is developable. The 

simulations for the lower Beaver River subbasin reflect large 

changes in land use, but changes in water withdrawals are 

expected to be less pronounced because they are expected to 

be partially offset by a decrease in agricultural withdrawals. 

The simulations for the lower Wood River subbasin reflect 

change in a large pristine basin. Anticipated changes for the 

lower Pawcatuck River subbasin reflect the overall change in 

the entire basin.

In general, simulations for buildout indicated that high 

flows would increase slightly and low flows would decrease 

slightly as a result of land-use change relative to simulations 

for land-use conditions in 1995, but the changes were generally not large. In some instances, decreased infiltration from 

urbanization was offset, or more than offset, by decreased 

evapotranspiration from deep-rooted vegetation. For example, 

simulation results for the lower Wood River subbasin showed 

slightly higher low flows under buildout than under 1995 

land-use conditions. In subbasins where water is currently 

extracted for agricultural irrigation, the irrigation withdrawals 

can exceed the urban buildout withdrawals that replace them, 

which results in higher simulated low flows under buildout 

conditions than under current conditions. The extent to which 

streamflow changes in response to development depends on 

exactly how the land is developed; development is expected 

to differ widely and to produce effects different from those 

simulated, particularly in local areas.

The Pawcatuck Basin HSPF model was conceptualized and calibrated to evaluate the effects of withdrawals on 

streamflow. Many water-resource-management issues can be 

evaluated through model simulations, but the model may not 

be appropriate for some analyses. Thus, care should be taken 

to consider the model uncertainties and limitations to ensure 

that inappropriate interpretation of simulation results does not 

lead to inaccurate conclusions.

Part 3. Simulated Effects of Withdrawals on 

Groundwater Flow (MODFLOW Models)

Groundwater-flow models were developed for two areas 

in the Pawcatuck River Basin—the lower Wood River and 

eastern Pawcatuck River areas—to assess the potential effects 

of groundwater pumping on streamflows and water levels at 

proposed irrigation and municipal water-supply sites in the 

study area, to compare results simulated by MODFLOW and 

the streamflow-depletion algorithm in the HSPF model, and 

to evaluate alternatives for the conjunctive management of the 

ground- and surface-water resources of the basin. 

The simulations included analyses of the effects of 

constant and varying pumping and constant and varying 

recharge rates, the effects of constant pumping and varying 

recharge rates, and the effects of different well distances from 

streams under constant and varying pumping rates. Simulations were made to compare and contrast the effects of these 

changes on smaller and larger streams with lower and higher 

flows, respectively, to determine whether the responses of the 

streams and the surrounding aquifer to the changes in simulated stresses differed with stream size. 

For constant pumping and constant recharge representing 

average conditions, the simulated decrease in streamflow in 

both a large and a small stream (with higher and lower flow, 

respectively) was about equal to the total pumping rate, with 

the remainder of the withdrawal derived from aquifer storage. 

As the recharge rate varied with time, however, the streamflow varied in response to the change in recharge, and the 

amount of base-flow reduction from pumping also varied. The 

simulated pumping rates from proposed wells near both of the 

streams were the same; however, the effects of pumping on the 

two streams differed substantially.

During wet periods when simulated streamflow was at or 

above average, the reduction in streamflow was similar to that 

calculated in the simulation in which pumping and recharge 

were constant. During the summer and early fall when 

simulated streamflow without pumping was at or near zero, 

however, the calculated reduction in streamflow from pumping decreased as streamflow decreased, because as a stream 

goes dry, it can no longer be a source of water to the pumped 

well. When a pumped well can no longer meet the demand 

for water by depleting streamflow, the demand must be met 

from another source, usually aquifer storage. Once the stream 

is dry, the water required to meet the simulated pumping rate 

is obtained solely from aquifer storage, a process resulting in 

drawdowns in the aquifer much greater than would have been 

produced near a flowing stream.

An analysis of the effects of varying the distances 

between pumping wells and streams was done to determine if 

the effects of instream withdrawals for turf irrigation during 

low-flow periods could be reduced if the withdrawals were 

shifted away from the streams. This analysis showed that 

streamflow increased during the normally dry summer months 

as the distance between the pumping wells and the rivers 

was increased because of the time lag in the response of the 
120 Effects of Water Withdrawals and Land-Use Changes on Streamflows and Groundwater Levels in Pawcatuck River Basin

streams to the pumping stress. As a result, simulated irrigation 

pumping during the summer did not affect streamflow until 

later in the fall when streamflows are typically higher. 

These simulations indicate that moving the irrigation 

withdrawals from the rivers to wells away from the rivers 

resulted in increased streamflows relative to current conditions 

during the summer low-flow periods and lower flows relative 

to current conditions in the early fall. The benefit of shifting 

streamflow depletion from the summer to the fall is that, by 

the fall, streamflow is increasing from increased recharge. In 

general, the effect of pumping on streamflow is greater when 

the base-flow depletion represents a smaller percentage of the 

total streamflow.

Part 4. Conjunctive-Management Models as 

Tools for Water-Resources Planning

The results of conjunctive-management modeling may 

be used to help balance groundwater and surface-water 

withdrawals needed for water-supply and aquatic-habitat 

protection. Conjunctive-management models were developed 

for two areas in the Pawcatuck River Basin to evaluate the 

potential for improvements in water-withdrawal strategies. 

These two areas are referred to herein as the eastern 

Pawcatuck River conjunctive-management-model (EPRCMM) 

area and lower Wood River conjunctive-management-model 

(LWRCMM) area. 

Conjunctive-management models were developed for 

each area by combining the results of statistical analysis of 

water-use data, simulations with the transient MODFLOW 

groundwater models, and simulations of streamflow from the 

basinwide HSPF surface-water model. In both areas, models 

with maximum withdrawal capacities of 1.0, 1.4, and 

2.0 Mgal/d were tested to illustrate the dynamic interplay 

among stream-depletion criteria, well-network design 

(the number, type, and location of withdrawal sites), and 

production capacity of the water-withdrawal network. The 

streamflow-response coefficients developed as part of the 

optimization process were useful for evaluating the timing and 

magnitude of streamflow depletions from withdrawals near 

different streams. A streamflow-management paradigm based 

on potentially allowable depletions that humans can control, 

rather than a minimum-streamflow paradigm, was developed 

for use by water-resource managers. Simulation results 

indicate that well-site selection, water-use patterns, and the 

timing of the annual minimum of the daily mean streamflows 

affected total annual water yields in the lower Wood River 

model area. Results from conjunctive-management models 

for the eastern Pawcatuck River model area indicate that 

well capacity was the limiting factor for maximizing 

withdrawals. Postoptimization analysis demonstrated the use 

of management-model results to estimate the risks of extreme 

low flows under different withdrawal plans. The examples 

demonstrated how conjunctive-management models may be 

used to balance water use with ecological protection.

Part 5. HSPF and MODFLOW—Capabilities, 

Limitations, and Integration

Water-resource managers rely on tools such as HSPF and 

MODFLOW to address water issues by simulating hydrologic responses of watersheds under alternative conditions or 

management strategies. The choice of model, or even the need 

for a model, however, largely depends on the questions posed. 

The fundamental differences between HSPF and MODFLOW 

were illustrated by comparing simulation results for the same 

type of simulation scenario. Simulation results for three 

examples from the study were used to describe the effects of 

stream-aquifer interactions and temporal and spatial discretization on flow components.

Example 1. Effects of a Pumped Well on 

Streamflow in Meadow Brook

In the lower Meadow Brook subbasin, a hypothetical 

well pumping at 1 Mgal/d was simulated 200 ft from the 

stream. Streamflow simulated with MODFLOW, with and 

without withdrawals, included several periods of no flow 

during the summer months, whereas streamflow simulated 

with showed flow during all periods. The HSPF-simulated 

flows were generally in good agreement with the Meadow 

Brook streamflow-gaging station records, but MODFLOW 

undersimulated streamflows. As a result, induced infiltration 

from Meadow Brook may be undersimulated by MODFLOW, 

with more water to the well captured from the neighboring 

subbasin (PAWC4), depletion of groundwater storage (with 

a lower water table), or both. This result and its implications 

underscore the importance of streamflow in representing 

hydrologic processes that influence how a system responds 

to a stressor. One reason HSPF-simulated flows are closer to 

measured flow is that HSPF simulates all flow components, 

whereas MODFLOW simulates only the baseflow component 

of streamflow. On the other hand, MODFLOW better 

represents the interaction between Meadow Brook and the 

aquifer near the pumped well by simulating changes in 

groundwater head and induced infiltration from the stream, 

provided the simulated streamflow does not incorrectly fall 

below the withdrawal rate. 

Example 2. Effects of Withdrawals near 

Diamond Bog

A hypothetical well pumping at 1 Mgal/d was also 

simulated in the lower Wood River (WOOD5) near Diamond 

Bog, which is considered an important ecological resource. 

The well was simulated about 500 ft from the Wood River and 

about an equal distance from Diamond Brook. Streamflow 

simulated in Diamond Brook was critical in determining the 

response of the aquifer to pumping in Diamond Bog for the 

same reasons described for the pumped well near Meadow 
Acknowledgments 121

Brook. Water-level changes simulated by MODFLOW in 

Diamond Bog in response to pumping are highly dependent on 

the simulated streamflow in Diamond Brook, which was frequently comparable to or less than the withdrawal rate. As the 

simulated flow in the brook decreased to less than the withdrawal rate, the drawdown in the aquifer around the pumped 

well increased and expanded laterally enough to influence the 

interaction between the bog and the pumped well. Simulations 

by HSPF, which is designed to simulate flows in the entire 

Pawcatuck River Basin, did not show the effects of pumping 

on streamflow in Diamond Brook, nor would HSPF be capable 

of simulating the interaction between the bog and the aquifer. 

Example 3. Effects of Converting from SurfaceWater to Groundwater Withdrawals

Changes in streamflow caused by converting withdrawals 

from surface water to groundwater are affected by the averaging of irregular withdrawals and by the assumptions inherent 

in the program (STRMDEPL) used to compute the lag effects 

of a pumped well on streamflow depletion in HSPF. In the 

lower Beaver River the hourly simulated hydrograph shows a 

daily oscillation from July through early September 2002 that 

reflects the intradaily withdrawal pattern; this oscillation does 

not appear in the daily mean hydrograph because the hourly 

oscillations are smoothed by the daily average. In MODFLOW simulations, which averaged irrigation withdrawals 

over weekly or monthly stress periods, the peak withdrawal 

rates decreased by as much as 94 percent, diminishing or 

masking their effects on streamflow. This simulation illustrated the potential benefits of converting in-stream withdrawals to groundwater, particularly if the withdrawal is large with 

respect to streamflow. 

In HSPF simulations of the lower Beaver River subbasin, 

the effects of converting in-stream withdrawals to groundwater are influenced by where streamflow depletion is applied. 

MODFLOW simulations do not force water to a pumped 

well from a particular source; rather, the groundwater flow 

path to the well is determined on the basis of the specified 

hydraulic conductance and the computed hydraulic gradient 

between the aquifer and the stream. In HSPF simulations, 

the streamflow depletion from withdrawals of the pumped 

wells near the lower Beaver River subbasin surface-water 

divide were only simulated in the subbasin where the wells 

are located. MODFLOW simulations, however, indicate that 

these wells near the lower Beaver River surface-water divide 

drew groundwater that would otherwise discharge to the lower 

Beaver River as baseflow. This result indicates that HSPF may 

oversimulate the benefits of converting in-stream withdrawals 

to groundwater. 

Thus, streamflow depletions allocated on the basis of 

subbasin surface-water divides can be inaccurate and lead 

to incorrect conclusions. Without prior knowledge of the 

source of water to a pumped well, allocation of stream depletion among different reaches in HSPF cannot be made. This 

problem applies to areas where a pumped well alters the 

groundwater flow path in ways that are not easily determined, 

such as near the groundwater (water-table) subbasin divide 

or where the water-table gradient is small or poorly defined. 

Although MODFLOW simulations are best suited for this 

type of analysis, constructing an accurate model commonly 

requires detailed field investigations, particularly at the local 

scale, to ensure that the controlling hydrologic factors are well 

defined.

One model used by itself can not adequately address 

all the hydrologic complexities of the real world, but 

understanding the capabilities and limitations of HSPF and of 

MODFLOW provides insight into the many factors that affect 

simulations and the management decisions made from those 

simulations. An integrated model can minimize some of the 

weaknesses of one model by coupling it with the strengths 

of the other model. The complexities of an integrated model 

are large, and further testing of integrated models would 

be needed to determine their potential use. An integrated 

model was tested for this study but it was determined to be 

impracticable due to limitations of a workable MODFLOW 

cell size, the number of additional hydrologic response units 

(HRUs) needed to represent head-dependent conditions 

throughout the basin, and the size of the database needed 

to link the models. Instead, HSPF and MODFLOW were 

informally linked in this study.

Water-resource managers rely on tools such as HSPF and 

MODFLOW to address water-resources issues by simulating 

alternative management strategies. The choice of model, or 

even the need for a model, however, largely depends on the 

questions posed. Each model has strengths and weaknesses 

related to the differing hydrologic processes the models are 

intended to simulate and the spatial and temporal scales of the 

models. Comparison of selected results simulated by these 

two models demonstrates these limitations and the judgment 

required to determine the suitability of a particular model for 

making management decisions.

Acknowledgments

The authors thank the private landowners, water users, 

towns, State of Rhode Island, the Audubon Society of Rhode 

Island, and The Nature Conservancy for allowing access to 

their land to monitor climate, streamflow, groundwater levels, 

and water withdrawals; data on these parameters were needed 

to develop the precipitation-runoff model, groundwater-flow 

models, and conjunctive-management models. The authors 

thank the local water suppliers (Kingston Water Department, 

Richmond Water Department, United Water of Rhode Island, 

and Westerly Water Department) who provided critical waterwithdrawal data that were needed for all the models. The 

authors also thank the NRCS, RIWRB, and the members of 

the Pawcatuck Watershed Partnership WUSG for providing 

input on water-management issues. Justin Tuthill, NRCS, 
122 Effects of Water Withdrawals and Land-Use Changes on Streamflows and Groundwater Levels in Pawcatuck River Basin

provided support and equipment for the surveying of pondlevel-gage altitudes. Vicky Drew, NRCS, also provided 

invaluable time and support in getting permission for the 

installation of water-withdrawal-monitoring sites at turf farms 

and golf courses. 

References Cited

Introduction

Allen, W.B., 1953, The ground-water resources of Rhode 

Island, with a section on surface-water resources, by 

H.B. Kinnison: Rhode Island Water Resources Board Geological Bulletin 6, 170 p.

Allen, W.B., Hahn, G.W., and Brackley, R.A., 1966, Availability of ground water, upper Pawcatuck Basin, Rhode Island: 

U.S. Geological Survey Water-Supply Paper 1821, 66 p., 

3 pls., scale 1:24,000.

Allen, W.B., Hahn, G.W., and Tuttle, C.R., 1963, Geohydrological data for the upper Pawcatuck Basin, Rhode Island: 

Rhode Island Water Resources Board Geological Bulletin 

13, 68 p., 3 pls., scale 1:24,000.

Allen, W.B., and Jeffords, R.M., 1948, Ground-water 

resources in the vicinity of Exeter, Rhode Island: Rhode 

Island Port and Industrial Development Commission 

Scientific Contribution 2, 42 p.

Armstrong, D.S., and Parker, G.W., 2003, Assessment of 

habitat and streamflow requirements for habitat protection, 

Usquepaug-Queen River, Rhode Island, 1999–2000: 

U.S. Geological Survey Open-File Report 02–438, 69 p.

Barlow, P.M., and Dickerman, D.C., 2001a, Balancing 

ground-water withdrawals and streamflow in the HuntAnnaquatucket-Pettaquamscutt Basin, Rhode Island: 

U.S. Geological Survey Fact Sheet 063–01, 6 p.

Barlow, P.M., and Dickerman, D.C., 2001b, Numericalsimulation and conjunctive-management models of the 

Hunt-Annaquatucket-Pettaquamscutt stream-aquifer system, 

Rhode Island: U.S. Geological Survey Professional 

Paper 1636, 88 p., 1 pl.

Bicknell, B.R., Imhoff, J.C., Kittle, J.L., Jr., Jobes, T.H., 

and Donigian, A.S., Jr., 2000, Hydrological Simulation 

Program—FORTRAN user’s manual for release 12: 

Mountain View, Calif., AQUA TERRA Consultants, 

variously paged. 

Bierschenk, W.H., 1956, Ground-water resources of the 

Kingston quadrangle, Rhode Island: Rhode Island Water 

Resources Board Geological Bulletin 9, 60 p., 3 pls., 

scale 1:24,000.

Bierschenk, W.H., and Hahn, G.W., 1959, Hope Valley quadrangle, Rhode Island: Rhode Island Water Resources Board 

Ground-Water Map 6, 1 pl., scale 1:24,000.

Cervione, M.A., Richardson, A.R., and Weiss, L.A., 1993, 

Low-flow characteristics of selected streams in Rhode 

Island: U.S. Geological Survey Water-Resources Investigations Report 93–4046, 16 p.

Craft, P.A., 2001, Hydrogeologic data for the Big River—

Mishnock River stream-aquifer system, central Rhode 

Island: U.S. Geological Survey Open-File Report 01–250, 

104 p.

Craft, P.A., Horn, M.A., and Medalie, Laura, 1995, Estimated 

withdrawals and use of freshwater in Rhode Island, 1990: 

U.S. Geological Survey Water-Resources Investigations 

Report 93–4150, 1 pl.

Denny, C.S., 1982, Geomorphology of New England: U.S. 

Geological Survey Professional Paper 1208, 18 p.

Desbonnet, Alan, 1999, Pawcatuck watershed water 

resources—A management issues profile: Rhode Island Sea 

Grant Program, Coastal Resources Center, University of 

Rhode Island, 52 p.

DeSimone, L.A., and Ostiguy, L.J., 1999, A vulnerability 

assessment of public-water supply wells in Rhode Island: 

U.S. Geological Survey Water-Resources Investigations 

Report 99–4160, 153 p.

Dickerman, D.C., 1976, Geohydrologic data for the Chipuxet 

River ground-water reservoir, Rhode Island: Rhode Island 

Water Resources Board Information Series Report 2, 86 p.

Dickerman, D.C., 1984, Aquifer tests in the stratified drift, 

Chipuxet Basin, Rhode Island: U.S. Geological Survey 

Water-Resources Investigations Report 83–4231, 39 p.

Dickerman, D.C., and Bell, R.W., 1993, Hydrogeology, water 

quality, and ground-water-development alternatives in the 

upper Wood River ground-water reservoir, Rhode Island: 

U.S. Geological Survey Water-Resources Investigations 

Report 92–4119, 87 p.

Dickerman, D.C., Bell, R.W., Mulvey, K.D., Peterman, E.L., 

and Russell, J.P., 1989, Geohydrologic data for the upper 

Wood River ground-water reservoir, Rhode Island: Rhode 

Island Water Resources Board Water Information Series 

Report 5, 274 p., 1 pl., scale 1:24,000.

Dickerman, D.C., and Johnston, H.E., 1977, Geohydrologic 

data for the Beaver-Pasquiset ground-water reservoir, 

Rhode Island: Rhode Island Water Resources Board Water 

Information Series Report 3, 128 p.
References Cited 123

Dickerman, D.C., Kliever, J.D., and Stone, J.R., 1997, 

Hydrogeology, water quality, and simulation of groundwater-development alternatives in the Usquepaug-Queen 

groundwater reservoir, southern Rhode Island: 

U.S. Geological Survey Water-Resources Investigations 

Report 97–4126, p. 48, 1 pl., scale 1:24,000.

Dickerman, D.C., and Ozbilgin, M.M., 1985, Hydrogeology, 

water quality, and ground-water development alternatives in 

the Beaver-Pasquiset ground-water reservoir, Rhode Island: 

U.S. Geological Survey Water-Resources Investigations 

Report 85–4190, 104 p.

Dickerman, D.C., and Silva, P.J., 1980, Geohydrologic data 

for the lower Wood River ground-water reservoir, Rhode 

Island: Rhode Island Water Resources Board Water Information Series Report 4, 193 p., 1 pl., scale 1:24,000.

Dickerman, D.C., Todd, E.C.T., and Russell, J.P., 1990, 

Hydrogeology, water quality and ground-water development 

alternatives in lower Wood River ground-water reservoir, 

Rhode Island: U.S. Geological Survey Water-Resources 

Investigations Report 89–4031, 109 p.

Feininger, Tomas, 1962, Surficial geology of the Hope Valley 

quadrangle, Rhode Island: U.S. Geological Survey Geologic Quadrangle Map GQ–166, 1 pl., scale 1:24,000.

Feininger, Tomas, 1965a, Bedrock geologic map of the 

Ashaway quadrangle, Connecticut-Rhode Island: 

U.S. Geological Survey Geologic Quadrangle Map 

GQ–403, 1 pl., scale 1:24,000.

Feininger, Tomas, 1965b, Bedrock geologic map of the 

Voluntown quadrangle, New London County, Connecticut, 

and Kent and Washington Counties, Rhode Island: 

U.S. Geological Survey Geologic Quadrangle Map 

GQ–436, 1 pl., scale 1:24,000.

Feininger, Tomas, 1965c, Surficial geologic map of the 

Voluntown quadrangle, Connecticut-Rhode Island: 

U.S. Geological Survey Geologic Quadrangle Map 

GQ–469, 1 pl., scale 1:24,000.

Friesz, P.J., 2004, Delineation of areas contributing recharge 

to selected public-supply wells in glacial valley-fill and 

wetland settings, Rhode Island: U.S. Geological Survey 

Scientific Investigations Report 2004–5070, 57 p.

Friesz, P.J., and Stone, J.R., 2007, Simulation of ground-water 

flow and areas contributing recharge to production wells in 

contrasting glacial valley-fill settings, Rhode Island: 

U.S. Geological Survey Scientific Investigations Report 

2007–5133, 50 p.

Goldsmith, Richard, 1985, Bedrock geologic map of the Old 

Mystic and part of the Mystic quadrangles, Connecticut, 

New York, and Rhode Island: U.S. Geological Survey 

Miscellaneous Investigations Series Map I–1524, 

scale 1:24,000, 8 p.

Gonthier, J.B., Johnston, H.E., and Malmberg, G.T., 1974, 

Availability of ground water in the lower Pawcatuck River 

basin, Rhode Island: U.S. Geological Survey Water-Supply 

Paper 2033, 40 p., 5 pls., scale 1:48,000.

Granato, G.E., and Barlow, P.M., 2005, Effects of alternative instream-flow criteria and water-supply demands on 

ground-water development options in the Big River area, 

Rhode Island: U.S. Geological Survey Scientific Investigations Report 2004–5301, 110 p.

Granato, G.E., Barlow, P.M., and Dickerman, D.C., 2003, 

Hydrogeology and simulated effects of ground-water withdrawals in the Big River area, Rhode Island: U.S. Geological Survey Water-Resources Investigations Report 03–4222, 

76 p.

Guthrie, R.C., and Stolgitis, J.A., 2000, Fisheries investigations and management in Rhode Island lakes and ponds: 

Rhode Island Department of Fish and Wildlife, Fisheries 

Report No. 3, 256 p.

Hahn, G.W., 1959, Slocum quadrangle, Rhode Island: Rhode 

Island Water Resources Board Ground-Water Map 2, 1 pl., 

scale 1:24,000.

Harbaugh, A.W., Banta, E.R., Hill, M.C., and Anderman, 

E.R., 2000, MODFLOW-2000, The U.S. Geological Survey 

modular ground-water model—User guide to modularization concepts and the ground-water flow process: U.S. 

Geological Survey Open-File Report 00–92, 121 p.

Harwood, D.S., and Goldsmith, Richard, 1971a, Bedrock 

geologic map of the Oneco quadrangle, Connecticut-Rhode 

Island: U.S. Geological Survey Geologic Quadrangle Map 

GQ–930, 1 pl., scale 1:24,000.

Harwood, D.S., and Goldsmith, Richard, 1971b, Surficial 

geologic map of the Oneco quadrangle, Connecticut-Rhode 

Island: U.S. Geological Survey Geologic Quadrangle Map 

GQ–917, 1 pl., scale 1:24,000.

Horn, M.A., 2000, 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.

Horn, M.A., and Craft, P.A., 1991, Plan for developing a 

water-use data program in Rhode Island: U.S. Geological 

Survey Water-Resources Investigations Report 90–4207, 

26 p.
124 Effects of Water Withdrawals and Land-Use Changes on Streamflows and Groundwater Levels in Pawcatuck River Basin

Johnson, K.E., 1961a, Rhode Island part of the Ashaway 

quadrangle and some adjacent areas of Connecticut: Rhode 

Island Water Resources Board Ground-Water Map 16, 1 pl., 

scale 1:24,000.

Johnson, K.E., 1961b, Watch Hill quadrangle, ConnecticutRhode Island: Rhode Island Water Resources Board 

Ground-Water Map 14, 1 pl., scale 1:24,000.

Johnson, K.E., and Marks, L.Y., 1959, Wickford quadrangle, 

Rhode Island: Rhode Island Water Resources Coordinating 

Board Ground-Water Map 1, 1 sheet, scale 1:24,000.

Johnson, K.E., Mason, R.A., and DeLuca, F.A., 1960, 

Oneco quadrangle, Connecticut-Rhode Island: Rhode 

Island Water Resources Board Ground-Water Map 10, 1 pl., 

scale 1:24,000.

Johnston, H.E., 1988, U.S. Geological Survey ground-water 

studies in Rhode Island: U.S. Geological Survey Open-File 

Report 88–139, 1 sheet.

Johnston, H.E., and Dickerman, D.C., 1985, Hydrology, 

water quality, and ground-water development alternatives 

in the Chipuxet ground-water reservoir, Rhode Island: 

U.S. Geological Survey Water-Resources Investigations 

Report 84–4254, 100 p.

Kaye, C.A., 1961, Surficial geology of Kingston quadrangle, 

Rhode Island: U.S. Geological Survey Geological Bulletin 

1071–I, p. 341–396, 3 pls.

Kliever, J.D., 1995, Hydrologic data for the Usquepaug–

Queen basin, Rhode Island: U.S. Geological Survey 

Open-File Report 95–305 and State of Rhode Island Water 

Resources Board Water Information Series Report 6, 68 p., 

1 pl., scale 1:24,000.

Korzendorfer, B.A., and Horn, M.A., 1995, Estimated water 

use in the New England States, 1990: U.S. Geological 

Survey Water-Resources Investigations Report 94–4252, 

21 p.

Lang, S.M., 1961, Appraisal of the ground-water reservoir 

areas in Rhode Island: Rhode Island Water Resources 

Board Geological Bulletin 11, 38 p.

Lang, S.M., Bierschenk, W.H., and Allen, W.B., 1960, 

Hydraulic characteristics of glacial outwash in Rhode 

Island: Rhode Island Water Resources Board Hydrologic 

Bulletin 3, 38 p.

LaSala, A.M., Jr., and Hahn, G.W., 1960, Carolina quadrangle, Rhode Island: Rhode Island Water Resources Board 

Ground-Water Map 9, 1 pl., scale 1:24,000.

LaSala, A.M., Jr., and Johnson, K.E., 1960, Quonochontaug 

quadrangle, Rhode Island: Rhode Island Water Resources 

Board Ground-Water Map 11, 1 pl., scale 1:24,000.

Mason, R.A., and Hahn, G.W., 1959, Hope Valley quadrangle, Rhode Island-Massachusetts: Rhode Island Water 

Resources Coordinating Board Ground-Water Map 6, 

1 sheet, scale 1:24,000.

Mason, R.A., and Hahn, G.W., 1960, Coventry Center quadrangle, Rhode Island: Rhode Island Water Resources Board 

Ground-Water Map 8, 1 pl., scale 1:24,000.

Mason, R.A., Allen, W.B., and Hahn, G.W., 1960, Coventry 

Center quadrangle, Rhode Island: Rhode Island Water 

Resources Coordinating Board Ground-Water Map 8, 

1 sheet, scale 1:24,000.

Masterson, J.P., Sorenson, J.R., Stone, J.R., Moran, S.B., and 

Hougham, Andrea, 2007, Hydrogeology and simulated 

ground-water flow in the salt pond region of southern 

Rhode Island: U.S. Geological Survey Scientific Investigations Report 2006–5271, 56 p.

Medalie, Laura, 1996, Wastewater collection and return flow 

in New England, 1990: U.S. Geological Survey WaterResources Investigations Report 95–4144, 79 p.

Moore, G.E., Jr., 1958, Bedrock geologic map of the Hope 

Valley quadrangle, Rhode Island: U.S. Geological Survey 

Geologic Quadrangle Map GQ–105, 1 pl., scale 1:24,000.

Moore, G.E., Jr., 1959, Bedrock geologic map of the Carolina 

and Quonochontaug quadrangles, Rhode Island: U.S. Geological Survey Geologic Quadrangle Map GQ–117, 

1 pl., scale 1:24,000.

Moore, G.E., Jr., 1964, Bedrock geology of the Kingston 

quadrangle, Rhode Island: U.S. Geological Survey Geologic Bulletin 1158–E, 21 p., 1 pl.

Moore, G.E., Jr., 1967, Bedrock geologic map of the Watch 

Hill quadrangle, Washington County, Rhode Island, and 

New London County, Connecticut: U.S. Geological Survey 

Geologic Quadrangle Map GQ–655, 1 pl., scale 1:24,000.

National Oceanic and Atmospheric Administration, 2002, 

Monthly station normals of temperature, precipitation, and 

heating and cooling degree days 1971–2000–37 Rhode 

Island: Climatography of the United States no. 81, 9 p., 

accessed March 3, 2007, at http://cdo.ncdc.noaa.gov/

climatenormals/clim81/RInorm.pdf.

Natural Resources Conservation Service, 2003, The Pawcatuck Watershed water use optimization project: Warwick, 

R.I., accessed May 4, 2007, at http://www.ri.nrcs.usda.gov/

pawcatuck.html.

Power, W.R., Jr., 1957, Surficial geology of the Slocum quadrangle, Rhode Island: U.S. Geological Survey Geologic 

Quadrangle Map GQ–106, 1 pl., scale 1:24,000.
References Cited 125

Power, W.R., Jr., 1959, Bedrock geology of the Slocum quadrangle, Rhode Island: U.S. Geological Survey Geologic 

Quadrangle Map GQ–114, 1 pl., scale 1:24,000.

Randall, A.D., Bierschenk, W.H., and Hahn, G.W., 1960, 

Voluntown quadrangle, Connecticut–Rhode Island: Rhode 

Island Water Resources Board Ground-Water Map 13, 1 pl., 

scale 1:24,000.

Rhode Island Water Resources Board, 2002, Rhode Island 

Water Resources Board home page, accessed December 10, 

2002, at http://www.wrb.state.ri.us/mission/index.html.

Schafer, J.P., 1961, Surficial geology of the Wickford quadrangle, Rhode Island: U.S. Geological Survey Geologic 

Quadrangle Map GQ–106, 1 pl., scale 1:24,000.

Schafer, J.P., 1965, Surficial geology of the Watch Hill quadrangle, Rhode Island-Connecticut: U.S. Geological Survey 

Geologic Quadrangle Map GQ–410, 1 pl., scale 1:24,000.

Schafer, J.P., 1968, Surficial geology of the Ashaway quadrangle, Connecticut-Rhode Island: U.S. Geological Survey 

Geologic Quadrangle Map GQ–712, 1 pl., scale 1:24,000.

Trench, E.C.T., 1991, Ground-water resources of Rhode 

Island: U.S. Geological Survey Open-File Report 91–199, 

169 p.

Trench, E.C.T., 1995, Sources of geologic and hydrologic 

information pertinent to ground-water resources in Rhode 

Island: U.S. Geological Survey Open-File Report 93–464, 

98 p.

U.S. Environmental Protection Agency, 1988, Sole source 

stratified-drift area designation for the Pawcatuck Basin 

stratified-drift area system, Rhode Island and Connecticut: 

Federal Register, v. 53, no. 93, May 13. (Also available at 

http://134.67.99.207/Region1//eco/drinkwater/

solepawc.html.)

U.S. Environmental Protection Agency, 2005, South County, 

R.I., watersheds: Fact Sheet/Spring 2005, EPA 901–F–05–

012, 2 p., accessed March 3, 2007, at http://www.epa.gov/

Region1/eco/specialp/southcounty06.pdf.

Wild, E.C., and Nimiroski, M.T., 2004, Estimated water use 

and availability in the Pawcatuck River Basin, southern 

Rhode Island and southeastern Connecticut: U.S. Geological Survey Scientific Investigations Report 2004–5020, 

72 p.

Zarriello, P.J., and Bent, G.C., 2004, A precipitation-runoff 

model for the analysis of the effects of water withdrawals 

and land-use change on streamflow in the UsquepaugQueen River Basin, Rhode Island: U.S. Geological Survey 

Scientific Investigations Report 2004–5139, 75 p.

Part 1. Water Resources in the Pawcatuck 

River Basin

Allen, W.B., Hahn, G.W., and Brackley, R.A., 1966, Availability of ground water, upper Pawcatuck Basin, Rhode Island: 

U.S. Geological Survey Water-Supply Paper 1821, 66 p., 

3 pls., scale 1:24,000.

Allen, W.B., Hahn, G.W., and Tuttle, C.R., 1963, Geohydrological data for the upper Pawcatuck Basin, Rhode Island: 

Rhode Island Water Resources Board Geological Bulletin 

13, 68 p., 3 pls., scale 1:24,000.

Barlow, P.M., and Dickerman, D.C., 2001, Numerical-simulation and conjunctive-management models of the HuntAnnaquatucket-Pettaquamscutt stream-aquifer system, 

Rhode Island: U.S. Geological Survey Professional Paper 

1636, 88 p., 1 pl.

Boothroyd, J.C., Freedman, J.H., Brenner, H.A., and Stone, 

J.R., 1998, The glacial geology of southern Rhode Island, 

in Murray, D.P., ed., Guidebook to field trips in Rhode 

Island and adjacent regions of Connecticut and Massachusetts: New England Intercollegiate Conference Guidebook, 

p. C5–1–C5–25.

Dickerman, D.C., and Bell, R.W., 1993, Hydrogeology, water 

quality, and ground-water-development alternatives in the 

upper Wood River ground-water reservoir, Rhode Island: 

U.S. Geological Survey Water-Resources Investigations 

Report 92–4119, 87 p.

Dickerman, D.C., Kliever, J.D., and Stone, J.R., 1997, Hydrogeology, water quality, and simulation of ground-waterdevelopment alternatives in the Usquepaug-Queen groundwater reservoir, southern Rhode Island: U.S. Geological 

Survey Water-Resources Investigations Report 97–4126, 

p. 48, 1 pl., scale 1:24,000.

Dickerman, D.C., and Ozbilgin, M.M., 1985, Hydrogeology, 

water quality, and ground-water development alternatives in 

the Beaver-Pasquiset ground-water reservoir, Rhode Island: 

U.S. Geological Survey Water-Resources Investigations 

Report 85–4190, 104 p.

Dickerman, D.C., Todd, E.C.T., and Russell, J.P., 1990, 

Hydrogeology, water quality and ground-water development 

alternatives in lower Wood River ground-water reservoir, 

Rhode Island: U.S. Geological Survey Water-Resources 

Investigations Report 89–4031, 109 p.

Duan, Naihua, 1983, A nonparametric retransformation 

method: Journal of American Statistical Association, v. 78, 

no. 383, p. 605–610.
126 Effects of Water Withdrawals and Land-Use Changes on Streamflows and Groundwater Levels in Pawcatuck River Basin

Friesz, P.J., 2004, Delineation of areas contributing recharge 

to selected public-supply wells in glacial valley-fill and 

wetland settings, Rhode Island: U.S. Geological Survey 

Scientific Investigations Report 2004–5070, 57 p.

Gonthier, J.B., Johnston, H.E., and Malmberg, G.T., 1974, 

Availability of ground water in the lower Pawcatuck River 

basin, Rhode Island: U.S. Geological Survey Water-Supply 

Paper 2033, 40 p., 5 pls., scale 1:48,000.

Granato, G.E., and Barlow, P.M., 2005, Effects of alternative instream-flow criteria and water-supply demands on 

ground-water development options in the Big River area, 

Rhode Island: U.S. Geological Survey Scientific Investigations Report 2004–5301, 110 p.

Granato, G.E., Barlow, P.M., and Dickerman, D.C., 2003, 

Hydrogeology and simulated effects of ground-water withdrawals in the Big River area, Rhode Island: U.S. Geological Survey Water-Resources Investigations Report 03–4222, 

76 p.

Helsel, D.R., and Hirsch, R.M., 1992, Statistical methods in 

water resources: Elsevier, N.Y., Studies in Environmental 

Science 49, 522 p.

Hermes, O.D., Gromet, L.P., and Murray, D.P., compilers, 

1994, Bedrock geologic map of Rhode Island: Rhode 

Island Map Series No. 1, University of Rhode Island, 

Kingston, R.I., scale 1:100,000.

Hirsch, R.M., 1982, A comparison of four streamflow record 

extension techniques: Water Resources Research, v. 18, 

no. 4, p. 1081–1088.

Johnston, H.E., and Dickerman, D.C., 1985, Hydrology, water 

quality, and ground-water development alternatives in 

the Chipuxet ground-water reservoir, Rhode Island: U.S. 

Geological Survey Water-Resources Investigations Report 

84–4254, 100 p.

Masterson, J.P., Sorenson, J.R., Stone, J.R., Moran, S.B., and 

Hougham, Andrea, 2007, Hydrogeology and simulated 

ground-water flow in the salt pond region of southern 

Rhode Island: U.S. Geological Survey Scientific Investigations Report 2006–5271, 56 p.

Melvin, R.L., de Lima, V., and Stone, B.D., 1992, The 

stratigraphy and hydraulic properties of till in southern 

New England: U.S. Geological Survey Open-File Report 

91–481, 53 p.

National Oceanic and Atmospheric Administration, 2002a, 

Monthly station normals of temperature, precipitation, and 

heating and cooling degree days 1971–2000–37 Rhode 

Island: Climatography of the United States no. 81, 9 p., 

accessed March 3, 2007, at http://cdo.ncdc.noaa.gov/

climatenormals/clim81/RInorm.pdf.

National Oceanic and Atmospheric Administration, 2002b, 

United States climate normals 1971–2000—National 

Weather Service snow normals—CLIM 20–02, accessed 

March 3, 2007, at http://cdo.ncdc.noaa.gov/climatenormals/

clim20-02/NWS_SNOW_MNFALL_fmt.dat.

National Oceanic and Atmospheric Administration, 2007, 

Climatological data annual summary: New England 

2000–04, v. 112–116, no. 13, variously paged, accessed 

March 3, 2007, at http://www7.ncdc.noaa.gov/IPS/

CDPubs?action=getpublication.

Randall, A.D., 2001, Hydrogeologic framework of stratifieddrift aquifers in the glaciated northeastern United States: 

U.S. Geological Survey Professional Paper 1415–B, 179 p., 

1 pl., scale 1:24,000.

Rutledge, A.T., 1998, Computer programs for describing the 

recession of ground-water discharge and for estimating 

mean ground-water recharge and discharge from streamflow 

records—update: U.S. Geological Survey Scientific Investigations Report 1998–4148, 43 p.

SAS Institute, Inc., 1989, SAS/STAT user’s guide version 6 

(4th ed.): Cary, N.C., SAS Institute, Inc., v. 2, 846 p. 

SAS Institute, Inc., 1995, Logistic regression examples 

using the SAS system, version 6 (1st ed.): Cary, N.C., 

SAS Institute, Inc., 163 p.

Schafer, J.P., 1965, Surficial geology of the Watch Hill quadrangle, Rhode Island-Connecticut: U.S. Geological Survey 

Geologic Quadrangle Map GQ–410, 1 pl., scale 1:24,000.

Socolow, R.S., Comeau, L.Y., Murino, Domenic, Jr., and 

Ramsbey, L.R., 2005, Water resources data for Massachusetts and Rhode Island, 2004: Water-Data Report 04–1, 

310 p.

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

Water resources data for Massachusetts and Rhode Island, 

2002: Water-Data Report 02–1, 339 p.

Socolow, R.S., Leighton, C.R., Whitley, J.F., and Ventetuolo, 

D.J., 2002, Water resources data for Massachusetts and 

Rhode Island, 2001: Water-Data Report 01–1, 307 p.

Socolow, R.S., Whitley, J.S., Murino, Domenic, Jr., and 

Ramsbey, L.R., 2001, Water resources data for 

Massachusetts and Rhode Island, 2000: Water-Data 

Report 01–1, 457 p.

Socolow, R.S., Zanca, J.L., Driskell, T.R., and Ramsbey, L.R., 

2004, Water resources data for Massachusetts and Rhode 

Island, 2003: Water-Data Report 03–1, 368 p.
References Cited 127

Stone, B.D., and Borns, H.W., 1986, Pleistocene glacial and 

interglacial stratigraphy of New England, Long Island and 

adjacent Georges Bank and Gulf of Maine, in Sibrava, 

B., Bowen, D.Q., and Richmond, G.M., eds., Quaternary 

glaciations in the northern hemisphere: Oxford, United 

Kingdom, Pergamon Press, p. 39–52.

Wild, E.C., and Nimiroski, M.T., 2004, Estimated water 

use and availability in the Pawcatuck River Basin, 

southern Rhode Island and southeastern Connecticut: 

U.S. Geological Survey Scientific Investigations Report 

2004–5020, 72 p.

Winter, T.C., Harvey, J.W., Franke, O.L., and Alley, W.M., 

1998, Ground water and surface water—A single resource: 

U.S. Geological Survey Circular 1139, 77 p.

Zarriello, P.J., and Bent, G.C., 2004, A precipitation-runoff 

model for the analysis of the effects of water withdrawals 

and land-use change on streamflow in the UsquepaugQueen River Basin, Rhode Island: U.S. Geological Survey 

Scientific Investigations Report 2004–5139, 75 p.

Part 2. Simulation of Water-Use and Land-Use 

Changes on Streamflow with a PrecipitationRunoff Model (HSPF)

Bicknell, B.R., Imhoff, J.C., Kittle, J.L., Jr., Jobes, T.H., 

and Donigian, A.S., Jr., 2000, Hydrological Simulation 

Program-FORTRAN user’s manual for release 12: AQUA 

TERRA Consultants, Mountain View, Calif., variously 

paged. 

Bovee, K.D., Lamb, B.L., Bartholow, J.M., Stalnaker, C.B., 

Taylor, Jonathon, and Henriksen, Jim, 1998, Stream habitat 

analysis using the instream flow incremental methodology: 

U.S. Geological Survey Biological Resource Division Information and Technology Report, 1998–004, 131 p. 

Espegren, G.D., 1996, Development of instream flow recommendations in Colorado using R2CROSS: Denver, Colo., 

Water Conservation Board, 34 p.

Nelsen, F.A., 1984, Guidelines for using the wetted perimeter 

(WETP) computer program of the Montana Department of 

Fish, Wildlife, and Parks: Montana Department of Fish, 

Wildlife, and Parks, Bozeman, Mont., variously paged.

Poff, N.L., Allen, J.D., Bain, M.B., Karr, J.R., Prestagaard, 

K.L., Richter, B.D., Sparks, R.E., and Stromberg, J.C., 

1998, The natural flow regime—A paradigm for river conservation and restoration: Bioscience, v. 47, p. 769–784.

Rhode Island Geographic Information System, [n.d.], Rhode 

Island Statewide Planning Program—Composite land use 

from municipal comprehensive plans 1990–1995: Providence, R.I., Rhode Island Statewide Planning Program, 

CD-ROM.

Rhode Island Statewide Planning, 2003, Population of Rhode 

Island by state, county and city and town, 1990 and 2000: 

Providence, R.I., Rhode Island Statewide Planning Program, accessed September 22, 2003, at http://www.planning.ri.gov/census/pdf%20files/miscpdf/popcity.pdf.

Richter, B.D., Baumgartner, J.V., Powell, J., and Braun, D.P., 

1996, A method for assessing hydrologic alteration within 

ecosystems: Conservation Biology, no. 10, p. 1163–1174.

Tennant, D.L., 1976, Instream flow regimens for fish, wildlife, 

recreation, and related environmental resources, in Instream 

flow needs (v. II): Boise, Idaho, Proceedings of the symposium and specialty conference on instream flow needs, May 

3–6, American Fisheries Society, p. 359–373.

U.S. Census Bureau, 2000, American FactFinder, accessed 

March 22, 2009, at http://factfinder.census.gov/.

U.S. Fish and Wildlife Service, 1981, Interim regional policy 

for New England stream flow recommendations: Newton 

Corner, Mass., U.S. Fish and Wildlife Service, 3 p.

Wild, E.C., and Nimiroski, M.T., 2004, Estimated water use 

and availability in the Pawcatuck River Basin, southern 

Rhode Island and southeastern Connecticut: U.S. Geological Survey Scientific Investigations Report 2004–5020, 

72 p.

Zarriello, P.J., and Bent, G.C., 2004, A precipitation-runoff 

model for the analysis of the effects of water withdrawals 

and land-use change on streamflow in the UsquepaugQueen River Basin, Rhode Island: U.S. Geological Survey 

Scientific Investigations Report 2004–5139, 75 p.

Part 3. Simulated Effects of Withdrawals on 

Groundwater Flow (MODFLOW Models)

Alley, W.M., Reilly, T.E., and Franke, O.L., 1999, Sustainability of ground-water resources: U.S. Geological Survey 

Circular 1186, 79 p.

Barlow, P.M., and Dickerman, D.C., 2001, Numerical-simulation and conjunctive-management models of the HuntAnnaquatucket-Pettaquamscutt stream-aquifer system, 

Rhode Island: U.S. Geological Survey Professional Paper 

1636, 88 p., 1 pl.

DeSimone, L.A., 2004, Simulation of ground-water flow and 

evaluation of water-management alternatives in the Assabet 

River Basin, eastern Massachusetts: U.S. Geological Survey Scientific Investigations Report 2004–5114, 133 p.
128 Effects of Water Withdrawals and Land-Use Changes on Streamflows and Groundwater Levels in Pawcatuck River Basin

DeSimone, L.A., Walter, D.A., Eggleston, J.R., and Nimiroski, 

M.T., 2002, Simulation of ground-water flow and evaluation of water-management alternatives in the Upper Charles 

River Basin, eastern Massachusetts: U.S. Geological Survey Water-Resources Investigations Report 02–4234, 

94 p.

Dickerman, D.C., Kliever, J.D., Stone, J.R., 1997, Hydrogeology, water quality, and simulation of ground-water development alternatives in the Usquepaug-Queen ground-water 

reservoir, Rhode Island: U.S. Geological Survey WaterResources Investigations Report 97–4126, 48 p.

Dickerman, D.C., Trench, E.C.T., and Russell, J.P., 1990, 

Hydrogeology, water quality and ground-water development 

alternatives in lower Wood River ground-water reservoir, 

Rhode Island: U.S. Geological Survey Water-Resources 

Investigations Report 89–4031, 109 p.

Friesz, P.J., 2004, Delineation of areas contributing recharge 

to selected public-supply wells in glacial valley-fill and 

wetland settings, Rhode Island: U.S. Geological Survey 

Scientific Investigations Report 2004–5070, 57 p.

Gonthier, J.B., Johnston, H.E., and Malmberg, G.T., 1974, 

Availability of ground water in the lower Pawcatuck River 

basin, Rhode Island: U.S. Geological Survey Water-Supply 

Paper 2033, 40 p., 5 pls., scale 1:48,000.

Granato, G.E., Barlow, P.M., and Dickerman, D.C., 2003, 

Hydrogeology and simulated effects of ground-water withdrawals in the Big River area, Rhode Island: U.S. Geological Survey Water-Resources Investigations Report 03–4222, 

76 p.

Harbaugh, A.W., Banta, E.R., Hill, M.C., and Anderman, E.R., 

2000, MODFLOW–2000, The U.S. Geological Survey 

modular ground-water model—User guide to modularization concepts and the ground-water flow process: U.S. 

Geological Survey Open-File Report 00–92, 121 p.

Heath, R.C., 1989, Basic ground-water hydrology: 

U.S. Geological Survey Water-Supply Paper 2220, 84 p.

Konikow, L.F., and Reilly, T.E., 1999, Groundwater modeling, 

in Delleur, J.W., ed., The handbook of groundwater engineering: Boca Raton, Fla., CRC Press, 40 p.

McDonald, M.G., and Harbaugh, A.W., 1988, A modular 

three-dimensional finite-difference ground-water flow 

model: U.S. Geological Survey Techniques of WaterResources Investigations, book 6, chap. A1, 586 p.

Melvin, R.L., de Lima, V., and Stone, B.D., 1992, The 

stratigraphy and hydraulic properties of till in southern 

New England: U.S. Geological Survey Open-File Report 

91–481, 53 p.

Prudic, D.E., 1989, Documentation of a computer program to 

simulate stream-aquifer relations using a modular, finitedifference, ground-water flow model: U.S. Geological 

Survey Open-File Report 88–729, 113 p.

Reilly, T.E., 2001, System and boundary conceptualization 

in ground-water flow simulation: U.S. Geological Survey 

Techniques of Water-Resources Investigations, book 3, 

chap. B8, 38 p.

Reilly, T.E., and Harbaugh, A.W., 2004, Guidelines for evaluating ground-water flow models: U.S. Geological Survey 

Scientific Investigations Report 2004–5038, 30 p. 

Rhode Island Geographic Information System, [n.d.], Rhode 

Island Statewide Planning Program—Composite Land Use 

from Municipal Comprehensive Plans 1990–1995: Providence, R.I., Rhode Island Statewide Planning Program, 

CD-ROM.

Wild, E.C., and Nimiroski, M.T., 2004, Estimated water use 

and availability in the Pawcatuck Basin, southern Rhode 

Island and southeastern Connecticut, 1995–99: U.S. Geological Survey Scientific Investigations Report 2004–5020, 

80 p.

Zarriello, P.J., and Bent, G.C., 2004, A precipitation-runoff 

model for the analysis of the effects of water withdrawals 

and land-use change on streamflow in the Usquepaug–

Queen River Basin, Rhode Island: U.S. Geological Survey 

Scientific Investigations Report 2004–5139, 75 p.

Part 4. Conjunctive-Management Models as 

Tools for Water-Resources Planning

Barlow, P.M., 1997, Dynamic models for conjunctive management of stream-aquifer systems of the glaciated Northeast: 

Storrs, Conn., University of Connecticut, Ph.D. dissertation, 

256 p.

Barlow, P.M., Ahlfeld, D.P., and Dickerman, D.C., 2003, 

Conjunctive-management models for sustained yield of 

stream-aquifer systems: Journal of Water Resources 

Planning and Management, v. 129, no. 1, p. 35–48.

Barlow, P.M., and Dickerman, D.C., 2001a, Balancing 

ground-water withdrawals and streamflow in the HuntAnnaquatucket-Pettaquamscutt Basin, Rhode Island: 

U.S. Geological Survey Fact Sheet FS–063–01, 6 p.

Barlow, P.M., and Dickerman, D.C., 2001b, Numericalsimulation and conjunctive-management models of the 

Hunt-Annaquatucket-Pettaquamscutt stream-aquifer system, 

Rhode Island: U.S. Geological Survey Professional Paper 

1636, 88 p.
References Cited 129

Granato, G.E., and Barlow, P.M., 2005, Effects of alternative instream-flow criteria and water-supply demands on 

ground-water development options in the Big River area, 

Rhode Island: U.S. Geological Survey Scientific Investigations Report 2004–5301, 110 p.

Walker, P.N., and Lautzenheiser, Robert, 1991, Rhode Island 

floods and droughts, in Paulson, R.W., Chase, E.B., 

Roberts, R.S., and Moody, D.W., compilers, National water 

summary 1988–89—Hydrologic events and floods and 

droughts: U.S. Geological Survey Water-Supply Paper 

2375, p. 483–488.

Part 5. HSPF and MODFLOW—Capabilities, 

Limitations, and Integration

Alley, W.M., Healy, R.W., LaBaugh, J.W., and Reilly, T.E., 

2002, Flow and storage in groundwater systems: Science, 

v. 296, p. 1985–1990.

Aly, A.H., Longsine, D.E., Jin, M., Lavenue, M.A., Tara, 

P.D., Donigian, A.S., Jobes, T.M., and Ross, M.A., 2003, 

Integrated hydrologic model (IHM) (v. II)—Users Guide: 

INTERA, AQUA TERRA Consultants, University of South 

Florida, variously paged.

Beven, K.J., 1993, Prophecy, reality, and uncertainty in 

distributed hydrologic modeling: Advances in Water 

Resources, v. 6, p. 253–254.

Beven, K.J., and Binley, A.M., 1992, The future of distributed 

models—Model calibration and predictive uncertainty: 

Hydrological Processes, v. 6, p. 279–298.

Dickerman, D.C., Kliever, J.D., and Stone, J.R., 1997, Hydrogeology, water quality, and simulation of ground-waterdevelopment alternatives in the Usquepaug-Queen groundwater reservoir, southern Rhode Island: U.S. Geological 

Survey Water-Resources Investigations Report 97–4126, 

p. 48, 1 pl.

Ross, M.A., Geurink, J.H., Aly, A.H., Tara, P.D., Trout, K., and 

Jobes, T.M., 2003, Integrated hydrologic model (IHM) 

(v. I)—Theory manual: INTERA, AQUA TERRA Consultants, University of South Florida, variously paged.

Winter, T.C., Harvey, J.W., Franke, O.L., and Alley, W.M., 

1998, Ground water and surface water—A single resource: 

U.S. Geological Survey Circular 1139, 77 p.

Zarriello, P.J., and Bent, G.C., 2004, A precipitation-runoff 

model for the analysis of the effects of water withdrawals 

and land-use change on streamflow in the UsquepaugQueen River Basin, Rhode Island: U.S. Geological Survey 

Scientific Investigations Report 2004–5139, 75 p.

Zarriello, P.J., and Ries, K.G., III, 2000, A precipitation runoff 

model for the 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.
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