The upper Pawcatuck River basin is a 70-square-mile area in southcentral Rhode Island consisting of broad, rolling hills and narrow valleys in the north and fiat-floored plains in the south. It is drained by the Pawcatuck River and its two major tributaries, the Usquepaug-Queen River and the Chipuxet River.
Analysis of the water budget for the basin shows that approximately 94 mgd (million gallons per day) or about 63 percent of the precipitation flows out of the basin as streamflow. Of this amount, about 66 mgd is from ground-water seepage.
Two ground-water reservoirs composed of glacial deposits of sand and gravel and capable of substantial yields are in the basin. The larger reservoir underlies the central part of the Usquepaug-Queen River valley. This reservoir ranges in width from 3,000 to 4,000 feet and is 32,000 feet long. A large part of the reservoir contains sand and gravel more than 100 feet thick, having a permeability of more than 1,000 gallons per day per square foot. The yield of this reservoir is estimated to be about 17 mgd.
The smaller ground-water reservoir is in the Chipuxet River valley. It is about 4,000 feet wide and 16,000 feet long. A large part of this reservoir contains sand and gravel more than 150 feet thick having a permeability of more than 1,000 gallons per day per square foot. The yield of the Chipuxet reservoir is estimated to be about 8.6 mgd.
Mineral content of water from both of the reservoirs is generally less than 200 parts per million of dissolved solids. However, in the Chipuxet groundwater reservoir the dissolved solids are somewhat higher, and the iron content is a problem.
Only about 1.5 mgd of water is used in the basin. Most of it is used for public supplies and is obtained from wells not tapping the Usquepaug-Queen or Chipuxet ground-water reservoirs. Estimates of the 25 mgd of ground water potentially available are believed to be conservative, and substantially larger quantities may actually be available when development takes place.
Additional Publication Details
USGS Numbered Series
Availability of ground water, upper Pawcatuck River basin, Rhode Island
Water Supply Paper
U.S. Govt. Print. Off.,
v, 66 p. :illus., maps (3 fold. (2 col.) in pocket) ;24 cm.