Geology topics

Research about Raritan River Basin

Source-linked reports with geographic coverage including Raritan River Basin.

4 recordsLinked to original sources

USGS2007

Potential effects of development on flow characteristics of two streams in the Raritan River Basin, New Jersey

Parts of the Raritan River basin in central New Jersey have undergone increasing development over the last several decades. The increasing population relies on the region's ground water and surface water sources for its residential, commercial, and industrial water supply. Urbanization, regionalized wastewater‐treatment facilities, stream channel alterations, and interbasin transfers of water can all affect water availability. This pilot study was conducted to determine whether significant trends exist in the base‐flow and overland‐runoff characteristics of streams in two subbasins with different percentages of urban/built‐up land (Anderson et at ., 1976). Changes in flow characteristics that could indicate future reductions in safe water yield of the Raritan River basin were examined. Flow and flow variability of the steams draining these two subbasins have increased over time. Many of the flow measures studied experienced pronounced trend shifts about 1960. The cause of these changes cannot be readily determined from the data, nor is it clear whether the increased flow variability lies outside the natural range of flow variability of the streams draining the subbasins.

New Jersey↗

USGS1999

Relations of surface-water quality to streamflow in the Raritan River basin, New Jersey, water years 1976-93

Relations of water quality to streamflow were determined for 18 water-quality constituents at 21 surface-water stations within the drainage area of the Raritan River Basin for water years 1976-93. Surface-water-quality and streamflow data were evaluated for trends (through time) in constituent concentrations during high and low flows, and relations between constituent concentration and streamflow, and between constituent load and streamflow, were determined. Median concentrations were calculated for the entire period of study (water years 1976-93) and for the last 5 years of the period of study (water years 1989-93) to determine whether any large variation in concentration exists between the two periods. Medians also were used to determine the seasonal Kendall’s tau statistic, which was then used to evaluate trends in concentrations during high and low flows. Trends in constituent concentrations during high and low flows were evaluated to determine whether the distribution of the observations changes through time for intermittent (nonpoint storm runoff) or constant (point sources and ground water) sources, respectively. Highand low-flow trends in concentrations were determined for some constituents at 13 of the 21 water-quality stations; 8 stations have insufficient data to determine trends. Seasonal effects on the relations of concentration to streamflow are evident for 16 of the 18 constituents. Negative slopes of relations of concentration to streamflow, which indicate a decrease in concentration at high flows, predominate over positive slopes because of the dilution of instream concentrations by storm runoff. The slopes of the regression lines of load to streamflow were determined in order to show the relative contributions to the instream load from constant (point sources and ground water) and intermittent sources (storm runoff). Greater slope values indicate larger contributions from storm runoff to instream load, which most likely indicate an increased relative importance of nonpoint sources. The slopes of load-to-streamflow relations along a stream reach that tend to increase in a downstream direction indicate the increased relative importance of contributions from storm runoff. The slopes of load-to-streamflow relations increase in the downstream direction for alkalinity at North Branch Raritan and Millstone Rivers, for some or all of the nutrient species at South Branch and North Branch Raritan Rivers, for hardness at South Branch Raritan River, for dissolved solids at North Branch Raritan River, for dissolved sodium at Lamington River, and for suspended sediment and dissolved oxygen at Millstone River. Likewise, the slopes of load-tostreamflow relations along a stream reach that tend to decrease in a downstream direction indicate the increased relative importance of point sources and ground-water discharge. The slopes of load-to-streamflow relations decrease in the downstream direction for dissolved solids at Raritan and Millstone Rivers; for dissolved sodium, dissolved chloride, total ammonia plus organic nitrogen, and total ammonia at South Branch Raritan, Raritan, and Millstone Rivers; for dissolved oxygen at North Branch Raritan and Lamington Rivers; for total nitrite at Lamington, Raritan, and Millstone Rivers; for total boron at South Branch Raritan and Millstone Rivers; for total organic carbon at North Branch Raritan River; for suspended sediment and total nitrogen at Raritan River; and for hardness, total phosphorus, and total lead at Millstone River.

New Jersey↗

USGS1996

Managing drought risk with a computer model of the Raritan River Basin water-supply system in central New Jersey

The reservoirs and pumping stations that comprise the Raritan River Basin water-supply system and its interconnections to the Delaware-Raritan Canal water-supply system, operated by the New Jersey Water Supply Authority (NJWSA), provide potable water to central New Jersey communities. The water reserve of this combined system can easily be depleted by an extended period of below-normal precipitation. Efficient operation of the combined system is vital to meeting the water-supply needs of central New Jersey. In an effort to improve the efficiency of the system operation, the U.S. Geological Survey (USGS), in cooperation with the NJWSA, has developed a computer model that provides a technical basis for evaluating the effects of alternative patterns of operation of the Raritan River Basin water-supply system. This fact sheet describes the model, its technical basis, and its operation.

New Jersey↗

USGS1974

Water quality and streamflow characteristics, Raritan River Basin, New Jersey

The findings of a problem-oriented river-system investigation of the stream-quality and streamflow characteristics of the Raritan River basin (1,105 square miles or 2,862 square kilometers drainage area) are described. The investigation covers mainly the period 1955-72. Precipitation in the basin is classified as ample and averages 47 inches or 120 centimeters per year (3-5 inches or 8-12 centimeters per month). During the study period four general precipitation trends were noted: less than normalin 1955-61 and 1966-70; extreme drought in 1962-66; and above normal in 1971-72. Analyses of streamflow measurements at eight gaging stations indicate a general trend toward lower flows during the study period, which is attributed to generally lower than normal precipitation. Highest flows were observed in 1958, concurrent with maximum annual precipitation; whereas lowest flows were observed in 1965 during extreme drought conditions. Non-tidal streams in the basin are grouped into three general regions of similar chemical quality based upon predominant constituents and dissolved-solids concentration during low-flow conditions. The predominant cations in solution in all regions are calcium and magnesium (usually exceeding 60 percent of total cation content). In headwater streams of the North and South Branch Raritan Rivers, bicarbonate is the predominant anion; a combination of sulfate, chloride, and nitrate are the predominant anions in the other two regions. The dissolved-solids concentration of streams in areas little influenced by man's activities generally range from 40 to 200 mg/L. Those in areas influenced by man often range much higher sometimes exceeding 800 mg/L. Suspended-sediment yields in the basin range from 25 to 500 tons per square mile annually. The water quality of the Raritan River and most tributaries above Manville (784 square miles of 2,030 square kilometers drainage area) generally is good for most industrial, domestic, and recreational uses, although pollution has been reported locally in some areas. A comparison of chemical analyses of water collected at several sampling sites in the 1920's with more recent data, however, indicate that there has been a significant increase in sulfate, chloride, and nitrate ions transported per unit of streamflow. These increases reflect increased waste-water discharges and nutrients in agricultural runoff in the upper basin. Trends in the dissolved-solids and dissolved-oxygen concentation of water in the Raritan and MIllstone Rivers above their confluence at Manville are described. The dissolved solids of the Millstone River are shown to increase, particularly at low streamflows. For example, at a flow of 100 cubic feet per second (2.83 cubic meters per second) this river tansported 13 percent more dissolved solids in 1969-70 than it did in 1957-58. A similar trend, however, was not apparent on the Raritan River. This phenomenon is attributed to dilution provided since 1964 by upstream reservoir releases during low flows. With the exception of low-flow periods on the Raritan River, dissolved-oxygen concentrations showed little or no significant time trends at Manville on either the Raritan or Millstone River. An improvement in dissolved-oxygen content at flows lower than 100 cubic feet per second (2.83 cubic meters per second) is observed with time on the Raritan River. This improvement is attributed to generally better quality water and dilution of nonconservative pollutants by upstream reservoir releases during low flows. The Raritan River between Manville and Perth Amboy flows through a large urban and industrial complex. Much of this reach is tidal. Detrimental activities of man are reflected in higher concentrations of most constituents below Manville than those observed upstream. For example, between Manville and the head of tide near South Bound Brook, the maximum concentration of dissolved solids observed during the study period increased from 464 to 1,520 mg/L; orthophosphates from 0.93 to 2.3 mg/L; phenolic materials from 22 to 312 μg/L; and coliform bacteria from 13,300 to 100,000 colonies per 100 milliliters. A general deterioration in water quality with time in the river below Manville is demonstrated through comparisons of dissolved-oxygen and biochemical-oxygen demand data collected between the late 1920's and early 1970's. Several time-of-travel measurements within the basin are reported. These data provide reasonable estimates of the time required for soluble contaminants to pass through particular parts of the river system. For example, the peak concentration of a contaminant injected into the river system at Clinton at a flow of 100 cubic feet per second (2.83 cubic meters per second) would be expected to travel to the head of tide near South Bound Brook, about 34 miles (55 kilometers), in about 70 hours; but at a flow of 50 cubic feet per second (1.42 cubic meters per second) the traveltime would increase to about 125 hours.

New Jersey↗