Summary of August 2017 Monthly Hydrologic Conditions
Compiled in cooperation with the New Jersey Department of Environmental Protection
Precipitation was above normal at the Newark and Atlantic City index stations, and below normal for the Trenton index station for the reference period 1981-2010. Newark reported 5.49 inches, which is 148.38 percent of normal. Atlantic City reported 4.23 inches, which is 102.92 percent of normal. Trenton reported 3.09 inches, which is 75.37 percent of normal. Total precipitation over the past 12 months was: 52.28 inches at Newark, which is 6.03 inches above normal; 51.29 inches at Atlantic City, which is 9.54 inches above normal; and 41.19 inches at Trenton, which is 5.25 inches below normal.
Combined storage in the thirteen major water supply reservoirs as of August 31 was 64.285 billion gallons (79.5 percent of capacity), which is greater than the average August contents for the reference period 1961-1990. The storage was 6.944 billion gallons less than one month ago and 10.722 billion gallons greater than one year ago. The thirteen major water supply reservoirs are as follows: Lake Tappan, Woodcliff Lake, Oradell Reservoir, DeForest Lake, Splitrock Reservoir, Boonton Reservoir, Canistear Reservoir, Oak Ridge Reservoir, Clinton Reservoir, Charlotteburg Reservoir, Echo Lake, Wanaque Reservoir and Spruce Run Reservoir.
Streamflow was below the long-term monthly-mean for the reference period 1981-2010 at the South Branch Raritan River near High Bridge index station, and above the long-term monthly-mean at the Great Egg Harbor River at Folsom and Delaware River at Trenton index stations. The monthly-mean discharge at South Branch Raritan River near High Bridge was 57.5 ft3/s, 86.1 percent of the long-term mean. The monthly-mean discharge of the Great Egg Harbor River at Folsom was 68.8 ft3/s, 128.4 percent of the long-term mean. The monthly mean discharge of the Delaware River at Trenton was 7,370 ft3/s, 120.8 percent of the long-term mean. The observed daily mean discharge of the Delaware River at Trenton on August 31 was 4,760 ft3/s.
Groundwater levels, as measured in water-table observation wells for the month of August, were above normal at Readington School 11 index well and below normal at the Morrell 1 and Vocational School 2 index wells. Levels decreased from last month and were higher than one year ago at all three index wells.
Water-quality parameters collected from the Delaware River at Trenton were within the range of historical monthly values. Water temperature ranged from 19.8 to 26.8 degrees Celsius. Dissolved oxygen ranged from 7.6 to 9.9 milligrams per liter. Specific conductance ranged from 199 to 266 microsiemens per centimeter at 25°C.
Note: The preceding data is preliminary and subject to revision.
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