New Jersey Water Science Center
Summary of July 2015 Monthly Hydrologic Conditions
Compiled in cooperation with the New Jersey Department of Environmental Protection
Precipitation was below normal at the Newark and Trenton index stations, and above normal for the Atlantic City index station for the reference period 1981-2010. Newark reported 2.69 inches, which is 56.61 percent of normal. Atlantic City reported 6.59 inches, which is 177.15 percent of normal. Trenton reported 3.11 inches, which is 62.83 percent of normal. Total precipitation over the past 12 months was: 42.77 inches at Newark, which is 3.48 inches below normal; 60.46 inches at Atlantic City, which is 18.71 inches above normal; and 39.49 inches at Trenton, which is 6.95 inches below normal.
Combined storage in the thirteen major water supply reservoirs as of July 31was 68.025 billion gallons (84.1 percent of capacity), which is higher than the average July contents for the reference period 1961-1990. The storage was 7.343 billion gallons less than one month ago and 2.773 billion gallons less 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 above the long-term monthly-mean for the reference period 1981-2010 at the Great Egg Harbor River at Folsom and Delaware River at Trenton index stations, and below the long-term monthly-mean at the South Branch Raritan River at High Bridge index station. The monthly-mean discharge at South Branch Raritan River near High Bridge was 48.3 ft3/s, 57.9 percent of the long-term mean. The monthly-mean discharge of the Great Egg Harbor River at Folsom was 102 ft3/s, 166.4 percent of the long-term mean. The monthly mean discharge of the Delaware River at Trenton was 14,200 ft3/s, 201.6 percent of the long-term mean. The observed daily mean discharge of the Delaware River at Trenton on July 31 was 8,530 ft3/s.
Groundwater levels, as measured in water-table observation wells for the month of July, were above normal at the Morrell 1 and Vocational School 2 index wells, and below normal at the Readington School 11 index well. Levels decreased from last month. Levels were lower than one year ago at the Readington School 11 and Morrell 1 index wells, and were higher than one year ago at the Vocational School 2 index well.
Water-quality parameters collected from the Delaware River at Trenton were within the range of historical monthly values. Water temperature ranged from 18.7 to 27.4 degrees Celsius. Dissolved oxygen ranged from 7.4 to 10.1 milligrams per liter. Specific conductance ranged from 121 to 219 microsiemens per centimeter at 25°C.
Note: The preceding data is preliminary and subject to revision.
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