New Jersey Water Science Center
Summary of April 2016 Monthly Hydrologic Conditions
Compiled in cooperation with the New Jersey Department of Environmental Protection
Precipitation was below normal at all three index stations for the reference period 1981-2010. Newark reported 1.12 inches, which is 26.67 percent of normal. Atlantic City reported 2.91 inches, which is 80.17 percent of normal. Trenton reported 1.67 inches, which is 47.18 percent of normal. Total precipitation over the past 12 months was: 36.85 inches at Newark, which is 9.40 inches below normal; 44.38 inches at Atlantic City, which is 2.63 inches above normal; and 36.86 inches at Trenton, which is 9.58 inches below normal.
Combined storage in the thirteen major water supply reservoirs as of April 30 was 72.783 billion gallons (90.0 percent of capacity), which is greater than the average April contents for the reference period 1961-1990. The storage was 0.477 billion gallons less than one month ago and 2.638 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 below the long-term monthly-mean for the reference period 1981-2010 at all three index stations. The monthly-mean discharge at South Branch Raritan River near High Bridge was 69.4 ft3/s, 34.4 percent of the long-term mean. The monthly-mean discharge of the Great Egg Harbor River at Folsom was 71.2 ft3/s, 59.3 percent of the long-term mean. The monthly mean discharge of the Delaware River at Trenton was 7,747 ft3/s, 36.5 percent of the long-term mean. The observed daily mean discharge of the Delaware River at Trenton on April 30 was 5,540 ft3/s.
Groundwater levels, as measured in water-table observation wells for the month of April, were below normal at the Readington School 11 index well, and above normal at the Morrell 1 and Vocational School 2 index wells. Levels decreased from last month and were lower 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, except for a new high in specific conductance. Water temperature ranged from 6.8 to 19.4 degrees Celsius. Dissolved oxygen ranged from 8.3 to 13.3 milligrams per liter. Specific conductance ranged from 160 to 259 microsiemens per centimeter at 25°C.
Note: The preceding data is preliminary and subject to revision.
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