New Jersey Water Science Center
Summary of May 2012 Monthly Hydrologic Conditions
Compiled in cooperation with the New Jersey Department of Environmental Protection
Precipitation was above normal at all three index stations for the reference period 1981-2010. Newark reported 4.32 inches, which is 105.62 percent of normal. Atlantic City reported 3.56 inches, which is 106.27 percent of normal. Trenton reported 5.05 inches, which is 115.56 percent of normal. Total precipitation over the past 12 months was: 58.58 inches at Newark, which is 12.33 inches above normal; 44.33 inches at Atlantic City, which is 2.58 inches above normal; and 53.96 inches at Trenton, which is 7.52 inches above normal.
Combined storage in the thirteen major water supply reservoirs as of May 31 was 77.166 billion gallons (95.4 percent of capacity), which is higher than the average May contents for the reference period 1961-1990. The storage was 4.489 billion gallons more than one month ago and -2.263 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 the South Branch Raritan River at High Bridge and Great Egg Harbor River at Folsom index stations, and above the long-term monthly-mean for the reference period 1981-2010 at the Delaware River at Trenton index Station. The monthly-mean discharge at South Branch Raritan River near High Bridge was 80.9 ft3/s, 52.9 percent of the long-term mean. The monthly-mean discharge of the Great Egg Harbor River at Folsom was 78.8 ft3/s, 84.9 percent of the long-term mean. The monthly mean discharge of the Delaware River at Trenton was 14,620 ft3/s, 105.8 percent of the long-term mean. The observed daily mean discharge of the Delaware River at Trenton on May 31 was 12,800 ft3/s.
Groundwater levels, as measured in water-table observation wells for the month of May, were above normal at the Morrell 1 and Vocational School 2 index wells, and below normal at the Readington School 11index well. Levels decreased from last month. Levels were higher than one year ago at the Morrell 1 and Vocational School 2 index wells, but lower than one year ago at the Readington School 11 index well.
Water-quality parameters collected from the Delaware River at Trenton were within recorded historical monthly extremes. Water temperature ranged from 12.7 to 24.1 degrees Celsius. Dissolved oxygen ranged from 7.9 to 12.9 milligrams per liter. Specific conductance ranged from 85 to 195 microsiemens per centimeter at 25°C.
Note: The preceding data is preliminary and subject to revision.
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