December 2008

Precipitation was well above normal at all three index stations for the month of December. Newark reported 5.88 inches, which is 165 percent of normal.  Atlantic City reported 7.27 inches, which is 231 percent of normal.  Trenton reported 5.58 inches, which is 165 percent of normal. Total precipitation over the past 12 months was: 48.83 inches at Newark, which is 2.58 inches above normal; 46.56 inches at Atlantic City, which is 5.97 inches above normal; and 45.38 inches at Trenton, which is 3.99 inches above normal.

Combined storage in the thirteen major water supply reservoirs increased substantially in December, climbing to 73.8 billion gallons (91.8 percent of capacity), which is greater than the average December contents for the reference period 1961-1990.  The storage was 11.3 billion gallons more than one month ago and 11.4 billion gallons more 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, Charlottesburg Reservoir, Echo Lake, Wanaque Reservoir and Spruce Run Reservoir.

Streamflow was also above normal at all three index stations. The monthly-mean discharge at South Branch Raritan River near High Bridge was 229 ft3/s, 148 percent of normal.  The monthly-mean discharge of the Great Egg Harbor River at Folsom was 131 ft3/s, 132 percent of normal.  The monthly mean discharge of the Delaware River at Trenton was 26,700 ft3/s, 187 percent of normal. The observed daily mean discharge of the Delaware River at Trenton on December 31 was 31,000 ft3/s.

Ground-water levels, as measured in water-table observation wells for the month of December, were above normal at the Readington School 11 and Morrell 1 wells, located in northern New Jersey. Levels were below normal at the Vocational School 2 well, located in southern New Jersey. Levels increased from last month, but were lower than one year ago at all three index wells.  

Water quality parameters collected from the Delaware River at Trenton were within recorded historical monthly extremes. Water temperature ranged from 0.4 to 5.1 degrees Celsius. Dissolved oxygen ranged from 12.1 to 14.7 milligrams per liter. Specific conductance ranged from 96 to 292 microsiemens per centimeter at 25°C.

Note: The preceding data is preliminary and subject to revision.

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Combined Storage in the 13 Major Water Supply Reservoirs

Monthly precipitation at three selected sites

Ground-water levels in selected Water-table observation wells

Streamflow at selected sites

Water quality for the Delaware River at Trenton