April 2008

Precipitation was below normal at the Trenton and Atlantic City index stations, and above normal at the Newark index station. Newark reported 2.70 inches, which is 68.88 percent of normal.  Atlantic City reported 3.27 inches, which is 94.78 percent of normal.  Trenton reported 2.20 inches, which is 61.11 percent of normal. Total precipitation over the past 12 months was: 48.21 inches at Newark, which is 1.96 inches above normal; 40.37 inches at Atlantic City, which is -0.22 inches below normal; and 36.73 inches at Trenton, which is -4.66 inches below normal.

Combined storage in the thirteen major water supply reservoirs as of April 30 was 78.557 billion gallons (97.7 percent of capacity), which is higher than the average April contents for the reference period 1961-1990.  The storage was 0.197 billion gallons higher than one month ago and 1.213 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, Charlottesburg Reservoir, Echo Lake, Wanaque Reservoir and Spruce Run Reservoir.              

Streamflow was below normal at all three index stations. The monthly-mean discharge at South Branch Raritan River near High Bridge was 139 ft3/s, 66.2 percent of normal.  The monthly-mean discharge of the Great Egg Harbor River at Folsom was 75.1 ft3/s, 62.1 percent of normal.  The monthly mean discharge of the Delaware River at Trenton was 17170 ft3/s, 79.5 percent of normal. The observed daily mean discharge of the Delaware River at Trenton on April 30 was 13300 ft3/s. 

Ground-water levels, as measured in water-table observation wells for the month of April, were below normal at the Readington School and Vocational School index wells, and above normal at the Morrell 1 index well. Levels decreased from last month at both the Readington School and Vocational School Index wells, but increased from last month at the Morrell 1 index well. All three index wells were lower than one year ago.

Water quality parameters collected from the Delaware River at Trenton were within recorded historical monthly extremes. Water temperature ranged from 18.8 to 6.5 degrees Celsius. Dissolved oxygen ranged from 14.4 to 9.6 milligrams per liter. Specific conductance ranged from 236 to 123 microsiemens per centimeter at 25°C.

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

All of the files listed below are in Portable Document Format(PDF) which can be viewed/printed with the Adobe Acrobat® Reader, freely available for most computer platforms.

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