SUMMARY OF HYDROLOGIC CONDITIONS
FOR THE
UPPER DELAWARE RIVER BASIN
December 2000


Prepared by the
Office of the Delaware River Master
Milford, Pennsylvania

Adjusted streamflow in the upper Delaware River Basin during December was excessive. The maximum daily discharge of 46,300 cfs occurred on December 18. The minimum daily discharge was 1,800 cfs on December 10. 

On the basis of a 5-station average, precipitation during December was 4.20 inches, which was 126 percent of the 60-year average. The maximum daily-average precipitation during December was 1.55 inches on December 17. Precipitation in the upper Delaware River Basin during the past 12 months was 5.75 inches greater than the long-term average. Precipitation during December was 0.86 inches more than the long-term average for the month.

The monthly mean streamflow of the Delaware River at Montague, N.J. during December was 6,631 cfs (observed), which was 135 percent of median. The flow at Montague, adjusted for diversions from the basin and change in storage in the major reservoirs was 8,972 cfs, or 170 percent of median (water years 1961-90).

Combined storage January 1, 2001, in Pepacton, Cannonsville, and Neversink Reservoirs was 90.2 percent of capacity above the point of maximum depletion. The combined storage of 244 billion gallons was 24 billion gallons more than that of one month ago and was 59 billion gallons more than that of one year ago. Median storage on the first day of January in 33 years of record is 186 billion gallons. 

As part of a statewide network, the USGS operates 13 observation wells in the Pennsylvania part of the Delaware River Basin. Mean water levels during December were below average in 11 of the wells. Water levels in 10 of the wells were trending upward in comparison to November levels. Water levels in 10 of the wells were below December 1999 levels.

 

 

HYDROLOGIC CONDITIONS IN THE UPPER DELAWARE RIVER BASIN
Compiled by the Office of the Delaware River Master, Milford, Pa.
(Preliminary data - subject to revision)
PRECIPITATION, IN INCHES

 

Dec. 1940 to Dec. 1999

January 2000 to December 2000

 

Average

Actual

Percent of average

Excess (+) or deficit (-)

 

Amount

Cumulative

Amount

Cumulative

By month

Cumulative

By month

Cumulative

Jan.

3.02 43.18 3.44 48.93 114 113 +.42 +5.75
Feb. 2.64 40.16 3.26 45.49 123 113 +.62 +5.33
Mar. 3.32 37.52 4.08 42.23 123 113 +.76 +4.71
Apr. 3.76 34.20 4.81 38.15 128 112 +1.05 +3.95
May 4.17 30.44 6.36 33.34 153 110 +2.19 +2.90
June 3.91 26.27 *6.50 26.98 166 103 +2.59 +.71
July 4.09 22.36 4.24 20.48 104 92 +.15 -1.88
Aug. 3.86 18.27 3.60 16.24 93 89 -.26 -2.03
Sept. 3.83 14.41 3.53 12.64 92 88 -.30 -1.77
Oct. 3.39 10.58 2.41 9.11 71 86 -.98 -1.47
Nov. 3.85 7.19 2.50 6.70 65 93 -1.35 -.49
Dec. 3.34 3.34 4.20 4.20 126 126 +.86 +.86

Note: Amount shown in cumulative columns is total from month shown to present.

* Revised since previous month

 

STREAMFLOW, IN CFS

DELAWARE RIVER AT MONTAGUE, N.J.

Month

1940-99

 

Percent of

Maximum

Median

Minimum

Monthly mean

median

December (observed) 18,830 1996 4,916 1,665 1998 6,631 135
December (adjusted) 20,880 1973 6,506 1,624 1998 8,972 138
 
January (observed) 15,600 1996 5,116 1,318 1981  
January (adjusted) 21,330 1996 5,939 1,064 1981