SUMMARY OF HYDROLOGIC CONDITIONS
FOR THE
UPPER DELAWARE RIVER BASIN
NOVEMBER 1999

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

Adjusted streamflow in the upper Delaware River basin during November was within the normal range. The maximum daily discharge of 12,900 cfs occurred on November 28. The minimum daily discharge was 1,740 cfs on November 24.

On the basis of a 5-station average, precipitation during November was 2.98 inches, which was 77 percent of the 58-year average. The maximum daily-average precipitation during November was 1.30 inches on November 27. Precipitation in the upper Delaware River Basin during the past 12 months was 2.56 inches less than the long-term average. Precipitation during November was 0.89 inches less than the long-term average for the month.

The monthly mean streamflow of the Delaware River at Montague, N.J. during November was 3,381 cfs (observed), which was 71 percent of the median. The flow at Montague, adjusted for diversions from the basin and change in storage in the major reservoirs was 5,248 cfs, or 98 percent of median (water years 1961-90).

Storage December 1, 1999 in Pepacton, Cannonsville and Neversink Reservoirs was 65.4 percent of capacity above the point of maximum depletion. The combined storage of 177 billion gallons was 12 billion gallons greater than that of one month ago and was 57 billion gallons more than that of one year ago. Median storage on the first day of December in 32 years of record is 164 billion gallons.

As part of a statewide network, the USGS operates 14 observation wells in the Pennsylvania part of the Delaware River Basin. Mean water levels during November were below average in 7 of the wells. Most observation well levels were trending downward in comparison to October 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 Nov. 1998 December 1998 to November 1999
 

Average

Actual Percent of average Excess (+) or deficit (-)
  Amount Cumulative Amount Cumulative By month Cumulative By month Cumulative
Dec. 3.40 43.24 1.53 40.68 45 94 -1.87 -2.56
Jan. 2.97 39.84 5.65 39.15 190 98 +2.68 -.69
Feb. 2.66 36.87 1.67 33.50 63 91 -.99 -3.37
Mar. 3.30 34.21 4.40 31.83 133 93 +1.10 -2.38
Apr. 3.78 30.91 2.29 27.43 61 89 -1.49 -3.48
May 4.19 27.13 3.32 25.14 79 93 -.87 -1.99
June 3.94 22.94 2.28 21.82 58 95 -1.66 -1.12
July 4.12 19.00 1.71 19.54 42 103 -2.41 +.54
Aug. 3.87 14.88 3.05 17.83 79 120 -.82 +2.95
Sept. 3.74 11.01 9.08 14.78 243 134 +5.34 +3.77
Oct. 3.40 7.27 2.72 5.70 80 78 -.68 -1.57
Nov. 3.87 3.87 2.98 2.98 77 77 -.89 -.89

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

 

STREAMFLOW, IN CFS

DELAWARE RIVER AT MONTAGUE, N.J.

Month 1940-98 1999 Percent of
Maximum Median Minimum Monthly mean median
November (observed) 11,760 (1951) 4,730 995 (1964) 3,381 71
November (adjusted) 16,160 (1972) 6,262 390 (1964)  5,248 84
             
December (observed) 18,830 (1996) 4,943 1,968 (1964)    
December (adjusted)  20,880 (1973) 6,735 2,051 (1946)