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


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

 

Adjusted streamflow in the upper Delaware River basin during August was excessive for the fourth consecutive month. The maximum daily discharge of 10,300 cfs occurred on August 13. The minimum daily discharge was 1,980 cfs on August 28. 

On the basis of a multi-station average, precipitation during August was 3.60 inches, which was 93 percent of the 59-year average. The maximum daily-average precipitation during August was 0.82 inches on August 13. Precipitation in the upper Delaware River Basin during the past 12 months was 8.95 inches greater than the long-term average. Precipitation during August was 0.26 inches less than the long-term average for the month. 

The monthly mean streamflow of the Delaware River at Montague, N.J. during August was 3,675 cfs (observed), which was 175 percent of median. The flow at Montague, adjusted for diversions from the basin and change in storage in the major reservoirs was 3,710 cfs, or 254 percent of median (water years 1961-90).

Storage September 1, 2000, in Pepacton, Cannonsville, and Neversink Reservoirs was 94.2 percent of capacity above the point of maximum depletion. The combined storage of 255 billion gallons was 11 billion gallons less than that of one month ago and was 104 billion gallons more than that of one year ago. Median storage on the first day of September in 33 years of record is 202 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 August were above average in 10 of the wells. Water levels in 10 of the wells were trending downward in comparison to July levels. Water levels in all 14 wells were above August 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 Aug. 1999

September 1999 to August 2000

 

Average

Actual

Percent of average

Excess (+) or deficit (-)

 

Amount

Cumulative

Amount

Cumulative

By month

Cumulative

By month

Cumulative

Sept.

3.74 43.15 9.11 52.10 244 121 +5.37 +8.95
Oct. 3.40 39.41 2.72 42.99 80 109 -.68 +3.58
Nov. 3.87 36.01 2.75 40.27 71 112 -1.12 +4.26
Dec. 3.37 32.14 1.84 37.52 55 117 -1.53 +5.38
Jan. 3.02 28.77 3.44 35.68 114 124 +.42 + 6.91
Feb. 2.64 25.75 3.26 32.24 123 125 +.62 + 6.49
Mar. 3.32 23.11 4.08 28.98 123 125 +.76 +5.87
Apr. 3.76 19.79 4.63 24.90 123 126 +.87 +5.11
May 4.17 16.03 5.76 20.27 138 126 +1.59 +4.24
June 3.91 11.86 6.67 14.51 171 122 +2.76 +2.65
July 4.09 7.95 4.24 7.84 104 99 +.15 -.11
Aug. 3.86 3.86 3.60 3.60 93 93 -.26 -.26

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

August (observed) 14,230 (1955) 2,096 715 (1954) 3,675 175
August (adjusted) 17,410 (1955) 1,380 364 (1964) 3,710 269
 
September (observed) 9,167 (1960) 2,016 892 (1941)  
September (adjusted) 10,720 (1960) 1,462 324 (1964)