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


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



Adjusted streamflow in the upper Delaware River basin during June was excessive. The maximum daily discharge of 24,700 cfs occurred on June 7. The minimum daily discharge was 4,230 cfs on June 5. 

On the basis of a 12-station average, precipitation during June was 6.67 inches, which was 171 percent of the 59-year average. The maximum daily-average precipitation during June was 1.96 inches on June 7. Precipitation in the upper Delaware River Basin during the past 12 months was 6.31 inches greater than the long-term average. Precipitation during June was 2.76 inches more than the long-term average for the month. 

The monthly mean streamflow of the Delaware River at Montague, N.J. during June was 9,562 cfs (observed), which was 299 percent of the median. The flow at Montague, adjusted for diversions from the basin and change in storage in the major reservoirs was 10,270 cfs, or 259 percent of median (water years 1961-90).

Storage July 1, 2000, in Pepacton, Cannonsville and Neversink Reservoirs was 100.0 percent of capacity above the point of maximum depletion. The combined storage of 271 billion gallons was 2.1 billion gallons less than that of one month ago and was 43 billion gallons more than that of one year ago. Median storage on the first day of July in 33 years of record is 257 billion gallons. Cannonsville Reservoir spilled continuously throughout the month and spilled more than 13 billion gallons. Pepacton Reservoir spilled on all days and spilled more than 13 billion gallons. Neversink Reservoir spilled from June 6 to June 10 and spilled nearly 2 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 June were above average in 7 of the wells. Water levels in 9 of the wells were trending downward in comparison to May levels. Water levels in all 14 wells were above the June 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 Feb. 1999

March 1999 to February 2000

Average

Actual

Percent of average

Excess (+) or deficit (-)

Amount

Cumulative

Amount

Cumulative

By month

Cumulative

By month

Cumulative

July

4.12 43.19 2.34 49.50 57 115 -1.78 +6.31
Aug. 3.87 39.07 3.00 47.16 78 121 -.87 +8.09
Sept. 3.74 35.20 9.11 44.16 244 125 +5.37 +8.96
Oct. 3.40 31.46 2.72 35.05 80 111 -.68 +3.59
Nov. 3.87 28.06 2.75 32.33 71 115 -1.12 +4.27
Dec. 3.37 24.19 1.84 29.58 55 122 -1.53 +5.39
Jan. 3.02 20.82 *3.44 27.74 114 133 +.42 +6.92
Feb. 2.64 17.80 *3.26 24.30 123 137 +.62 +6.50
Mar. 3.32 15.16 3.98 21.04 120 139 +.66 +5.88
Apr. 3.76 11.84 4.63 17.06 123 144 +.87 +5.22
May 4.17 8.08 5.76 12.43 138 154 +1.59 +4.35
June 3.91 3.91 6.67 6.67 171 171 +2.76 +2.76

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

* Revised since previous month

 

STREAMFLOW, IN CFS

DELAWARE RIVER AT MONTAGUE, N.J.

Month

1940-98

 

Percent of

Maximum

Median

Minimum

Monthly mean

median

June (observed) 15,200 (1972) 3,199 1,214 (1965) 9,562 299
June (adjusted) 16,010 (1972) 3,948 1,024 (1962) 10,270 260
 
July (observed) 11,200 (1945) 2,486 864 (1954)  
July (adjusted) 11,470 (1945) 2,193 391 (1965)