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Virginia DEQ

Virginia Water Science Center

 
  Duration Plot and Table of 7-Day Average Streamflow
 
01672500 SOUTH ANNA RIVER NEAR ASHLAND, VA
LOCATION.--Latitude 37°47'48", Longitude 77°32'57", North American Datum of 1927,
                    Hanover County, VA, Hydrologic Unit 02080106.
DRAINAGE AREA.--395 square miles.
PERIOD OF RECORD.--October 1930 to September 1997, June 2003 to current year.
DURATION STATISTIC COMPUTATION PERIOD.--All data through September 2015.
REGULATION.--Small diurnal fluctuation at low flow in some years caused by mills upstream from station. Since 1966, diversion upstream averaged less than 0.6 cfs. Capacity of the diversion is about 1.5 cfs.
GAGE OPERATION.--U.S. Geological Survey, Virginia Water Science Center.
     Duration Plot with 7-Day Average Streamflow Conditions
Provisional Data Subject to Revision 01672500 plot. SOUTH ANNA RIVER NEAR ASHLAND, VA
Provisional Data Subject to Revision

                    

The current 7-day running-average value for 03/22/2017 is 297.86 cubic feet per second.

  explanation   Percentile Description Duration Plot Description 28 Day 14 Day 7 Day Daily
      Duration Table of 7-Day Average Streamflow
            Flow values in cubic feet per second


                01672500     SOUTH ANNA RIVER NEAR ASHLAND, VA

   Minimum daily flow
   5th percentile
 
   10th percentile
 
   25th percentile
 
 
   Median
 
 
   75th percentile
 
 
 
   90th percentile
 
 
 
   95th percentile
 
 
 
 
   Maximum daily flow
         
Years of record
January
53.4
93.3
128
226
380
629
1,090
1,450
4,360
 
79
February
49.6
124
171
273
419
695
1,000
1,380
4,590
 
79
March
94.3
182
227
323
484
783
1,180
1,440
5,610
 
79
April
111
163
186
265
408
674
1,110
1,420
6,690
 
79
May
66.9
108
128
174
263
430
786
1,060
6,790
 
79
June
29.0
60.0
69.7
98.4
160
267
457
662
7,450
 
79
July
17.9
35.1
42.1
65.1
105
177
421
661
3,320
 
79
August
6.14
20.9
26.6
45.7
84.5
180
392
715
8,520
 
80
September
4.43
12.0
18.1
30.0
73.1
145
398
764
3,900
 
80
October
5.77
13.3
20.7
45.1
88.6
183
492
800
4,460
 
78
November
15.6
40.4
50.9
85.2
146
314
608
903
4,360
 
79
December
29.6
68.4
86.3
141
269
493
845
1,230
3,500
 
79
 
       

The current 7-day running-average value for 03/22/2017 is 297.86 cubic feet per second.

---- Provisional Data Subject to Revision ----

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