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Virginia DEQ

Virginia Water Science Center

 
  Duration Plot and Table of 28-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 2007.
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 28-Day Average Streamflow Conditions
Provisional Data Subject to Revision 01672500 plot. SOUTH ANNA RIVER NEAR ASHLAND, VA
Provisional Data Subject to Revision

                    

The current 28-day running-average value for 10/11/2008 is 72.46 cubic feet per second.

  explanation   Percentile Description Duration Plot Description 28 Day 14 Day 7 Day Daily
      Duration Table of 28-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
53.8
97.3
148
278
416
636
857
986
2,010
 
71
February
63.6
150
211
323
503
704
954
1,160
2,150
 
71
March
91.2
231
284
392
554
729
974
1,300
2,000
 
71
April
117
199
263
387
557
775
1,090
1,290
2,090
 
71
May
93.0
143
169
243
353
526
813
982
2,140
 
71
June
51.1
83.7
103
153
233
341
505
718
2,110
 
71
July
23.2
55.8
65.6
90.8
136
210
377
517
2,200
 
71
August
11.2
29.2
39.2
70.3
116
258
447
688
2,610
 
72
September
5.96
19.9
24.7
46.6
109
247
483
790
2,520
 
72
October
6.29
17.2
23.8
50.5
99.4
257
508
985
1,560
 
70
November
11.3
33.4
51.0
86.5
148
338
626
887
1,610
 
71
December
26.9
62.1
93.5
152
275
484
738
1,020
1,610
 
71
 
       

The current 28-day running-average value for 10/11/2008 is 72.46 cubic feet per second.

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

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