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Water-Year Summary for Site USGS 01646500

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  • Water-Year Summary reports summarize a year of hydrologic data in a printer-friendly format.
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Available Parameters
00010 Temperature, water(Max.,Min.,Mean) [Discontinued]  
00010 Temperature, water(Max.,Min.,Mean) [Discontinued]  
00010 Temperature, water(Max.,Min.,Mean) [Discontinued]  
00010 Temperature, water(Min.,Max.,Mean)  
00010 Temperature, water(Max.,Min.,Mean) [Discontinued]  
00060 Discharge(Mean)  
00095 Specific cond at 25C(Max.,Min.,Mean)  
00095 Specific cond at 25C(Max.,Min.,Mean) [Discontinued]  
00095 Specific cond at 25C(Max.,Min.,Mean) [Discontinued]  
00300 Dissolved oxygen(Max.,Min.,Mean)  
00300 Dissolved oxygen(Max.,Min.,Mean) [Discontinued]  
00400 pH(Max.,Min.,Med.)  
00400 pH(Max.,Min.,Med.) [Discontinued]  
63680 Turbidity, Form Neph(Max.,Min.,Mean)  
63680 Turbidity, Form Neph(Mean,Max.,Min.) [Discontinued]  
99133 NO3+NO2,water,insitu(Max.,Mean,Min.)  
99133 NO3+NO2,water,insitu(Max.,Min.,Mean) [Discontinued]  

Water year 2018: 2017-10-01 to 2018-09-30
 

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USGS Water-Year Summary 2018
01646500 POTOMAC RIVER NEAR WASHINGTON, DC
LOCATION - Lat 38°56'59.2", long 77°07'39.5" referenced to North American Datum of 1983, Montgomery County, MD, Hydrologic Unit 02070008, on left bank just upstream from Little Falls Dam, 1 mi upstream from District of Columbia boundary line, 1.2 mi upstream from Chain Bridge, 1.8 mi east of Langley, Fairfax County, and at mile 117.4.
DRAINAGE AREA - 11,560 mi².
REVISIONS HISTORY -
  • WSP 726: Drainage area.
  • WDR MD-DE-75-1: 1973-74(M).
  • https://waterdata.usgs.gov/nwis/dv/?site_no=01646500: 2018.
  • https://waterdata.usgs.gov/nwis/uv/?site_no=01646500: 2021.
  • Discharge for Measurement 385 made on 06/25/2021 was revised on 09/22/2021 due to an error in computation.
SURFACE-WATER RECORDS
PERIOD OF RECORD - March 1930 to current year.
GAGE - Water-stage recorder, crest-stage gage, and concrete control. Datum of gage is 37.20 ft above North American Vertical Datum of 1988. Prior to June 7, 1930, nonrecording gage, and June 7, 1930 to Jan. 22, 1965, water-stage recorder at site 1 mi upstream on right bank at same gage datum.
REMARKS -
  • Water Years 2017-2021: Records good, except those for estimated discharges, which are poor.
  • Water Years 2014-2016: Records good, except those for estimated daily discharges, which are poor.
  • Water Year 2013 and prior years’ accuracy statements can be found in Annual Water Data Reports.

  • Diversions since June 1959. For unregulated statistics of monthly mean data and summary statistics for water years 1930 to 1958, reference WDR MD-DE-DC-02-1. Diversions at Great Falls through aqueducts since June 1959, from gage pool at Little Falls Dam; since October 1958, at Rockville Filtration Plant; since April 1961, at Potomac Filtration Plant; since October 1961, at Fairfax Water Treatment Plant (from Goose Creek); since April 1964, at Violets Lock to Chesapeake and Ohio Canal; and since October 1985, at Fairfax County Water Authority Treatment Plant. Low flow affected slightly prior to July 1981 by Stony River Reservoir, since December 1950, by Savage River Reservoir (see station 01597500), and since July 1981, by Jennings Randolph Lake. U.S. Geological Survey satellite data-collection platform at station.
    EXTREMES OUTSIDE PERIOD OF RECORD - Flood of June 2, 1889, was of approximately the same magnitude as that of March 19, 1936.
    Water-Data Report 2018
    01646500 POTOMAC RIVER NEAR WASHINGTON, DC -- Continued
    DISCHARGE, CUBIC FEET PER SECOND
    YEAR 2017-10-01 to 2018-09-30
    DAILY MEAN VALUES
    [e, Value has been estimated.]
    Day Oct
     2017
    11,350
    21,280
    31,250
    41,300
    51,270
    61,420
    71,340
    81,330
    91,630
    101,810
    112,230
    123,040
    133,150
    143,710
    153,810
    163,410
    173,010
    182,710
    192,400
    202,050
    211,970
    221,890
    231,690
    241,920
    252,330
    262,260
    272,370
    282,440
    292,440
    304,160
    3116,700
    Total83,670
    Mean2,698
    Max16700
    Min1250
    Ac-ft166,000
    Day Nov
    2017
    122,300
    213,800
    39,590
    47,370
    56,680
    65,940
    76,090
    87,750
    97,020
    109,230
    1110,000
    128,580
    137,580
    146,580
    155,520
    165,070
    175,060
    184,640
    194,180
    204,470
    215,850
    225,550
    235,020
    244,630
    254,340
    264,120
    273,900
    283,750
    293,600
    303,410
     -- 
    Total201,600
    Mean6,721
    Max22300
    Min3410
    Ac-ft399,900
    Day Dec
    2017
    13,300
    23,220
    33,120
    42,980
    52,980
    63,000
    72,890
    82,970
    93,050
    102,920
    112,630
    122,630
    132,600
    142,430
    152,430
    162,390
    172,290
    182,300
    192,310
    202,290
    212,240
    222,210
    232,270
    242,480
    252,570
    262,680
    272,800
    282,590
    292,680
    302,440
    311,760
    Total81,450
    Mean2,627
    Max3300
    Min1760
    Ac-ft161,600
    Day Jan
    2018
    11,620
    21,600
    31,680
    41,870
    51,230
    61,320
    71,760
    81,920
    92,090
    101,970
    112,040
    122,400
    135,800
    1410,900
    159,960
    1611,500
    1710,700
    189,990
    197,610
    207,060
    216,740
    225,980
    235,770
    2410,100
    2512,600
    2610,600
    278,690
    287,640
    297,120
    306,750
    316,410
    Total183,400
    Mean5,917
    Max12600
    Min1230
    Ac-ft363,800
    Day Feb
    2018
    16,040
    25,770
    35,610
    45,880
    57,590
    67,450
    77,650
    810,600
    913,200
    1015,900
    1119,800
    1224,300
    1330,300
    1429,600
    1525,200
    1621,100
    1723,600
    1831,600
    1930,600
    2027,200
    2123,700
    2221,000
    2319,100
    2418,900
    2519,800
    2628,600
    2739,500
    2834,100
     -- 
     -- 
     -- 
    Total553,700
    Mean19,780
    Max39500
    Min5610
    Ac-ft1,098,000
    Day Mar
    2018
    127,200
    2e22,900
    323,700
    421,300
    518,400
    615,600
    714,000
    812,900
    912,000
    1011,100
    1110,100
    129,000
    138,260
    147,760
    157,240
    166,800
    176,540
    186,180
    195,770
    205,910
    216,540
    226,670
    236,990
    247,370
    258,760
    2610,200
    2711,400
    2812,400
    2913,000
    3016,000
    3122,600
    Total374,600
    Mean12,080
    Max27200
    Min5770
    Ac-ft743,000
    Day Apr
    2018
    123,200
    219,700
    318,000
    422,100
    533,300
    630,700
    724,400
    819,400
    916,000
    1014,100
    1112,500
    1211,300
    1310,100
    149,240
    158,510
    1617,800
    1740,100
    1873,200
    1952,300
    2035,700
    2127,500
    2222,300
    2318,000
    2415,800
    2515,900
    2616,900
    2721,700
    2825,000
    2922,200
    3019,600
     -- 
    Total696,600
    Mean23,220
    Max73200
    Min8510
    Ac-ft1,382,000
    Day May
    2018
    116,600
    214,300
    312,900
    411,800
    510,700
    610,000
    710,900
    821,100
    923,800
    1019,000
    1115,800
    1213,100
    1311,900
    1412,000
    1524,000
    1650,000
    1756,900
    1871,600
    19101,000
    20109,000
    2188,600
    2259,800
    2347,300
    2445,500
    2533,900
    2626,400
    2722,000
    2821,100
    2921,100
    3023,900
    3119,800
    Total1,026,000
    Mean33,090
    Max109000
    Min10000
    Ac-ft2,034,999
    Day Jun
    2018
    122,500
    232,000
    359,300
    4126,000
    5148,000
    667,700
    7e44,100
    8e32,500
    9e25,500
    10e21,400
    11e22,300
    12e36,900
    13e43,200
    14e35,700
    1527,200
    1622,300
    1717,900
    1814,800
    1913,300
    2012,400
    2112,500
    2218,800
    2337,700
    2474,800
    2558,200
    2638,900
    27e27,800
    28e21,700
    29e18,300
    30e17,400
     -- 
    Total1,151,000
    Mean38,370
    Max148000
    Min12400
    Ac-ft2,283,000
    Day Jul
    2018
    1e15,900
    2e13,100
    3e10,600
    4e9,710
    59,040
    610,400
    711,900
    810,700
    910,000
    109,000
    117,780
    126,640
    135,950
    145,610
    155,320
    165,200
    175,540
    185,610
    195,300
    205,150
    218,800
    2235,800
    2332,800
    2426,900
    2528,500
    2633,900
    2732,000
    2826,000
    2918,300
    3013,800
    3114,800
    Total440,000
    Mean14,190
    Max35800
    Min5150
    Ac-ft872,800
    Day Aug
    2018
    121,900
    224,300
    335,300
    453,300
    562,100
    641,000
    729,100
    823,000
    920,800
    1021,600
    1117,700
    1215,100
    1315,800
    1415,000
    1515,300
    1615,200
    1713,100
    1811,800
    1911,300
    2013,500
    2113,300
    2226,800
    2335,800
    2424,800
    2518,000
    2614,200
    2711,700
    2810,300
    299,580
    308,610
    318,060
    Total657,300
    Mean21,200
    Max62100
    Min8060
    Ac-ft1,303,999
    Day Sep
    2018
    110,100
    212,700
    311,600
    411,800
    59,900
    68,590
    77,900
    89,610
    918,000
    1069,100
    11130,000
    1288,900
    1354,300
    1448,600
    1540,300
    1630,200
    1725,500
    1828,700
    1961,000
    2061,600
    2141,000
    2231,800
    2327,200
    2426,100
    2535,100
    2653,100
    2780,500
    2894,300
    29132,000
    30108,000
     -- 
    Total1,368,000
    Mean45,580
    Max132000
    Min7900
    Ac-ft2,712,000
    STATISTICS OF MONTHLY MEAN DATA FOR WATER YEARS 1930 - 2018, BY WATER YEAR (WY)
    Oct Nov Dec Jan Feb Mar Apr May Jun Jul Aug Sep
    Mean 5,966 7,346 11,190 13,660 16,760 23,010 19,920 15,530 9,410 4,954 4,678 5,320
    Max 44,100 42,030 37,630 52,890 61,040 76,510 57,850 40,410 46,630 21,040 28,210 45,580
    (WY) (1943) (1986) (1997) (1996) (1998) (1936) (1993) (1989) (1972) (1949) (1955) (2018)
    Min 583 700 1,038 1,681 1,882 4,495 5,810 3,921 1,535 599 538 679
    (WY) (1931) (1931) (1966) (1981) (2002) (2009) (1995) (1969) (1999) (1999) (1966) (1930)
    Water-Data Report 2018
    01646500 POTOMAC RIVER NEAR WASHINGTON, DC -- Continued
    SUMMARY STATISTICS
    Water Year 2018 Water Years 1930 - 2018
    Annual total 6,817,000                   
    Annual mean 18,680          11,500         
    Highest annual mean           23,760          1996
    Lowest annual mean           4,017          2002
    Highest daily mean 148,000          Jun 05 426,000          Mar 19, 1936
    Lowest daily mean 1,230          Jan 05 121.0        Sep 09, 1966
    Annual 7-day minimum 1,313          Oct 02 181.4        Sep 07, 1966
    Maximum peak flow 175,000          Jun 05 484,000          Mar 19, 1936
    Maximum peak stage 12.47       Jun 05 28.10a      Mar 19, 1936
    Annual runoff (cfsm) 1.62       0.991     
    Annual runoff (inches) 21.9        13.5       
    10 percent exceeds 40,180          25,500         
    50 percent exceeds 11,800          6,580         
    90 percent exceeds 2,322          1,690         
    a Gage height at different site and(or) datum
    USGS Water-data graph for site USGS 01646500