HydrionisGlobal Water Intelligence
Monitored reservoir

Lake Ellsworth Near Elgin, OK

United States Geological Survey reservoir gauge 07308990 in OK, with published storage from 1995.

Storage record07308990

Storage now, against this reservoir's own record

23.39 Mm³
Stored, August 2026
7th
Percentile among 31 Augs on record
-61.2%
Against the Aug 1991–2020 average
-51.8%
Change over the 12 months to 2026-08

Storage in August 2026 was lower than almost every other Aug on record, ranked against 31 other Augs held for this reservoir.

Storage, 1995–2026

Monthly mean storage
371 monthly values, 1995 to 2026
Monthly mean storageMonthly mean storage: Lake Ellsworth Near Elgin, OK in Mm³, from 1995.75 to 2026.5833333333333.0255075100Mm³1995.751999.66666666666672003.58333333333332007.52011.41666666666672015.33333333333332019.252023.1666666666667Year

Monthly means of the publisher's daily record. Volume, not percentage of capacity: without a capacity whose definition is stated, fullness cannot be computed.

View the data behind this chart
Underlying data
PeriodLake Ellsworth Near Elgin, OK (Mm³)
October 199574.4
November 199572.5
December 199572.7
January 199673.5
February 199673.4
March 199672.8
April 199672.5
May 199667.7
June 199666.3
July 199671.1
August 199673.0
September 199683.6
October 199675.3
November 199675.9
December 199679.3
January 199780.2
February 199782.2
March 199781.3
April 199776.1
May 199778.5
June 199777.7
July 199781.5
August 199778.5
September 199770.9
October 199774.7
November 199775.1
December 199778.7
January 199886.5
February 199887.4
March 199886.6
April 199882.3
May 199873.4
June 199872.0
July 199867.4
August 199860.5
September 199853.6
October 199849.0
November 199853.3
December 199855.3
January 199955.2
February 199962.0
March 199969.4
April 199974.1
May 199973.6
June 199975.2
July 199982.9
August 199977.5
September 199971.0
October 199966.5
November 199961.9
December 199962.7
January 200063.3
February 200062.6
March 200068.0
April 200073.6
May 200078.4
June 200076.1
July 200083.6
August 200078.2
September 200072.2
October 200073.9
November 200086.9
December 200083.5
January 200184.0
February 200185.8
March 200181.2
April 200173.7
May 200174.8
June 200180.8
July 200177.0
August 200172.7
September 200169.8
October 200163.7
November 200158.3
December 200154.4
January 200250.6
February 200248.6
March 200245.3
April 200247.6
May 200250.3
June 200248.2
July 200244.4
August 200238.1
September 200232.5
October 200230.2
November 200234.2
December 200232.4
January 200334.3
February 200332.8
March 200331.9
April 200332.0
May 200331.5
June 200334.8
July 200336.3
August 200331.2
September 200328.0
October 200324.5
November 200321.6
December 200319.6
January 200416.6
February 200414.3
March 200418.9
April 200419.4
May 200418.4
June 200416.7
July 200416.5
August 200414.4
September 200411.7
October 200419.8
November 200432.5
December 200446.5
January 200551.5
February 200555.6
March 200558.2
April 200558.1
May 200557.7
June 200556.7
July 200551.9
August 200547.3
September 200545.7
October 200543.2
November 200539.7
December 200535.8
January 200632.6
February 200630.0
March 200628.4
April 200627.0
May 200627.9
June 200626.1
July 200624.5
August 200621.6
September 200623.0
October 200623.9
November 200622.3
December 200621.6
January 200722.7
February 200724.4
March 200725.2
April 200744.1
May 200770.0
June 200782.6
July 200778.4
August 200778.7
September 200773.8
October 200774.4
November 200774.7
December 200774.7
January 200874.3
February 200874.8
March 200874.6
April 200876.8
May 200874.1
June 200873.5
July 200871.8
August 200869.6
September 200866.8
October 200861.3
November 200856.1
December 200851.2
January 200947.6
February 200945.0
March 200943.1
April 200941.9
May 200966.3
June 200973.1
July 200970.2
August 200972.4
September 200967.5
October 200966.6
November 200969.6
December 200968.6
January 201068.3
February 201074.5
March 201074.6
April 201074.7
May 201075.1
June 201075.1
July 201075.2
August 201069.7
September 201066.1
October 201062.8
November 201063.7
December 201061.8
January 201159.3
February 201157.8
March 201156.0
April 201150.7
May 201151.2
June 201151.9
July 201144.3
August 201138.5
September 201132.6
October 201128.9
November 201127.1
December 201125.8
January 201225.3
February 201225.0
March 201227.8
April 201242.2
May 201250.5
June 201251.2
July 201249.1
August 201243.4
September 201239.0
October 201235.6
November 201231.6
December 201228.5
January 201326.6
February 201325.5
March 201326.5
April 201336.6
May 201349.7
June 201353.3
July 201356.8
August 201374.8
September 201370.8
October 201367.7
November 201365.5
December 201364.4
January 201462.3
February 201458.1
March 201456.5
April 201454.4
May 201451.4
June 201452.2
July 201451.1
August 201445.4
September 201439.9
October 201434.7
November 201430.5
December 201429.2
January 201530.1
February 201530.4
March 201529.0
April 201527.7
May 201564.6
June 201580.5
July 201578.4
August 201574.9
September 201569.6
October 201564.8
November 201563.6
December 201571.3
January 201681.0
February 201682.5
March 201682.3
April 201682.7
May 201682.2
June 201683.7
July 201679.9
August 201677.1
September 201674.9
October 201671.1
November 201667.0
December 201665.1
January 201763.7
February 201767.5
March 201775.1
April 201777.3
May 201776.0
June 201774.3
July 201772.5
August 201774.7
September 201775.9
October 201777.7
November 201776.1
December 201775.5
January 201873.8
February 201874.4
March 201873.4
April 201872.5
May 201874.2
June 201872.0
July 201867.2
August 201860.9
September 201863.0
October 201875.2
November 201874.8
December 201876.6
January 201974.5
February 201974.4
March 201975.4
April 201975.4
May 201975.9
June 201972.9
July 201968.7
August 201964.4
September 201963.2
October 201960.1
November 201956.2
December 201955.3
January 202055.4
February 202058.8
March 202066.3
April 202074.4
May 202074.7
June 202074.6
July 202071.7
August 202068.2
September 202071.8
October 202071.4
November 202074.8
December 202074.9
January 202174.6
February 202175.6
March 202173.9
April 202173.8
May 202175.0
June 202177.5
July 202175.6
August 202173.4
September 202171.0
October 202170.7
November 202169.3
December 202165.8
January 202263.9
February 202262.0
March 202258.3
April 202258.5
May 202269.7
June 202275.0
July 202270.5
August 202266.1
September 202262.3
October 202257.9
November 202260.4
December 202263.4
January 202364.8
February 202365.3
March 202366.0
April 202365.3
May 202365.9
June 202369.4
July 202372.4
August 202369.6
September 202365.0
October 202359.7
November 202355.9
December 202355.3
January 202456.9
February 202460.6
March 202463.5
April 202465.3
May 202475.6
June 202473.2
July 202470.0
August 202466.0
September 202462.5
October 202456.5
November 202471.6
December 202473.6
January 202573.2
February 202572.6
March 202572.5
April 202576.0
May 202571.1
June 202557.3
July 202551.4
August 202548.6
September 202547.1
October 202544.4
November 202541.2
December 202540.5
January 202639.2
February 202638.0
March 202634.5
April 202631.8
May 202629.9
June 202628.5
July 202626.7
August 202623.4

The reservoir's year

Seasonal storage profile
Each calendar month's reference average, against the most recent year
Seasonal storage profileSeasonal storage profile: 1991–2020 average, Most recent 12 months in Mm³, from 1 to 12.020406080Mm³123456789101112Month1991–2020 average 1: 55.7 Mm³1991–2020 average 2: 56.3 Mm³1991–2020 average 3: 57.1 Mm³1991–2020 average 4: 58.7 Mm³1991–2020 average 5: 62.7 Mm³1991–2020 average 6: 64.1 Mm³1991–2020 average 7: 62.9 Mm³1991–2020 average 8: 60.2 Mm³1991–2020 average 9: 57.5 Mm³1991–2020 average 10: 56.6 Mm³1991–2020 average 11: 56.4 Mm³1991–2020 average 12: 56.4 Mm³Most recent 12 months 1: 39.2 Mm³Most recent 12 months 2: 38.0 Mm³Most recent 12 months 3: 34.5 Mm³Most recent 12 months 4: 31.8 Mm³Most recent 12 months 5: 29.9 Mm³Most recent 12 months 6: 28.5 Mm³Most recent 12 months 7: 26.7 Mm³Most recent 12 months 8: 23.4 Mm³Most recent 12 months 9: 47.1 Mm³Most recent 12 months 10: 44.4 Mm³Most recent 12 months 11: 41.2 Mm³Most recent 12 months 12: 40.5 Mm³
  • 1991–2020 average
  • Most recent 12 months

Twelve separate averages, one per calendar month. A January average describes Januaries only. Months are plotted 1–12.

View the data behind this chart
Underlying data
Period1991–2020 average (Mm³)Most recent 12 months (Mm³)
Jan55.739.2
Feb56.338.0
Mar57.134.5
Apr58.731.8
May62.729.9
Jun64.128.5
Jul62.926.7
Aug60.223.4
Sep57.547.1
Oct56.644.4
Nov56.441.2
Dec56.440.5

Rate and persistence

-2.10 Mm³
Mean drawdown per month over 12 months
5 of 24
Months in the last two years below the 20th percentile for their own month

Rates are computed only across an unbroken run of months, so a rate is never divided by a period in which some of the change was not observed. Percentile counts compare each month with the same calendar month in every other year held.

Location

Lake Ellsworth Near Elgin, OK
Gauge location
Lake Ellsworth Near Elgin, OKLake Ellsworth Near Elgin, OK — 23.39 Mm³Lake Ellsworth Near Elgin, OK — 23.39 Mm³

Where this comes from

371 monthly observations 1995–2026 Mm³
Spatially aggregatedHigh confidenceAugust 2026

Source: USGS — National Water Information System, 07308990. Licence: Open.

Method: Monthly mean of daily reservoir storage published by the USGS in acre-feet and converted to millions of cubic metres. Months with fewer than 20 days of record are not published rather than averaged from a partial month.

Reservoir storage is managed as well as observed: a drawdown may reflect an operating rule, flood-control rule curve or scheduled release rather than a shortage. Compare a month against the same month in other years, and do not read a fall as a supply signal without knowing the operating regime.

Retrieved 25 August 2026.

Monthly mean of daily reservoir storage published by the USGS in acre-feet and converted to millions of cubic metres. Months with fewer than 20 days of record are not published rather than averaged from a partial month.

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