HydrionisGlobal Water Intelligence
Monitored reservoir

Lk Mcclure A Exchequer CA

United States Geological Survey reservoir gauge 11269500 in CA, with published storage from 1930.

Storage record11269500

Storage now, against this reservoir's own record

816.80 Mm³
Stored, September 2025
71st
Percentile among 92 Seps on record
+24.2%
Against the Sep 1991–2020 average
-9.4%
Change over the 12 months to 2025-09

Storage in September 2025 was higher than most Seps on record, ranked against 92 other Seps held for this reservoir.

Storage, 1930–2025

Monthly mean storage
1,131 monthly values, 1930 to 2025
Monthly mean storageMonthly mean storage: Lk Mcclure A Exchequer CA in Mm³, from 1930.9166666666667 to 2025.6666666666667.05001,0001,500Mm³1930.91666666666671943.251955.166666666666719671978.83333333333331990.66666666666672002.52014.3333333333333Year

Monthly means of the publisher's daily record. Volume, not percentage of capacity — see below for why.

What the shaded periods are (0 events)

Not shown on this chart

  • The 1976 drought — This event’s area does not contain this chart’s subject. Sharing a country is not sharing an event, so it is not drawn.
  • The 2022 drought — This event’s area does not contain this chart’s subject. Sharing a country is not sharing an event, so it is not drawn.
  • Yorkshire drought — This event’s area does not contain this chart’s subject. Sharing a country is not sharing an event, so it is not drawn.
  • Cantareira water crisis, São Paulo — This event’s area does not contain this chart’s subject. Sharing a country is not sharing an event, so it is not drawn.
  • Cape Town Day Zero — This event’s area does not contain this chart’s subject. Sharing a country is not sharing an event, so it is not drawn.
  • European drought — This event’s area does not contain this chart’s subject. Sharing a country is not sharing an event, so it is not drawn.
View the data behind this chart
240 of 1,131 periods, evenly spaced across the record. Every value is in the download and the API; a table of all 1,131 would be longer than this page and unusable with a screen reader.
PeriodLk Mcclure A Exchequer CA (Mm³)
December 19307.95
May 193184.8
January 193296.4
June 1932346
November 193279.7
April 193389.9
August 1933125
January 193455.2
June 1934139
January 193599.4
May 1935314
October 193584.5
March 1936304
July 1936321
December 193684.8
May 1937326
October 193763.6
February 1938288
July 1938349
December 1938213
May 1939336
September 193919.6
February 1940204
July 1940288
November 194022.3
April 1941292
September 1941203
February 1942295
June 1942334
November 1942134
April 1943289
September 1943153
January 194498.9
June 1944349
November 194448.5
March 1945287
August 1945225
January 1946238
June 1946345
October 194618.0
March 1947225
August 1947112
February 194846.3
June 1948350
November 194837.3
April 1949162
August 1949136
January 195038.1
June 1950344
November 1950136
March 1951294
August 1951173
January 1952143
June 1952325
October 1952123
March 1953135
August 1953195
December 195347.3
May 1954344
October 19549.92
March 1955106
July 1955251
December 1955103
May 1956340
October 1956139
February 1957185
July 1957294
December 195741.1
May 1958310
September 1958184
February 1959177
July 1959185
November 195931.2
April 1960193
September 19604.33
February 196143.5
June 1961111
November 19613.08
April 1962224
September 196290.9
January 196357.0
June 1963341
November 196393.6
March 1964195
August 196441.5
January 1965312
June 1965334
October 1965126
March 1966233
August 1966337
January 1967500
May 1967958
October 1967843
March 1968796
July 1968698
December 1968435
May 1969996
October 1969873
February 1970832
July 1970977
December 1970692
May 1971847
September 1971770
February 1972688
July 1972718
November 1972339
April 1973719
September 1973871
February 1974800
June 19741,254
November 1974825
April 1975938
September 1975942
January 1976760
June 1976648
November 1976289
March 1977257
August 1977142
January 1978190
June 19781,067
October 1978866
March 1979855
August 19791,009
January 1980840
May 1980917
October 1980794
March 1981750
July 1981742
December 1981489
May 19821,114
October 1982862
February 1983911
July 19831,236
December 1983868
May 1984981
September 1984751
February 1985571
July 1985576
November 1985292
April 1986930
September 1986900
February 1987779
June 1987777
November 1987382
April 1988418
September 1988192
January 1989164
June 1989425
November 1989179
March 1990207
August 1990181
January 199189.6
June 1991459
October 1991215
March 1992264
August 1992258
January 1993258
May 1993861
October 1993859
March 1994798
July 1994665
December 1994341
May 1995942
October 1995883
February 1996891
July 19961,151
December 1996898
May 1997983
September 1997822
February 1998836
July 19981,241
November 1998831
April 1999868
September 1999874
February 2000836
June 20001,179
November 2000761
April 2001825
September 2001568
January 2002507
June 2002736
November 2002365
April 2003510
August 2003659
January 2004493
June 2004684
October 2004324
March 2005771
August 20051,089
January 2006842
May 20061,052
October 2006857
March 2007810
August 2007511
December 2007314
May 2008497
October 2008331
February 2009372
July 2009767
December 2009501
May 2010869
September 2010891
February 2011909
July 20111,229
December 2011821
April 2012865
September 2012576
February 2013556
June 2013680
November 2013309
April 2014318
September 2014171
January 201583.8
June 2015164
November 201583.5
April 2016510
August 2016586
January 2017795
June 20171,161
October 2017875
March 2018903
August 2018909
January 2019722
May 20191,064
October 2019819
March 2020776
August 2020654
December 2020470
May 2021553
October 2021239
February 2022350
July 2022449
December 2022250
May 2023840
September 2023965
February 2024812
July 20241,134
December 2024791
April 2025992
September 2025817

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 12.05001,000Mm³123456789101112Month1991–2020 average 1: 582 Mm³1991–2020 average 2: 622 Mm³1991–2020 average 3: 653 Mm³1991–2020 average 4: 703 Mm³1991–2020 average 5: 796 Mm³1991–2020 average 6: 887 Mm³1991–2020 average 7: 861 Mm³1991–2020 average 8: 756 Mm³1991–2020 average 9: 657 Mm³1991–2020 average 10: 581 Mm³1991–2020 average 11: 547 Mm³1991–2020 average 12: 551 Mm³Most recent 12 months 1: 796 Mm³Most recent 12 months 2: 844 Mm³Most recent 12 months 3: 900 Mm³Most recent 12 months 4: 992 Mm³Most recent 12 months 5: 1,126 Mm³Most recent 12 months 6: 1,151 Mm³Most recent 12 months 7: 1,039 Mm³Most recent 12 months 8: 913 Mm³Most recent 12 months 9: 817 Mm³Most recent 12 months 10: 833 Mm³Most recent 12 months 11: 798 Mm³Most recent 12 months 12: 791 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)
Jan582796
Feb622844
Mar653900
Apr703992
May7961,126
Jun8871,151
Jul8611,039
Aug756913
Sep657817
Oct581833
Nov547798
Dec551791

Why this page shows a volume and not a percentage

Rate and persistence

-7.09 Mm³
Mean drawdown per month over 12 months
0 of 24
Recent months 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

Lk Mcclure A Exchequer CA
Gauge location
Lk Mcclure A Exchequer CALk Mcclure A Exchequer CA — 816.80 Mm³Lk Mcclure A Exchequer CA — 816.80 Mm³

About this data

About this data

Everything below is a property of the data rather than a rating of it. There is deliberately no single confidence score: how much a gap matters depends on what you are about to do with the series, and only you know that.

Source
United States Geological Survey — National Water Information System · US Government work — public domain
How the values came to existMeasured
Period held1930–2025
Completeness98.2% of the periods in that span are held. Gaps are drawn as breaks and never interpolated.
Known gaps
  • Storage is a managed quantity. A falling line can be a rule curve, a scheduled release or a transfer to another system rather than a shortage of water, and nothing here distinguishes them.
  • No capacity figure on a stated basis is held for this reservoir, so no percentage of capacity is computed.
Continuity98% of the months between 1930 and 2025 are held. Monthly means of the publisher's own daily record.
Last read from the publisher2026-10-01
RedistributionPermitted by the upstream licences
Commercial reusePermitted by the upstream licences. No Hydrionis access tier can widen this.
MethodologyHow this was produced

Use this data

Use this data

No bulk download is offered here, which is a licence position rather than a product one: at least one contributing publisher does not permit redistribution. The values can be read on the page, cited, and pointed to at source.

Attribution and citation

Suggested citation for Hydrionis

Hydrionis (2026), Lk Mcclure A Exchequer CA reservoir records, accessed 2026-10-05, hydrionis.com/reservoirs/reservoir-usgs-11269500/

Cite Hydrionis where you rely on the compilation, the normalisation, the eligibility judgements or a chart. Where you use an unmodified published value, the publisher’s attribution is the one that is required; crediting Hydrionis as well is welcome and is not something Hydrionis can require of you.

Recommended, not required. Hydrionis does not claim rights over unmodified public data it relayed, and doing arithmetic on somebody else’s measurements does not make them Hydrionis’s. Cite the version and the access date: the Lk Mcclure A Exchequer CA record changes as publishers release and as methods are revised, and a citation without both cannot be checked later. Full guidance is on cite and reuse.

None of the contributing licences requires attribution. Crediting the publishers is still good practice and they are listed above.

Where this comes from

1,131 monthly observations 1930–2025 Mm³
Spatially aggregatedHigh confidenceSeptember 2025

Source: USGS — National Water Information System, 11269500. 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. The USGS publishes this reservoir's storage as one reading a day at a fixed hour, and changed the hour: from 2021-10-01 the record continues under the later hour rather than ending where the earlier one stops.

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 1 October 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. The USGS publishes this reservoir's storage as one reading a day at a fixed hour, and changed the hour: from 2021-10-01 the record continues under the later hour rather than ending where the earlier one stops.

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