HydrionisGlobal Water Intelligence
Monitored reservoir

John Martin Reservoir At Caddoa, CO

United States Geological Survey reservoir gauge 07130000 in CO, with published storage from 1977.

Storage record07130000

Storage now, against this reservoir's own record

39.10 Mm³
Stored, October 2020
51st
Percentile among 44 Octs on record
-64.4%
Against the Oct 1991–2020 average
-55.8%
Change over the 12 months to 2020-10

Storage in October 2020 was around the middle of the Oct record, ranked against 44 other Octs held for this reservoir.

Storage, 1977–2020

Monthly mean storage
517 monthly values, 1977 to 2020
Monthly mean storageMonthly mean storage: John Martin Reservoir At Caddoa, CO in Mm³, from 1977.75 to 2020.75.0200400600Mm³1977.751983.16666666666671988.583333333333319941999.41666666666672004.83333333333332010.252015.6666666666667Year

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 517 periods, evenly spaced across the record. Every value is in the download and the API; a table of all 517 would be longer than this page and unusable with a screen reader.
PeriodJohn Martin Reservoir At Caddoa, CO (Mm³)
October 19770
December 19770.808
February 19785.38
April 19783.02
July 19780.736
September 19780
November 19780.584
January 19794.17
March 197917.5
May 19793.84
August 19797.63
October 19795.12
December 197914.6
February 198037.5
April 198054.5
June 1980208
September 1980143
November 198046.1
January 198172.3
March 198191.0
May 198157.2
July 198139.1
September 198128.8
December 198128.2
February 198250.8
April 198259.7
June 198232.3
August 198218.6
October 198215.7
January 198353.0
March 198384.9
May 1983121
July 1983249
September 1983118
November 198387.8
February 1984141
April 1984189
June 1984250
August 1984216
October 1984206
December 1984295
March 1985417
May 1985409
July 1985406
September 1985355
November 1985349
January 1986392
March 1986411
June 1986293
August 1986245
October 1986263
December 1986338
February 1987406
April 1987436
July 1987424
September 1987326
November 1987306
January 1988343
March 1988376
May 1988329
August 1988148
October 198899.4
December 1988115
February 1989141
April 1989134
June 1989101
August 198950.6
November 198938.0
January 199060.1
March 199084.9
May 199076.0
July 199042.2
September 199028.5
December 199041.2
February 199167.4
April 199169.1
June 199139.2
August 199113.6
October 199111.0
January 199248.3
March 199283.8
May 199247.4
July 199231.9
September 199218.6
November 199222.5
February 199369.9
April 1993105
June 1993115
August 199371.0
October 199351.3
December 199377.9
February 1994106
May 1994123
July 1994135
September 199493.6
November 199486.5
January 1995115
March 1995138
June 1995323
August 1995406
October 1995324
December 1995330
February 1996372
April 1996348
July 1996284
September 1996286
November 1996291
January 1997322
March 1997365
May 1997296
July 1997351
October 1997352
December 1997422
February 1998424
April 1998426
June 1998384
August 1998333
November 1998310
January 1999350
March 1999393
May 1999527
July 1999411
September 1999409
December 1999407
February 2000427
April 2000412
June 2000332
August 2000197
October 2000140
January 2001178
March 2001207
May 2001193
July 2001149
September 200177.8
November 200165.6
January 200291.7
April 2002106
June 200264.9
August 200233.8
October 200227.0
December 200232.4
February 200345.2
May 200343.5
July 200332.4
September 200326.7
November 200324.9
January 200436.3
March 200446.6
June 20047.11
August 200416.5
October 200421.0
December 200440.2
February 200567.5
April 200592.6
June 200561.2
September 200511.1
November 200514.3
January 200631.6
March 200646.8
May 200630.1
July 20069.92
October 20065.71
December 200631.2
February 200756.6
April 200793.1
June 2007107
August 200747.2
November 200731.4
January 200857.3
March 200879.4
May 200863.5
July 200833.0
September 200836.3
December 200861.9
February 200984.0
April 2009101
June 200994.4
August 200935.9
October 200928.3
December 200953.0
March 201094.5
May 2010106
July 201054.0
September 201029.4
November 201036.4
January 201157.2
April 201172.1
June 201143.0
August 201113.1
October 201112.1
December 201123.8
February 201244.1
May 201238.4
July 201228.4
September 201220.9
November 201220.8
January 201329.8
March 201337.4
May 201332.3
August 201326.5
October 201323.8
December 201329.1
February 201446.2
April 201455.2
June 201432.6
September 201410.2
November 201412.8
January 201532.1
March 201556.9
May 2015103
July 2015383
October 2015263
December 2015271
February 2016291
April 2016284
June 2016249
August 2016165
November 2016120
January 2017142
March 2017160
May 2017215
July 2017295
September 2017306
November 2017311
February 2018374
April 2018370
June 2018305
August 2018204
October 2018165
December 2018177
March 2019210
May 2019198
July 2019190
September 2019110
November 201992.0
January 2020113
April 2020144
June 202092.7
August 202050.3
October 202039.1

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 12.050100150200Mm³123456789101112Month1991–2020 average 1: 139 Mm³1991–2020 average 2: 151 Mm³1991–2020 average 3: 162 Mm³1991–2020 average 4: 159 Mm³1991–2020 average 5: 152 Mm³1991–2020 average 6: 161 Mm³1991–2020 average 7: 144 Mm³1991–2020 average 8: 128 Mm³1991–2020 average 9: 117 Mm³1991–2020 average 10: 110 Mm³1991–2020 average 11: 117 Mm³1991–2020 average 12: 130 Mm³Most recent 12 months 1: 113 Mm³Most recent 12 months 2: 122 Mm³Most recent 12 months 3: 142 Mm³Most recent 12 months 4: 144 Mm³Most recent 12 months 5: 116 Mm³Most recent 12 months 6: 92.7 Mm³Most recent 12 months 7: 59.3 Mm³Most recent 12 months 8: 50.3 Mm³Most recent 12 months 9: 42.8 Mm³Most recent 12 months 10: 39.1 Mm³Most recent 12 months 11: 92.0 Mm³Most recent 12 months 12: 103 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)
Jan139113
Feb151122
Mar162142
Apr159144
May152116
Jun16192.7
Jul14459.3
Aug12850.3
Sep11742.8
Oct11039.1
Nov11792.0
Dec130103

Why this page shows a volume and not a percentage

Rate and persistence

-4.11 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

John Martin Reservoir At Caddoa, CO
Gauge location
John Martin Reservoir At Caddoa, COJohn Martin Reservoir At Caddoa, CO — 39.10 Mm³John Martin Reservoir At Caddoa, CO — 39.10 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 held1977–2020
Completeness97.9% 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 1977 and 2020 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), John Martin Reservoir At Caddoa, CO reservoir records, accessed 2026-10-05, hydrionis.com/reservoirs/reservoir-usgs-07130000/

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 John Martin Reservoir At Caddoa, CO 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

517 monthly observations 1977–2020 Mm³
Spatially aggregatedHigh confidenceOctober 2020

Source: USGS — National Water Information System, 07130000. 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 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.

Hydrionis would like to measure which pages are read, using HEKNO Analytics, which HEKNO Ltd runs itself, and Google Analytics. Google Analytics stores an identifier on your device, so we only do this if you agree. Nothing is measured if you decline, and the site works identically either way. See cookies for what is set and how to change your mind.