HydrionisGlobal Water Intelligence
Monitored reservoir

Ridgway Reservoir Near Ridgway, CO

United States Geological Survey reservoir gauge 09147022 in CO, with published storage from 1990.

Storage record09147022

Storage now, against this reservoir's own record

78.96 Mm³
Stored, September 2026
67th
Percentile among 22 Seps on record
+10.0%
Change over the 12 months to 2026-09

Storage in September 2026 was around the middle of the Sep record, ranked against 22 other Seps held for this reservoir.

No percentage departure from the Sep average is published here. No long-term average is held for this month, so there is nothing to compare with.

Storage, 1990–2026

Monthly mean storage
264 monthly values, 1990 to 2026
Monthly mean storageMonthly mean storage: Ridgway Reservoir Near Ridgway, CO in Mm³, from 1990.75 to 2026.6666666666667.050100Mm³1990.751993.52010.2520132015.752018.52021.252024Year

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 264 periods, evenly spaced across the record. Every value is in the download and the API; a table of all 264 would be longer than this page and unusable with a screen reader.
PeriodRidgway Reservoir Near Ridgway, CO (Mm³)
October 199088.3
November 199093.8
December 199092.1
January 199190.5
February 199189.4
April 199183.2
May 199170.6
June 199191.9
July 1991103
August 199199.6
September 199190.7
October 199184.9
November 199183.8
December 199182.7
January 199282.2
March 199285.5
April 199282.0
May 199275.8
June 199294.6
July 1992101
August 199294.2
September 199286.9
October 199285.6
November 199283.8
December 199281.3
February 199378.5
March 199376.8
April 199366.2
May 199365.4
June 199383.5
July 199393.5
August 199384.1
September 199387.2
October 200576.5
November 200580.8
January 200684.9
February 200686.0
March 200687.3
April 200691.1
May 200692.4
June 2006102
July 200697.4
August 200691.5
September 200681.1
October 200875.2
December 200880.3
January 200982.2
February 200983.6
March 200985.6
April 200988.3
May 200998.8
June 2009103
July 200998.3
August 200979.7
September 200971.2
November 200977.4
December 200979.4
January 201080.3
February 201080.8
March 201081.8
April 201084.2
May 201086.4
June 2010102
July 201095.7
August 201087.6
October 201075.9
November 201079.2
December 201081.3
January 201182.6
February 201183.1
March 201181.9
April 201173.7
May 201167.8
June 201185.3
July 2011102
September 201179.8
October 201181.9
November 201184.4
December 201185.0
January 201284.6
February 201284.1
March 201285.0
April 201289.9
May 201291.9
June 201292.8
August 201275.2
September 201263.2
October 201263.5
November 201264.6
December 201266.1
January 201367.1
February 201367.1
March 201367.2
April 201367.3
May 201367.4
July 201367.5
August 201367.6
September 201367.7
October 201367.8
November 201367.8
December 201367.9
January 201468.0
February 201468.1
March 201468.2
April 201468.2
June 201468.4
July 201468.5
August 201468.6
September 201468.6
October 201468.7
November 201468.8
December 201468.9
January 201569.0
February 201569.0
March 201569.1
May 201569.3
June 201569.4
July 201569.4
August 201569.5
September 201569.6
October 201569.7
November 201569.8
December 201569.8
January 201669.9
February 201670.0
April 201670.1
May 201670.2
June 201670.3
July 201670.4
August 201670.5
September 201670.5
October 201670.6
November 201670.7
December 201670.8
January 201770.9
March 201771.0
April 201771.1
May 201771.2
June 201771.3
July 201771.3
August 201771.4
September 201771.5
October 201771.2
November 201773.2
December 201774.2
February 201875.6
March 201876.4
April 201878.1
May 201879.1
June 201878.6
July 201868.6
August 201856.7
September 201854.0
October 201853.7
November 201854.8
January 201956.9
February 201957.5
March 201959.7
April 201964.4
May 201972.4
June 201980.8
July 201996.2
August 201996.0
September 201979.9
October 201974.5
December 201978.9
January 202080.0
February 202080.9
March 202082.0
April 202083.1
May 202081.5
June 202091.3
July 202086.6
August 202074.9
September 202063.5
November 202063.5
December 202064.8
January 202165.3
February 202165.9
March 202167.1
April 202170.1
May 202172.5
June 202188.3
July 202194.7
August 202186.1
October 202175.1
November 202177.5
December 202179.0
January 202280.0
February 202280.4
March 202281.5
April 202283.1
May 202276.3
June 202283.5
July 202282.2
September 202275.0
October 202278.1
November 202281.1
December 202282.6
January 202384.6
February 202385.8
March 202385.7
April 202375.0
May 202366.1
June 202383.6
August 202385.7
September 202373.9
October 202373.9
November 202375.6
December 202377.6
January 202478.8
February 202480.2
March 202481.5
April 202482.4
May 202474.6
July 202495.8
August 202486.5
September 202487.2
October 202485.5
November 202485.1
December 202485.8
January 202585.5
February 202586.0
March 202587.6
April 202587.9
June 202594.5
July 202593.8
August 202579.5
September 202571.8
October 202576.2
November 202581.6
December 202584.4
January 202685.6
February 202686.2
March 202688.5
May 202692.5
June 202695.5
July 202692.1
August 202685.3
September 202679.0

Why this page shows a volume and not a percentage

Rate and persistence

+0.60 Mm³
Mean change 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

Ridgway Reservoir Near Ridgway, CO
Gauge location
Ridgway Reservoir Near Ridgway, CORidgway Reservoir Near Ridgway, CO — 78.96 Mm³Ridgway Reservoir Near Ridgway, CO — 78.96 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 held1990–2026
Completeness59.5% 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.
Continuity59% of the months between 1990 and 2026 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), Ridgway Reservoir Near Ridgway, CO reservoir records, accessed 2026-10-05, hydrionis.com/reservoirs/reservoir-usgs-09147022/

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 Ridgway Reservoir Near Ridgway, 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

264 monthly observations 1990–2026 Mm³
Spatially aggregatedHigh confidenceSeptember 2026

Source: USGS — National Water Information System, 09147022. 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.

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