Payette Lake And Payette Lake — storage

Storage now, against this reservoir's own record

31.19 Mm³

Stored, September 2026

82nd

Percentile among 83 Seps on record

+6.0%

Against the Sep 1991–2020 average

+1.4%

Change over the 12 months to 2026-09

Storage in September 2026 was higher than most Seps on record, ranked against 83 other Seps held for this reservoir.

Storage, 1943–2026

Monthly mean storage

996 monthly values, 1943 to 2026

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 996 periods, evenly spaced across the record. Every value is in the download and the API; a table of all 996 would be longer than this page and unusable with a screen reader.
Period	Payette Lake And Payette Lake (Mm³)
October 1943	12.4
February 1944	12.2
June 1944	48.9
October 1944	9.30
March 1945	18.8
July 1945	47.1
November 1945	12.2
March 1946	13.0
July 1946	46.3
November 1946	17.6
April 1947	19.6
August 1947	31.0
December 1947	18.4
April 1948	19.9
August 1948	33.5
December 1948	14.7
May 1949	34.9
September 1949	22.2
January 1950	21.1
May 1950	23.6
September 1950	30.3
January 1951	25.2
June 1951	34.8
October 1951	20.1
February 1952	12.8
June 1952	37.0
October 1952	16.6
February 1953	15.0
July 1953	42.8
November 1953	18.4
March 1954	12.0
July 1954	37.7
November 1954	35.1
March 1955	10.5
August 1955	39.7
December 1955	15.7
April 1956	18.4
August 1956	41.7
December 1956	10.8
April 1957	14.1
September 1957	36.3
January 1958	12.7
May 1958	32.4
September 1958	35.6
January 1959	12.6
May 1959	24.5
October 1959	26.3
February 1960	11.5
June 1960	40.0
October 1960	12.1
February 1961	18.1
June 1961	40.1
October 1961	11.3
March 1962	23.6
July 1962	42.5
November 1962	19.9
March 1963	22.0
July 1963	42.6
November 1963	11.9
April 1964	12.2
August 1964	33.9
December 1964	18.0
April 1965	19.5
August 1965	34.5
December 1965	12.9
May 1966	20.4
September 1966	29.9
January 1967	18.8
May 1967	27.4
September 1967	24.4
January 1968	13.8
June 1968	34.0
October 1968	14.3
February 1969	12.5
June 1969	36.3
October 1969	12.4
February 1970	12.6
July 1970	39.5
November 1970	11.7
March 1971	11.6
July 1971	38.1
November 1971	8.69
March 1972	11.4
August 1972	32.6
December 1972	11.3
April 1973	15.2
August 1973	32.9
December 1973	14.8
April 1974	16.2
September 1974	27.4
January 1975	10.4
May 1975	17.8
September 1975	24.7
January 1976	13.3
May 1976	29.3
October 1976	18.6
February 1977	8.73
June 1977	44.5
October 1977	12.7
February 1978	18.9
June 1978	32.2
October 1978	17.0
March 1979	10.6
July 1979	39.1
November 1979	15.4
March 1980	10.7
July 1980	43.0
November 1980	12.7
April 1981	15.1
August 1981	37.1
December 1981	14.2
April 1982	13.7
August 1982	38.2
December 1982	12.1
May 1983	23.4
September 1983	25.3
January 1984	11.6
May 1984	23.5
September 1984	24.5
January 1985	8.13
June 1985	39.8
October 1985	15.5
February 1986	10.3
June 1986	37.6
October 1986	13.2
February 1987	7.67
July 1987	41.9
November 1987	6.11
March 1988	6.84
July 1988	41.8
November 1988	7.35
March 1989	8.72
August 1989	37.2
December 1989	7.94
April 1990	19.2
August 1990	35.9
December 1990	6.99
April 1991	10.8
September 1991	24.9
January 1992	6.51
May 1992	31.1
September 1992	27.2
January 1993	7.67
May 1993	28.3
September 1993	31.3
February 1994	6.61
June 1994	42.1
October 1994	14.1
February 1995	10.8
June 1995	32.1
October 1995	17.3
March 1996	11.2
July 1996	41.8
November 1996	12.3
March 1997	11.5
July 1997	42.3
November 1997	11.0
April 1998	16.1
August 1998	36.4
December 1998	9.03
April 1999	13.3
August 1999	36.3
December 1999	9.28
May 2000	26.6
September 2000	29.2
January 2001	6.59
May 2001	34.0
September 2001	22.1
January 2002	9.16
June 2002	35.6
October 2002	14.2
February 2003	10.3
June 2003	40.9
October 2003	14.2
February 2004	7.63
July 2004	40.1
November 2004	8.83
March 2005	8.81
July 2005	39.3
November 2005	8.14
March 2006	9.65
August 2006	35.7
December 2006	10.4
April 2007	17.5
August 2007	33.0
December 2007	11.2
April 2008	9.64
September 2008	30.6
January 2009	8.36
May 2009	27.6
September 2009	32.3
January 2010	7.16
May 2010	21.5
September 2010	31.1
February 2011	8.53
June 2011	33.8
October 2011	12.6
February 2012	7.27
June 2012	38.7
October 2012	18.0
March 2013	9.22
July 2013	39.5
November 2013	9.02
March 2014	12.2
July 2014	40.5
November 2014	8.98
April 2015	18.5
August 2015	32.6
December 2015	8.89
April 2016	21.9
August 2016	36.2
December 2016	9.78
May 2017	29.3
September 2017	30.1
January 2018	9.91
May 2018	34.0
September 2018	29.1
January 2019	7.38
June 2019	40.7
October 2019	13.6
February 2020	7.47
June 2020	42.8
October 2020	13.5
February 2021	7.11
July 2021	38.2
November 2021	9.17
March 2022	8.82
July 2022	40.4
November 2022	6.73
March 2023	8.37
August 2023	37.0
December 2023	8.77
April 2024	16.8
August 2024	35.8
December 2024	7.38
April 2025	15.4
September 2025	30.7
January 2026	12.5
May 2026	37.1
September 2026	31.2

The reservoir's year

Seasonal storage profile

Each calendar month's reference average, against the most recent year

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
Period	1991–2020 average (Mm³)	Most recent 12 months (Mm³)
Jan	8.73	12.5
Feb	8.88	10.6
Mar	9.89	12.8
Apr	15.4	20.5
May	29.4	37.1
Jun	38.8	43.1
Jul	40.4	40.3
Aug	35.9	36.6
Sep	29.4	31.2
Oct	14.5	13.5
Nov	9.00	10.2
Dec	8.87	13.4

Why this page shows a volume and not a percentage

Percentage full is a division, and the denominator is missing

“Percentage full” is the figure a drought is discussed in, and it is stored volume divided by capacity. Capacity is published on several different bases — gross, usable, live, and the figure at a particular spillway or licence condition — and dividing a stored volume by the wrong one produces a percentage confidently wrong by the ratio between them, at exactly the moment the number matters most.

Hydrionis holds storage measurements for this reservoir and does not hold a compatible authoritative capacity figure for it, so percentage full is not calculated. The volume above is what was actually measured. Where you need a percentage, take the publisher’s own capacity on its own stated basis and divide it yourself — the source is linked below, and knowing which basis you used is the whole point.

Water level

Monthly mean water surface elevation

992 monthly values

An elevation above a datum, not a depth of water and not a distance below the crest. Levels at different reservoirs are measured against different datums and must not be read against one another; this line is comparable only with its own history. Elevation and volume are not proportional either — a metre near the bottom of a reservoir holds far less water than a metre near the top, because the surface area grows with height.

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 992 periods, evenly spaced across the record. Every value is in the download and the API; a table of all 992 would be longer than this page and unusable with a screen reader.
Period	Payette Lake And Payette Lake (m)
1943.75	0.611
1944.0833333333333	0.603
1944.4166666666667	2.41
1944.75	0.460
1945.1666666666667	0.928
1945.5	2.32
1945.8333333333333	0.605
1946.1666666666667	0.642
1946.5	2.29
1946.8333333333333	0.872
1947.1666666666667	0.677
1947.5833333333333	1.53
1947.9166666666667	0.911
1948.25	0.982
1948.5833333333333	1.66
1948.9166666666667	0.728
1949.25	0.893
1949.5833333333333	1.54
1950	1.04
1950.3333333333333	1.17
1950.6666666666667	1.50
1951	1.25
1951.3333333333333	1.46
1951.6666666666667	1.29
1952.0833333333333	0.634
1952.4166666666667	1.83
1952.75	0.818
1953.0833333333333	0.742
1953.4166666666667	1.73
1953.75	1.72
1954.0833333333333	0.585
1954.5	1.86
1954.8333333333333	1.73
1955.1666666666667	0.518
1955.5	2.08
1955.8333333333333	0.664
1956.1666666666667	0.647
1956.5	2.10
1956.9166666666667	0.536
1957.25	0.695
1957.5833333333333	1.91
1957.9166666666667	0.551
1958.25	0.720
1958.5833333333333	1.92
1958.9166666666667	0.594
1959.3333333333333	1.21
1959.6666666666667	1.96
1960	0.565
1960.3333333333333	1.31
1960.6666666666667	1.22
1961	0.803
1961.3333333333333	1.78
1961.75	0.557
1962.0833333333333	1.13
1962.4166666666667	1.92
1962.75	1.32
1963.0833333333333	1.57
1963.4166666666667	1.76
1963.75	1.02
1964.1666666666667	0.662
1964.5	1.95
1964.8333333333333	0.558
1965.1666666666667	0.744
1965.5	1.99
1965.8333333333333	0.788
1966.25	0.870
1966.5833333333333	1.62
1966.9166666666667	0.815
1967.25	0.972
1967.5833333333333	1.61
1967.9166666666667	0.739
1968.25	0.927
1968.6666666666667	1.22
1969	0.660
1969.3333333333333	1.65
1969.6666666666667	1.02
1970	0.568
1970.3333333333333	1.29
1970.6666666666667	1.14
1971.0833333333333	0.610
1971.4166666666667	1.73
1971.75	0.482
1972.0833333333333	0.479
1972.4166666666667	1.72
1972.75	0.895
1973.0833333333333	0.665
1973.5	1.86
1973.8333333333333	0.898
1974.1666666666667	0.733
1974.5	1.77
1974.8333333333333	0.483
1975.1666666666667	0.543
1975.5	2.04
1975.9166666666667	0.707
1976.25	0.692
1976.5833333333333	1.61
1976.9166666666667	0.448
1977.25	0.869
1977.5833333333333	1.03
1977.9166666666667	0.933
1978.3333333333333	1.23
1978.6666666666667	1.12
1979	0.501
1979.3333333333333	1.23
1979.6666666666667	0.789
1980	0.548
1980.4166666666667	1.73
1980.75	0.528
1981.0833333333333	0.621
1981.4166666666667	2.05
1981.75	0.572
1982.0833333333333	0.631
1982.4166666666667	1.69
1982.8333333333333	0.620
1983.1666666666667	0.621
1983.5	2.10
1983.8333333333333	0.680
1984.1666666666667	0.551
1984.5	1.93
1984.8333333333333	0.433
1985.25	0.688
1985.5833333333333	1.71
1985.9166666666667	0.495
1986.25	0.918
1986.5833333333333	1.88
1986.9166666666667	0.375
1987.25	0.731
1987.6666666666667	1.21
1988	0.322
1988.3333333333333	1.61
1988.6666666666667	1.33
1989	0.362
1989.4166666666667	1.80
1989.75	0.657
1990.1666666666667	0.406
1990.5	2.00
1990.8333333333333	0.397
1991.1666666666667	0.393
1991.5	2.08
1991.8333333333333	7.00
1992.4166666666667	2.14
1992.75	0.564
1993.0833333333333	0.354
1993.4166666666667	1.61
1993.75	0.687
1994.0833333333333	0.758
1994.4166666666667	2.08
1994.8333333333333	0.409
1995.1666666666667	0.683
1995.5	1.95
1995.8333333333333	0.573
1996.1666666666667	0.555
1996.5	2.07
1996.8333333333333	0.610
1997.25	0.892
1997.5833333333333	1.82
1997.9166666666667	0.462
1998.25	0.797
1998.5833333333333	1.80
1998.9166666666667	0.446
1999.25	0.558
1999.6666666666667	1.47
2000	0.417
2000.3333333333333	1.31
2000.6666666666667	1.44
2001	0.326
2001.3333333333333	1.68
2001.6666666666667	1.09
2002.0833333333333	0.456
2002.4166666666667	1.65
2002.75	0.703
2003.0833333333333	0.511
2003.4166666666667	2.02
2003.75	0.702
2004.0833333333333	0.377
2004.5	1.98
2004.8333333333333	0.436
2005.1666666666667	0.435
2005.5	1.94
2005.8333333333333	0.402
2006.1666666666667	0.477
2006.5833333333333	1.76
2006.9166666666667	0.513
2007.25	0.862
2007.5833333333333	1.63
2007.9166666666667	0.554
2008.25	0.477
2008.5833333333333	1.80
2009	0.411
2009.4166666666667	1.82
2009.75	0.777
2010.0833333333333	0.341
2010.4166666666667	1.79
2010.75	0.670
2011.0833333333333	0.422
2011.5	1.92
2011.8333333333333	0.368
2012.1666666666667	0.440
2012.5	1.97
2012.8333333333333	0.501
2013.1666666666667	0.456
2013.5	1.95
2013.9166666666667	0.427
2014.25	0.760
2014.5833333333333	1.82
2014.9166666666667	0.504
2015.25	0.915
2015.5833333333333	1.61
2015.9166666666667	0.439
2016.3333333333333	1.68
2016.6666666666667	1.54
2017	0.443
2017.3333333333333	1.45
2017.6666666666667	1.49
2018	0.490
2018.3333333333333	1.68
2018.75	0.699
2019.0833333333333	0.541
2019.4166666666667	2.01
2019.75	0.672
2020.0833333333333	0.369
2020.4166666666667	2.11
2020.8333333333333	0.352
2021.1666666666667	0.318
2021.5	1.89
2021.8333333333333	0.453
2022.1666666666667	0.436
2022.5	2.00
2022.8333333333333	0.333
2023.25	0.460
2023.5833333333333	1.83
2023.9166666666667	0.434
2024.25	0.828
2024.5833333333333	1.77
2024.9166666666667	0.365
2025.25	0.762
2025.6666666666667	1.52
2026	0.616
2026.3333333333333	1.84
2026.6666666666667	1.54

Rate and persistence

+0.04 Mm³

Mean change per month over 12 months

6 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

Payette Lake And Payette Lake

Gauge location

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 Bureau of Reclamation — Reservoir operations and Colorado River data · US Government work — public domain
How the values came to exist	Measured
Period held	1943–2026
Completeness	98.8% 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.
Continuity	99% of the months between 1943 and 2026 are held. Monthly means of the publisher's own daily record.
Last read from the publisher	2026-10-01
Redistribution	Permitted by the upstream licences
Commercial reuse	Permitted by the upstream licences. No Hydrionis access tier can widen this.
Methodology	How this was produced

Use this data

Machine-readable JSON /api/v1/observations/by-subject/reservoir-usbr-7194.json
How to cite this, and who you must credit
How these figures were produced
Request this at a different scale, format or geography

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), Payette Lake And Payette Lake reservoir records, accessed 2026-10-05, hydrionis.com/reservoirs/reservoir-usbr-7194/

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 Payette Lake And Payette Lake 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

996 monthly observations 1943–2026 Mm³

Spatially aggregatedHigh confidenceSeptember 2026

Source: USBR — Reservoir operations and Colorado River data, RISE catalogue item 132374. Licence: Open.

Method: Monthly mean of the daily values published by the Bureau of Reclamation in acre-feet, converted to Mm³. Months with fewer than 20 days of record are not published rather than averaged from a partial month.

Stored as a volume and not as a share of capacity: the operator publishes what is in the reservoir but not what it holds when full, so a percentage cannot be computed without inventing the denominator.

Retrieved 1 October 2026.

Monthly mean of the daily values published by the Bureau of Reclamation in acre-feet, converted to Mm³. Months with fewer than 20 days of record are not published rather than averaged from a partial month.