Payette Lake And Payette Lake — storage

Storage now, against this reservoir's own record

36.64 Mm³

Stored, August 2026

71st

Percentile among 83 Augs on record

+2.2%

Against the Aug 1991–2020 average

+2.3%

Change over the 12 months to 2026-08

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

Storage, 1943–2026

Monthly mean storage

995 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 995 periods, evenly spaced across the record. Every value is in the download and the API; a table of all 995 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
May 1951	29.5
October 1951	20.1
February 1952	12.8
June 1952	37.0
October 1952	16.6
February 1953	15.0
June 1953	35.1
November 1953	18.4
March 1954	12.0
July 1954	37.7
November 1954	35.1
March 1955	10.5
July 1955	42.2
December 1955	15.7
April 1956	18.4
August 1956	41.7
December 1956	10.8
April 1957	14.1
August 1957	38.7
January 1958	12.7
May 1958	32.4
September 1958	35.6
January 1959	12.6
May 1959	24.5
September 1959	39.6
January 1960	11.4
June 1960	40.0
October 1960	12.1
February 1961	18.1
June 1961	40.1
October 1961	11.3
February 1962	22.8
July 1962	42.5
November 1962	19.9
March 1963	22.0
July 1963	42.6
November 1963	11.9
March 1964	13.4
August 1964	33.9
December 1964	18.0
April 1965	19.5
August 1965	34.5
December 1965	12.9
April 1966	17.6
August 1966	32.7
January 1967	18.8
May 1967	27.4
September 1967	24.4
January 1968	13.8
May 1968	27.3
September 1968	24.7
February 1969	12.5
June 1969	36.3
October 1969	12.4
February 1970	12.6
June 1970	37.5
October 1970	13.1
March 1971	11.6
July 1971	38.1
November 1971	8.69
March 1972	11.4
July 1972	41.4
November 1972	13.2
April 1973	15.2
August 1973	32.9
December 1973	14.8
April 1974	16.2
August 1974	31.6
December 1974	9.90
April 1975	11.7
September 1975	24.7
January 1976	13.3
May 1976	29.3
September 1976	25.1
January 1977	8.85
May 1977	43.6
October 1977	12.7
February 1978	18.9
June 1978	32.2
October 1978	17.0
February 1979	10.5
June 1979	39.3
November 1979	15.4
March 1980	10.7
July 1980	43.0
November 1980	12.7
March 1981	12.6
July 1981	43.1
November 1981	13.8
April 1982	13.7
August 1982	38.2
December 1982	12.1
April 1983	12.6
August 1983	36.8
December 1983	12.7
May 1984	23.5
September 1984	24.5
January 1985	8.13
May 1985	28.2
September 1985	28.4
January 1986	9.28
June 1986	37.6
October 1986	13.2
February 1987	7.67
June 1987	43.6
October 1987	9.91
February 1988	6.62
July 1988	41.8
November 1988	7.35
March 1989	8.72
July 1989	42.7
November 1989	8.76
March 1990	8.21
July 1990	40.4
December 1990	6.99
April 1991	10.8
August 1991	36.3
December 1991	7.18
April 1992	17.7
August 1992	34.5
January 1993	7.67
May 1993	28.3
September 1993	31.3
January 1994	6.57
May 1994	29.4
September 1994	28.3
February 1995	10.8
June 1995	32.1
October 1995	17.3
February 1996	11.4
June 1996	35.2
October 1996	10.2
February 1997	11.9
July 1997	42.3
November 1997	11.0
March 1998	10.9
July 1998	42.0
November 1998	9.17
March 1999	9.11
August 1999	36.3
December 1999	9.28
April 2000	17.9
August 2000	33.4
December 2000	6.92
April 2001	11.4
September 2001	22.1
January 2002	9.16
May 2002	25.2
September 2002	28.5
January 2003	8.30
May 2003	26.3
October 2003	14.2
February 2004	7.63
June 2004	42.2
October 2004	13.6
February 2005	7.80
June 2005	41.9
October 2005	13.1
March 2006	9.65
July 2006	40.2
November 2006	11.7
March 2007	10.9
July 2007	38.8
November 2007	11.2
April 2008	9.64
August 2008	36.4
December 2008	8.46
April 2009	12.8
August 2009	37.1
December 2009	6.90
May 2010	21.5
September 2010	31.1
January 2011	9.05
May 2011	22.7
September 2011	29.9
January 2012	7.33
May 2012	28.1
October 2012	18.0
February 2013	9.18
June 2013	42.4
October 2013	16.4
February 2014	8.20
June 2014	39.6
November 2014	8.98
March 2015	15.4
July 2015	38.0
November 2015	7.78
March 2016	12.5
July 2016	41.0
December 2016	9.78
April 2017	19.1
August 2017	36.3
December 2017	11.1
April 2018	16.2
August 2018	34.5
January 2019	7.38
May 2019	31.6
September 2019	31.2
January 2020	7.31
May 2020	28.4
September 2020	30.6
January 2021	6.81
June 2021	43.0
October 2021	10.9
February 2022	7.49
June 2022	38.7
October 2022	11.6
February 2023	7.42
July 2023	39.7
November 2023	9.28
March 2024	9.99
July 2024	39.8
November 2024	7.29
March 2025	8.32
August 2025	35.8
December 2025	13.4
April 2026	20.5
August 2026	36.6

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	30.7
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

991 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 991 periods, evenly spaced across the record. Every value is in the download and the API; a table of all 991 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	0.666
1952.4166666666667	1.83
1952.75	0.818
1953.0833333333333	0.742
1953.4166666666667	1.73
1953.75	1.72
1954.0833333333333	0.585
1954.4166666666667	1.64
1954.8333333333333	1.73
1955.1666666666667	0.518
1955.5	2.08
1955.8333333333333	0.664
1956.1666666666667	0.647
1956.5	2.10
1956.8333333333333	0.564
1957.25	0.695
1957.5833333333333	1.91
1957.9166666666667	0.551
1958.25	0.720
1958.5833333333333	1.92
1958.9166666666667	0.594
1959.25	0.768
1959.6666666666667	1.96
1960	0.565
1960.3333333333333	1.31
1960.6666666666667	1.22
1961	0.803
1961.3333333333333	1.78
1961.6666666666667	0.833
1962.0833333333333	1.13
1962.4166666666667	1.92
1962.75	1.32
1963.0833333333333	1.57
1963.4166666666667	1.76
1963.75	1.02
1964.0833333333333	0.831
1964.5	1.95
1964.8333333333333	0.558
1965.1666666666667	0.744
1965.5	1.99
1965.8333333333333	0.788
1966.1666666666667	0.567
1966.5	2.03
1966.9166666666667	0.815
1967.25	0.972
1967.5833333333333	1.61
1967.9166666666667	0.739
1968.25	0.927
1968.5833333333333	1.70
1968.9166666666667	0.639
1969.3333333333333	1.65
1969.6666666666667	1.02
1970	0.568
1970.3333333333333	1.29
1970.6666666666667	1.14
1971	0.636
1971.3333333333333	1.43
1971.75	0.482
1972.0833333333333	0.479
1972.4166666666667	1.72
1972.75	0.895
1973.0833333333333	0.665
1973.4166666666667	1.96
1973.75	0.677
1974.1666666666667	0.733
1974.5	1.77
1974.8333333333333	0.483
1975.1666666666667	0.543
1975.5	2.04
1975.8333333333333	0.736
1976.1666666666667	0.581
1976.5833333333333	1.61
1976.9166666666667	0.448
1977.25	0.869
1977.5833333333333	1.03
1977.9166666666667	0.933
1978.25	0.901
1978.5833333333333	1.68
1979	0.501
1979.3333333333333	1.23
1979.6666666666667	0.789
1980	0.548
1980.3333333333333	1.46
1980.6666666666667	1.13
1981	0.674
1981.4166666666667	2.05
1981.75	0.572
1982.0833333333333	0.631
1982.4166666666667	1.69
1982.75	0.636
1983.0833333333333	0.542
1983.4166666666667	1.81
1983.8333333333333	0.680
1984.1666666666667	0.551
1984.5	1.93
1984.8333333333333	0.433
1985.1666666666667	0.380
1985.5	1.91
1985.8333333333333	0.651
1986.1666666666667	0.728
1986.5833333333333	1.88
1986.9166666666667	0.375
1987.25	0.731
1987.5833333333333	1.67
1987.9166666666667	0.315
1988.25	0.672
1988.5833333333333	1.70
1989	0.362
1989.4166666666667	1.80
1989.75	0.657
1990.0833333333333	0.391
1990.4166666666667	1.98
1990.75	0.658
1991.0833333333333	0.476
1991.5	2.08
1991.8333333333333	7.00
1992.3333333333333	1.54
1992.6666666666667	1.34
1993	0.379
1993.3333333333333	1.40
1993.6666666666667	1.55
1994.0833333333333	0.758
1994.4166666666667	2.08
1994.75	0.696
1995.0833333333333	0.536
1995.4166666666667	1.59
1995.75	0.857
1996.0833333333333	0.563
1996.5	2.07
1996.8333333333333	0.610
1997.1666666666667	0.570
1997.5	2.09
1997.8333333333333	0.543
1998.1666666666667	0.537
1998.5	2.08
1998.9166666666667	0.446
1999.25	0.558
1999.5833333333333	1.79
1999.9166666666667	0.459
2000.25	0.887
2000.5833333333333	1.65
2000.9166666666667	0.342
2001.3333333333333	1.68
2001.6666666666667	1.09
2002	0.452
2002.3333333333333	1.24
2002.6666666666667	1.41
2003	0.410
2003.3333333333333	1.30
2003.75	0.702
2004.0833333333333	0.377
2004.4166666666667	2.09
2004.75	0.671
2005.0833333333333	0.385
2005.4166666666667	2.07
2005.75	0.649
2006.1666666666667	0.477
2006.5	1.99
2006.8333333333333	0.580
2007.1666666666667	0.540
2007.5	1.92
2007.8333333333333	0.555
2008.1666666666667	0.426
2008.5833333333333	1.80
2008.9166666666667	0.418
2009.3333333333333	1.36
2009.6666666666667	1.59
2010	0.354
2010.3333333333333	1.06
2010.6666666666667	1.54
2011.0833333333333	0.422
2011.4166666666667	1.67
2011.75	0.625
2012.0833333333333	0.359
2012.4166666666667	1.91
2012.75	0.892
2013.0833333333333	0.454
2013.5	1.95
2013.8333333333333	0.446
2014.1666666666667	0.603
2014.5	2.00
2014.8333333333333	0.444
2015.1666666666667	0.761
2015.5	1.88
2015.9166666666667	0.439
2016.25	1.08
2016.5833333333333	1.79
2016.9166666666667	0.483
2017.25	0.942
2017.5833333333333	1.79
2017.9166666666667	0.549
2018.3333333333333	1.68
2018.6666666666667	1.44
2019	0.365
2019.3333333333333	1.56
2019.6666666666667	1.54
2020	0.361
2020.3333333333333	1.41
2020.75	0.669
2021.0833333333333	0.351
2021.4166666666667	2.13
2021.75	0.541
2022.0833333333333	0.370
2022.4166666666667	1.91
2022.75	0.574
2023.1666666666667	0.414
2023.5	1.96
2023.8333333333333	0.459
2024.1666666666667	0.493
2024.5	1.97
2024.8333333333333	0.360
2025.1666666666667	0.411
2025.5833333333333	1.77
2025.9166666666667	0.661
2026.25	1.02
2026.5833333333333	1.81

Rate and persistence

+0.07 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	98.7% 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	2026-09-01
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 2026-09-02, 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

995 monthly observations 1943–2026 Mm³

Spatially aggregatedHigh confidenceAugust 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 September 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.