Lucky Peak Lake — storage

Storage now, against this reservoir's own record

286.04 Mm³

Stored, August 2026

31st

Percentile among 72 Augs on record

+0.9%

Against the Aug 1991–2020 average

-6.8%

Change over the 12 months to 2026-08

Storage in August 2026 was around the middle of the Aug record, ranked against 72 other Augs held for this reservoir.

Storage, 1955–2026

Monthly mean storage

856 monthly values, 1955 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 856 periods, evenly spaced across the record. Every value is in the download and the API; a table of all 856 would be longer than this page and unusable with a screen reader.
Period	Lucky Peak Lake (Mm³)
May 1955	79.9
September 1955	72.1
December 1955	28.1
April 1956	59.8
July 1956	328
November 1956	91.1
February 1957	296
June 1957	313
October 1957	36.6
January 1958	81.4
May 1958	208
August 1958	324
December 1958	116
April 1959	245
July 1959	319
November 1959	149
February 1960	237
June 1960	328
September 1960	121
January 1961	65.3
May 1961	281
August 1961	110
December 1961	13.8
March 1962	47.3
July 1962	326
October 1962	30.6
February 1963	144
June 1963	335
September 1963	168
January 1964	53.2
April 1964	227
August 1964	326
November 1964	67.5
March 1965	21.3
July 1965	327
October 1965	91.9
February 1966	251
May 1966	319
September 1966	86.7
January 1967	58.6
April 1967	47.5
August 1967	304
November 1967	35.6
March 1968	145
June 1968	328
October 1968	11.8
February 1969	61.7
May 1969	168
September 1969	206
December 1969	69.8
April 1970	148
July 1970	329
November 1970	123
March 1971	48.9
June 1971	297
October 1971	81.8
January 1972	143
May 1972	54.8
August 1972	326
December 1972	78.7
April 1973	297
July 1973	327
November 1973	56.8
February 1974	115
June 1974	248
October 1974	71.3
January 1975	60.6
May 1975	107
August 1975	327
December 1975	49.1
March 1976	96.5
July 1976	328
November 1976	89.6
February 1977	81.2
June 1977	259
September 1977	18.0
January 1978	52.7
April 1978	162
August 1978	326
December 1978	87.2
March 1979	154
July 1979	327
October 1979	33.6
February 1980	44.9
June 1980	311
September 1980	230
January 1981	276
April 1981	305
August 1981	294
November 1981	16.3
March 1982	137
July 1982	328
October 1982	97.6
February 1983	219
May 1983	229
September 1983	249
December 1983	125
April 1984	253
August 1984	327
November 1984	31.8
March 1985	41.7
June 1985	326
October 1985	47.1
January 1986	18.0
May 1986	223
September 1986	67.0
December 1986	40.4
April 1987	289
July 1987	293
November 1987	60.9
March 1988	108
June 1988	322
October 1988	16.2
January 1989	35.0
May 1989	285
August 1989	261
December 1989	65.3
April 1990	195
July 1990	325
November 1990	61.0
February 1991	44.2
June 1991	323
September 1991	27.4
January 1992	49.1
May 1992	293
August 1992	19.2
December 1992	26.0
March 1993	99.0
July 1993	325
October 1993	112
February 1994	78.8
June 1994	323
September 1994	26.2
January 1995	49.6
April 1995	245
August 1995	325
December 1995	142
March 1996	116
July 1996	325
October 1996	124
February 1997	161
May 1997	131
September 1997	250
January 1998	109
April 1998	229
August 1998	325
November 1998	95.5
March 1999	133
June 1999	307
October 1999	73.0
February 2000	96.7
May 2000	298
September 2000	190
December 2000	90.3
April 2001	195
July 2001	325
November 2001	77.6
March 2002	118
June 2002	324
October 2002	10.0
January 2003	102
May 2003	280
September 2003	162
December 2003	136
April 2004	233
July 2004	325
November 2004	16.3
February 2005	77.3
June 2005	325
October 2005	43.8
January 2006	66.8
May 2006	191
August 2006	325
December 2006	64.8
March 2007	204
July 2007	321
November 2007	71.0
February 2008	79.8
June 2008	323
September 2008	236
January 2009	73.9
May 2009	286
August 2009	325
December 2009	69.1
March 2010	116
July 2010	324
October 2010	52.5
February 2011	106
June 2011	289
September 2011	248
January 2012	75.9
April 2012	214
August 2012	325
November 2012	49.2
March 2013	143
July 2013	315
October 2013	123
February 2014	100
May 2014	282
September 2014	197
December 2014	89.5
April 2015	300
August 2015	300
November 2015	54.2
March 2016	190
June 2016	320
October 2016	44.8
February 2017	96.5
May 2017	205
September 2017	238
December 2017	79.8
April 2018	258
July 2018	326
November 2018	52.7
March 2019	157
June 2019	325
October 2019	104
January 2020	73.6
May 2020	293
August 2020	311
December 2020	61.3
April 2021	223
July 2021	311
November 2021	61.8
February 2022	75.9
June 2022	307
September 2022	98.3
January 2023	73.6
May 2023	221
August 2023	311
December 2023	57.0
March 2024	179
July 2024	317
November 2024	53.1
February 2025	78.6
June 2025	325
September 2025	147
January 2026	78.9
April 2026	314
August 2026	286

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	84.1	78.9
Feb	100.0	133
Mar	146	214
Apr	211	314
May	269	323
Jun	312	324
Jul	314	325
Aug	283	286
Sep	179	147
Oct	71.8	56.2
Nov	69.4	56.9
Dec	77.0	61.5

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

596 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 596 periods, evenly spaced across the record. Every value is in the download and the API; a table of all 596 would be longer than this page and unusable with a screen reader.
Period	Lucky Peak Lake (m)
1976.75	909
1976.9166666666667	902
1977.1666666666667	918
1977.3333333333333	928
1977.5833333333333	901
1977.75	890
1978	898
1978.1666666666667	905
1978.4166666666667	929
1978.5833333333333	931
1978.8333333333333	904
1979	903
1979.25	922
1979.4166666666667	931
1979.6666666666667	908
1979.8333333333333	894
1980.0833333333333	896
1980.25	914
1980.5	931
1980.6666666666667	921
1980.9166666666667	926
1981.0833333333333	927
1981.3333333333333	931
1981.5	931
1981.75	891
1981.9166666666667	891
1982.1666666666667	911
1982.3333333333333	894
1982.5833333333333	931
1982.75	905
1983	924
1983.1666666666667	924
1983.4166666666667	927
1983.5833333333333	931
1983.8333333333333	902
1984	922
1984.25	924
1984.4166666666667	925
1984.6666666666667	917
1984.8333333333333	894
1985.0833333333333	893
1985.25	922
1985.5	931
1985.6666666666667	916
1985.9166666666667	891
1986.0833333333333	893
1986.3333333333333	921
1986.5	931
1986.6666666666667	900
1986.9166666666667	895
1987.0833333333333	891
1987.3333333333333	931
1987.5	928
1987.75	900
1987.9166666666667	898
1988.1666666666667	907
1988.3333333333333	930
1988.5833333333333	911
1988.75	890
1989	894
1989.1666666666667	903
1989.4166666666667	931
1989.5833333333333	925
1989.8333333333333	897
1990	903
1990.25	918
1990.4166666666667	931
1990.6666666666667	913
1990.8333333333333	899
1991.0833333333333	896
1991.25	915
1991.5	927
1991.6666666666667	892
1991.9166666666667	892
1992.0833333333333	901
1992.3333333333333	928
1992.5	910
1992.75	890
1992.9166666666667	892
1993.1666666666667	905
1993.3333333333333	928
1993.5833333333333	931
1993.75	907
1994	904
1994.1666666666667	908
1994.4166666666667	931
1994.5833333333333	907
1994.8333333333333	895
1995	897
1995.25	923
1995.4166666666667	928
1995.6666666666667	927
1995.8333333333333	911
1996.0833333333333	907
1996.25	910
1996.5	931
1996.6666666666667	922
1996.8333333333333	906
1997.0833333333333	914
1997.25	905
1997.5	931
1997.6666666666667	924
1997.9166666666667	906
1998.0833333333333	912
1998.3333333333333	928
1998.5	931
1998.75	905
1998.9166666666667	906
1999.1666666666667	910
1999.3333333333333	919
1999.5833333333333	931
1999.75	901
2000	905
2000.1666666666667	917
2000.4166666666667	931
2000.5833333333333	930
2000.8333333333333	903
2001	905
2001.25	918
2001.4166666666667	931
2001.6666666666667	904
2001.8333333333333	902
2002.0833333333333	906
2002.25	922
2002.5	931
2002.6666666666667	906
2002.9166666666667	905
2003.0833333333333	906
2003.3333333333333	927
2003.5	931
2003.75	900
2003.9166666666667	911
2004.1666666666667	919
2004.3333333333333	927
2004.5833333333333	928
2004.75	887
2005	901
2005.1666666666667	906
2005.4166666666667	931
2005.5833333333333	928
2005.8333333333333	898
2006	900
2006.25	909
2006.4166666666667	931
2006.5833333333333	931
2006.8333333333333	898
2007	902
2007.25	928
2007.4166666666667	931
2007.6666666666667	911
2007.8333333333333	901
2008.0833333333333	902
2008.25	921
2008.5	931
2008.6666666666667	922
2008.9166666666667	903
2009.0833333333333	902
2009.3333333333333	927
2009.5	931
2009.75	906
2009.9166666666667	901
2010.1666666666667	908
2010.3333333333333	923
2010.5833333333333	931
2010.75	898
2011	901
2011.1666666666667	916
2011.4166666666667	928
2011.5833333333333	931
2011.8333333333333	900
2012	902
2012.25	920
2012.4166666666667	931
2012.6666666666667	922
2012.8333333333333	897
2013.0833333333333	904
2013.25	920
2013.5	930
2013.6666666666667	911
2013.9166666666667	905
2014.0833333333333	905
2014.3333333333333	927
2014.5	931
2014.75	903
2014.9166666666667	904
2015.1666666666667	926
2015.3333333333333	929
2015.5833333333333	929
2015.75	897
2016	901
2016.1666666666667	917
2016.4166666666667	931
2016.5833333333333	929
2016.75	896
2017	900
2017.1666666666667	909
2017.4166666666667	928
2017.5833333333333	931
2017.8333333333333	899
2018	910
2018.25	925
2018.4166666666667	931
2018.6666666666667	914
2018.8333333333333	898
2019.0833333333333	902
2019.25	921
2019.5	931
2019.6666666666667	920
2019.9166666666667	902
2020.0833333333333	903
2020.3333333333333	928
2020.5	931
2020.75	899
2020.9166666666667	899
2021.25	921
2021.4166666666667	930
2021.6666666666667	898
2021.8333333333333	899
2022.0833333333333	902
2022.25	917
2022.5	931
2022.6666666666667	905
2023.0833333333333	901
2023.25	913
2023.5	931
2023.6666666666667	910
2023.9166666666667	899
2024.0833333333333	904
2024.3333333333333	930
2024.5	930
2024.75	893
2024.9166666666667	900
2025.1666666666667	913
2025.3333333333333	928
2025.5833333333333	929
2025.75	898
2026	902
2026.1666666666667	920
2026.4166666666667	931
2026.5833333333333	927

Rate and persistence

-1.73 Mm³

Mean drawdown per month over 12 months

2 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

Lucky Peak 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	1955–2026
Completeness	99.1% 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 1955 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-7189.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), Lucky Peak Lake reservoir records, accessed 2026-09-02, hydrionis.com/reservoirs/reservoir-usbr-7189/

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 Lucky Peak 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

856 monthly observations 1955–2026 Mm³

Spatially aggregatedHigh confidenceAugust 2026

Source: USBR — Reservoir operations and Colorado River data, RISE catalogue item 131596. 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.