Lucky Peak Lake — storage

Storage now, against this reservoir's own record

107.95 Mm³

Stored, September 2026

21st

Percentile among 72 Seps on record

-39.5%

Against the Sep 1991–2020 average

-26.5%

Change over the 12 months to 2026-09

Storage in September 2026 was lower than most Seps on record, ranked against 72 other Seps held for this reservoir.

Storage, 1955–2026

Monthly mean storage

857 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 857 periods, evenly spaced across the record. Every value is in the download and the API; a table of all 857 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
November 1962	39.2
February 1963	144
June 1963	335
September 1963	168
January 1964	53.2
April 1964	227
August 1964	326
December 1964	81.0
March 1965	21.3
July 1965	327
October 1965	91.9
February 1966	251
June 1966	328
September 1966	86.7
January 1967	58.6
April 1967	47.5
August 1967	304
November 1967	35.6
March 1968	145
July 1968	287
October 1968	11.8
February 1969	61.7
May 1969	168
September 1969	206
December 1969	69.8
April 1970	148
August 1970	327
November 1970	123
March 1971	48.9
June 1971	297
October 1971	81.8
February 1972	89.0
May 1972	54.8
September 1972	248
December 1972	78.7
April 1973	297
July 1973	327
November 1973	56.8
March 1974	94.4
June 1974	248
October 1974	71.3
January 1975	60.6
May 1975	107
September 1975	286
December 1975	49.1
April 1976	170
July 1976	328
November 1976	89.6
February 1977	81.2
June 1977	259
October 1977	17.3
January 1978	52.7
May 1978	202
August 1978	326
December 1978	87.2
April 1979	233
July 1979	327
November 1979	33.0
February 1980	44.9
June 1980	311
September 1980	230
January 1981	276
May 1981	322
August 1981	294
December 1981	18.9
March 1982	137
July 1982	328
November 1982	152
February 1983	219
June 1983	286
September 1983	249
January 1984	234
April 1984	253
August 1984	327
December 1984	32.1
March 1985	41.7
July 1985	327
October 1985	47.1
February 1986	33.1
May 1986	223
September 1986	67.0
January 1987	35.5
April 1987	289
August 1987	219
November 1987	60.9
March 1988	108
July 1988	267
October 1988	16.2
February 1989	46.3
May 1989	285
September 1989	129
December 1989	65.3
April 1990	195
August 1990	280
November 1990	61.0
March 1991	56.9
June 1991	323
October 1991	0.874
February 1992	73.9
May 1992	293
September 1992	10.3
December 1992	26.0
April 1993	247
July 1993	325
November 1993	94.2
March 1994	114
June 1994	323
October 1994	28.9
January 1995	49.6
May 1995	266
September 1995	283
December 1995	142
April 1996	128
July 1996	325
November 1996	103
February 1997	161
June 1997	248
October 1997	124
January 1998	109
May 1998	291
August 1998	325
December 1998	100
March 1999	133
July 1999	324
November 1999	78.1
February 2000	96.7
June 2000	326
September 2000	190
January 2001	95.0
May 2001	310
August 2001	223
December 2001	84.7
March 2002	118
July 2002	325
October 2002	10.0
February 2003	105
June 2003	323
September 2003	162
January 2004	167
April 2004	233
August 2004	292
December 2004	51.8
March 2005	105
July 2005	325
October 2005	43.8
February 2006	76.5
May 2006	191
September 2006	240
January 2007	76.3
April 2007	296
August 2007	239
November 2007	71.0
March 2008	136
July 2008	325
October 2008	119
February 2009	79.9
May 2009	286
September 2009	257
December 2009	69.1
April 2010	174
August 2010	321
November 2010	51.4
March 2011	183
June 2011	289
October 2011	80.2
February 2012	92.6
May 2012	264
September 2012	235
December 2012	72.4
April 2013	212
July 2013	315
November 2013	108
March 2014	204
June 2014	324
October 2014	81.7
January 2015	88.9
May 2015	307
August 2015	300
December 2015	64.3
April 2016	245
July 2016	325
November 2016	50.0
February 2017	96.5
June 2017	293
October 2017	74.1
January 2018	134
May 2018	311
August 2018	311
December 2018	55.2
March 2019	157
July 2019	325
November 2019	87.4
February 2020	83.1
June 2020	324
September 2020	173
January 2021	64.3
May 2021	290
August 2021	167
December 2021	66.2
March 2022	99.1
July 2022	324
October 2022	54.2
February 2023	72.9
June 2023	319
September 2023	134
January 2024	66.8
April 2024	276
August 2024	158
December 2024	63.1
March 2025	152
July 2025	325
October 2025	56.2
February 2026	133
May 2026	323
September 2026	108

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	283
Sep	179	108
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

597 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 597 periods, evenly spaced across the record. Every value is in the download and the API; a table of all 597 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
1986.75	897
1986.9166666666667	895
1987.1666666666667	913
1987.3333333333333	931
1987.5833333333333	921
1987.75	900
1988	898
1988.1666666666667	907
1988.4166666666667	931
1988.5833333333333	911
1988.8333333333333	891
1989	894
1989.25	920
1989.4166666666667	931
1989.6666666666667	909
1989.8333333333333	897
1990.0833333333333	905
1990.25	918
1990.5	931
1990.6666666666667	913
1990.9166666666667	898
1991.0833333333333	896
1991.3333333333333	929
1991.5	927
1991.75	886
1991.9166666666667	892
1992.1666666666667	909
1992.3333333333333	928
1992.5833333333333	891
1992.75	890
1993	893
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
1996.9166666666667	906
1997.0833333333333	914
1997.3333333333333	910
1997.5	931
1997.75	909
1997.9166666666667	906
1998.1666666666667	915
1998.3333333333333	928
1998.5833333333333	931
1998.75	905
1999	906
1999.1666666666667	910
1999.4166666666667	929
1999.5833333333333	931
1999.8333333333333	902
2000	905
2000.25	926
2000.4166666666667	931
2000.6666666666667	917
2000.8333333333333	903
2001.0833333333333	905
2001.25	918
2001.5	931
2001.6666666666667	904
2001.9166666666667	903
2002.0833333333333	906
2002.3333333333333	927
2002.5	931
2002.75	888
2002.9166666666667	905
2003.1666666666667	907
2003.3333333333333	927
2003.5833333333333	928
2003.75	900
2004	915
2004.1666666666667	919
2004.4166666666667	931
2004.5833333333333	928
2004.8333333333333	890
2005	901
2005.25	916
2005.4166666666667	931
2005.6666666666667	910
2005.8333333333333	898
2006.0833333333333	902
2006.25	909
2006.5	931
2006.6666666666667	923
2006.9166666666667	900
2007.0833333333333	905
2007.3333333333333	930
2007.5	931
2007.75	900
2007.9166666666667	901
2008.1666666666667	910
2008.3333333333333	928
2008.5833333333333	931
2008.75	908
2009	901
2009.1666666666667	910
2009.4166666666667	931
2009.5833333333333	931
2009.8333333333333	904
2010	899
2010.1666666666667	908
2010.4166666666667	931
2010.5833333333333	931
2010.8333333333333	897
2011	901
2011.25	923
2011.4166666666667	928
2011.6666666666667	923
2011.8333333333333	900
2012.0833333333333	904
2012.25	920
2012.5	931
2012.6666666666667	922
2012.9166666666667	901
2013.0833333333333	904
2013.3333333333333	927
2013.5	930
2013.75	909
2013.9166666666667	905
2014.1666666666667	919
2014.3333333333333	927
2014.5833333333333	930
2014.75	903
2015	904
2015.1666666666667	926
2015.4166666666667	931
2015.5833333333333	929
2015.8333333333333	898
2016	901
2016.25	923
2016.4166666666667	931
2016.6666666666667	914
2016.8333333333333	897
2017.0833333333333	905
2017.25	917
2017.5	931
2017.6666666666667	922
2017.9166666666667	902
2018.0833333333333	918
2018.3333333333333	930
2018.5	931
2018.75	898
2018.9166666666667	898
2019.1666666666667	913
2019.3333333333333	926
2019.5833333333333	930
2019.75	906
2020	900
2020.1666666666667	912
2020.4166666666667	931
2020.5833333333333	930
2020.8333333333333	899
2021.0833333333333	901
2021.3333333333333	928
2021.5	930
2021.75	898
2021.9166666666667	900
2022.1666666666667	905
2022.3333333333333	922
2022.5833333333333	927
2022.75	898
2023.1666666666667	906
2023.3333333333333	921
2023.5833333333333	930
2023.75	895
2024	900
2024.1666666666667	916
2024.4166666666667	931
2024.5833333333333	915
2024.8333333333333	898
2025	901
2025.25	921
2025.4166666666667	931
2025.6666666666667	912
2025.8333333333333	899
2026.0833333333333	910
2026.25	930
2026.5	931
2026.6666666666667	906

Rate and persistence

-3.25 Mm³

Mean drawdown per month over 12 months

1 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	99.2% 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	2026-10-01
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-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 2026-10-05, 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

857 monthly observations 1955–2026 Mm³

Spatially aggregatedHigh confidenceSeptember 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 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.