HydrionisGlobal Water Intelligence
Monitored reservoir

Lake Cascade

Lake Cascade is a federal reservoir operated by the United States Bureau of Reclamation in its Pacific Northwest region, with published operating records from 1979.

Storage recordLake Cascade and Cascade Dam (CSC)

Storage now, against this reservoir's own record

530.57 Mm³
Stored, August 2026
23rd
Percentile among 79 Augs on record
-10.2%
Against the Aug 1991–2020 average
-3.8%
Change over the 12 months to 2026-08

Storage in August 2026 was lower than most Augs on record, ranked against 79 other Augs held for this reservoir.

Storage, 1948–2026

Monthly mean storage
925 monthly values, 1948 to 2026
Monthly mean storageMonthly mean storage: Lake Cascade in Mm³, from 1948 to 2026.5833333333333.02505007501,000Mm³19481959.251968.91666666666671978.58333333333331988.251997.91666666666672007.58333333333332017.25Year

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 925 periods, evenly spaced across the record. Every value is in the download and the API; a table of all 925 would be longer than this page and unusable with a screen reader.
PeriodLake Cascade (Mm³)
January 19482.04
December 194811.4
July 1949249
August 1950222
November 195040.2
March 195129.6
July 1951105
November 195150.2
March 1952127
July 1952307
November 195241.8
March 1953108
June 1953424
October 1953154
February 195498.5
June 1954392
October 1954143
February 195581.6
June 1955367
September 1955220
January 1956290
May 1956316
September 1956414
January 1957379
May 1957648
September 1957508
January 1958349
April 1958368
August 1958634
December 1958490
April 1959511
August 1959676
December 1959558
April 1960623
July 1960739
November 1960366
March 1961300
July 1961684
November 1961300
March 1962191
July 1962753
November 1962591
February 1963686
June 1963813
October 1963465
February 1964392
June 1964753
October 1964483
February 1965465
May 1965481
September 1965687
January 1966632
May 1966676
September 1966367
January 1967137
May 1967295
September 1967549
December 1967417
April 1968454
August 1968596
December 1968428
April 1969305
August 1969669
December 1969329
March 1970385
July 1970795
November 1970507
March 1971418
July 1971805
November 1971557
March 1972325
June 1972702
October 1972458
February 1973445
June 1973678
October 1973265
February 1974490
June 1974691
October 1974564
January 1975467
May 1975335
September 1975612
January 1976593
May 1976549
September 1976626
January 1977472
April 1977453
August 1977279
December 1977277
April 1978459
August 1978744
December 1978540
April 1979449
August 1979514
November 1979241
March 1980364
July 1980792
November 1980491
March 1981659
July 1981766
November 1981457
February 1982533
June 1982678
October 1982591
February 1983463
June 1983743
October 1983592
February 1984499
June 1984728
September 1984553
January 1985490
May 1985677
September 1985487
January 1986504
May 1986579
September 1986535
December 1986506
April 1987589
August 1987550
December 1987378
April 1988442
August 1988550
December 1988421
April 1989540
July 1989744
November 1989492
March 1990536
July 1990777
November 1990559
March 1991513
July 1991749
October 1991483
February 1992446
June 1992633
October 1992393
February 1993339
June 1993798
October 1993498
February 1994505
May 1994642
September 1994371
January 1995389
May 1995638
September 1995728
January 1996683
May 1996649
August 1996708
December 1996672
April 1997336
August 1997695
December 1997625
April 1998642
August 1998681
December 1998616
March 1999488
July 1999774
November 1999563
March 2000576
July 2000720
November 2000441
March 2001459
June 2001566
October 2001311
February 2002360
June 2002775
October 2002447
February 2003506
June 2003790
October 2003432
January 2004449
May 2004703
September 2004500
January 2005518
May 2005723
September 2005477
January 2006529
April 2006448
August 2006589
December 2006518
April 2007647
August 2007536
December 2007489
April 2008493
July 2008727
November 2008487
March 2009541
July 2009705
November 2009471
March 2010492
July 2010698
November 2010459
February 2011509
June 2011671
October 2011528
February 2012560
June 2012782
October 2012440
February 2013592
May 2013748
September 2013425
January 2014479
May 2014686
September 2014462
January 2015515
May 2015751
September 2015383
December 2015404
April 2016609
August 2016541
December 2016460
April 2017566
August 2017624
December 2017600
March 2018608
July 2018687
November 2018461
March 2019497
July 2019682
November 2019469
March 2020503
July 2020703
October 2020462
February 2021498
June 2021728
October 2021408
February 2022463
June 2022758
October 2022451
January 2023478
May 2023596
September 2023490
January 2024520
May 2024706
September 2024472
January 2025503
May 2025636
August 2025552
December 2025516
April 2026751
August 2026531

The reservoir's year

Seasonal storage profile
Each calendar month's reference average, against the most recent year
Seasonal storage profileSeasonal storage profile: 1991–2020 average, Most recent 12 months in Mm³, from 1 to 12.0200400600800Mm³123456789101112Month1991–2020 average 1: 509 Mm³1991–2020 average 2: 514 Mm³1991–2020 average 3: 522 Mm³1991–2020 average 4: 551 Mm³1991–2020 average 5: 646 Mm³1991–2020 average 6: 758 Mm³1991–2020 average 7: 706 Mm³1991–2020 average 8: 591 Mm³1991–2020 average 9: 496 Mm³1991–2020 average 10: 472 Mm³1991–2020 average 11: 484 Mm³1991–2020 average 12: 499 Mm³Most recent 12 months 1: 591 Mm³Most recent 12 months 2: 623 Mm³Most recent 12 months 3: 658 Mm³Most recent 12 months 4: 751 Mm³Most recent 12 months 5: 769 Mm³Most recent 12 months 6: 728 Mm³Most recent 12 months 7: 627 Mm³Most recent 12 months 8: 531 Mm³Most recent 12 months 9: 465 Mm³Most recent 12 months 10: 459 Mm³Most recent 12 months 11: 477 Mm³Most recent 12 months 12: 516 Mm³
  • 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
Period1991–2020 average (Mm³)Most recent 12 months (Mm³)
Jan509591
Feb514623
Mar522658
Apr551751
May646769
Jun758728
Jul706627
Aug591531
Sep496465
Oct472459
Nov484477
Dec499516

Why this page shows a volume and not a percentage

Water level

Monthly mean water surface elevation
561 monthly values
Monthly mean water surface elevationMonthly mean water surface elevation: Lake Cascade in m, from 1979.75 to 2026.5833333333333.1,4641,4661,4681,4701,472m1979.751985.751991.751997.66666666666672003.58333333333332009.52015.41666666666672021.3333333333333Year

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 561 periods, evenly spaced across the record. Every value is in the download and the API; a table of all 561 would be longer than this page and unusable with a screen reader.
PeriodLake Cascade (m)
1979.751,465
1979.91666666666671,465
1980.16666666666671,467
1980.33333333333331,470
1980.51,471
1980.751,469
1980.91666666666671,469
1981.08333333333331,470
1981.33333333333331,472
1981.51,471
1981.66666666666671,468
1981.91666666666671,469
1982.08333333333331,469
1982.251,467
1982.51,471
1982.66666666666671,470
1982.83333333333331,470
1983.08333333333331,468
1983.251,468
1983.51,471
1983.66666666666671,470
1983.83333333333331,469
1984.08333333333331,468
1984.251,469
1984.41666666666671,471
1984.751,468
1984.91666666666671,468
1985.08333333333331,468
1985.33333333333331,470
1985.51,471
1985.66666666666671,468
1985.91666666666671,468
1986.08333333333331,469
1986.33333333333331,469
1986.58333333333331,470
1986.751,468
1986.91666666666671,468
1987.16666666666671,469
1987.33333333333331,470
1987.51,470
1987.751,467
1987.91666666666671,467
1988.08333333333331,467
1988.33333333333331,469
1988.51,470
1988.66666666666671,468
1988.91666666666671,467
1989.08333333333331,468
1989.251,469
1989.51,471
1989.66666666666671,469
1989.83333333333331,468
1990.08333333333331,469
1990.251,470
1990.51,471
1990.66666666666671,470
1990.83333333333331,469
1991.08333333333331,468
1991.251,469
1991.41666666666671,471
1991.66666666666671,469
1991.83333333333331,468
19921,468
1992.251,469
1992.41666666666671,470
1992.58333333333331,468
1992.83333333333331,467
19931,467
1993.16666666666671,466
1993.41666666666671,472
1993.58333333333331,470
1993.751,468
19941,468
1994.16666666666671,469
1994.33333333333331,470
1994.58333333333331,468
1994.751,466
1994.91666666666671,467
1995.16666666666671,468
1995.33333333333331,470
1995.51,472
1995.751,471
1995.91666666666671,471
1996.08333333333331,470
1996.33333333333331,470
1996.51,471
1996.751,470
1996.91666666666671,470
1997.08333333333331,469
1997.33333333333331,469
1997.51,471
1997.66666666666671,470
1997.91666666666671,470
1998.08333333333331,470
1998.251,470
1998.51,471
1998.66666666666671,469
1998.83333333333331,469
1999.08333333333331,469
1999.251,467
1999.41666666666671,471
1999.66666666666671,470
1999.83333333333331,469
20001,469
2000.251,470
2000.41666666666671,472
2000.58333333333331,470
2000.83333333333331,468
20011,468
2001.16666666666671,468
2001.41666666666671,469
2001.58333333333331,467
2001.751,466
20021,466
2002.16666666666671,467
2002.33333333333331,469
2002.58333333333331,470
2002.751,468
2002.91666666666671,468
2003.16666666666671,469
2003.33333333333331,470
2003.58333333333331,469
2003.751,468
2003.91666666666671,468
2004.16666666666671,468
2004.33333333333331,471
2004.51,471
2004.751,468
2004.91666666666671,469
2005.08333333333331,469
2005.33333333333331,471
2005.51,471
2005.66666666666671,468
2005.91666666666671,468
2006.08333333333331,469
2006.251,468
2006.51,471
2006.66666666666671,468
2006.83333333333331,468
2007.08333333333331,469
2007.251,470
2007.41666666666671,471
2007.66666666666671,468
2007.83333333333331,468
20081,469
2008.251,468
2008.41666666666671,471
2008.58333333333331,469
2008.83333333333331,468
20091,469
2009.16666666666671,469
2009.41666666666671,471
2009.58333333333331,469
2009.751,468
20101,468
2010.16666666666671,468
2010.41666666666671,471
2010.58333333333331,469
2010.751,468
20111,468
2011.16666666666671,469
2011.33333333333331,469
2011.58333333333331,470
2011.751,469
2011.91666666666671,469
2012.16666666666671,469
2012.33333333333331,471
2012.51,471
2012.751,468
2012.91666666666671,469
2013.08333333333331,469
2013.33333333333331,471
2013.51,470
2013.66666666666671,468
2013.91666666666671,468
2014.08333333333331,468
2014.251,470
2014.51,470
2014.66666666666671,468
2014.83333333333331,468
2015.08333333333331,469
2015.251,470
2015.41666666666671,471
2015.66666666666671,467
2015.83333333333331,467
20161,468
2016.251,470
2016.41666666666671,471
2016.66666666666671,468
2016.83333333333331,468
20171,468
2017.251,469
2017.41666666666671,471
2017.58333333333331,470
2017.83333333333331,469
20181,470
2018.16666666666671,470
2018.41666666666671,471
2018.58333333333331,469
2018.751,468
20191,468
2019.16666666666671,468
2019.33333333333331,470
2019.58333333333331,469
2019.751,468
2019.91666666666671,468
2020.16666666666671,468
2020.33333333333331,470
2020.51,471
2020.751,468
2020.91666666666671,468
2021.08333333333331,468
2021.33333333333331,470
2021.51,470
2021.66666666666671,467
2021.91666666666671,468
2022.08333333333331,468
2022.251,469
2022.51,471
2022.66666666666671,468
2022.83333333333331,468
2023.08333333333331,468
2023.251,468
2023.51,471
2023.66666666666671,468
2023.83333333333331,468
2024.08333333333331,469
2024.251,470
2024.41666666666671,471
2024.66666666666671,468
2024.83333333333331,468
20251,468
2025.251,468
2025.41666666666671,471
2025.58333333333331,469
2025.83333333333331,468
20261,469
2026.16666666666671,470
2026.41666666666671,471
2026.58333333333331,469

Rate and persistence

-1.77 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

Lake Cascade
Gauge location
Lake CascadeLake Cascade — 530.57 Mm³Lake Cascade — 530.57 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 Bureau of Reclamation — Reservoir operations and Colorado River data · US Government work — public domain
How the values came to existMeasured
Period held1948–2026
Completeness97.6% 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.
Continuity98% of the months between 1948 and 2026 are held. Monthly means of the publisher's own daily record.
Last read from the publisher2026-09-01
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), Lake Cascade reservoir records, accessed 2026-09-02, hydrionis.com/reservoirs/reservoir-usbr-3645/

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 Lake Cascade 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

925 monthly observations 1948–2026 Mm³
Spatially aggregatedHigh confidenceAugust 2026

Source: USBR — Reservoir operations and Colorado River data, RISE catalogue item 129978. 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.

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