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

456.20 Mm³
Stored, September 2026
29th
Percentile among 77 Seps on record
-8.0%
Against the Sep 1991–2020 average
-1.9%
Change over the 12 months to 2026-09

Storage in September 2026 was lower than most Seps on record, ranked against 77 other Seps held for this reservoir.

Storage, 1948–2026

Monthly mean storage
926 monthly values, 1948 to 2026
Monthly mean storageMonthly mean storage: Lake Cascade in Mm³, from 1948 to 2026.6666666666667.02505007501,000Mm³19481959.251968.91666666666671978.58333333333331988.251997.91666666666672007.58333333333332017.25Year

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 926 periods, evenly spaced across the record. Every value is in the download and the API; a table of all 926 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
October 1955143
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
August 1960577
November 1960366
March 1961300
July 1961684
November 1961300
March 1962191
July 1962753
November 1962591
March 1963725
June 1963813
October 1963465
February 1964392
June 1964753
October 1964483
February 1965465
June 1965744
October 1965604
January 1966632
May 1966676
September 1966367
January 1967137
May 1967295
September 1967549
January 1968392
April 1968454
August 1968596
December 1968428
April 1969305
August 1969669
December 1969329
April 1970374
August 1970700
November 1970507
March 1971418
July 1971805
November 1971557
March 1972325
July 1972772
November 1972452
March 1973445
June 1973678
October 1973265
February 1974490
June 1974691
October 1974564
February 1975440
June 1975540
September 1975612
January 1976593
May 1976549
September 1976626
January 1977472
May 1977420
September 1977214
January 1978326
April 1978459
August 1978744
December 1978540
April 1979449
August 1979514
December 1979264
April 1980420
August 1980718
November 1980491
March 1981659
July 1981766
November 1981457
March 1982495
July 1982793
November 1982605
March 1983507
June 1983743
October 1983592
February 1984499
June 1984728
October 1984468
February 1985484
June 1985780
September 1985487
January 1986504
May 1986579
September 1986535
January 1987510
May 1987688
September 1987436
January 1988382
April 1988442
August 1988550
December 1988421
April 1989540
August 1989620
December 1989497
April 1990604
August 1990709
November 1990559
March 1991513
July 1991749
November 1991485
March 1992478
July 1992587
November 1992399
February 1993339
June 1993798
October 1993498
February 1994505
June 1994696
October 1994347
February 1995432
June 1995784
September 1995728
January 1996683
May 1996649
September 1996632
January 1997676
May 1997543
September 1997634
January 1998622
April 1998642
August 1998681
December 1998616
April 1999394
August 1999685
December 1999540
April 2000596
August 2000599
November 2000441
March 2001459
July 2001495
November 2001321
March 2002372
July 2002734
November 2002445
February 2003506
June 2003790
October 2003432
February 2004459
June 2004793
October 2004490
February 2005525
June 2005786
September 2005477
January 2006529
May 2006548
September 2006489
January 2007545
May 2007744
September 2007437
January 2008518
April 2008493
August 2008594
December 2008500
April 2009568
August 2009578
December 2009471
April 2010534
July 2010698
November 2010459
March 2011534
July 2011764
November 2011534
March 2012579
July 2012722
November 2012465
February 2013592
June 2013776
October 2013433
February 2014493
June 2014769
October 2014441
February 2015556
June 2015743
September 2015383
January 2016426
May 2016742
September 2016431
January 2017483
May 2017573
September 2017529
January 2018615
April 2018603
August 2018573
December 2018466
April 2019531
August 2019576
December 2019474
April 2020546
July 2020703
November 2020467
March 2021509
July 2021627
November 2021422
March 2022480
July 2022696
November 2022457
February 2023484
June 2023750
October 2023470
February 2024544
June 2024767
October 2024454
February 2025520
June 2025768
September 2025465
January 2026591
May 2026769
September 2026456

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: 529 Mm³Most recent 12 months 9: 456 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
Aug591529
Sep496456
Oct472459
Nov484477
Dec499516

Why this page shows a volume and not a percentage

Water level

Monthly mean water surface elevation
562 monthly values
Monthly mean water surface elevationMonthly mean water surface elevation: Lake Cascade in m, from 1979.75 to 2026.6666666666667.1,4641,4661,4681,4701,472m1979.751985.751991.751997.66666666666672003.58333333333332009.52015.41666666666672021.3333333333333Year

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 562 periods, evenly spaced across the record. Every value is in the download and the API; a table of all 562 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
1982.33333333333331,468
1982.51,471
1982.66666666666671,470
1982.91666666666671,469
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
19871,469
1987.16666666666671,469
1987.33333333333331,470
1987.58333333333331,469
1987.751,467
1987.91666666666671,467
1988.16666666666671,467
1988.33333333333331,469
1988.51,470
1988.751,467
1988.91666666666671,467
1989.08333333333331,468
1989.33333333333331,470
1989.51,471
1989.66666666666671,469
1989.91666666666671,468
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
1992.08333333333331,468
1992.251,469
1992.41666666666671,470
1992.66666666666671,467
1992.83333333333331,467
19931,467
1993.251,468
1993.41666666666671,472
1993.58333333333331,470
1993.83333333333331,468
19941,468
1994.16666666666671,469
1994.41666666666671,471
1994.58333333333331,468
1994.751,466
19951,467
1995.16666666666671,468
1995.33333333333331,470
1995.58333333333331,471
1995.751,471
1995.91666666666671,471
1996.16666666666671,469
1996.33333333333331,470
1996.58333333333331,471
1996.751,470
1996.91666666666671,470
1997.16666666666671,466
1997.33333333333331,469
1997.51,471
1997.751,470
1997.91666666666671,470
1998.08333333333331,470
1998.33333333333331,471
1998.51,471
1998.66666666666671,469
1998.91666666666671,470
1999.08333333333331,469
1999.251,467
1999.51,471
1999.66666666666671,470
1999.83333333333331,469
2000.08333333333331,469
2000.251,470
2000.41666666666671,472
2000.66666666666671,468
2000.83333333333331,468
2001.08333333333331,468
2001.251,468
2001.41666666666671,469
2001.66666666666671,466
2001.83333333333331,466
20021,466
2002.251,468
2002.41666666666671,471
2002.58333333333331,470
2002.83333333333331,468
20031,468
2003.16666666666671,469
2003.41666666666671,472
2003.58333333333331,469
2003.751,468
20041,468
2004.16666666666671,468
2004.33333333333331,471
2004.58333333333331,469
2004.751,468
2004.91666666666671,469
2005.16666666666671,469
2005.33333333333331,471
2005.51,471
2005.751,468
2005.91666666666671,468
2006.16666666666671,469
2006.33333333333331,469
2006.51,471
2006.751,468
2006.91666666666671,469
2007.08333333333331,469
2007.33333333333331,471
2007.51,470
2007.66666666666671,468
2007.91666666666671,468
2008.08333333333331,469
2008.251,468
2008.51,471
2008.66666666666671,468
2008.83333333333331,468
2009.08333333333331,469
2009.251,469
2009.41666666666671,471
2009.66666666666671,468
2009.83333333333331,468
20101,468
2010.251,469
2010.41666666666671,471
2010.66666666666671,468
2010.83333333333331,468
20111,468
2011.251,469
2011.41666666666671,470
2011.58333333333331,470
2011.83333333333331,469
20121,469
2012.16666666666671,469
2012.41666666666671,471
2012.58333333333331,469
2012.751,468
20131,469
2013.16666666666671,470
2013.33333333333331,471
2013.58333333333331,469
2013.751,468
2013.91666666666671,468
2014.16666666666671,469
2014.33333333333331,470
2014.51,470
2014.751,468
2014.91666666666671,468
2015.16666666666671,470
2015.33333333333331,471
2015.51,470
2015.751,467
2015.91666666666671,467
2016.08333333333331,468
2016.33333333333331,471
2016.51,470
2016.66666666666671,468
2016.91666666666671,468
2017.08333333333331,469
2017.251,469
2017.51,471
2017.66666666666671,469
2017.83333333333331,469
2018.08333333333331,470
2018.251,470
2018.41666666666671,471
2018.66666666666671,468
2018.83333333333331,468
20191,468
2019.251,469
2019.41666666666671,471
2019.58333333333331,469
2019.83333333333331,468
20201,468
2020.251,469
2020.41666666666671,471
2020.58333333333331,469
2020.83333333333331,468
20211,468
2021.16666666666671,469
2021.41666666666671,471
2021.58333333333331,468
2021.751,467
20221,468
2022.16666666666671,468
2022.33333333333331,470
2022.58333333333331,469
2022.751,468
2022.91666666666671,468
2023.16666666666671,468
2023.33333333333331,470
2023.51,471
2023.751,468
2023.91666666666671,468
2024.08333333333331,469
2024.33333333333331,471
2024.51,470
2024.751,468
2024.91666666666671,468
2025.08333333333331,469
2025.33333333333331,470
2025.51,470
2025.66666666666671,468
2025.91666666666671,469
2026.08333333333331,470
2026.251,471
2026.51,470
2026.66666666666671,468

Rate and persistence

-0.73 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 — 456.20 Mm³Lake Cascade — 456.20 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
Completeness97.7% 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.
Continuity98% of the months between 1948 and 2026 are held. Monthly means of the publisher's own daily record.
Last read from the publisher2026-10-01
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 2026-10-05, 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

926 monthly observations 1948–2026 Mm³
Spatially aggregatedHigh confidenceSeptember 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 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.

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