Bucks Lk — storage

Storage now, against this reservoir's own record

98.40 Mm³

Stored, September 2025

68th

Percentile among 97 Seps on record

+2.1%

Against the Sep 1991–2020 average

-6.1%

Change over the 12 months to 2025-09

Storage in September 2025 was around the middle of the Sep record, ranked against 97 other Seps held for this reservoir.

Storage, 1928–2025

Monthly mean storage

1,164 monthly values, 1928 to 2025

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 1,164 periods, evenly spaced across the record. Every value is in the download and the API; a table of all 1,164 would be longer than this page and unusable with a screen reader.
Period	Bucks Lk Nr Bucks Lodge CA (Mm³)
October 1928	53.7
March 1929	18.1
August 1929	35.8
January 1930	40.5
May 1930	89.6
October 1930	51.4
March 1931	23.0
August 1931	38.4
January 1932	37.3
June 1932	97.3
November 1932	103
April 1933	81.7
August 1933	103
January 1934	100
June 1934	121
November 1934	79.4
April 1935	93.9
September 1935	115
February 1936	91.5
June 1936	127
November 1936	76.3
April 1937	91.6
September 1937	113
February 1938	108
July 1938	128
December 1938	98.0
May 1939	99.7
September 1939	93.8
February 1940	101
July 1940	120
December 1940	87.5
May 1941	119
October 1941	108
March 1942	106
July 1942	126
December 1942	111
May 1943	125
October 1943	114
March 1944	94.0
August 1944	110
January 1945	101
June 1945	127
October 1945	91.2
March 1946	92.9
August 1946	113
January 1947	88.9
June 1947	125
November 1947	87.9
April 1948	79.3
August 1948	115
January 1949	90.7
June 1949	107
November 1949	93.2
April 1950	82.1
September 1950	103
February 1951	110
July 1951	113
November 1951	83.5
April 1952	69.0
September 1952	93.4
February 1953	78.4
July 1953	126
December 1953	63.7
May 1954	120
September 1954	80.4
February 1955	41.6
July 1955	73.0
December 1955	48.5
May 1956	94.2
October 1956	63.4
March 1957	63.7
July 1957	107
December 1957	48.3
May 1958	92.9
October 1958	65.7
March 1959	64.8
August 1959	80.1
January 1960	45.5
June 1960	105
October 1960	55.8
March 1961	58.5
August 1961	64.0
January 1962	58.4
June 1962	122
November 1962	96.8
April 1963	115
August 1963	90.8
January 1964	48.2
June 1964	86.2
November 1964	44.9
April 1965	85.8
September 1965	68.4
February 1966	50.1
July 1966	91.9
November 1966	49.7
April 1967	82.2
September 1967	90.0
February 1968	55.0
July 1968	99.6
December 1968	45.7
May 1969	89.3
September 1969	82.7
February 1970	107
July 1970	123
December 1970	67.0
May 1971	82.1
October 1971	76.7
March 1972	63.0
August 1972	96.8
December 1972	70.5
May 1973	81.2
October 1973	73.6
March 1974	125
August 1974	115
January 1975	74.6
June 1975	117
October 1975	79.5
March 1976	50.0
August 1976	66.3
January 1977	53.7
June 1977	62.4
November 1977	45.3
April 1978	71.4
September 1978	91.9
January 1979	59.4
June 1979	93.7
November 1979	56.0
April 1980	97.2
September 1980	97.8
February 1981	65.5
July 1981	97.3
November 1981	79.4
April 1982	127
September 1982	86.9
February 1983	74.1
July 1983	129
December 1983	90.9
May 1984	104
October 1984	59.5
February 1985	48.4
July 1985	78.3
December 1985	56.0
May 1986	129
October 1986	94.9
March 1987	81.8
August 1987	91.0
December 1987	57.9
May 1988	78.2
October 1988	63.5
March 1989	75.4
August 1989	105
January 1990	66.6
June 1990	97.6
November 1990	77.0
March 1991	70.8
August 1991	103
January 1992	67.5
June 1992	98.7
November 1992	71.8
April 1993	78.0
September 1993	107
January 1994	79.4
June 1994	112
November 1994	75.4
April 1995	109
September 1995	96.2
February 1996	102
July 1996	123
December 1996	76.1
April 1997	121
September 1997	104
February 1998	77.6
July 1998	127
December 1998	71.8
May 1999	98.9
October 1999	86.0
February 2000	74.8
July 2000	115
December 2000	56.8
May 2001	81.0
October 2001	78.5
March 2002	82.7
August 2002	109
December 2002	62.9
May 2003	119
October 2003	87.1
March 2004	79.9
August 2004	107
January 2005	60.3
June 2005	128
November 2005	73.7
March 2006	103
August 2006	106
January 2007	73.8
June 2007	109
November 2007	68.5
April 2008	72.1
September 2008	84.4
January 2009	67.6
June 2009	124
November 2009	85.4
April 2010	84.6
September 2010	103
February 2011	97.9
July 2011	127
December 2011	88.6
April 2012	111
September 2012	90.8
February 2013	96.5
July 2013	108
December 2013	64.3
May 2014	88.6
October 2014	81.5
February 2015	97.5
July 2015	99.4
December 2015	80.2
May 2016	129
October 2016	99.2
March 2017	126
August 2017	107
January 2018	86.8
May 2018	124
October 2018	91.6
March 2019	124
August 2019	114
January 2020	64.0
June 2020	92.9
November 2020	88.9
March 2021	90.8
August 2021	97.2
January 2022	104
June 2022	127
November 2022	97.8
April 2023	101
September 2023	112
February 2024	98.5
June 2024	120
November 2024	96.1
April 2025	107
September 2025	98.4

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	77.9	91.3
Feb	81.7	100.0
Mar	87.7	98.2
Apr	96.8	107
May	109	123
Jun	117	122
Jul	114	119
Aug	105	111
Sep	96.4	98.4
Oct	87.7	101
Nov	79.6	96.1
Dec	76.0	94.4

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.

Rate and persistence

-0.54 Mm³

Mean drawdown per month over 12 months

0 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

Bucks Lk Nr Bucks Lodge CA

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 Geological Survey — National Water Information System · US Government work — public domain
How the values came to exist	Measured
Period held	1928–2025
Completeness	99.0% 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 1928 and 2025 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-usgs-11403500.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), Bucks Lk Nr Bucks Lodge CA reservoir records, accessed 2026-10-05, hydrionis.com/reservoirs/reservoir-usgs-11403500/

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 Bucks Lk Nr Bucks Lodge CA 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

1,164 monthly observations 1928–2025 Mm³

Spatially aggregatedHigh confidenceSeptember 2025

Source: USGS — National Water Information System, 11403500. Licence: Open.

Method: Monthly mean of daily reservoir storage published by the USGS in acre-feet and converted to millions of cubic metres. Months with fewer than 20 days of record are not published rather than averaged from a partial month.

Reservoir storage is managed as well as observed: a drawdown may reflect an operating rule, flood-control rule curve or scheduled release rather than a shortage. Compare a month against the same month in other years, and do not read a fall as a supply signal without knowing the operating regime.

Retrieved 1 October 2026.

Monthly mean of daily reservoir storage published by the USGS in acre-feet and converted to millions of cubic metres. Months with fewer than 20 days of record are not published rather than averaged from a partial month.