Milner Lake — storage

Storage now, against this reservoir's own record

38.45 Mm³

Stored, February 2017

43rd

Percentile among 38 Febs on record

-1.8%

Against the Feb 1991–2020 average

+16.4%

Change over the 12 months to 2017-02

Storage in February 2017 was around the middle of the Feb record, ranked against 38 other Febs held for this reservoir.

Storage, 1978–2017

Monthly mean storage

448 monthly values, 1978 to 2017

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 448 periods, evenly spaced across the record. Every value is in the download and the API; a table of all 448 would be longer than this page and unusable with a screen reader.
Period	Milner Lake At Milner Dam ID (Mm³)
October 1978	36.4
December 1978	21.0
February 1979	27.9
April 1979	39.6
May 1979	43.6
July 1979	45.3
September 1979	40.9
November 1979	10.6
January 1980	16.5
March 1980	33.7
May 1980	49.4
July 1980	45.3
August 1980	44.6
October 1980	39.3
December 1980	18.4
February 1981	16.4
April 1981	40.9
June 1981	47.6
August 1981	44.8
October 1981	27.8
November 1981	9.82
January 1982	11.2
March 1982	20.2
May 1982	51.7
July 1982	46.6
September 1982	43.3
November 1982	35.3
December 1982	33.8
February 1983	25.9
April 1983	37.8
June 1983	53.0
August 1983	44.7
October 1983	43.2
December 1983	34.8
February 1984	27.2
March 1984	30.3
May 1984	53.1
July 1984	48.9
September 1984	45.2
November 1984	42.5
January 1985	35.7
March 1985	33.9
May 1985	48.6
June 1985	46.7
August 1985	46.7
October 1985	38.6
December 1985	25.1
February 1986	26.8
April 1986	50.3
June 1986	53.0
August 1986	46.4
September 1986	45.2
November 1986	36.0
January 1987	27.4
March 1987	28.2
May 1987	45.3
July 1987	46.2
September 1987	44.5
October 1987	37.1
December 1987	15.1
February 1988	14.7
April 1988	42.1
June 1988	45.9
August 1988	45.7
October 1988	30.5
December 1988	14.0
January 1989	14.0
March 1989	26.3
May 1989	44.9
July 1989	47.4
September 1989	44.4
November 1989	17.7
January 1990	14.8
March 1990	33.7
April 1990	42.3
June 1990	44.9
August 1990	46.1
October 1990	33.3
December 1990	14.2
February 1991	14.2
April 1991	42.0
May 1991	44.2
July 1991	47.0
September 1991	44.3
November 1991	16.0
January 1992	16.2
March 1992	23.5
May 1992	45.2
July 1992	44.7
August 1992	45.0
October 1992	42.2
December 1992	41.3
February 1993	41.6
April 1993	42.0
June 1993	48.1
August 1993	46.4
October 1993	43.2
November 1993	42.1
January 1994	42.1
March 1994	42.0
May 1994	45.3
July 1994	47.7
September 1994	44.4
November 1994	40.5
January 1995	40.7
February 1995	41.3
April 1995	42.3
June 1995	48.5
August 1995	46.8
October 1995	41.6
December 1995	42.8
February 1996	44.2
March 1996	49.6
May 1996	47.5
July 1996	47.6
September 1996	44.4
November 1996	41.3
January 1997	44.7
March 1997	50.5
May 1997	50.3
June 1997	60.8
August 1997	47.9
October 1998	42.5
December 1998	43.8
February 1999	45.0
April 1999	48.1
June 1999	52.0
August 1999	47.3
September 1999	45.2
November 1999	35.0
January 2000	43.9
March 2000	42.5
May 2000	45.2
July 2000	48.2
September 2000	45.0
October 2000	39.7
January 2001	39.3
March 2001	40.4
May 2001	45.1
July 2001	45.6
September 2001	44.1
November 2001	41.1
January 2002	40.3
February 2002	40.3
April 2002	41.6
June 2002	45.4
August 2002	45.7
October 2002	35.6
December 2002	40.7
February 2003	41.1
April 2003	41.9
May 2003	44.2
July 2003	45.5
September 2003	43.9
November 2003	39.4
January 2004	40.9
March 2004	41.2
May 2004	44.2
July 2004	43.9
August 2004	40.9
October 2004	36.6
December 2004	40.9
February 2005	41.4
April 2005	42.2
June 2005	44.2
August 2005	45.2
September 2005	43.7
November 2005	21.1
January 2006	40.9
March 2006	41.6
May 2006	47.3
July 2006	48.0
September 2006	43.9
November 2006	36.4
December 2006	42.1
February 2007	41.9
April 2007	42.7
June 2007	45.8
August 2007	45.4
October 2007	36.8
December 2007	41.3
February 2008	41.2
March 2008	40.7
May 2008	44.7
July 2008	48.0
September 2008	44.6
November 2008	39.6
January 2009	41.6
March 2009	40.7
April 2009	47.4
June 2009	49.2
August 2009	45.9
October 2009	40.8
December 2009	42.0
February 2010	42.6
April 2010	41.7
June 2010	44.6
July 2010	47.0
September 2010	44.3
November 2010	22.6
January 2011	42.6
March 2011	41.9
May 2011	54.4
July 2011	49.3
September 2011	48.5
October 2011	43.6
December 2011	42.5
February 2012	36.9
April 2012	43.8
June 2012	46.7
August 2012	45.8
October 2012	37.1
December 2012	38.9
January 2013	39.0
March 2013	40.1
May 2013	46.5
July 2013	46.2
September 2013	44.0
November 2013	39.9
January 2014	40.8
February 2014	40.7
April 2014	42.9
June 2014	48.3
August 2014	45.5
October 2014	39.1
December 2014	38.5
February 2015	40.6
April 2015	43.1
May 2015	45.0
July 2015	46.6
September 2015	44.7
November 2015	34.6
January 2016	35.8
March 2016	30.1
May 2016	44.3
July 2016	47.0
August 2016	46.3
October 2016	41.0
December 2016	38.2
February 2017	38.5

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	38.8	37.3
Feb	39.2	38.5
Mar	40.5	30.1
Apr	43.9	41.6
May	46.1	44.3
Jun	47.5	47.7
Jul	47.1	47.0
Aug	46.0	46.3
Sep	44.6	44.6
Oct	39.7	41.0
Nov	36.2	37.8
Dec	39.0	38.2

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

+0.45 Mm³

Mean change per month over 12 months

3 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

Milner Lake At Milner Dam ID

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	1978–2017
Completeness	93.3% 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	93% of the months between 1978 and 2017 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-13087900.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), Milner Lake At Milner Dam ID reservoir records, accessed 2026-10-05, hydrionis.com/reservoirs/reservoir-usgs-13087900/

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 Milner Lake At Milner Dam ID 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

448 monthly observations 1978–2017 Mm³

Spatially aggregatedHigh confidenceFebruary 2017

Source: USGS — National Water Information System, 13087900. 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.