Lk Nasworthy, TX — storage

Storage now, against this reservoir's own record

11.07 Mm³

Stored, September 2001

45th

Percentile among 72 Seps on record

+14.9%

Change over the 12 months to 2001-09

Storage in September 2001 was around the middle of the Sep record, ranked against 72 other Seps held for this reservoir.

No percentage departure from the Sep average is published here. No long-term average is held for this month, so there is nothing to compare with.

Storage, 1930–2001

Monthly mean storage

855 monthly values, 1930 to 2001

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 855 periods, evenly spaced across the record. Every value is in the download and the API; a table of all 855 would be longer than this page and unusable with a screen reader.
Period	Lk Nasworthy Nr San Angelo, TX (Mm³)
April 1930	0.273
August 1930	5.31
December 1930	13.0
April 1931	13.0
September 1931	11.8
January 1932	13.2
April 1932	12.7
August 1932	11.8
December 1932	12.3
March 1933	12.0
July 1933	10.1
October 1933	7.52
February 1934	12.3
May 1934	10.9
September 1934	6.64
January 1935	7.66
April 1935	11.4
August 1935	11.3
November 1935	12.1
March 1936	11.9
June 1936	12.8
October 1936	2.44
February 1937	10.8
May 1937	10.6
September 1937	9.91
December 1937	10.9
April 1938	11.0
July 1938	8.87
November 1938	11.0
March 1939	10.3
June 1939	10.1
October 1939	8.74
January 1940	11.2
May 1940	10.3
August 1940	10.8
December 1940	9.51
April 1941	10.6
July 1941	10.7
November 1941	10.6
February 1942	9.90
June 1942	11.3
October 1942	10.7
January 1943	10.5
May 1943	10.7
August 1943	7.81
December 1943	11.3
March 1944	10.7
July 1944	8.46
November 1944	10.3
February 1945	10.8
June 1945	8.14
September 1945	8.54
January 1946	9.75
April 1946	9.89
August 1946	6.03
December 1946	10.1
March 1947	9.69
July 1947	10.2
October 1947	4.01
February 1948	5.64
May 1948	6.74
September 1948	9.39
January 1949	13.3
April 1949	15.8
August 1949	10.9
November 1949	16.4
March 1950	16.1
June 1950	15.1
October 1950	15.1
February 1951	12.4
May 1951	7.97
September 1951	9.29
December 1951	4.75
April 1952	3.39
July 1952	4.42
November 1952	1.59
March 1953	10.3
June 1953	12.7
October 1953	16.9
January 1954	15.2
May 1954	16.5
August 1954	10.8
December 1954	2.00
April 1955	0.680
July 1955	12.6
November 1955	11.6
February 1956	9.24
June 1956	12.3
September 1956	5.64
January 1957	9.74
May 1957	13.1
August 1957	12.2
December 1957	15.2
March 1958	15.4
July 1958	14.9
October 1958	14.7
February 1959	15.1
June 1959	13.7
September 1959	12.4
January 1960	15.3
April 1960	15.2
August 1960	12.3
November 1960	12.3
March 1961	15.3
July 1961	15.4
October 1961	14.8
February 1962	15.0
May 1962	14.7
September 1962	8.13
December 1962	4.89
April 1963	2.78
August 1963	1.02
November 1963	0.576
March 1964	0.974
June 1964	0.603
October 1964	6.34
January 1965	7.88
May 1965	7.43
September 1965	10.0
December 1965	8.08
April 1966	6.85
July 1966	12.7
November 1966	12.9
March 1967	12.8
June 1967	12.8
October 1967	13.1
January 1968	12.5
May 1968	12.9
August 1968	11.8
December 1968	10.2
April 1969	10.0
July 1969	11.4
November 1969	12.8
February 1970	12.6
June 1970	12.6
September 1970	10.7
January 1971	10.6
May 1971	11.3
August 1971	14.3
December 1971	13.0
March 1972	12.9
July 1972	13.0
October 1972	13.3
February 1973	13.8
June 1973	12.9
September 1973	13.5
January 1974	12.8
April 1974	13.0
August 1974	13.1
November 1974	12.9
March 1975	13.4
July 1975	12.9
October 1975	13.0
February 1976	13.0
May 1976	13.1
September 1976	13.1
December 1976	12.8
April 1977	13.1
August 1977	12.9
November 1977	13.0
March 1978	13.3
June 1978	13.1
October 1978	12.9
January 1979	12.9
May 1979	12.9
September 1979	12.8
December 1979	13.0
April 1980	12.9
July 1980	12.9
November 1980	13.3
February 1981	12.8
June 1981	12.8
October 1981	13.7
January 1982	12.8
May 1982	12.7
August 1982	12.9
December 1982	11.3
March 1983	11.1
July 1983	13.0
November 1983	12.9
February 1984	12.8
June 1984	13.0
September 1984	12.6
January 1985	14.0
April 1985	12.0
August 1985	12.2
December 1985	12.3
March 1986	12.0
July 1986	12.2
October 1986	13.6
February 1987	15.0
May 1987	13.7
September 1987	14.3
January 1988	13.8
April 1988	13.6
August 1988	13.4
November 1988	13.3
March 1989	14.7
June 1989	13.8
October 1989	13.6
February 1990	13.6
May 1990	13.2
September 1990	14.3
December 1990	13.1
April 1991	13.4
August 1991	14.1
November 1991	13.3
March 1992	14.5
June 1992	14.3
October 1992	10.8
January 1993	8.16
May 1993	13.9
September 1993	13.9
December 1993	13.5
April 1994	13.7
July 1994	13.7
November 1994	13.7
February 1995	13.5
June 1995	13.7
October 1995	11.0
January 1996	11.0
May 1996	11.0
August 1996	10.8
December 1996	10.2
March 1997	11.6
July 1997	11.0
November 1997	11.2
February 1998	10.9
June 1998	11.0
September 1998	10.9
January 1999	11.0
April 1999	11.0
August 1999	10.9
December 1999	10.6
March 2000	10.3
July 2000	10.8
October 2000	8.87
February 2001	10.8
May 2001	10.8
September 2001	11.1

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

+0.12 Mm³

Mean change per month over 12 months

2 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

Lk Nasworthy Nr San Angelo, TX

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	1930–2001
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 1930 and 2001 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-08132000.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), Lk Nasworthy Nr San Angelo, TX reservoir records, accessed 2026-10-05, hydrionis.com/reservoirs/reservoir-usgs-08132000/

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 Lk Nasworthy Nr San Angelo, TX 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

855 monthly observations 1930–2001 Mm³

Spatially aggregatedHigh confidenceSeptember 2001

Source: USGS — National Water Information System, 08132000. 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.