United States Groundwater Monitoring Dataset

43,885

Observations

103

Series

103

Subjects

1942–2026

Period covered

What this looks like

One real series from the dataset, and real rows from the head of its published extract. Neither is a mock-up: the rows below are the same rows, unchanged, that are in the file you would download.

Depth to groundwater at Well 315950081161201

The longest single series this dataset holds — 952 monthly values, one of 103. Drawn from 600 of them, evenly spaced across the record. The dataset is not this chart.

Drawn to show the shape and resolution of what the dataset contains, not to make a point about Well 315950081161201. Gaps are breaks, never interpolated.

View the data behind this chart

240 of 600 periods, evenly spaced across the record. Every value is in the download and the API; a table of all 600 would be longer than this page and unusable with a screen reader.
Period	Well 315950081161201 (m)
1942.5833333333333	2.48
1943	2.67
1943.25	1.81
1943.6666666666667	1.50
1943.9166666666667	2.93
1944.3333333333333	1.27
1944.5833333333333	1.19
1945	1.50
1945.25	1.85
1945.6666666666667	0.791
1945.9166666666667	1.62
1946.25	1.58
1946.5833333333333	1.96
1946.9166666666667	1.74
1947.25	1.19
1947.5833333333333	1.88
1947.9166666666667	0.515
1948.25	0.684
1948.5	1.36
1948.9166666666667	1.43
1949.1666666666667	1.52
1949.5833333333333	2.20
1949.8333333333333	1.71
1950.25	1.76
1950.5	1.59
1950.9166666666667	1.38
1951.1666666666667	1.70
1951.5833333333333	2.02
1951.8333333333333	1.28
1952.25	1.53
1952.5	1.93
1952.9166666666667	3.07
1953.1666666666667	1.36
1953.5833333333333	0.949
1953.8333333333333	1.43
1954.25	2.15
1954.5	2.97
1954.9166666666667	2.82
1955.1666666666667	1.87
1955.5833333333333	2.66
1955.8333333333333	2.97
1956.25	2.97
1956.5	3.02
1956.8333333333333	2.49
1957.1666666666667	3.25
1957.5	1.00
1957.8333333333333	1.55
1958.1666666666667	0.960
1958.5	1.28
1958.8333333333333	3.06
1959.0833333333333	1.96
1959.5	1.42
1959.75	1.15
1960.1666666666667	1.01
1960.4166666666667	1.48
1960.8333333333333	2.15
1961.0833333333333	1.88
1961.5	1.60
1961.75	1.91
1962.1666666666667	1.31
1962.4166666666667	1.27
1962.8333333333333	1.91
1963.0833333333333	1.10
1963.5	0.976
1963.75	1.87
1964.1666666666667	0.558
1964.4166666666667	2.17
1964.8333333333333	1.32
1965.0833333333333	1.29
1965.5	1.57
1965.75	2.44
1966.1666666666667	0.869
1966.4166666666667	1.46
1966.8333333333333	3.12
1967.0833333333333	1.81
1967.4166666666667	2.37
1967.75	1.82
1968.0833333333333	2.51
1968.4166666666667	1.80
1968.75	2.77
1969.1666666666667	1.64
1969.4166666666667	1.46
1969.8333333333333	1.20
1970.0833333333333	1.20
1970.5	1.33
1970.75	1.51
1971.1666666666667	1.38
1971.4166666666667	1.90
1971.8333333333333	1.23
1972.0833333333333	0.870
1972.5	2.62
1972.75	3.27
1973.1666666666667	1.27
1973.4166666666667	2.29
1973.8333333333333	2.75
1974.0833333333333	2.80
1974.5	2.05
1974.75	2.04
1975.1666666666667	1.69
1975.4166666666667	1.94
1975.75	2.70
1976.0833333333333	2.78
1976.4166666666667	1.14
1976.75	0.767
1977.0833333333333	1.06
1977.4166666666667	2.58
1977.75	2.04
1978	1.34
1978.4166666666667	2.12
1978.6666666666667	2.90
1979.0833333333333	2.60
1979.3333333333333	1.40
1979.75	1.72
1980	1.84
1980.4166666666667	1.96
1980.6666666666667	3.12
1981.0833333333333	3.19
1981.3333333333333	2.82
1981.75	2.59
1982	2.25
1982.4166666666667	1.70
1982.6666666666667	1.38
1983.0833333333333	1.01
1983.3333333333333	1.21
1983.75	3.17
1984	1.72
1984.4166666666667	1.81
1984.6666666666667	2.45
1985.0833333333333	3.05
1985.3333333333333	3.19
1985.75	2.89
1986.0833333333333	1.45
1986.5	3.21
1986.75	2.24
1987.0833333333333	0.630
1987.4166666666667	1.44
1987.75	1.38
1988.0833333333333	1.42
1988.4166666666667	2.37
1988.75	1.00
1989.0833333333333	2.23
1989.3333333333333	2.25
1989.75	0.818
1990	0.816
1990.4166666666667	2.47
1990.6666666666667	2.37
1991.0833333333333	0.884
1991.3333333333333	0.474
1991.75	2.09
1992	2.06
1992.4166666666667	1.46
1992.6666666666667	1.18
1993.0833333333333	0.970
1993.4166666666667	1.95
1993.8333333333333	3.00
1994.0833333333333	1.80
1994.5	1.80
1994.75	0.751
1995.25	1.26
1995.5833333333333	1.15
1996	1.69
1996.5	1.59
1996.8333333333333	1.64
1997.1666666666667	1.45
1997.5	1.98
1997.8333333333333	1.06
1998.0833333333333	0.538
1998.5	1.80
1998.75	1.32
1999.1666666666667	1.57
1999.5	0.683
1999.9166666666667	2.14
2000.1666666666667	1.79
2000.5833333333333	2.20
2000.8333333333333	2.31
2001.25	1.55
2001.5	1.50
2002.9166666666667	1.16
2003.1666666666667	0.664
2003.5833333333333	1.17
2003.8333333333333	2.11
2004.25	1.85
2004.5	1.15
2004.9166666666667	1.75
2005.1666666666667	1.23
2005.5833333333333	1.52
2005.8333333333333	1.56
2006.25	1.56
2006.5	2.04
2006.9166666666667	2.36
2007.1666666666667	1.83
2007.5	2.05
2007.8333333333333	1.67
2008.1666666666667	1.25
2008.5	2.66
2008.8333333333333	1.62
2009.1666666666667	1.87
2009.5	1.55
2009.75	1.46
2010.1666666666667	0.998
2010.4166666666667	1.96
2010.8333333333333	2.56
2011.0833333333333	2.12
2011.5	2.39
2011.9166666666667	2.32
2012.4166666666667	2.00
2012.6666666666667	1.48
2013.0833333333333	1.71
2013.4166666666667	1.26
2014	1.88
2014.3333333333333	1.63
2014.75	1.45
2015.4166666666667	1.66
2015.8333333333333	1.26
2016.1666666666667	1.40
2016.5833333333333	2.18
2016.8333333333333	1.59
2017.4166666666667	1.92
2017.6666666666667	1.55
2018.0833333333333	1.87
2018.3333333333333	2.05
2018.75	2.32
2019	1.25
2019.3333333333333	2.17
2019.6666666666667	2.21
2020	1.04
2020.3333333333333	0.977
2020.6666666666667	1.77
2021	1.83
2021.3333333333333	1.80
2021.5833333333333	1.03
2022	1.72
2022.25	2.12
2022.6666666666667	1.39
2022.9166666666667	2.28
2023.3333333333333	1.58
2023.5833333333333	0.967
2024	1.62
2024.25	1.17
2024.6666666666667	1.06

Sample rows

12 of 43,897 rows Taken from the start of observations-groundwater-usgs-nwis.csv. These are sample rows, not the dataset.

Sample rows from the United States Groundwater Monitoring Dataset extract
`metric_id`	`subject_id`	`subject_kind`	`value`	`censored`	`censor_operator`	`censor_threshold`	`censor_limit`	`censor_reported`	`unit`	`period_start`	`period_end`	`period_kind`	`basis`	`confidence`	`source_id`	`source_ref`	`qualifier`	`superseded`	`retrieved`
groundwater-depth-below-surface	borehole-us-mo005-360425089485001	geography	3.892296	—	—	—	—	—	m	1980-11-01	1980-11-30	month	aggregated	high	usgs-nwis	MO005-360425089485001	—	—	2026-09-01
groundwater-depth-below-surface	borehole-us-mo005-360425089485001	geography	3.701452	—	—	—	—	—	m	1980-12-01	1980-12-31	month	aggregated	high	usgs-nwis	MO005-360425089485001	—	—	2026-09-01
groundwater-depth-below-surface	borehole-us-mo005-360425089485001	geography	3.848269	—	—	—	—	—	m	1981-01-01	1981-01-31	month	aggregated	high	usgs-nwis	MO005-360425089485001	—	—	2026-09-01
groundwater-depth-below-surface	borehole-us-mo005-360425089485001	geography	3.674516	—	—	—	—	—	m	1981-03-01	1981-03-31	month	aggregated	high	usgs-nwis	MO005-360425089485001	—	—	2026-09-01
groundwater-depth-below-surface	borehole-us-mo005-360425089485001	geography	3.720592	—	—	—	—	—	m	1981-04-01	1981-04-30	month	aggregated	high	usgs-nwis	MO005-360425089485001	—	—	2026-09-01
groundwater-depth-below-surface	borehole-us-mo005-360425089485001	geography	3.683066	—	—	—	—	—	m	1981-05-01	1981-05-31	month	aggregated	high	usgs-nwis	MO005-360425089485001	—	—	2026-09-01
groundwater-depth-below-surface	borehole-us-mo005-360425089485001	geography	2.926182	—	—	—	—	—	m	1981-06-01	1981-06-30	month	aggregated	high	usgs-nwis	MO005-360425089485001	—	—	2026-09-01
groundwater-depth-below-surface	borehole-us-mo005-360425089485001	geography	2.987237	—	—	—	—	—	m	1981-07-01	1981-07-31	month	aggregated	high	usgs-nwis	MO005-360425089485001	—	—	2026-09-01
groundwater-depth-below-surface	borehole-us-mo005-360425089485001	geography	3.404813	—	—	—	—	—	m	1981-08-01	1981-08-31	month	aggregated	high	usgs-nwis	MO005-360425089485001	—	—	2026-09-01
groundwater-depth-below-surface	borehole-us-mo005-360425089485001	geography	3.66522	—	—	—	—	—	m	1981-09-01	1981-09-30	month	aggregated	high	usgs-nwis	MO005-360425089485001	—	—	2026-09-01
groundwater-depth-below-surface	borehole-us-mo005-360425089485001	geography	3.96535	—	—	—	—	—	m	1981-12-01	1981-12-31	month	aggregated	high	usgs-nwis	MO005-360425089485001	—	—	2026-09-01
groundwater-depth-below-surface	borehole-us-mo005-360425089485001	geography	3.752088	—	—	—	—	—	m	1982-01-01	1982-01-31	month	aggregated	high	usgs-nwis	MO005-360425089485001	—	—	2026-09-01

Download these rows as CSV — the same twelve, with the column header, for testing a loader before committing to the full file.

Methodology

Aggregated by Hydrionis from the daily mean depth to water published by the USGS through its water data interface. Values are published in feet below the land surface and converted to metres using the exact definition of the international foot. A month is published only where at least fifteen days of record exist. Wells need twenty-five years of record, and at most twelve are taken from each state so that coverage is national rather than concentrated in the few states that drilled the most observation wells. Depth is stored rather than groundwater elevation because it is the quantity the United States actually publishes for most of its network, and the two are opposite measurements that are never combined.

What this dataset cannot tell you

Read before relying on these figures

Depth is measured downwards from the land surface at the well, so it rises as the water table falls. It is not a groundwater level, which is an elevation above a levelling datum and moves in the opposite direction, and the two must never be compared or combined.
Depth is referenced to the ground at each well, so it is specific to that well and must be read against that well’s own historic range rather than against another well’s.
A negative depth is ordinary at a flowing artesian well, where the pressure surface stands above the ground, and is not an error.
Coverage follows where the United States has historically drilled observation wells, and the per-state cap means the dataset is a national spread rather than the longest records available.
The collection is still filling. The publisher serves a fixed allowance each hour and the full selection needs more than one hour allows, so wells are gathered in tranches and most states are currently represented by their single longest record rather than by the twelve the cap permits.

Coverage

Subjects	United States observation wells with 25+ years of record, capped at twelve per state; 103 wells across 35 states held so far — 103 held
Period	1942–2026
Units	m
Update cadence	Monthly
Identifier	`us-groundwater-depth` v1.0.0

Fields

Data dictionary →

Every metric this dataset carries, with the unit it is stored in and the geography level it is reported at. Full definitions are in the data dictionary.

Identifier	Field	Unit	Reported at
`groundwater-depth-below-surface`	Depth to groundwater Depth from the land surface down to the water table at a monitoring well, measured downwards.	m	borehole

Rights and access

Licence position

Open. Derivative use true; redistribution true; commercial reuse true.

Applies to material authored by US federal agencies. Third-party material carried within a federal product may be separately protected.

Permitted uses

Public display
Derived analysis
API delivery
Bulk download
Commercial use

Available to: Public, Developer, Research, Professional, Enterprise. These follow from the rights of the contributing publishers, not from a Hydrionis pricing decision — no access tier can widen what a publisher withheld.

Contributing sources

United States Geological Survey — National Water Information System (US Government work — public domain)

Attribution and citation

Cite and reuse →

Two different obligations, deliberately kept apart. One is a condition of somebody else's licence; the other is a request Hydrionis has no standing to enforce.

Suggested citation for Hydrionis

Hydrionis (2026), United States Groundwater Monitoring Dataset, version 1.0.0, accessed 2026-09-02, hydrionis.com/data/datasets/us-groundwater-depth/

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: United States Groundwater Monitoring Dataset 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.

Changelog

Version 1.0.0 — 2026-09-01

First release. Hydrionis holds United States groundwater for the first time, completing the American water cycle alongside rainfall, river flow, flood peaks, runoff, snowpack and drought status.

Additions

Monthly mean depth to water for long-record United States observation wells.

Use this data

Download groundwater observations from USGS (43,897 rows) (CSV)
Machine-readable JSON /api/v1/datasets/us-groundwater-depth.json
How to cite this, and who you must credit
How these figures were produced
Request this at a different scale, format or geography

Every bulk extract ships with a companion metadata file carrying this dataset’s version, its sources, their licences, the attribution you are required to give and the suggested citation — so the terms travel with the file rather than staying on this page.

About this data

The fields a professional user needs to judge whether this is fit for a particular purpose. Deliberately not a score.

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	Mixed across the series — the basis is recorded on every individual value.
Period held	1942–2026
Known gaps	Depth is measured downwards from the land surface at the well, so it rises as the water table falls. It is not a groundwater level, which is an elevation above a levelling datum and moves in the opposite direction, and the two must never be compared or combined. Depth is referenced to the ground at each well, so it is specific to that well and must be read against that well’s own historic range rather than against another well’s. A negative depth is ordinary at a flowing artesian well, where the pressure surface stands above the ground, and is not an error.
Continuity	Version 1.0.0, released 2026-09-01. 1 recorded version; breaking changes and corrections are listed in the changelog above.
Last read from the publisher	2026-09-01 · publisher updates monthly
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