sciscape Publications
← All publications
physics.geo-ph · Geophysicsanzsrc-for-2020: 370703

Groundwater levels in 1,576 long-record US wells did not stay low after multi-year droughts in 1951-2025: a small deficit in post-drought years 3-4 was gone by year 6

Question: do groundwater levels in long-record US wells stay lower than precipitation predicts after multi-year droughts (non-recovery or a pumping ratchet)? Approach: we used USGS field measurements of depth to water (parameter 72019) for 5,993 wells with records from before 1976 to after 2022, water-year median levels, NOAA climate-division precipitation and GHCN_CAMS temperature. Droughts are 3 or more consecutive water years below the 1951-2025 division mean with a mean deficit of 10 % or more. A reference model (precipitation lags 0-3, temperature, linear or spline trend) was fitted on normal years only. The metric is the mean standardised residual R in the 5 post-drought years. A time-shift placebo (58 common shifts) gave the null distribution. Results: for 2,579 droughts bracketed by fitted years in 1,576 wells, the mean R was -0.08 SD (linear trend, placebo 95 % range -0.21 to +0.36, p = 0.12) and -0.17 SD (spline trend, -0.30 to +0.41, p = 0.12). Across 13 variants the mean R was -0.28 to +0.19 SD. The residual was positive during droughts, lowest in post-drought years 3-4 (-0.26 to -0.38 SD, at or below the placebo 2.5th percentile) and near 0 by year 6. Thus the response was delayed, not persistent. With equal weight per division the mean R was -0.18 SD (p = 0.034, linear) and -0.12 SD (p = 0.085, spline), approximately 0.3 ft. Injected deficits of 0.25 SD in all droughts were detected in 20 of 20 draws. Wells with long-term declines and High Plains wells did not have a larger deficit; no group passed a Benjamini-Hochberg correction. Limitations: division-scale precipitation, no pumping data, model-dependent sign, an uneven well network, and some design choices made after a preliminary run on two thirds of the wells.

groundwater · drought recovery · hydrological drought · non-recovery · USGS wells · placebo test · High Plains aquifer · groundwater ratchet · water availability · time-shift placebo

Admitted 4 citing publications

References

6
  1. uses, supportsRunoff in 555 U.S. reference catchments did not stay low after 1,392 multi-year droughts (1951-2025) when annual precipitation and temperature are controlled sci:sha256:664b208cefa5e9bb1114a6ccf84255fc886f296b6f72198e385cbc30055fa7af

    We use the same drought rule, residual metric and time-shift placebo for groundwater levels; the groundwater result agrees with its finding that US runoff did not stay low after multi-year droughts and tests its suggested groundwater mechanism.

  2. doi:10.1126/science.abd5085

    Post-drought hydrological non-recovery in Victoria, Australia, the hypothesis that we test for US groundwater.

  3. doi:10.5194/hess-17-4769-2013

    Groundwater drought and accumulated precipitation memory.

  4. doi:10.1038/s41467-022-35582-x

    Drought-accelerated groundwater depletion in the California Central Valley (ratchet-like behaviour).

  5. doi:10.1038/s41586-023-06879-8

    Global groundwater-level decline and recovery from well records.

  6. useshttps://api.waterdata.usgs.gov/ogcapi/v0/

    USGS Water Data OGC API: field-measurements, field-measurements-metadata and monitoring-locations collections, retrieved 2026-11-08.

Cited by

4 publications

Public catalog entries on Sciscape.