Data from: Monitoring groundwater levels in Oasis Valley, NV, and evaluating potential drawdown during the North Bullfrog aquifer test

The Nature Conservancy (TNC) owns ecologically rich properties that
include groundwater-dependent ecosystems (GDEs) in Oasis Valley, Nevada.
AngloGold Ashanti has acquired the rights to several gold mines in Oasis
Valley, including the North Bullfrog Project, where the company conducted
two multiday aquifer tests in 2023 and 2024 to assess aquifer hydraulics
and evaluate water level drawdown. In partnership with TNC, Desert
Research Institute (DRI) monitored groundwater levels at sites within
Oasis Valley to identify potential hydrologic impacts that could be
attributed to the aquifer tests. Combined water level and water
temperature sensors were installed and activated with a five-minute
measurement frequency between August 30, 2023, and March 20, 2024, at the
NC-GWE-OV-2 well (in Parker Ranch), OVU Lower ET Well (in the Atwood
Preserve), and Crystal Spring. DRI also operates systems for monitoring
meteorology at Colson Pond (in the Atwood Preserve) and diverted flow from
Crystal Spring. Water level modeling was performed using SeriesSEE to
assess whether drawdown was detected at the three monitoring points that
can be attributed to groundwater pumping during aquifer testing. The water
level modeling approach isolates pumping effects from environmental
fluctuations (i.e., background water levels and barometric pressure). The
modeling analysis indicates that no measurable drawdown can be attributed
to the aquifer tests, which is likely due to a combination of aquifer
conditions and testing parameters. It is recommended that monitoring
continues at the three established stations and expands to other
monitoring points in Oasis Valley to establish a baseline of natural
variability to identify future impacts from pumping and to better
understand groundwater interactions that may affect water availability at
GDEs.