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 Sprin..., Transducer water level data were post-processed after each field trip. Quality control is performed through the Trainset program (https://trainset.geocene.com/). This program allows for the visualization and labeling of large sets of data. The data from each well were analyzed and labeled with different indicators, such as data offloads, adjusting periods (time soon after the sensor was first installed, when readings may be less accurate), dry (transducer out of the water), frozen (if sensor temperature drops to freezing), spikes, dips, wide dips (drop > 1.0 inch [2.5 cm], and then return to the original water level multiple hours later), steps (sudden increase or decrease to a new fairly constant water level), and flatlines. These labels help to identify different trends and possible erroneous data., , # Supplemental dataset: Monitoring Groundwater Levels in Oasis Valley, NV, and Evaluating Potential Drawdown During the North Bullfrog Aquifer Test

[https://doi.org/10.5061/dryad.0zpc8676t](https://doi.org/10.5061/dryad.0zpc8676t)

## Description of the data and file structure

This data folder contains offloads from the following sensors:

| **Site Name** | **Description** | **Latitude** | **Longitude** | **Date Range** | **Manufacturer** | **Sensor Type** | **Logging Frequency** |
| :------------- | :------------------------------------------- | :----------- | :------------ | :------------------- | :--------------- | :-------------- | :-------------------- |
| Parker Ranch | Water Level in Monitoring Well (NC-GWE-OV-2) | 36.96457° | -116.72300° | 8/30/2023-5/15/2024 | Hobo | MX2001-04-SS | 5 minutes |
| Parker Ranch | Pump Electrical Current Meter | 36.964843° | -116.72412° | 10/11/2023-5/15/2...