- · Developed a regional-scale, 3D groundwater flow model using MODFLOW.
- · Delivered a perennial yield estimate for NV Basin 222.
- · Provided actionable recommendations for future modeling and groundwater
GZA d/b/a Glorieta Geoscience (GG) developed a comprehensive regional-scale groundwater flow model for the lower Virgin River basin in Nevada. The primary goal was to provide the Virgin Valley Water District (VVWD) with a robust, data-driven estimate of perennial yield for Nevada Basin 222. This estimate supports water resource planning, ensuring sustainable groundwater (GW) management for the district.
Challenge
VVWD sought a scientifically robust estimate of perennial GW yield for Nevada Basin 222 to support long-term water management and regulatory compliance. The basin’s complex hydrogeology—including variable recharge rates, multiple groundwater users, and intricate fault systems—required advanced modeling and data integration. GGI leveraged hydrogeologic analysis and numerical modeling to accurately characterize groundwater resources and inform sustainable management decisions.
Solution
To address the complex challenge of estimating perennial GW yield, GGI implemented a multi-step scientific approach. The team first developed and calibrated a water balance model using the USGS Basin Characterization Model (BCM) software, followed by a 3D MODFLOW GW model. These models incorporated detailed climate, geologic, and field data, and were verified against field measured GW elevations and streamflow. The result was a robust, data-driven estimate of perennial yield (20,421 ac-ft/yr) for Nevada Basin 222, providing VVWD with a reliable foundation for water resource planning.
Benefit
This modeling effort provided VVWD with a scientifically defensible estimate of perennial groundwater yield for Nevada Basin 222. The proven methodology can be adapted to other basins, offering clients a robust framework for evidence-based resource planning.