MODFLOW-NWT groundwater model used for simulating a potential future pumping scenario and forecasting associated groundwater-level changes in the Hualapai Valley, Northwestern Arizona

A numerical groundwater flow model of the Hualapai Valley Basin, using MODFLOW-NWT, 
was developed to assist water-resource managers in understanding the potential effects of 
projected groundwater withdrawals on groundwater levels in the basin. Hualapai Valley Basin
is a broad, internally drained, intermountain desert basin in Mohave County, northwestern 
Arizona. Basin-fill aquifers are the primary groundwater source for many desert communities, 
and the residents, commerce, and agriculture in and near to the Hualapai Valley Basin must 
rely on such groundwater to meet water needs. As in many parts of the western United States, 
population growth in this part of Arizona is substantial. From 2000 to 2018 the population of the 
City of Kingman, Arizona, grew from 20,069 to 30,314, an increase of 51 percent, whereas the 
population of Mohave County grew from 155,062 to 209,550, an increase of 35 percent.  Water 
managers in Mohave County have raised concern about the potential for future groundwater 
development and additional stresses on the groundwater system in the Hualapai Valley Basin. 
In particular, the City of Kingman, Ariz., water supply is primarily groundwater withdrawn from 
the Kingman subbasin of the Hualapai Valley Basin, northeast of the city. The potential effects 
of future water development on the City of Kingman well field have become a top concern to 
regional water-resource managers.  To address these concerns the Hualapai Valley Hydrologic 
Model (HVHM) simulates the hydrologic system for the years 1935 through 2219, including 
future withdrawal scenarios that simulate large-scale agricultural expansion with and without 
enhanced groundwater recharge from potential new infiltration basin projects. HVHM is a highly 
parameterized model (75,586 adjustable parameters) capable of simulating grid-scale variability 
in aquifer properties (for example, conductivity, specific yield, and specific storage) and system 
stresses (for instance, natural recharge and groundwater withdrawals). System stresses were 
partially adopted from a previously-published groundwater model (Tillman and others, 2013). 
Parameter estimation and uncertainty quantification were performed using an iterative ensemble 
smoother software (PESTPP-IES) to produce an ensemble of models fit to historical data. Two 
future scenarios were simulated with a subset of the posterior parameter ensemble comprising 
the 40 best-fit realizations. In scenario 1, future pumping was simulated to increase linearly from 
2019 through 2029 and then held constant through 2219. Scenario 2 includes the same specified 
future pumping, but also simulates enhanced recharge at proposed infiltration basins throughout 
the Kingman subbasin beginning in 2019.  This USGS data release contains all of the input and 
output files for the simulations described in the associated model documentation report 
(https://doi.org/10.3133/sir20215077).

Tags: arizona, environment, geoscientificinformation, groundwater, groundwater-model, hualapai-valley, inlandwaters, kingman, modflow-nwt, mohave-county, pest, pestpp-ies, swb, usgs-410c65da-1ac4-4930-a3af-35daf535e8b9, usgsgroundwatermodel
Organization: Department of the Interior