We present an approach to develop groundwater numerical simulation models for arid regional aquifers systems with sparse hydrogeologic data.  Population growth is stressing groundwater resources globally.  As population expands, groundwater development in previously undeveloped regions is occurring.  One such area is the Cuatrocienégas Basin (CCB) of Coahuila, Mexico, a UNESCO Biosphere Reserve located in the Chihuahuan Desert of NE Mexico.  Over 500 springs support groundwater‑dependent ecosystems and irrigated agriculture. Groundwater development in adjacent basins for industrial agriculture has lowered groundwater levels 10s of meters and reserve managers are concerned that continued groundwater withdrawals may reduce springs flow.  We integrate disparate, sparse sources of hydrogeologic data (e.g., aqueous geochemistry, isotopic analyses, spring water temperature, and spring discharge) with surface water catchments delineated from regional digital elevation models, surface geophysical analysis of geologic controls on springs, and regional geologic maps to develop a regional hydrogeologic conceptual model.  A numerical groundwater simulation model is constructed to evaluate regional groundwater recharge processes and permeability and map groundwater catchments contributing to CCB spring flow.  Ultimately, the groundwater model can be used by Mexican groundwater resource managers to evaluate potential effects of regional groundwater development and climate change on spring discharge.   We develop this procedure for CCB; however, these procedures may be applicable in many similar settings.