Mr. Umstot has served as a testifying expert in water rights and groundwater adjudication proceedings before the New Mexico Office of the State Engineer, the Nevada State Engineer, and state district courts in New Mexico and Arizona. He has also been a designated expert in Colorado district court to address the availability of groundwater in non-tributary status aquifers. His testimony has addressed the impacts of water right transfers on surface and groundwater flows, climate and recharge processes, and the response of aquifers to pumping and recharge. He has represented clients in contested matters involving complex mountain-block hydrogeology, fault-influenced groundwater flow, and has evaluated and challenged opposing experts’ modeling assumptions.
Beyond litigation, Mr. Umstot has developed and applied numerical groundwater models (including MODFLOW, MODFLOW-SURFACT, and MT3D) and vadose zone models (including HYDRUS) across a wide range of settings from mountain-front recharge and watershed-scale water balance studies to contaminant fate and transport analyses involving MTBE, chlorinated solvents, perchlorate, and metals. He is the author of the Distributed Parameter Watershed Model (DPWM) that has been used in many water rights proceedings and also by the Texas Water Development Board (TWDB) in support of their Groundwater Availability Modeling projects. His project work also extends to carbon capture, utilization, and storage (CCUS), where he has modeled brine and CO2 migration along wellbores and faults (including MODFLOW-SEAWAT) for underground source of drinking water protection. He has used GEM and ECLIPSE reservoir simulators to evaluate CO2 plume migration and pressure front extent for Area of Review (AOR) determinations in support of EPA Class VI permitting.
