The Colorado River and its tributaries supply water to more than 35 million people in the United States and 3 million people in Mexico, irrigating more than 4.5 million acres of farmland, and generating about 12 billion kilowatt hours of hydroelectric power annually. Planning for the sustainable management of the Colorado River in future climates requires an understanding of the Lower Colorado River Basin groundwater system. This data release contains summarized output from Soil-Water Balance groundwater infiltration model simulations for the Lower Colorado River Basin. Model output available in this release includes groundwater infiltration, potential evapotranspiration (PET), actual evapotranspiration (AET), precipitation, and temperature.