Cienega Creek contains critical habitat for plants and wildlife including threatened and endangered species and has been designated as an “Outstanding Water” by the State of Arizona. With limited surface water and various demands for water in the region, the presence of perennial surface water may be impacted by reduced water in the watershed. Within the groundwater basin, potential impacts include reduced precipitation and increased evaporation related to climate change as well as increased groundwater pumping from development and/or related to potential mining activities. Understanding where surface water is sourced can help inform water management strategies. Previous studies and recently collected data indicate that perennial flow in Lower Cienega Creek is primarily sustained by water from the local basin fill aquifer with contributions from Davidson Canyon. Preliminary data indicates that Davidson Canyon surface flow is primarily sourced from the shallow alluvial groundwater in the Davidson Canyon subwatershed. This study uses water chemistry data from groundwater (basin fill and shallow alluvial aquifers), precipitation, and perennial surface water to model the geochemical evolution of potential source waters to the resulting surface water perennial reaches in the Lower Cienega Creek watershed.