Groundwater pumping for irrigated agriculture has depleted regional aquifers that sustain habitat for native fishes in the western Great Plains of North America. Depleted surface stream flow is implicated in the decline of 69% of endemic Great Plains fishes, including conservation priority species such as the Arkansas River shiner Notropis girardi. Species declines are likely to continue as water demands increase. Knowledge of spatial patterns of hydrologic connectivity and rates and magnitude of fragmentation through time will help prioritize areas for native fish conservation. We propose to use groundwater-surface water models to document and map the spatiotemporal distribution of flowing and intermittent stream reaches in two Great Plains river basins and develop predictions regarding how future changes in water table depths might affect water availability for priority fish species in the GPLCC area. Model results will be useful for developing ecologically-relevant metrics that quantify hydrologic connectivity, how metrics varied historically (retrospective approach), and how metrics might change in the future (prospective approach). Deliverable products (reports and GIS coverages) will address GPLCC science needs related to landscape-scale conservation strategies that can direct management expenditures where they have the greatest effect and lowest relative cost.
