Freshwater Sustainability under Climate Change in the Nueces River Basin, TX

Abstract:

Freshwater sustainability in arid and semi-arid regions is threatened due to climate change as well as competing water demands for agriculture, urban development, industrial use and ecosystem needs. Such changes have forced the local water supply systems to update their water supply plans once in five years. Developments of such water supply plans not only require reliable assessment of water availability and demands but also incorporate uncertainties due to regional climate change projections.

In this study, we focus our analysis on one of the basins in the South Texas – Nueces River Basin (NRB) which provide inflows to the Choke Canyon - Lake Corpus Christi reservoir system. This reservoir system is the major freshwater source for the coastal communities in the basin and the Nueces Bay, which serve as a habitat for several key fish species such as blue crab, brown shrimp, and southern flounder. Freshwater inflows in the NRB have decreased in the past decades, resulting in increased salinity of the Nueces Bay, thus impacting the natural habitat for several fish species. Therefore, estimating the impacts of climate change in the NRB is critical to develop sustainable water resources management in the region. We will implement a physically based hydrologic model under historical climate change scenarios from multiple General Circulation Models (GCMs) over the past 30 years to understand how well we could have used large scale climate change projections in improving water resources management over the overlapping observations. A water management model will be developed for the Choke Canyon – Lake Corpus Christi Reservoir System, which will be ingested with inflow projections under multiple GCM scenarios over the past 30 years to incorporate uncertainty in water resources management. Finally, water management scenarios will be developed to minimize deficits between water availability and demands in the region.