Unprecedented Drought Challenges for Texas Water Resources in a Changing Climate: What Do Researchers and Stakeholders Need to Know?

Abstract

Long‐range water planning is complicated by factors that are rapidly changing in the 21st century, including climate, population, and water use. Here, we analyze climate factors and drought projections for Texas as an example of a diverse society straddling an aridity gradient to examine how the projections can best serve water stakeholder needs. We find that climate models are robust in projecting drying of summer‐season soil moisture and decreasing reservoir supplies for both the eastern and western portions of Texas during the 21st century. Further, projections indicate drier conditions during the latter half of the 21st century than even the most arid centuries of the last 1,000 years that included megadroughts. To illustrate how accounting for drought nonstationarity may increase water resiliency, we consider generalized case studies involving four key stakeholder groups: agricultural producers, large surface water suppliers, small groundwater management districts, and regional water planning districts. We also examine an example of customized climate information being used as input to long‐range water planning. We find that while stakeholders value the quantitative capability of climate model outputs, more specific climate‐related information better supports resilience planning across multiple stakeholder groups. New suites of tools could provide necessary capacity for both short‐ and long‐term, stakeholder‐specific adaptive planning.

How a Simple Question About Freshwater Inflow to Estuaries Shaped a Career

“…In contrast, if the climate is wetter in the future, then the estuaries will change to resemble estuaries in the northeastern range today. This is important for 2 reasons: 1) the hydrologic cycle controls the dynamics of freshwater delivery to coastal ecosystems and that cycle is likely to change under a changing climate (Scavia et al 2002) and 2) the southwest of the United States will be hotter and drier (Seager et al 2007, Wentz et al 2007, and this will compound water deficits leading to unprecedented drought challenges (Nielsen-Gammon et al 2020).…”

An assessment of trends in the frequency and duration of Karenia brevis red tide blooms on the South Texas coast (western Gulf of Mexico)

“…data) [34]. Long-term increases in salinity are linked to damming and growing human water demands in coastal watersheds over the past~50 years [36]. Population and climate projections suggest that over the coming century, Texas will see additional increases in population and water demands, as well as a warmer and drier climate [35,36].…”

“…Long-term increases in salinity are linked to damming and growing human water demands in coastal watersheds over the past~50 years [36]. Population and climate projections suggest that over the coming century, Texas will see additional increases in population and water demands, as well as a warmer and drier climate [35,36]. This will likely lead to further increases in salinity in Texas estuaries, leading to conditions that are more similar to seawater and thus more hospitable to K. brevis [58].…”

“…Bugica et al [34] recently demonstrated significant increases in salinity in the Nueces Estuary and other Texas Coastal Bend estuaries over the past 20-30 years due to damming and increased human demands on water resources. This trend is likely to continue with projected population growth in Texas coastal counties (Texas State Data Center, http://txsdc.utsa.edu/Data/TPEPP/Projections/Index.aspx) and warmer and drier conditions expected in the western Gulf of Mexico under changing climate pressures [35,36]. Understanding how anthropogenic activities are affecting salinity regimes in these estuarine systems will be critical for assessing potential future frequency of red tides.…”

“…This is important because estuaries of the South-Central Texas coast are undergoing significant environmental change due to rapid population growth and climate change [34]. Furthermore, climate scenarios suggest that the region will become hotter and drier in the future [35,36]. Results from this study offer insight into the utility of non-traditional data for detection of long-term trends and red tide population dynamics in a data poor region (Texas coast).…”