Observed trends in air temperature, precipitation, and water quality for Texas reservoirs: 1960-2010

Changes in climate, environmental management, and land use can affect water quality in lakes and reservoirs. Here, we quantify observed trends in water temperature and water quality in the 57 Texas reservoirs that have sufficient data for the period 1960 to 2010. We also quantify trends in air temperature and precipitation at 120 long-term weather stations adjacent to those reservoirs. Annual average temperature, seasonal average temperature, and cold temperature extremes are all becoming warmer near many Texas reservoirs. These air temperature trends are highly correlated with observed increases in water temperature across the state. Slight statewide increases in annual and winter, spring, and summer precipitation have contributed to greater increases in precipitation intensity, which are moderated by increases in the average number of dry days per year. Changes in precipitation can affect runoff and evaporation rates, which may alter levels of salts and minerals in the lakes. In addition, local human activities could be an important contributor to the observed increases in pH and phosphorus across the state and changes in specific conductance, sulfate, and chloride throughout Texas. Citation: Gelca R, Hayhoe K, Scott-Fleming I. 2014. Observed trends in air temperature, precipitation, and water quality for Texas reservoirs: 1960-2010. Texas Water Journal. 5(1):36-54. Available from: https://doi.org/10.21423/twj.v5i1.7001