Annual mean and annual minimum and maximum daily mean streamflow were compared with associated annual index precipitation for sites on the main channel and tributaries of the Apalachicola, Pearl, Trinity, and Nueces Rivers in the Gulf of Mexico Basin. Precipitation and annual minimum streamflow at the downstream station on each river increased over the available periods of record. No long-term changes were identified in mean and maximum streamflow to the Gulf from the Apalachicola River Basin. Annual mean and maximum streamflow to the Gulf increased with time from the Pearl River Basin and decreased from the Trinity River Basin. Annual mean streamflow showed varied trends and annual maximum streamflow decreased for the Nueces River Basin. Short-term trends in streamflow and precipitation generally corresponded at most stations. Total reported surface-water withdrawals from the Trinity River Basin increased more than fourfold since 1940 and currently represent about one-fourth of the mean streamflow near the mouth of the river. Total reported withdrawals from the Nueces River Basin increased more than eightfold since 1940 and currently represent about one-third of the annual mean streamflow near the mouth. Predicted peak streamflow into the Gulf from the Apalachicola River was 23 percent less for the 50-year peak streamflow after reservoirs were constructed. Annual mean streamflow to the Gulf was reduced following construction of the downstream reservoirs on the Apalachicola and Trinity Rivers. Peak streamflows from the Pearl and Trinity Rivers have not been affected. The annual mean streamflow from the Nueces River was reduced by about 24 percent as a result of filling and evaporation at Choke Canyon Reservoir.
Additional publication details
USGS Numbered Series
Streamflow analysis of the Apalachicola, Pearl, Trinity, and Nueces River basins, southeastern United States
Water-Resources Investigations Report
U.S. Geological Survey ;
Earth Science Information Center, Open-File Reports Section [distributor],