Long-term trend analysis of reservoir water quality and quantity at the landscape scale in two major river basins of Texas, USA.

Land and Reservoir Management
By: , and 

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Abstract

Trends in water quality and quantity were assessed for 11 major reservoirs of the Brazos and Colorado river basins in the southern Great Plains (maximum period of record, 1965–2010). Water quality, major contributing-stream inflow, storage, local precipitation, and basin-wide total water withdrawals were analyzed. Inflow and storage decreased and total phosphorus increased in most reservoirs. The overall, warmest-, or coldest-monthly temperatures increased in 7 reservoirs, decreased in 1 reservoir, and did not significantly change in 3 reservoirs. The most common monotonic trend in salinity-related variables (specific conductance, chloride, sulfate) was one of no change, and when significant change occurred, it was inconsistent among reservoirs. No significant change was detected in monthly sums of local precipitation. Annual water withdrawals increased in both basins, but the increase was significant (P < 0.05) only in the Colorado River and marginally significant (P < 0.1) in the Brazos River. Salinity-related variables dominated spatial variability in water quality data due to the presence of high- and low-salinity reservoirs in both basins. These observations present a landscape in the Brazos and Colorado river basins where, in the last ∼40 years, reservoir inflow and storage generally decreased, eutrophication generally increased, and water temperature generally increased in at least 1 of 3 temperature indicators evaluated. Because local precipitation remained generally stable, observed reductions in reservoir inflow and storage during the study period may be attributable to other proximate factors, including increased water withdrawals (at least in the Colorado River basin) or decreased runoff from contributing watersheds.

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Additional publication details

Publication type Article
Publication Subtype Journal Article
Title Long-term trend analysis of reservoir water quality and quantity at the landscape scale in two major river basins of Texas, USA.
Series title Land and Reservoir Management
DOI 10.1080/10402381.2015.1074324
Volume 31
Issue 3
Year Published 2016
Language English
Publisher Taylor & Francis
Publisher location Milton Park, Abingdon
Contributing office(s) Coop Res Unit Atlanta
Description 26 p.
First page 254
Last page 279
Country United States
State California, Colorado, Nevada, New Mexico, Texas, Utah, Wyoming
Other Geospatial Brazos and Colorado River basins, southern Great Plains
Online Only (Y/N) N
Additional Online Files (Y/N) N