Hydrologic effects of phreatophyte control, Acme-Artesia reach of the Pecos River, New Mexico, 1967-82

The U.S. Bureau of Reclamation began a phreatophyte clearing and control program in the bottom land of the Acme-Artesia reach of the Pecos River in March 1967. The initial cutting of 19,000 acres of saltcedar trees, the dominant phreatophyte in the area, was completed in May 1969. Saltcedar regrowth continued each year until July 1975, when root plowing eradicated most of the regrowth. The major objective of the clearing and control program was to salvage water that could be put to beneficial use. Measurements of changes in the water table in the bottom land and changes in the base flow of the Pecos River were made in order to determine the hydrologic effects of the program. Some salvage of water was indicated, but it is not readily recognized as an increase in base flow. The quantity of salvage probably is less than the average annual base-flow gain of 19 ,110 acre-ft in the reach during 1967-82. (Author 's abstract)