Estimates of evapotranspiration by young saltcedar, based on energy budget measurements, were made for an unfilled portion of the San Carlos Reservoir in east-central Arizona. Foty-eight days of record were obtained before the site was inundated. The young saltcedar, which had grown from seed earlier in the season , had an average daily evapotranspiration of 5.8 millimeters of water during the period August 17, 1971, to October 3, 1971. Daily values ranged from 9.2 millimeters to a low of 0.23 millimeters which occurred during a stormy day. (USGS)