We evaluated treatments designed to remove saltcedar (Tamarix ramosissima) monocultures from riparian habitats using root plows (mechanical treatment) and aerial applications of the herbicide imazapyr (chemical treatment) within twelve 4-ha impoundments in the Middle Rio Grande Valley in central New Mexico, USA. Following these treatments, impoundments were flooded and water levels were reduced to stimulate native species re-establishment from seed. Water manipulations within saltcedar-removal areas consisted of stage drawdowns of 5 cm/day and 10 cm/day. Mechanically cleared areas had fewer saltcedar resprouts (26 resprouts/ha) than chemically treated areas (2,500 resprouts/ha). Saltcedar and cottonwood (Populus deltoides subsp. wislizinii) seedling density and cottonwood survival were greater in mechanically treated areas than in chemically treated areas. This effect is attributed to soil disturbance resulting from root plowing. Cottonwood seedling density and survival did not differ between 5 cm/day and 10 cm/day stage drawdowns and decreased throughout summer as a result of excessive moisture stress. The absence of a drawdown treatment effect indicates that both drawdowns were too fast for seedling roots to keep up with declining water tables. Seedlings that survived were using moisture from the unsaturated zone.