Changes in ground-water withdrawals, water levels, and quality of water occurred in the artesian aquifers of the Sevier Desert, Utah during 1963-81. Ground-water withdrawals increased from an average of 9,500 acre-feet (11.7 cubic hectometers) per year between 1951 and 1963 to an average of 27,500 acre-feet (33.9 cubic hectometers) per year between 1964 and 1981. Most of the increased withdrawal was from the deep artesian aquifer. Water levels declined as much as 19 feet (5.8 meters) in the deep artesian aquifer and as much as 13 feet (4.0 meters) in the shallow artesian aquifer between 1963 and 1981. The declines probably are due to increased ground-water withdrawals for irrigation and municipal use. Quality of water in parts of the shallow artesian aquifer is deteriorating. The deterioration probably is the result of recharge of poor quality from the overlying water-table aquifer. A digital-computer model was constructed to predict water-level changes resulting from changes in recharge and discharge for 20 years (1981-2000) at one-half, one, and two times the 1977-79 average rate. The model computer water-level declines of more than 80 feet (24 meters) in the deep artesian aquifer with withdrawals twice the 1977-79 average, declines of more than 40 feet (12 meters) if withdrawals were equal to the 1977-79 average, and declines of more than 15 feet (4.6 meters) if withdrawals were one-half the 1977-79 average. Computer water-level declines after 20 years in the shallow artesian aquifer were more than 50 feet (15 meters) at two times the 1977-79 average rate, more than 15 feet (4.6 meters) at the 1977-79 average, and less than 4 feet (1.2 meters) at one-half the 1977-79 average. The model also was used to predict the effects of approximate changes in ground-water withdrawals related to the Intermountain Power Project. Water-level declines in the deep artesian aquifer of more than 15 feet (4.6 meters), and only small changes in water levels in the shallow artesian aquifer after 20 years. These changes are in addition to changes computed for 20 years of withdrawals at the 1977-79 rate. (USGS)