Ground-water use in the Stovepipe Wells Hotel area in Death Valley National Monument is expected to increase significantly if the nonpotable, as well as potable, water supply is treated by reverse osmosis. During the peak tourist season, October through March, ground-water pumpage could increase by 37,500 gallons per day, or 76%. The effects of this additional pumpage on water levels in the area, particularly near a strand of phreatophytes about 10,000 feet east of the well field, are of concern. In order to evaluate the effects of increased pumpage on water levels in the Stovepipe Wells Hotel area well field, two aquifer tests were performed at the well field to determine the transmissivity and storage coefficients of the aquifer. Analysis of the aquifer test determined that a transmissivity of 1,360 feet squared per day was representative of the aquifer. The estimated value of transmissivity and the storage-coefficient values that are representative of confined (1.2 x .0004) and unconfined (0.25) conditions were used in the Theis equation to calculate the additional drawdown that might occur after 1, 10, and 50 years of increased pumpage. The drawdown calculated by using the lower storage-coefficient value represents the maximum additional drawdown that might be expected from the assumed increase in pumpage; the drawdown calculated by using the higher storage-coefficient value represents the minimum additional drawdown. Calculated additional drawdowns after 50 years of pumping range from 7.8 feet near the pumped well to 2.4 feet at the phreatophyte stand assuming confined conditions, and from 5.7 feet near the pumped well to 0.3 foot at the phreatophyte stand assuming unconfined conditions. Actual drawdowns probably will be somewhere between these values. Drawdowns measured in observation wells during 1973-85, in response to an average pumpage of 34,200 gallons per day at the Stovepipe Wells Hotel well field, are similar to the drawdowns calculated by the Theis equation for the assumed increase in pumpage. (Author 's abstract)