ARTIFICIAL RECHARGE OF THE DELTA AQUIFER, WEBER COUNTY, UTAH

Aquifer artificial recharge is being conducted in Weber County, Northern Utah. One of the principal aquifers of the study area, the Delta aquifer, has experienced a decline in hydraulic head since the early 1950s. Growing population density resulting in increasing water usage, combined with recent drought conditions caused the potentiometric surface to decline up to 100 feet in some areas. A proposed artificial recharge not only would restore the aquifer storage but also would reduce losses caused by evaporation of surface water used in the recharge experiment. The proposed artificial recharge would enhance naturally occurring recharge from the Weber River through a thick sequence of deltaic deposits. Students at Weber State University, as a part of this project conducted by the U.S. Bureau of Reclamation, Weber Basin Water Conservancy District, Utah Geological Survey and Utah Division of Water Resources, reconstructed preliminary recharge experiments conducted between 1952 and 1958 in the same area. Results of these experiments are being used to model stress simulations on the Delta aquifer for the currently conducted recharge project A Modflow model is used to reconstruct the past stress conditions and possible future recharge scenarios. Difficulties and uncertainties in the model are caused by the close proximity of the major fault zone and limited amount of information regarding deeper sections of unconsolidated basin-fill sediments. The presented simulation maps are developed using ArcView 3.3 and ArcInfo 8.3.