Numerical simulation of freshwater storage in the Dammam Formation, Kuwait

Numerical modeling of artificial recharge of the Dammam Formation in Kuwait was carried out to assess the feasibility of the recharge project and to optimize the operation. The two parameters that were considered for this assessment were induced rise in head during injection; and the volume of recovered water with specified quality (recovery efficiency). The MODFLOW-MT3D and HST3D software were used for the numerical simulation. Results of scenario runs suggest that alternate injection (655 m(3)/d/well) and recovery (1310 m(3)/d/well) cycles would give acceptable recovery efficiency with manageable rise in potentiometric heads. Shifting of the recharge site to the southwestern corner of the selected area would allow better injection hydraulics due to higher transmissivity of the aquifer and would result in improved recovery efficiency due to lower salinity of the native groundwater. The sensitivity runs indicate that the vertical hydraulic conductivity of the layer overlying the Dammam Formation and the horizontal hydraulic conductivity of the Dammam Formation have the largest influence on the potentiometric head. The recovery efficiency was mostly controlled by the horizontal hydraulic conductivity and the dispersivity of the Dammam Formation and the difference in the salinity between the injection water and the native water.