Abstract Sedimentary process simulation permits delta-forming processes to be represented directly reproducing volume, geometry, and sedimentary architecture of a delta, albeit in simplified form. Input parameters for simulations are process field data that describe the depositional environment of the actual delta. The spatial sediment distribution of the coarse-grained, unconfined aquifer of the early Holocene Gardermoen delta complex near Oslo, Norway, is simulated with sedsim. The simulated depositional environment consists of a glacier-contact delta complex developing within less than 100 yr, implying an extremely rapid sedimentation rate. A spatial distribution of hydraulic conductivities is determined from the simulated sediment distribution by using an empirical relationship between grain size and conductivity. Geostatistical analyses show that field data and hydraulic conductivities derived from simulations have similar spatial continuity and anisotropy. To test the quality of modeling results, estimates of hydraulic conductivity are determined from the semivariogram of the simulated distribution conditioned to only a subset of field data points. The difference between field data and simulated values is for the main part of the area within only ±0.5 log hydraulic conductivity in meters/second. These results show that sedimentary process simulations can be used to predict hydraulic conductivities in areas where field data are missing if process data can be constrained well enough.