As such it contains a significant amount of variability that can be attributed to climatic and seasonal changes, and the cumulative effect of pumping from the alluvial aquifers. Final model adjustment was made by increasing the recharge adjustment factor in cells adjacent to the Kc contact along Chetolah Creek. Lower cell transmissivities in northeastern Hays could have achieved the same quality of fit with observed heads, but were not indicated by well tests or the lithologic model.
Boundary conditions default to no-flow around the margins of the model.
These head values were adopted from the interpolated water-table observation data from Table 3 . Recharge into Layer 1 and 2 is concentrated adjacent to the Kc contact, to simulate overland flow on the upland which then recharges the alluvial aquifers. The concentration factor is 8 times the model average recharge. A factor of 10 times concentration was required in the Chetolah Creek area in northeastern Hays to match observed head. A few potential model inconsistencies are present in these results.