Distribution of Hydraulic Head in the Clearwater Hydrostratigraphic Unit

This map depicts the distribution of hydraulic head in groundwater in the Clearwater hydrostratigraphic unit (HSU). The map is a result of a simple kriging technique using representative hydraulic head values calculated from drill  stem test pressures and static water level data from water wells. 

The distribution of hydraulic head was mapped at a regional scale using many years of data, thus providing a good indication of regional hydraulic head within the unit rather than site-specific values. The uncertainty of prediction is depicted on an inset map, which shows the residual values (predicted value minus measured value) plotted at each location to indicate where underprediction and overprediction occurs. Thre additional inset maps show the location of tests removed during the Cumulative Interference Index (CII) process, the distribution of total dissolved solids, and the results of water driving force analysis, respectively. The geometry and variable thickness of the Clearwater HSU are illustrated on schematic cross-sections. The regional lithostratigraphy and hydrostratigraphy of the Clearwater HSU and overlying and underlying units are highlighted in a table.