820
815
810
805
800
. 795
790
785
780
775
770
765      .    .    .    ..             .    .
0   0.1  0.2  0.3  0.4  0.5  0.6  0.7  0.8  0.9   1
time (days)
Figure 4.14. Decline in head in a hypothetical monitoring well located near the screen of the
pumping well. Steady-state is reached in less than one day.
4.4.2 Vernon Marsh Model
The Vernon Marsh model was run to steady-state with the addition of three recently
installed pumping wells (Table 3.7) in order to determine the effects of these wells on
groundwater heads and surface water features. Heads are lowered by more than 1 ft north of
Vernon Marsh (Fig 4.15) with a maximum water table drop of 22 ft as a result of pumping.
The marsh stages change very little with pumping (Table 4.10). The northernmost (upper)
part of the marsh has only a 3% decrease in groundwater inflow, but a 40% increase in
groundwater outflow (Table 4.10). These results are similar to those of the regional model,
which showed an 8% reduction in groundwater inflow to the northernmost section of the
marsh. The model predicts the reach of the Fox River directly east of the pumping wells is
dry, but the heads directly below the streambed are less than 1 ft below the bottom of the