Dakota Home Report Archive FY92 Ann Rep

Kansas Geological Survey, Open-File Rept. 93-1
Annual Report, FY92--Page 11 of 20

Effect of River Valleys..., continued

Ground-Water Flow Patterns in the Upper Part of the Regional Flow System

Figure 29 is a vertical profile of freshwater equivalent hydraulic heads in the upper part of the regional flow system. Ground-water flow directions are assumed to be from higher to lower head and perpendicular to the equipotentials. The dominant flow direction in the upper aquifers above the Permian-Pennsylvanian aquitard is parallel to the regional topography from elevated recharge areas in southeastern Colorado to discharge areas in central Kansas. In the deeper part of the system in southeastern Colorado, the flow direction is downward and away from the upthrown Precambrian block on the west side of the Freezeout Creek fault zone. Farther east in the Western Kansas basin and the Central Kansas uplift areas, the vertical flow direction is downward across all the aquitards toward the deeper part of the regional flow system. In these areas the nearly horizontal orientation of the equipotentials in the Permian-Pennsylvanian and evaporite aquitards indicates that the Dakota aquifer and other shallow aquifers are hydraulically isolated from the deeper aquifers below the evaporite aquitards.

Figure 29--Predevelopment distribution of head (ft above mean sea level) in the vertical profile. The boundary between the intermediate-scale flow system and the regional flow system is shown by the bold line.

The boundary separating the upper from the lower part of the flow system is a flow line and is shown in Figure 29. Ground-water flow above this flow line is dominated by the lateral movement of ground water in aquifers from recharge areas in southeastern Colorado to discharge areas in central Kansas and points eastward. Below the boundary ground-water flow is across the thick Permian-Pennsylvanian and the evaporite aquitards to the deeper aquifers in southeastern Colorado and western and central Kansas. This conceptualization of the flow system is consistent with Belitz (1985), Belitz and Bredehoeft (1988), and Jorgensen et al. (1993). The upper portion of the flow system is interpreted as part of a large intermediate-scale system, whereas the lower part is interpreted as a portion of the regional system.

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Kansas Geological Survey, Dakota Project
Updated Jan. 1997
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