Simulation of ground-water flow in the Prairie du Chien-Jordan and overlying aquifers near the Mississippi River, Fridley, Minnesota
Water-Resources Investigations Report 90-4165
Prepared in cooperation with the Minneapolis Water Works
- R.J. Lindgren
A three-dimensional, ground-water-flow model was developed to gain an improved understanding of the ground-water-flow system and its response to withdrawals near the Minneapolis Water Works in Fridley, Minnesota. Eight hydrogeologic units are represented in the ground-water-flow model. Aquifers represented are the unconfined-drift, confined-drift, St. Peter, and Prairie du Chien-Jordan. Confining units represented are the upper drift, basal-drift, Decorah-Platteville-Glenwood, and basal St. Peter confining units. The ground-water-flow model was calibrated for steady-state conditions fbr a period before substantial ground-water development (1885-1930) and for a period of significant pumping stress (winter conditions, 1970-79). The principle of superposition was used in the steady-state simulation for 1970- 79. Transient conditions were simulated for an aquifer test conducted at the Minneapolis Water Works site and for seasonal variations in ground-water withdrawals resulting in seasonal fluctuations of hydraulic heads of as much as about 45 ft. Sensitivity analysis indicated that hydraulic heads in the confined-drift and St. Peter aquifers and Prairie du Chien-Jordan aquifer were most affected by varying the vertical hydraulic conductivity of the upper drift confining unit and recharge to the confined-drift and St. Peter aquifers.
Spatially variable leakage to the confined-drift and St. Peter aquifers in the steady-state simulation for 1885-1930 ranged from 1.0 to 2.3 inches per year. Leakage to the confined-drift and St. Peter aquifers in the steady-state simulation for 1970-79 increased 0 to 3.0 inches per year above the initial steady-state results. This increase represents additional leakage caused by the lowering of hydraulic heads due to ground-water withdrawals. Simulated leakage to the confined-drift and St. Peter aquifers for the transient simulation for 1987 varied both seasonally (0.4 to 2.1 inches per stress period) and spatially (2.6 to 5.7 inches per year).
Additional publication details
- Publication type:
- Publication Subtype:
- USGS Numbered Series
- Simulation of ground-water flow in the Prairie du Chien-Jordan and overlying aquifers near the Mississippi River, Fridley, Minnesota
- Series title:
- Water-Resources Investigations Report
- Series number:
- Year Published:
- U.S. Geological Survey
- Publisher location:
- St. Paul, MN
- Contributing office(s):
- Minnesota Water Science Center
- xi, 152 p.
- United States
- Online Only (Y/N):
- Additional Online Files (Y/N):