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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
By:

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Abstract

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). 

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Additional publication details

Publication type:
Report
Publication Subtype:
USGS Numbered Series
Title:
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:
90-4165
Year Published:
1990
Language:
English
Publisher:
U.S. Geological Survey
Publisher location:
St. Paul, MN
Contributing office(s):
Minnesota Water Science Center
Description:
xi, 152 p.
Country:
United States
State:
Minnesota
City:
Fridley
Online Only (Y/N):
N
Additional Online Files (Y/N):
N