USGS

Simulation of the Ground-Water-Flow System in the Kalamazoo County area, Michigan

In cooperation with the City of Kalamazoo, City of Portage, Kalamazoo County Human Services Department, and Michigan Department of Environmental Quality

 

By Carol L. Luukkonen, Stephen P. Blumer, T.L. Weaver, and Julie Jean

Scientific Investigations Report 2004-5054

Report available in PDF (12,505  KB)

Abstract

A ground-water-flow model was developed to investigate the ground-water resources of Kalamazoo County. Ground water is widely used as a source of water for drinking and industry in Kalamazoo County and the surrounding area. Additionally, lakes and streams are valued for their recreational and aesthetic uses. Stresses on the ground-water system, both natural and human-induced, have raised concerns about the long-term availability of ground water for people to use and for replenishment of lakes and streams. Potential changes in these stresses, including withdrawals and recharge, were simulated using a ground-water-flow model.

Simulations included steady-state conditions (in which stresses remained constant and changes in storage were not included) and transient conditions (in which stresses changed in seasonal and monthly time scales and storage within the system was included). Steady-state simulations were used to investigate the long-term effects on water levels and streamflow of a reduction in recharge or an increase in pumping to projected 2010 withdrawal rates, withdrawal and application of water for irrigation, and a reduction in recharge in urban areas caused by impervious surfaces. Transient simulations were used to investigate changes in withdrawals to match seasonal and monthly patterns under various recharge conditions, and the potential effects of the use of water for irrigation over the summer months.

With a reduction in recharge, simulated water levels declined over most of the model area in Kalamazoo County; with an increase in pumping, water levels declined primarily near pumping centers. Because withdrawals by wells intercept water that would have discharged possibly to a stream or lake, model simulations indicated that streamflow was reduced with increased withdrawals. With withdrawal and consumption of water for irrigation, simulated water levels declined. Assuming a reduction in recharge due to urbanization, water levels declined and flow to streams was reduced based on steady-state simulation results. Transient results indicated a reduction of water levels with the simulated use of water for irrigation over the summer months. Generally the transient simulation with recharge only in the winter provided the best fit to observed water levels collected during synoptic water-level measurements in some wells and to the trends observed in water levels for other wells.

Analysis of the regional hydrologic budgets provides an increased understanding of water movement within the ground-water-flow system in Kalamazoo County. Budgets for the steady-state simulations indicated that with reduced recharge, less water was available for streamflow and less water left the model area through the model boundaries. Similarly, with an increase in pumping rates, less water was available to enter streams and become streamflow. When recharge was assumed to remain constant and when it was allowed to vary throughout the year, the amount of water that entered storage was greater than that which left storage. However, when recharge was distributed through October–May only or when recharge rates were reduced from October to May, the amount of water that entered storage was less than that which left storage. Thus, on the basis of model simulations, with reduced recharge or increased withdrawals, water must come from storage, rivers, or from ground-flow-system boundaries to meet withdrawal demands.

Contents

Abstract

Introduction

Purpose and Scope

Previous Studies

Description of Study Area

Methods of Investigation

Water Levels and Stream Discharge

Seepage Measurements

Well Measurements

Temperature Monitoring

Hydrogeologic Setting

Geologic Setting

Description of Bedrock Units

Description of Glacial Deposits

Hydrologic Setting

Aquifers and Confining Units

Ground-Water Levels

Streamflow and Surface-Water Levels

Surface-Water/Ground-Water Interaction

Recharge

Historical Estimates of Recharge

Estimates Determined During this Study

History of Municipal Pumpage

Conceptual Model of Ground-Water Flow

Simulation of Ground-Water Flow

Spatial Discretization

Boundary Conditions

Hydraulic Properties and Stresses

Steady-State Calibration

Parameter Estimation

Simulation Results

Model Sensitivity Analysis

Transient Calibration

Aquifer Storage Characteristics

Initial Conditions

Temporal Discretization

Simulation Results

Model Assumptions and Limitations

Simulation of Potential Effects of Urbanization, Irrigation, and Changes in Withdrawals and Recharge

Potential Effects of Urbanization

Potential Effects of Irrigation

Potential Effects of Changes in Withdrawals and Recharge

Regional Ground-Water Budgets for Kalamazoo County

Conclusions

Acknowledgments

References Cited


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For further information, contact:

 

Jim Nichols, District Chief

U.S. Geological Survey

6520 Mercantile Way, Suite 5

Lansing, MI 48911-5991

 

mi_dc@usgs.gov

 

or visit our Web site at:

 

http://mi.water.usgs.gov


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