Prepared in cooperation with the city of Cadillac, Michigan

Simulation of Ground-Water Flow and Areas Contributing Ground Water to Production Wells, Cadillac, Michigan


By C.J. Hoard and D.B. Westjohn
U.S. Geological Survey Scientific Investigations Report 2004-5175


Report is available in PDF ( 3,736 KB)


Ground water is the primary source of water for domestic, municipal, and industrial use within the northwest section of Michigan's Lower Peninsula. Because of the importance of this resource, numerous communities including the city of Cadillac in Wexford County, Michigan, have begun local wellhead protection programs. In these programs, communities protect their ground-water resources by identifying the areas that contribute water to production wells, identifying potential sources of contamination, and developing methods to cooperatively manage and minimize threats to the water supply.

The U.S. Geological Survey, in cooperation with the city of Cadillac, simulated regional ground-water flow and estimated areas contributing recharge and zones of transport to the production well field. Ground-water flow models for the Clam River watershed, in Wexford and Missaukee Counties, were developed using the U.S. Geological Survey modular three-dimensional finite-difference ground-water flow model (MODFLOW 2000). Ground-water flow models were calibrated using the observation, sensitivity, and parameter estimation packages of MODFLOW 2000. Ground-water-head solutions from calibrated flow models were used in conjunction with MODPATH, a particle-tracking program, to simulate regional ground-water flow and estimate areas contributing recharge and zones of transport to the Cadillac production-well field for a 10-year period.

Model simulations match the conceptual model in that regional ground-water flow in the deep ground-water system is from southeast to northwest across the watershed. Areas contributing water were determined for the optimized parameter set and an alternate parameter set that included increased recharge and hydraulic conductivity values. Although substantially different hydrologic parameters (assumed to represent end-member ranges of realistic hydrologic parameters) were used in alternate numerical simulations, simulation results differ little in predictions of the size of the contributing area to the city well field. However, increasing recharge and hydraulic conductivity values appreciably affected the shape of the contributing area and zone of contribution of reacharge. Simulation results indicate that the region immediately to the south and southeast of the well field is contributing water to the production wells. Detailed aquifer characterization would be needed to describe and simulate the heterogeneous glacial deposits in the watershed.

Table of Contents




Purpose and Scope

Previous Studies

Description of Study Area

Simulation of Ground Water Flow

Model Development




Model Calibration and Sensitivity

Delineation of Contributing Areas

Optimized Scenario

Alternate Scenario

Limitations of Model Simulations



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


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Last modified: Thursday, January 10 2013, 06:38:23 PM
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