by J.F. Ruhl
Prepared in cooperation with the Prairie Island Indian Community
This report is available as a pdf below
The Prairie Island Indian Community in east-central Minnesota uses ground water from the Mt. Simon-Hinckley aquifer as its source of water supply. Tribal officials implemented a Source Water Protection Program to protect the quality of this water. Areas of contributing recharge were delineated for two community well fields. At well field A are two wells 325 m apart, and at well field B are two wells 25 m apart.
A steady state single layer, two-dimensional ground-water flow model constructed with the computer program MODFLOW,combined with the particle-tracking computer program MODPATH, was used to track water particles (upgradient) from the two well fields. A withdrawal rate of 625 m3/d was simulated for each well field. The ground-water flow paths delineated areas of contributing recharge that are 0.38 and 0.65 km2 based on 10- and 50-year travel times, respectively. The flow paths that define these areas extend for maximum distances of about 350 and 450 m, respectively, from the wells. At well field A the area of contributing recharge was delineated for each well as separate withdrawal points. At well field B the area of contributing recharge was delineated for the two wells as a single withdrawal point. Delineation of areas of contributing recharge to the well fields from land surface would require construction of a multi-layer ground-water flow model.
Abstract
Introduction
Purpose and scope
Previous investigations
Hydrogeologic setting
Simulation of ground-water flow
Model design and discretization
Model geometry and hydraulic properties
Model boundary conditions
Inflows
Outflows
Model calibration
Model sensitivity
Delineation of recharge areas
Model limitations
Summary
References
Use of trade, product, or firm names in this report is for identification purposes only and does not constitute endorsement by the U.S. Geological Survey.
For additional information write to:
U.S. Geological Survey
District Chief
2280 Woodale Drive
Mounds View, MN 55112
Copies of this report can be purchased from:
U.S. Geological Survey
Branch of Information Services
Box 25286, MS 517
Federal Center
Denver, CO 80225
You may also connect to the Minnesota District Home Page at http://mn.water.usgs.gov
For more information on all USGS reports and products (including maps, images, and computerized data),
call 1-888-ASK-USGS
The text and graphics are presented here in pdf format (print quality):
The report is also available in sections below in pdf, for a faster download.
If you have Adobe Acrobat Reader installed on your computer, you may view and/or print the PDF version of this report. If you do not have Acrobat Reader, you may download it here.
| AccessibilityFOIAPrivacyPolicies and Notices | |
  |
|