Wisconsin's Role in Great Lakes Restoration - American Water ...
Wisconsin's Role in Great Lakes Restoration - American Water ...
Wisconsin's Role in Great Lakes Restoration - American Water ...
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Integrated Interpretation of Borehole Flow, Aquifer-Test Results, and Spr<strong>in</strong>g<br />
Discharge—Culver Spr<strong>in</strong>gs, Wiscons<strong>in</strong><br />
Michael N. Fienen, U.S. Geological Survey, Middleton, WI, mnfienen@usgs.gov<br />
Keith J. Halford, U.S. Geological Survey, Carson City, NV, khalford@usgs.gov<br />
David J. Hart, Wiscons<strong>in</strong> Geological and Natural History Survey, Madison, WI<br />
djhart@wisc.edu<br />
Borehole flow logs can be used to estimate hydraulic conductivities and heads of the larger<br />
flow system. Flow logs typically are <strong>in</strong>terpreted with variants of the Theim solution, which<br />
assume flow to the wellbore is horizontal. Vertical flow can be simulated with radially<br />
symmetric MODFLOW models which are created easily with a new tool, AnalyzeHOLE. This<br />
tool also facilitates estimation of hydraulic conductivity distributions <strong>in</strong> the surround<strong>in</strong>g aquifer<br />
system with regularized <strong>in</strong>version to flow and drawdown observations. Differences between<br />
measured and simulated observations are m<strong>in</strong>imized, and atta<strong>in</strong>ment of a unique solution is<br />
atta<strong>in</strong>ed through regularization, with<strong>in</strong> PEST.<br />
We measured flows under ambient and pump<strong>in</strong>g conditions <strong>in</strong> well CS2 located near Culver<br />
Spr<strong>in</strong>gs <strong>in</strong> northeastern Dane County, WI. Measured flows through well CS2 and spr<strong>in</strong>g<br />
discharge were simulated with a three-dimensional flow model to constra<strong>in</strong> vertical-tohorizontal<br />
anisotropy and transmissivity upgradient of Culver Spr<strong>in</strong>gs. Ambient wellbore flow<br />
def<strong>in</strong>ed vertical-to-horizontal anisotropy. Spr<strong>in</strong>g discharge <strong>in</strong>formed transmissivity of the<br />
Tunnel City formation on a regional scale. Significant ambient flow, nearly 150 gpm, has been<br />
measured <strong>in</strong> the borehole emanat<strong>in</strong>g from and discharg<strong>in</strong>g to bedd<strong>in</strong>g planes <strong>in</strong> the Tunnel<br />
City formation. The vertical hydraulic-conductivity distribution, transmissivities, and vertical-tohorizontal<br />
anisotropy were estimable because simple models were fit simultaneously to<br />
borehole flow changes from pump<strong>in</strong>g, drawdown, ambient borehole flow, and spr<strong>in</strong>g<br />
discharge. Hydraulic property estimates from this <strong>in</strong>vestigation are comparable <strong>in</strong> scale to<br />
regional flow-model parameters. These estimates appropriately will def<strong>in</strong>e simulated<br />
hydrostratigraphic discharge <strong>in</strong> the Dane County regional model which currently is be<strong>in</strong>g<br />
revised.<br />
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