Hydrogeologic Data from a Shallow Flooding Demonstration Project, Twitchell Island, California, 19972001

By James M. Gamble, Karen R. Burow, Gail A. Wheeler, Robert Hilditch, and Judy Z. Drexler



Open–File Report 03-378

Sacramento, California 2003

Prepared in cooperation with the
California Department of Water Resources

Complete accessible text of report (3.22 MB PDF)

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    Data were collected during a study to determine the effects of continuous shallow flooding on ground-water discharge to an agricultural drainage ditch on Twitchell Island, California. The conceptual model of the hydrogeologic setting was detailed with soil coring and borehole-geophysical logs. Twenty-two monitoring wells were installed to observe hydraulic head. Ten aquifer slug tests were done in peat and mineral sediments. Ground-water and surface-water temperature was monitored at 14 locations. Flow to and from the pond was monitored through direct measurement of flows and through the calculation of a water budget.

    These data were gathered to support the development of a two-dimensional ground-water flow model. The model will be used to estimate subsurface discharge to the drainage ditch as a result of the pond. The estimated discharge will be used to estimate the concentrations of DOC that can be expected in the ditch.





Study Site

Data Collection Methods

Soil Coring

Borehole-Geophysical Data

Monitoring Wells

Temperature Monitoring

Slug Tests

Flow Monitoring


Lithologic Characterization

Water Levels

Water Temperatures

Estimates of Hydraulic Conductivity

Seepage Estimates


References Cited

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