Date of Award

5-2015

Degree Name

Master of Science

Department

Geosciences

First Advisor

Dr. Duane R. Hampton

Second Advisor

Dr. Alan E. Kehew

Third Advisor

Dr. Steve Kohler

Access Setting

Masters Thesis-Open Access

Abstract

The Fallasburg Dam on the Flat River is required to release 110 cfs to the Bypass Channel. Residents have often reported low flows in the river, especially during the summer. The hydrology of the Bypass Channel downstream from the dam was investigated to determine whether the required flow was being released. Discharge measured at multiple transects reveal a shifts from gaining to losing conditions during the year. Gaining conditions occur during the spring and after significant rain events; losing conditions occur in the summer during dry periods. Five discharge measurements in 2013 and three in 2014 reveal flows less than 110 cfs. Much of the summer of 2013 likely had losing conditions because it was a dry year and had low groundwater levels. Only middle to late summer of 2014 experienced losing conditions. Groundwater elevations from wells on both sides of the river indicate losing conditions occur when levels in wells BCN and BCS are both below 655.5 feet. Concentrations of Fe(II), Mn(II), and PO43- in the groundwater and surface water mostly agree with discharge measurements, showing increases in surface water concentrations during gaining conditions. Seepage meter data reveals gaining after rainfall and losing during dry periods. Actual minimum discharge from the dam is likely less than 110 cfs because it is calibrated by measuring 110 cfs downstream from the dam when gaining conditions are likely to occur.

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