Title

Methods of Assessing Streamflow and Shallow Groundwater Interactions

Presenter Information

Jacob Presher
Cristopher Morton

Document Type

Oral Presentation

Location

SURC Ballroom B/C/D

Start Date

21-5-2015

End Date

21-5-2015

Keywords

Stream Restoration, Hyporheic Flow, Stream Ecology

Abstract

In recent years, the importance of groundwater-surface water interactions to stream ecology has been increasingly recognized. Interactions between stream flow and hyporheic flow, which is shallow groundwater connected to stream water, are important to stream ecology by moderating surface-water temperatures, slowing stream velocity, increasing nutrient residence times, and providing water to the ecosystem beyond the immediate area of the stream channel. The purpose of our research was to determine if and how stream restoration efforts impact interactions between stream flow and hyporheic flow. We collected stream stage and hyporheic potentiometric elevation data from sites in the Reecer Creek Floodplain Restoration project and an unrestored section of Reecer Creek. We installed a piezometer, a perforated hollow steel pipe, to a depth of one to two feet in the stream substrate, and inserted a water pressure sensor within the piezometer. Comparing piezometer water depth to stream depth allowed us to determine the extent of the interaction between the stream and the groundwater within the hyporheic zone. Discharge of hyporheic flow to stream flow (i.e., upwelling) is indicated by a higher water level within the piezometer, while stream flow discharge to hyporheic flow (i.e., downwelling) is indicated by lower water levels in the piezometer. We predict more interaction between stream and hyporheic flow in restored reaches due to higher permeability of the stream bed, resulting from less silt and more gravel in the substrate. Ultimately, we hope to determine if restoration efforts measurably improved stream flow interactions with the hyporheic zone, which directly affects stream ecology.

Poster Number

12

Faculty Mentor(s)

Lisa Ely, Carey Gazis

Department/Program

Environmental Studies

Additional Mentoring Department

Geological Sciences

Additional Mentoring Department

Geological Sciences

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May 21st, 8:30 AM May 21st, 11:00 AM

Methods of Assessing Streamflow and Shallow Groundwater Interactions

SURC Ballroom B/C/D

In recent years, the importance of groundwater-surface water interactions to stream ecology has been increasingly recognized. Interactions between stream flow and hyporheic flow, which is shallow groundwater connected to stream water, are important to stream ecology by moderating surface-water temperatures, slowing stream velocity, increasing nutrient residence times, and providing water to the ecosystem beyond the immediate area of the stream channel. The purpose of our research was to determine if and how stream restoration efforts impact interactions between stream flow and hyporheic flow. We collected stream stage and hyporheic potentiometric elevation data from sites in the Reecer Creek Floodplain Restoration project and an unrestored section of Reecer Creek. We installed a piezometer, a perforated hollow steel pipe, to a depth of one to two feet in the stream substrate, and inserted a water pressure sensor within the piezometer. Comparing piezometer water depth to stream depth allowed us to determine the extent of the interaction between the stream and the groundwater within the hyporheic zone. Discharge of hyporheic flow to stream flow (i.e., upwelling) is indicated by a higher water level within the piezometer, while stream flow discharge to hyporheic flow (i.e., downwelling) is indicated by lower water levels in the piezometer. We predict more interaction between stream and hyporheic flow in restored reaches due to higher permeability of the stream bed, resulting from less silt and more gravel in the substrate. Ultimately, we hope to determine if restoration efforts measurably improved stream flow interactions with the hyporheic zone, which directly affects stream ecology.