Effect of Large Wood Restoration on Alluvial Aquifer Storage in Yakima Basin Headwater Tributaries
Date published: May 2023
Authors: Carey A. Gazis and Lisa L. Ely (CWU Geology)
Reference:
Gazis, Carey A., and Lisa L. Ely. “Effect of Large Wood Restoration on Alluvial Aquifer Storage in Yakima Basin Headwater Tributaries.” Washington State Department of Ecology, May 2023.
Abstract:
This project focused on two sites in the Teanaway River basin: Indian Creek and Teanaway Valley Family Farm (TVFF). Indian Creek is a small tributary on the North Fork of the Teanaway River where large wood (LW) was emplaced in stages from 2016 to 2018. The authors assessed whether the restoration of instream LW had consistent, detectable effects on the recharge and storage of groundwater in the alluvial floodplain aquifer at Indian Creek. Possible changes to the groundwater in the floodplain before and after the LW installation were investigated through analysis of the floodplain stratigraphy and sediment grain-size, stream-flow modeling, and monitoring of groundwater levels from 2014-2021.
The results of the research at Indian Creek suggest that the wood in the stream is yet to have an impact on the groundwater recharge and storage in the Indian Creek floodplain. This being said, the large wood restoration project at Indian Creek is still relatively recent, and restoration work is still being performed at the site.
At TVFF, groundwater elevation data from the ten monitoring wells define three aquifers in the study area. A cobble-rich alluvial aquifer occupies the lower two-thirds of the floodplain. Stable isotope data indicates that Teanaway River water infiltrates fully into this aquifer and completely flushes through the aquifer in the riparian forest along the river. In the upper third of the floodplain, there is a confined aquifer below the thick clay deposit. The hydraulic head of that aquifer is controlled by snowmelt and streamflow in the hillslopes.
Contact person/agency: Carey Gazis or Lisa Ely (CWU Geology)
File Format: pdf
Associated Data:
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