Date of Award

Spring 2024

Rights

Access is available to all users

Document Type

Thesis

Degree Name

Master of Science (MS) in Biology

Department

Biology

Abstract

Widespread stream incision in the Western United States, exacerbated by climate change and anthropogenic activities, necessitates effective restoration strategies. My study compares water retention by Beaver Dam Analogs (BDAs) to natural beaver dams and undammed control reaches. I compared how dam dimensions affect the hydraulic performance of both BDAs and beaver dams, revealing gaps in research on their comparative effectiveness. My study was conducted across eight watersheds in Washington state and two in Idaho. Hydraulic retention time (HRT), water travel time, and pool volume were response variables used to determine dam effectiveness. Dam height, thickness, length and porosity were the predictor variables. While BDA water travel times were significantly longer than control sites, natural beaver sites exhibited significantly higher HRT than BDA sites. Beaver dams were also significantly thicker and longer than BDAs. I identified dam thickness, height, and dam type as the most influential factors in determining HRT for both types. For BDAs, height and porosity significantly affected HRT, but among beaver dams, HRT had no significant predictors. Beaver dams also held a significantly larger volume of water than BDAs, with height and discharge as significant predictors. For BDAs, height alone significantly affected pool volume. Findings suggest that, while BDAs have a shorter water retention time compared to beaver dams, they do slow water compared to their control sites. My study highlights the need to consider dam dimensions and surface porosity in the design of BDAs to enhance their effectiveness.

Download
Off-Campus Download

Share

COinS