Failure modes in cedar tree revetments: Observations on rivers and streams in eastern Kansas, USA

Abstract

A cedar tree revetment is a bioengineering technique intended to stabilize eroding stream banks using longitudinally placed cedar trees. This technique, which has been implemented on many rivers and streams across the United States, has been proposed as a less expensive, ecologically compatible bank stabilization method. The limited documentation of these types of bioengineering techniques indicates high failure rates. River engineers need to understand the potential failure modes of cedar tree revetments, so they can take appropriate countermeasures when applying this technique. This article documents four common failure modes observed during postproject site assessments on 12 streams in eastern Kansas, USA that took place in 2019 and 2020. These modes are (1) bed degradation with structure perching, (2) fail-

Can deciduous tree revetments reduce streambank erosion rates on a sand‐bed stream?

“…Improper anchoring of large wood structures has been reported as the primary failure mechanism in several case studies of large wood structures (e.g., Miller & Kochel, 2013; Russell et al, 2021; Shelley et al, 2022; Shields et al, 2006). Therefore, a large wood (LW) design spreadsheet developed by Rafferty (2017) was used on the designed deciduous tree revetments (Figure 1) to assist in conducting vertical (i.e.…”

“…footer log and duckbill anchor) were used. Coniferous tree revetments are another technique that is similar to the described deciduous tree revetment approach (e.g., Dave & Mittelstet, 2017; Shelley et al, 2022); however, they differ in that (1) they are anchored with only a cable and duckbill anchor and (2) they are laid parallel with the streambank toe. Permeable spurs are also similar to the described deciduous tree revetment technique.…”

Baseline data for a cedar tree revetment monitoring site near Wichita, Kansas

“…In 2019, 2020, and 2021, the authors visited cedar tree revetment project sites in Kansas, Missouri, Tennessee, and Minnesota * (Shelley et al 2022) The level of pre-project, as-built, and post-project monitoring varied significantly but was typically sparse. At several locations, the angle of the cabling suggested that the cedars may have both floated upwards and translated downstream.…”