Bio-Inspired Stabilization of a Test Levee Slope Using Vetiver Grass on Highly Plastic Clay

According to the National Centers for Environmental Information (NCEI), the US was impacted by 20 separate billion-dollar disasters in 2021, including inland floods, severe storms, and tropical cyclones. Shallow landslides are common on earthen infrastructure that contains high plasticity clay due to its swelling nature, particularly when exposed to moisture during extreme weather events. As severe weather becomes more common due to climate change, levee slopes are further compromised. Vetiver grass implanted as a bio-inspired slope stabilization method in levees built using marginal soils, such as Yazoo clay in Mississippi, provides an economically and environmentally sustainable solution. Vetiver has deep grassroots that can exceed 10 ft (3 m) in depth; this makes it ideal for water conservation and stormwater management. The current paper presents a 40 ft (12.2 m) × 30 ft (9.1 m) study area of a test levee slope improved using vetiver grass. A finite element (FE) seepage analyses and limit equilibrium stability analysis considered the effect of seepage, flooding, and rainfall on the stability of a comparable levee design with and without vetiver implantation. This research demonstrates that planting vetiver in Yazoo and loess clays is feasible and can improve the stability of the levee. With increased probability of extreme weather, vetiver’s use on levees holds promise as a climate-resilient solution.