The State of Hawaii Department of Transportation, Highways Division, Oahu District (DOT-HWYS) has been very busy over the last year repairing eroded slopes along its highways as part of the Permanent Erosion Control Program. Since the start of 2016 permanent erosion repair projects have been completed at 14 sites, island wide. If you drive on the H-1, H-2 or H-3 freeways you have likely seen these projects. The general technique DOT-HWYS uses to repair these eroded sites involves removing invasive plant species and preparing the slope, adding mulch and fertilizer, installing erosion control fabric, then planting the slope with native grasses and shrubs. During the design process the selection of hydromulch, fertilizer, erosion control fabric and plant species is determined based on the specific conditions and location of each site. The goal is to establish vegetation that will be self-sustaining to eliminate future erosion issues. Keep your eyes open for many more slope repair projects in 2017!
Prior to construction this H-1 Freeway site located next to Pearl Ridge Elementary was an area of significant, ongoing soil erosion.
During the construction repair the soil was cleared of invasive grasses, the soil was prepped and erosion control fabric was secured to the slope.
A few weeks after it was planted, the new Kawelu grass at the site near Pearl Ridge Elementary is thriving.
During the new plant establishment period landscapers are working to remove invasive species in order to give the Kawelu grass an opportunity to become established.