Integrated bioengineering and geotechnical treatments for streambank restoration and stabilization along a landfill

ABSTRACT:

Vegetative-based bioengineering treatments were integrated with geotechnical treatments to provide effective, affordable and environmentally sound restoration and stabilization of an eroding streambank [8 m (27 ft) high and 145 m (470 ft) long] along a sanitary landfill adjacent to Mill Creek in Cincinnati, Ohio. Bank stabilization design featured the use of dormant live brush in several configurations: live poles installed through interstices in a rock toe; brush layers laid between geogrid-wrapped soil lifts; live stakes through a coir blanket, and a brush fascine staked in a trench near the top of bank. Vegetation has grown vigorously and no erosion problems have been observed. Bank stability was confirmed by a topographic survey in 2004 showing no observable difference from a post-construction survey in 1999. A quantitative vegetation survey in April 2004 determined essentially 100 percent grass coverage on the banks. Seventy-four percent of stakes/poles installed in the upper bank survived, while 39 percent in the lower bank survived. Overall, percent coverage by the shrub/tree layer was visually estimated at about 75 percent.