Geosynthetics and erosion control

Terra firma often does not morph in ways that modern society appreciates. Erosion from stormwater, snowmelt, long-term water flow and unrelenting waves sweep away soil and rock from steep slopes, riverbanks, ditches, channels, shorelines, building foundations and much more. To understand the power of erosion, simply think about the Grand Canyon, which was formed by the scouring and cutting power of the Colorado River, as well as six million years of winter snowmelt and flow from summer monsoon rainstorms at the canyon’s high-elevation rims washing over and cutting down into (mostly) sedimentary rock.

Although erosion is celebrated at that national park, it is less appreciated at a former nuclear weapons site on the Colorado plains, a village along the banks of a scouring river in Mexico, in walls for steep slopes along heavily traveled highways and in coastlines battered by historic hurricanes. That’s where the geosynthetics industry comes in, with a variety of products for a multitude of applications to stop, reroute and mitigate erosion. Geosynthetics are critical for erosion control.

To outfox Mother Nature, the geosynthetics industry and civil engineers working with geosynthetics have developed and used mechanically stabilized earth (MSE) walls, geotextile tubes, erosion control blankets (ECBs) and turf reinforcement mats (TRMs), among other products. Some of these products—including ECBs and TRMs—facilitate vegetation growth in areas such as steep slopes and along the sides of drainage ditches that would not otherwise give vegetation a chance to take hold.

This issue of Geosynthetics magazine looks at geosynthetics and erosion control from several angles, traveling to Colorado, Mexico and Taiwan to examine innovative projects; proposing a risk assessment method for MSE wall projects; evaluating anchor systems for rolled erosion control products (RECPs); and focusing on recent new specifications for RECPs from the Erosion Control Technology Council.

It is reasonable to express certainty that erosion in areas where humankind does not want it to occur will continue to be an issue for society long term. As geosynthetics find wider usage in civil and geotechnical engineering, the tide will begin to turn.