Artificial grass precents erosion near repaved road

When the Missouri Department of Transportation repaved a 3-mile stretch of Route 370 north of St. Charles, the project involved land along the Missouri River floodplain. Contractors needed to dredge fill material out of the riverbed to raise the highway elevation.

However, the sandy fill material, while minimizing susceptibility to flooding, increased the threat of erosion. In response, the DOT decided to install a 5-foot-wide “transition strip” of dirt adjacent to the repaved surface and plant grass seeds.

Simply waiting for the vegetation to establish itself along the shoulder would have taken a year or so, leaving minimal deterrent to erosion for several months. And the prime contractor, St. Louis-based Millstone Bangert, decided against using sod because of concerns that it would not establish itself if sustained hot and dry weather followed installation.

The specialty erosion control subcontractor, St. Louis-based Safety Construction, proposed use of a native grass seed mix in conjunction with Curlex I Quickgrass, an erosion control blanket made by Arlington, Texas-based American Excelsior Co. The blanket was manufactured from biodegradable Aspen wood fibers and polypropylene netting combined into 80-square-yard rolls. The fibers would protect the seedbed from erosion by reducing the impact of raindrops and by slowing runoff from pavement. They also would reduce the likelihood of burnout and increase moisture retention, thus fostering seed germination and growth.

Once the paving and grading were completed, about 55,000 square yards of the green-dyed product were installed alongside the roadway. Wire staples were used to secure the blankets.

Following installation, the St. Louis area weather, as feared, was unusually hot and dry. However, the native fescue and perennial rye seeds found enough moisture to germinate, and seedlings were established. As the artificial green color faded, the natural green vegetation replaced it.