In an attempt to control roadside erosion, riprap had been placed in several sections along main thoroughfares and range access points of the Army base at Fort Campbell, KY. One such location is the intersection of Range 2 and Mabry Road. This area had become a recurring maintenance problem as sediment in stormwater runoff clogged culverts, crumbled pavement from the roadside surface, and rendered the earthen culvert ineffective. Several attempts to shore up the earthen ditch with riprap material failed, resulting in significantly higher maintenance costs and debris washing into nearby Dry Creek Stream.

 “The riprap was difficult to install, and after a while the material became laden with sediment. It was hard to maintain and overall failed to significantly control erosion,” says James Harmon, US Army Integrated Training Area Management director. “We needed something that we could install fast.” The Army opted to use a corrugated channel lining system called SmartDitch.

Photo: Penda Corp

SmartDitch can be used in combination with other EC solutions, such as rock.

Installation was straightforward. It took only a couple of days to prepare the existing channel and anchor the liner. The relined portion of the roadside culvert spanned nearly 100 feet, with the intersection of an adjacent gravel road that required a short segment of subsurface piping connecting the culvert.

 “The installation crew was able to install the liner quickly and easily,” says Harmon. “Each section of the liner could be maneuvered and installed by two people, which was much easier than moving and setting up riprap across the entire ditch.

 “The lining system proved to be a versatile solution, working in combination with rock, piping, and other erosion control applications,” Harmon adds, “including riprap on one end of the roadside ditch where the existing ditch is not as deep and shows no signs of erosion.”

A crew of four installed about two sections of the engineered polymer liner using simple hand tools. A backhoe was used to prepare portions of the ditch for relining. A mixture of gravel and sand was used to create a solid foundation for the ditch liner. Coir matting was used as a base layer for the riprap in the transitional area between the SmartDitch system and the native ditch. About 12 more sections of the liner will be used to complete the project.

The anchoring system included driving a duck-billed anchor into the ground along the sides of the liner, securing each anchor with a wire and cable-lock device. Each 8-foot section of the liner was secured by drilling preset holes on each end and placing a rivet along the connected edges.

Some recent torrential rain put the system to the test. Water flow alongside the road was noticeably strong, and rainwater was quickly moved away to Dry Creek Stream without the erosion debris. The immediate area surrounding the ditch has been reseeded, and plant life is taking hold, not washing away.

 “The liner has significantly reduced erosion of the immediate area between the ditch and road,” says Harmon. “As plants and grass begin to take root again, the area will return to its once green landscape, a sight not seen for years.”

SmartDitch, manufactured by Penda Corp., is constructed from engineered polymers and tested to last more than 20 years. The material resists punctures and withstands extreme heat and cold, accommodating freeze/thaw cycles. SmartDitch has been engineered to ISO 14001 standards regarding environmental impacts, and ISO 9001 requirements for quality. The liner can be placed aboveground or in an existing unlined or concrete-lined ditch. Its trapezoidal design is lightweight and agile yet durable enough to be utilized in all settings or conditions.

 “Now the liner is a key component of our stormwater management program on the base,” says Harmon.

EC - November/December 2006