Geosynthetics in the Greater Grand Forks Greenway

By Adam Regn Arvidson

The turf reinforcement mat (TRM) in the Red River Greenway project is Enkamat, manufactured by Colbond, a Dutch company with production facilities in Europe and the U.S.

The 3-dimensional nondegradable matting is made of continuous nylon or polypropylene filaments fused at their intersections, with 95% of the matting open. The 3-D mat is woven and designed for both soil stabilization and ease of seeding. Applied on soil, it looks a bit like a tangled fishing net.

For this Red River project, after the riprap anchor was in place, contractors spread a 2in.(50.8mm)-thick layer of topsoil and studded the levee slopes with a combination of seeds and small plant plugs. The plant plugs were placed into holes cut in the mat, allowing them to root through to the native soil below. Another layer — a biodegradable fiber blanket — was placed over the top for additional erosion control.

Adam Regn Arvidson is a landscape architect and freelance writer based in Minneapolis. He is founder of Treeline, a design/writing consultancy that focuses on environmentally sustainable projects. Ron Bygness, editor of Geosynthetics magazine, also contributed to this article.