Extreme water flows produced by Hurricane Irene caused severe erosion to the earthen emergency spillways at the 40-year-old Maplecrest, Nauvoo and Mitchell Hollow Dams serving the Batavia Kill (River) Watershed District in Windham, N.Y. The Tensar VMax P550 turf reinforcement mat (TRM), a permanent and economical erosion control solution, was chosen to permanently protect and revegetate the site.
The timing of the repairs was critical, because vegetation needed to be established in advance of the rainy season and snow. Also, the spillways were surrounded by farmland, so the district preferred a more natural, reinforced, vegetated solution. Cool weather, a short timeline and heavy, compacted clay soils posed additional challenges for the site.
A competitive TRM product was considered, but engineering test reports on the performance of the VMax P550 TRM and its track record of establishing vegetation was the determining factor in its use on the spillway site.
The VMax P550 TRM, part of the RollMax Systems family of rolled erosion control products, combines a UV-stabilized 3-D matting with a 100% polypropylene fiber matrix to offer one of the line’s most rigorous erosion protection, vegetation establishment and reinforcement properties. One of the benefits of the mat is its ability to quickly establish vegetation through the mat, providing both an anchor for vegetation and the ability to filter fines during inclement weather.
Fastracs Inc. construction crews completed the four installations of VMax P550 TRM over a five-week period (interrupted by periods of cold weather) in fall 2012. Altogether, 35,000 sq yd of product, covering nearly seven acres of graded surface with a 3-in. layer of native topsoil, were placed. Jerry Paschal, project manager for Fastracs, scheduled 12- to 16-man crews for the installation.