A decorative living fence at a Maryland water treatment plant had to be built extra sturdy to resist powerful prevailing winds.
In downtown Havre de Grace, a 17-foot-tall living fence graces the front and one side of the highly visible water treatment plant.
Hundreds of newly planted perennials such as bugleweed and lily turf climb the fence along with coral and trumpet honeysuckles. Ornamentals such as switchgrass and deciduous shrubs like St. John’s wort provide ground cover along the nearly 200 feet of specially constructed metal fencing.
“The plants will bud during different seasons, so when they mature, we will have flowers of various colors on the fence all year long,” says Bill Reeder, deputy director of construction and program management for the city.
The fence was not easy to build. Started in 2012 as part of the city’s initiative toward earning Maryland certification as a sustainable city, construction proceeded for nearly a year before anyone considered the effects of strong winds. That’s when Reeder’s department got involved and essentially redesigned the project.
Havre de Grace sits at the mouth of the Susquehanna River and at the head of the Chesapeake Bay, 40 miles northeast of Baltimore. The prevailing southerly wind comes up the bay unobstructed, and the 4 mgd treatment facility along the river can experience high winds even during times of relative calm.
The initial fence design would not have withstood the winds. “It would have been blown down quicker than we could put it up,” Reeder says. After rebidding the entire project, the city chose a welded wire-mesh ornamental fence, called the Patriot, made by Jerith Manufacturing Corp. of Philadelphia. The fence is a strong alternative to aluminum chain-link fence, but with a more subtle visual appearance that blends with the environment.
Installed in an uneven zigzag format with section spacing of 2 to 8 feet, the fence is supported on a rebar-reinforced monolith concrete foundation that extends 30 inches below grade.
Each of 27 vertical posts is mounted on a 1-foot-thick outrigger. The 3,000 psi high-strength concrete is air-entrained for freeze protection. A 3-inch pipe forms the fence’s center rail.
“This fence is designed for high winds and is not going anywhere,” says Jim Newby, deputy director of administration. He says that once the perennials are fully grown, the dense screen of flora will block the view of some plant equipment, such as a large generator. Even though the fence does deter access to the plant, its purpose is to create a green, aesthetic appearance and add a beautiful natural feature to the city.
Seventy percent of the funding for the $120,000 project was through a community legacy grant from the Maryland Department of Housing. Reeder says that because of the special structural features needed to handle the high winds, the fence is not typical of what many other water plants would build.
Says Newby, “We worked hard to control the costs, yet make it a sustainable and beautiful addition to the plant.”