Editor’s Comments: Restoring Shorelines With Hard- and Soft-Armor Techniques

Nov. 1, 2000

The Wynstone Golf Club in North Barrington, IL, northwest of Chicago, boasts a championship 18-hole golf course designed by Jack Nicklaus and was rated by Golf Digest as one of the top 100 courses in the United States as recently as 1994. With the golf course and surrounding wetlands covering 250 ac., water figures in 14 of the 18 holes, and 11 of the greens are flanked by water. All of that water has a downside, though: Wynstone has a tremendous erosion problem. Only 12 years old, the course had severe erosion along 6,000 ft. of shoreline and had lost up to 15 ft. of shoreline in some areas.

“We looked at just about every option to restore our shorelines,” says Ted Fist, golf course superintendent. “At Wynstone and most other courses, it is important that we provide an effective erosion solution and also an aesthetic look for the membership.”

Comparing Options

The first decision was whether to go with hard-armor shoreline protection or a softer bioengineered solution. The conclusion: both. Steel sheet piling has been installed along 500 ft. of shoreline in the most critical areas, and North American Green’s C350 composite turf reinforcement mat is being used for the rest. “We have used both techniques as the sheer stresses and soil conditions dictate,” notes Fist. “It was also important to preserve the architectural integrity of the golf course.”

With the help of Geo-Synthetics Inc., Fist researched the options. “Dan Salsinger, our sales representative, put me in touch with contractors from across the country and Canada to learn the benefits, limitations, and costs of some of the products we had previously considered.” One of the discoveries was North American Green’s DS75 straw blanket. “We use it on top of everything we seed. It’s easy to install, and we’re very happy with the way it breaks down,” remarks Fist. Because the single-net, photodegradable straw blanket degrades in about two months, it can be used in areas like golf courses that need to be mowed as soon as the vegetation starts growing.

A hard-armor solution was chosen for the three greens and bunker complexes that were immediately threatened by wave action. The nearly 1:1 slopes around some of the complexes dictated heavy-duty reinforcement. “The members initially wanted mortared stone walls,” says Fist. “We would have had to dewater 110 ac. of lakes, install a concrete footer into peat soils, and then build the wall. This seemed like a recipe for failure to me.” Steel sheet piling was finally chosen as the most cost-effective solution. “We looked at all other options, but we kept coming back to steel.” Riverwalls Ltd. of Barrington, IL, performed the installation.

Working Without Disrupting the Course

Accomplishing the task with minimal disruption to the course was a priority. “The sheet piling could be installed using lightweight equipment, and it would follow our original contours,” says Fist. “To reduce the visibility of the steel, we requested that only 18 inches of wall be exposed. This gave us the low profile we were looking for. It also allowed our contractor to weld his back wales and tiebacks onto the wall at a height to ensure that they would not be underwater.”

Added benefits were the piling’s quick installation and low long-term maintenance costs. “We felt good about our contractor. He installed 500 feet of steel and was able to work directly on top of our green surfaces without damage. This saved us a lot of money in repair costs and allowed us to finish each green complex in about a week.” Wynstone’s staff worked with the contractor to install the gravel backfill, nonwoven fabric, topsoil, and sod. “We finished the project using our smaller vehicles. We could not have installed the turf reinforcement mat in these areas with as little damage, as heavy equipment would have been required to rebuild a slope.”

The turf reinforcement mat, however, was used for another 5,500 ft. of shoreline. About one-quarter the cost of the piling, the mat provided effective erosion control on the 4:1 and 5:1 slopes and allowed a more attractive vegetated shoreline. Accommodating the club’s members, keeping the course open, and causing as little disturbance as possible to the nearby homeowners required some careful coordination with the contractor, Kanzler Excavating.

“Our first task was to reestablish the original shape of the eroded shorelines,” recalls Fist. “We used aerial photos and did a lot of probing to locate the original edges. Pulling the original material back out of the lakes to rebuild the shoreline was considered, but we felt that the time it would take to dry down and become workable again would cause us to lose our seeding window.” Another factor that influenced the decision: “We are surrounded by homes, and the odor of the saturated material would have been offensive. The soil along the original shorelines had failed once before and we didn’t want to repair it again.” The lakes were dewatered to 3 ft. below the normal water line, then clay provided from a nearby construction site was hauled to the shoreline edges and compacted.

“We had 11 semis and six dump trucks running, with two dozers, three loaders, and a backhoe on-site for the three weeks it took to do the job. We kept them restricted to several 12-foot-wide access roads that began at vacant lots adjacent to the golf course,” describes Fist. The trucks dumped the clay along the lake edge, where it was leveled with a bulldozer, creating a roadbed for the trucks along the lake. The clay also became compacted in the process. When enough clay had been delivered, a backhoe and a dozer reshaped the shoreline and applied topsoil on their way out. This arrangement kept all the equipment off the fairways and allowed the entire course to remain open during construction. “I couldn’t be happier with the way Kanzler handled its end of the project,” comments Fist. “They worked seven days a week from dawn to dark so we could get the shoreline seeded as quickly as possible.”

The banks were seeded with a blend of Kentucky bluegrass and rye grass. “We had germination in about six days. We kept the water levels down through the winter, and the shorelines are now in great shape. Our access roads have grown in, and any damage from construction is a distant memory. And the members are very pleased. It looks like a new golf course out here.”

This fall, Wynstone will start the final phase of the project, using both steel sheet piling and turf reinforcement mat for another 4,500 ft. of shoreline. Fist and first and second assistants Chuck Ardell and Steve Swanson are gearing up to handle the job. “We still have a golf course to care for,” says Fist. “A project like this can’t be done alone. Knowing both the abilities and limitations of our staff and contractors allowed us to maximize each of our strengths to successfully complete the project with as little damage to the course as possible.”

“I think that hard-armor and soft-armor techniques can be combined very effectively,” he concludes. “We are using both techniques here at Wynstone to provide the membership with the aesthetics of a vegetated shoreline, and we are still getting maximum performance from steel sheet piling where necessary.” 

About the Author

Janice Kaspersen

Janice Kaspersen is the former editor of Erosion Control and Stormwater magazines.