Keeping Soil on Course

by Hugh Leslie Haun

Why is Erosion Control Important?
Seeing golf course plans become reality often requires extensive excavation and topographical changes to the land, as well as dramatic changes in vegetation patterns. It is no secret that during course construction there is great potential for damaging soil erosion if proper steps are not taken to prevent such problems. Proper planning and use of Best Management Practices (BMPs) during golf course construction and maintenance will reduce the risk of adverse environmental impacts in and around the course. In addition, adamant use of BMPs, such as using rolled erosion control products (RECPs), will ensure a reduction in expenses normally associated with repairing eroded areas.

Because of the emphasis on aesthetic appeal, golf courses have every incentive to take proper, proactive measures to control soil erosion. Establishing grass in a dense, uniform manner is an obvious construction objective. Hence, the loss of fertile topsoil due to erosion can hinder efforts to establish vegetation after construction ceases, not to mention added cost for regrading and possible course opening delays. In addition, topsoil lost to erosion is generally bound for the nearest waterway where sediment-laden runoff not only degrades the water’s aesthetic appeal but, more importantly, degrades habitat for fish and many other aquatic organisms.

A number of products are currently available for effective erosion control during golf course construction and maintenance. In particular, both temporary and permanent RECPs have proven their effectiveness and gained preference with many golf course superintendents throughout the nation. This is due to the versatility and proven performance of RECPs in controlling soil erosion on slopes, in drainage channels, and along shorelines while also promoting the rapid, dense establishment of vegetation so critical on golf courses. As illustrated here, specific applications require specific RECPs.

Reinforced turf effectivly shields the shoreline against constant erosive wave action.

The Product Should Fit the Situation
In the final construction phase of the Longaberger Golf Course in Newark, Ohio, turf establishment on parts of the course was addressed by hydroseeding a vast area of gently rolling hills totaling over 9 hectares (22 acres) of the 203 hectare (500 acre) course. The contoured landscape resulted in small 3:1 to 5:1 (H:V) slopes with many shallow drainage swales tracing the course like narrow veins. Initially, erosion control measures were thought to be unnecessary because of the limited slope gradients. However, subsequent summer storms proved detrimental to the first hydroseeded application. There was a heavy impact of rainwater on the bare ground, dislodging and transporting seed, soil and fertilizer down the small hills and into the drainage swales below. As a result, concentrated rainwater in these small swales caused excessive soil erosion, necessitating additional expenditures for regrading, along with another hydroseeding application. Again, rain washed large amounts of soil, seed and fertilizer from the course, leaving the course’s superintendent looking for a better solution to for this problem.

Hydroseeding alone was not the answer for this golf course. The course’s superintendent, Mark Rawlings, found a more effective solution to his turf establishment and soil erosion woes. North American Green’s single-netted straw erosion control blanket, the S75, was used on the rolling hills to control sheet flow, reduce raindrop impact, hold seed in-place, and retain moisture at the soil surface to increase the rate of seed germination. Unlike hydroseed or hydromulch alone, the S75’s agricultural straw matrix is sewn to a single photodegradable netting on 3.81 cm (1.50 inch) centers to effectively retain the straw matrix. Again the site was hydroseeded; however, this time the blanket was stapled down over the hydroseeded surface to ensure that seed, fertilizer, and soil remained undisturbed while vegetation became established.

Because of the drainage swales’ concentrated flow, a higher performance erosion control blanket was needed in this area to prevent excessive soil erosion prior to vegetation establishment. North American Green’s SC150 blanket was selected because of its ability to withstand expected flows of up to 86.40 Pascals (1.80 lbs/ft 2) of shear stress. This blanket has a typical functional longevity of 24 months, allowing ample time for thick vegetative establishment in the swales before the protective blanket degrades.

The blankets effectively stopped erosion where they were applied and limited further expenses associated with repairs. Ultimately, over 30,100 m2 (36,000 yds2) of blankets were installed throughout the site. In testament to the effectiveness of the products, only a few weeks passed before the golden sheen of erosion control blankets was transformed into a green expanse over the rolling hills as seeds quickly germinated and began to grow.

TRMs in Erosion Control Design
Traditionally, even low-flow drainageways and small ponds were commonly lined with rock riprap or some other form of “hard” treatment, mainly because alternative treatments were either unavailable or not well understood. However, in the last 10 years the introduction and proven performance of turf reinforcement mats (TRMs) have dramatically changed the way golf course architects and contractors view permanent erosion control. The distinct advantages to using TRMs are evident in the extraordinary erosion control capabilities of reinforced vegetation, the greater aesthetic appeal of vegetative liners, and substantial cost savings over the conventional “hard” options.

Temporary erosion control blankets protect fairways from rainfall and overland runoff while encouraging quick turf establishment.

Protecting Golf Course Shorelines
From small public courses to championship links, the advanced erosion control performance of TRMs can be utilized with equal ease and success. The Tournament Players Championship (TPC) courses, for instance, are some of the most prestigious courses in the United States. Boasting large budgets, PGA endorsement, and difficult layouts, they are also some of the more challenging courses to construct and protect.

Plans for the TPC course in Blaine, Minnesota included construction of 25 hectares (61 acres) of water features, including lakes, ponds, and streams. In order to enhance the aesthetic appeal of the ponds and lakes, as well as maintain safety, course designers elected not to use rock or concrete as a means for shoreline erosion protec-tion. Instead, shorelines were seeded with a mixture of wetland plants, and North American Green’s C350 Composite Turf Reinforcement Mat (C-TRM) was surface applied to retain the soil and seed. This mat was chosen for this course because of its proven turf reinforcement capability and innovative construction using three permanent, heavyweight polypropylene nets with a dense coconut fiber matrix sewn between the bottom and middle nets.

Although seemingly minor, the repetitive action of wind-driven waves across lakes and ponds can gradually erode shorelines to a point where they may encroach upon nearby homes or landscape features. Repairs for such receding shoreline damage can be very costly if the problem is not promptly addressed. Prevention is certainly the best medicine. By installing the mat both above the high water line and below the low water line, shorelines can be protected against erosive wave action throughout yearly precipitation cycles.

With erosion control blankets having done their job, vegetation is well established with minimal loss of soil, and the course is ready for play.

In just two short weeks, vegetation at Blaine had become 70 percent established and fully established in only one month. This established vegetation is now reinforced at the stem by the blanket’s net structure, forming a permanent barrier to protect the shorelines against erosion. As golf courses become more prevalent fixtures in many urban and suburban landscapes, and erosion control laws become more stringent, the benefits of proper RECP use are needed more than ever. L&W

For more information, contact Roy Nelsen, North American Green, 14649 Highway 41 North, Evansville, Indiana 47725, (812)867-6632 In Indiana, (800)772-2040, (800)448-2040 In Canada, fax (812)867-0247, www.nagreen.com, e-mail: rjnelsen@nagreen.com