New regulations for erosion control are now in place. Areas even as small as one acre must follow the NPDES permitting procedures. U.S. EPA National Pollutant Discharge Elimination System (NPDES) has become quite strict with the approval of NPDES Phase II.
The popularity of golf as a sport has grown over the past few years creating a demand for the construction of golf courses. Erosion control has become more challenging as a result. In addition to erosion control, golf courses must create areas that are easy to mow on a playable turf. While standard erosion control blankets or ECBs, do a great job at controlling erosion while allowing for great growing conditions, the netting being used presents a problem for golf courses. The problem, golf courses must be mowed before the netting can degrade. Usually, netting containing UV degrader additives has been used on golf courses because the netting photo degrades within 90 days. Golf courses cannot wait months on end to get the surfaces mowed. Therefore, erosion control blanket netting is often found wrapped around mowing equipment. While sod is another alternative, for timely mowable turf, the cost is approximately twice as much as ECBs and demands cumbersome watering in order to survive.
South Lake at Stonebrook
The golf course is owned by Stonebrook Billiage Ltd and construction began in the autumn of 2003. It consisted of 185 acres, 18 holes, and allowed for 650 homes. In turn, this led to erosion issues that needed to be addressed quickly. The project engineer, Jay Baynes recognized the erosion control issue early in the planning stages of the course.
The director of American Excelsior Company’s Earth Science Division, Jerry Bohannon, considered a new erosion control and vegetation solution and brought it to the attention of Jay Baynes. The solution was Curlex® NetFree™ which is the first erosion control blanket that does not contain netting.
This product is 100% weed seed-free Great Lakes Aspen curled wood excelsior and 80% of the fibers are less than 6 inches long. It is stitched together to a consistent thickness with fiber evenly disbursed throughout the entire blanket. The engineered curled and barbed properties of the fibers do not require the use of ECB netting to maintain its integrity. Testing of the ECBs followed the standard protocols published by ASTM and conducted at the Erosion Lab in Rice Lake, Wisconsin during the summer of 2003. The testing showed that ECB without netting performed like the conventional netted blankets.
Baynes chose to use the product on the sandy clay soils of the golf course. They installed approximately 200 rolls of netless ECB to prevent soil erosion while enhancing the establishment of vegetation without complications of ECB netting. The product was used on the slopes of hills (3H:1V), as well as retention areas, and holding ponds.
Golf Professional Hiram J. Cook Jr watched over the construction at Stonebrook. No outside contractors were needed on this project because course personnel did all the work. The largest application of the new ECBs was applied in a large stormwater retention ditch. This was performed to manage runoff generated on the golf course. Retention areas are created to slow down and retain stormwater runoff. Pollutants found in stormwater runoffs are prevented from going into receiving bodies of water including elements found in fertilizers. The ditch was trapezoidal in shape having a 100 ft wide bottom, 40 ft long side slope ( 4H:1V), and a total length of 700 ft. The flows are not expected to go beyond 1.0 lb/ft2 shear stress which is based on the design of the retention ditch. The soil was compacted, seeded with Winter Rye, and blanketed after construction was completed. A crew consisting of only two or three people was used to install the erosion control blankets. Common Bermuda has applied to over-seed the retention areas in 2004 because Winter Rye is only an annual grass.
The Learning Process
The installation crew ran into minor problems during the installation of the blankets. It seems a percentage of the center cores were crushed inside the blanket rolls. The manufacturer of the ECBs was informed of the problem and provided a soft core in the center of the blankets that would prevent crushing.
The benefits of this product were realized shortly after the installation. Rainfall-runoff caused rills to form in the soil that unprotected while the soil under the erosion control blankets was held in place. The threat of seeding washing away will happen anytime rills form in the soil. Vegetation is the main goal in erosion control so the seedbed is protected for the generation to take place.
Lush vegetation now exists on the slopes, the holding ponds, and retention ditches where the Curlex NetFree was installed. Cook said course personnel are very pleased with the results and believed the blankets will hold without using a lot of staples.
It is not recommended that you install any ECB without anchoring it to the subgrade but personnel recognized the ability of the product to conform to the soil. John Slupecki at American Excelsior Company has been monitoring the success of the project and he believes the product offers great contact with the subgrade because it does not have any nettling which can reduce contact with soil. Contact between the product and the subgrade is very important in all erosion control operations.
Since the removal of all netting from ECB, course personnel was able to mow the protected areas directly after vegetation was established. Over the past few years, the popularity of golf has grown in leaps and bounds causing a huge demand for the construction of new golf courses. The rise for more golf courses comes with many challenges that must meet the regulations required for controlling erosion. U.S. EPA National Pollutant Discharge Elimination System (NPDES) has its procedures in place. The new Curlex Netfree has removed the need for netting, making future projects for golf courses more productive during construction.