Golf course implements shoreline stabilization & sediment control measures
Golf courses are designed around and rely on water features, whether those features are oceans, lakes, rivers or streams. These water features offer aesthetic benefits, play hazards, water storage for irrigation, and environmental benefits, such as storm water drainage and habitat. As nature and gravity take over, the shorelines around these water features begin to recede, while the water depth becomes increasingly shallow.
Shoreline erosion not only causes the course to lose water holding capacity, it also causes it to lose land. Erosion often occurs as trenches or gullies become larger or as portions of the shoreline break off and fall into the water. These unsightly and unsafe conditions around the water also cause the water feature to lose functionality. The lake or stream will have less storage capacity for storm water runoff and irrigation, and nutrient and sediment overload becomes a hotbed for aquatic plant growth. Thus, the water feature no longer efficiently serves its purpose and becomes an aesthetic nightmare for course superintendents and maintenance personnel.
After completion, the pond has a new living shoreline that meets or exceeds BMP guidelines.
A private golf course in San Antonio, Texas, was experiencing persistent erosion, and the shoreline embankment had been breaking off in large segments and falling into the water. As a result, the golf course was losing land around the greens. The pond also was becoming more shallow, which led to the flooding of several holes and other portions of the course during rain events.
Best management practices (BMP) for erosion control normally mandate that bare soil is seeded or covered immediately, sediment barriers are used to trap soil contained in runoff, slopes are protected against gullying, and vegetation near waterways is preserved. Additionally, bioengineered erosion control devices should:
- Provide strength to protect and stabilize the shoreline;
- Support new and existing vegetation;
- Wick and retain water and nutrients to maintain new vegetation;
- Contain safe and biodegradable organic material without causing additional contamination to nearby waterways; and
- Filter unwanted nutrients to protect water quality.
After evaluating several shoreline embankment erosion control products, it was determined that a DredgeSox containment system met this criteria and provided the best solution for this project.
“It was comparative in cost to some of the other products we considered, but being able to provide a natural, aesthetically pleasing solution was important to our customer,” said Steve Perry, owner and project manager for Envirodredge.
The system helped stabilize the pond shoreline and used the accumulated sediment from the pond to reclaim the land around the greens. It provided erosion control around the shoreline, using the sediment removed from the water body to fill the containment system. This solution solved the erosion and sediment overload in the water, and reclaimed the land around the water.
“The containment system is made from a double layer photodegradable mesh. It can be planted through or sodded over allowing the vegetation to root through the mesh armor and create a new living system,” said Brian Fischer, manufacturer of DredgeSox. “Revegetation of a shoreline is the only true cure to completely halt shoreline erosion using a system that imitates mother nature.”
Envirodredge mobilized an amphibious dredge boat to the job site location. The small amphibious dredge was chosen for its low ground pressure and was instrumental in accessing small or confined areas. Because of its light weight and low ground pressure, when driven correctly, the amphibious dredge can drive across the course landscape with little or no ground disturbance.
“Instead of bringing heavy trucks and equipment across the course, the dredge is simply driven off the trailer, across the course and down the embankment into the water,” Perry said. “This is especially important when factoring in the impact and cost to restore the surrounding turf when we are finished with a project. With the amphibious dredge, we won’t have to worry about damage or restoration expenses.”
The containment system worked well with the amphibious dredge. As sediment was dredged from the lake, it was pumped directly into the containment system to permanently repair the eroding shoreline, while eliminating excess sediment accumulation. Removing the excess sediment restored water holding capacity and made aquatic vegetation management possible.
After launching the dredge, the containment system was placed around the entire shoreline. It then was secured to the embankment, and the dredge began backfilling the containment system with sediment from the pond. The sediment mixed with water created a slurry that was pumped through a temporary pipeline from the dredge to the system. As the slurry settled into the containment system, the sediment remained trapped while the water passed through the mesh and returned to the pond. It effectively contained the sediment and allowed it to dewater, much like geo-textile dewatering tubes; however, the system became the new shoreline. The sub-surface anchoring system secures it to firm ground, so material does not shift or slide down into the water and has no potential to loosen or break away. The entire project is anchored below the surface of the ground and there are no stakes left in the water or sticking up around the shoreline.
Erosion caused large segments of the shorelines to break off and fall into the water.
For this project, plugs from aerating the golf course greens and locally sourced fill dirt were used in addition to the sediment taken from the bottom of the pond to completely fill and firm up the new shoreline. The anchoring system then was used to finish securing the containment system and complete the installation. Once filled and secured, sod was placed on the new shoreline and it immediately was able to begin buffering runoff water.
The water depth and holding capacity has been restored, and the pond has a new living shoreline that meets or exceeds the BMP guidelines. The project was successfully completed in three days. There was no disruption to golf play or other course activities, and there was no surrounding ground disturbance.