What is a Coir Log?
The Erosion Control Coir Log is a natural fiber product designed to provide stabilization and support along river banks, slopes, steams, hillsides and erosion prone areas. Offering a high level of strength and reinforcement, these fiber rolls feature densely packed mattress coir fibers that are placed inside a tubular coir twine netting. Both components are all natural and biodegradeable, making the product safe for the surrounding environment.
A small pilot project got started in Summer 2015 on a 15’ section of seawall at pier 705 on Lake Wawasee. At this time, there has not been any other known attempt to use a Coir log in conjunction with glacial stone along an existing cement seawall.
The project was undertaken to understand the following key points:
- Can a coir log be successfully anchored to remain in place along a cement seawall?
- What is the best placement of the coir log, and the best use of rock with it?
- How long does it take for the native species planted in the coir log to bloom?
- Where is the best location for use of a coir log along a seawall for practical and ecologic benefit?
- What are the effects of ice on a coir log over the Winter, and what repair if any is needed in the Spring?
Here are some important specifications learned from this pilot already that any prospective property owner can use for planning their project:
6″ – 12″ glacial stone covers approximately 25 square feet per ton. A total of three (3) tons were ordered to have enough for 75 square feet. The actual pilot project was about 45 square feet, knowing that it is better to have more stone than not enough to do the job effectively. Also, the use of a coir log require more stone in order to make a trough along the seawall for placing the coir log. Piling stone to hold the coir log in place, forces more stone out away from the seawall, so it doesn’t cover as much surface area as without a coir log.
Loading time for 3 tons of glacial stone was 90 minutes by wheel barrow, transported about 50 feet from drop point to the seawall. An average load was 6 to 8 stones. Installing the coir log was done in 2 hours by one person. Seawall section is 15′ long, about 3′ height. It takes 1 ton to cover 25 sq ft. So my project is 3 x 15 = 45 sq ft. To cover a 50 foot seawall, 3′ in height you would need 150 sq ft or 6 tons.