Erosion Control Case Study

Overview
GEOCOIR® 700 and GEOCOIR® Log erosion control applications were used to stabilize a river bank and protect a bridge overpass support in Roseburg, OR. Specific products used included GEOCOIR® 700 (4 meters wide) and GEOCOIR® Bio-logs (12″ diameter, 7-9 lbs/cubic foot).

Challenge/Need
Over time, the South Umpqua River in Roseburg had begun to erode its bank along Stewart City Park as well as the bridge support area of the Stewart Parkway overpass.

Objectives
Fill in and reclaim lost embankment. Use long-lasting, biodegradable GEOCOIR® products to stabilize the repaired embankment. Grow new vegetation with the help of GEOCOIR® products. Employ an all-natural approach since the park has an abundance of “children at play.”

Product Solution/Innovation
GEOCOIR® 700 was used to hold the new soil in place, and seeding was done prior to blanket installation. The blanket was trenched in at the toe using a rock-filled GEOCOIR® wrap below the normal water line and trenched in at the top of the slope. The 12″ coir logs were placed on top of the GEOCOIR® 700 blanket running about halfway up the slope. The logs were then secured in the embankment with 24″ wooden stakes. Finally, coir twine was tied over the top of the logs to keep them in place.

Although rain and snow melt caused dramatic variations in the water levels over the course of the project, the design had its desired effect. GEOCOIR® generally lasts from three to five years, and the GEOCOIR® 700 and logs worked well to help ensure the stabilization of the slope.