Geocells Restore Eroding Streambank

Project Name: Brooktree Creek Along Park Oaks Drive

Project Location: Citrus Heights, California

The Erosion Problem

A concrete-lined ditch and culvert were directing a concentrated flow of stormwater runoff into the natural bank of the Brooktree Creek, causing severe erosion in some areas and exposing the roots of mature oak trees. The erosion had caused the banks to move dangerously close to a homeowner’s property, with large oak trees at risk of falling into the creek or onto the property.

The Channel Solution

The GEOWEB Channel Protection System was designed as a tiered structure to protect the streambank from further erosion. Large boulders set in concrete were also included in the design to effectively channel the runoff water by creating a series of overflow pools, which help prevent downstream erosion.

GEOWEB Channel Protection Advantages

The GEOWEB multi-layered channel solution provided several benefits:

Protection of the streambank from further erosion
A vegetated face for a more natural appearance
Minimized the construction footprint

The Components Of Installation

Once the project was designed, construction commenced with the removal of oak trees that had exposed roots and could not be saved during the excavation of the new channel.

Platipus Percussion Driven Earth Anchors (PDEA®) were driven into the bank and tied off to a deadman anchoring pipe.
Kevlar tendons were attached to the GEOWEB panels and tied off to the deadman anchor to secure the wall.
Mirafi 3XT geogrid was installed every fourth lift to provide the support required for this installation.
The GEOWEB footing courses were filled with concrete to provide a non-erodible base.
Upper GEOWEB courses were filled with topsoil in the front exposed fascia cells to provide a growing medium for vegetation, then covered with Enkamat 7010 Turf Reinforcement Mat to prevent infill loss.

The GEOWEB Channel Protection System Performance

The GEOWEB Channel System was completed in fall 2016, just in time for the drought-ending rains of late 2016 through spring 2017.

The channel has been exposed to several rain events since construction. The wall structure has remained stable and vegetation is becoming established as expected.