Stream Stabilization and Restoration
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The Issue
Over time, stream banks become eroded and may start to endanger structures and land located nearby. Stream stabilization techniques are utilized to stabilize the stream and reduce erosion. It is important to note that a systemic analysis of the entire reach of stream must be conducted in order to avoid unintended negative impacts on a stream as a result of a corrective action at an isolated location. A wide array of products and methodologies can be used to stabilize streams: live stakes, cellular confinement matrices, articulated block pavers, riprap, gabion baskets, turf reinforcement mats, revetments, large woody debris, grade controlling structures, stilling basins, etc.
Innovate Engineering had the opportunity in 2011 to participate in the stream resoration of Browns Canal in Valdosta, Georgia. Several structures were at risk of falling into the canal. We designed and implemented the use of green gabion walls to stabilize the stream banks.
Gabion Walls
A gabion wall is a retaining wall made of rectangular containers (baskets) fabricated of thick galvanized wire, which are filled with stone and stacked on one another, usually in tiers that step back with the slope rather than vertically.
The most common civil engineering use of gabions is to stabilize shorelines or slopes against erosion. Other uses include retaining walls, temporary floodwalls, to filter silt from runoff, for small or temporary/permanent dams, river training, channel lining. Gabion baskets have some advantages over loose riprap because of their modularity and ability to be stacked in various shapes; they are also resistant to being washed away by moving water. Gabions also have advantages over more rigid structures because they can conform to ground movement, dissipate energy from flowing water, and drain freely. Their strength and effectiveness may increase with time in some cases, as silt and vegetation fill the voids and reinforce the structure. They are sometimes used to keep stones which may fall from a cutting or cliff from endangering traffic on a thoughfare.
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