Erosion Control

 

Erosion control blankets prevent surface erosion while accelerating the establishment of vegetation.  They temporarily stabilize and protect disturbed soil from raindrop impact and surface erosion.  They also increase filtration, conserve soil moisture, and decrease compaction and soil crusting. Erosion blankets are machine produced mats of biodegradable mulch such as excelsior, straw, coconut fibers or a combination thereof.  These materials are evenly distributed on or between photodegradable polypropylene or biodegradable natural fiber netting.

Temporary

Temporary erosion control blankets are manufactured from natural fibers such as straw or wood excelsior.  They have a photodegradable netting stitched on one or both sides.  They provide short-term rainfall/rainsplash protection of slopes.  They are also effective as a channel liner in low risk/low gradient scenarios where vegetation establishes quickly.

Extended Term

Extended term erosion control blankets are manufactured from natural straw, excelsior, coconut or a combination thereof.  They also have a photodegradable netting stitched on both sides.  The blankets provide extended longevity while yielding protection for 24-36 months.  They are also ideal for arid environments, steep slopes, channels or situations where vegetation establishes slowly.

Permanent

Permanent Turf Reinforcement Mat (TRM) is a long-term reinforcement mat.  It is composed of UV stabilized, non-degradable synthetic fibers, filaments, and mesh netting.  They are then processed into a three dimensional reinforcement matrix.  TRM’s are specifically designed for permanent and critical hydraulic applications where design discharges exert velocities and shear stress exceed the limits of mature natural vegetation.  TRM’s also provide sufficient thickness, strength, and void space.  This permits soil filling as well as retention and development of vegetation within the matrix.

All Natural

All natural erosion control blankets are manufactured from the same natural fibers above.  The difference is the fiber matrix is confined by a biodegradable, jute/scrim net on top and bottom and then mechanically (stitch) bound with a biodegradable cotton thread.  There are also two other all natural choices for erosion control blankets.  However, both jute and coir matting utilize a different manufacturing technique.

Jute Matting

Jute matting is made from unbleached, undyed natural jute fibers.  The fibers are then woven together to produce a mat of uniform openings.  Jute is also lightweight and highly absorbent.  The open weave of the matting hugs the soil and holds the vegetation in place while giving the roots a chance to establish.  The jute also biodegrades completely in two years.  This provides organic matter and nutrients for the soil.

Coir Matting

Coir Fiber Mats are made from pure coir fiber (the husk of a coconut).  The fibers are then woven into blankets with specific weight, strength and open area.  Coir also has one of the highest durability and tensile strengths of all natural fibers.  It is suitable for the most severe erosion control problems, such as steep slopes and high velocity flow channels.  It also effectively stabilizes stream banks and shorelines.  Additionally, the high flexibility of the woven coir mat easily conforms to the soil contour, creating a tight bond.

This woven feature also allows planting directly into the soil through the blanket without cutting it.  In addition, coir’s natural ability to absorb and retain water creates an ideal microclimate for vegetation growth.  Thus, the mat’s extended longevity allows for full vegetation establishment.  After years of effective erosion control and vegetation anchoring, the mat biodegrades while returning nutrients back into the soil.  Available in 400, 700, and 900-gram weights.

 Product Comparison

Type Typical Longevity Flow Slopes
Single Net Excelsior 12 months
Temporary
Channel flow velocity to 7’/s 2:1 or less
Single Net Straw 12 months
Temporary
Low flow on channels velocity to 4.5’/s Up to 3:1
Double Net Excelsior 12-24 months
Temporary
Channel flow velocity to 9’/s Up to 1:1
Double Net Straw 12-24 months
Temporary
Moderate flow on channels velocity to 7’/s Slopes up to 2:1
Double Net Coconut/Straw 12-24 months
Extended Term
Moderate flow on channels velocity to 8.5’/s Slopes up to 1:1
Double Net Coconut 36 months
Extended Term
Heavy flow on channels velocity to 9’/s Slopes 1:1 and greater
High Velocity Excelsior 36+ months
Extended Term
Channel flow velocity 10-12 fps Slopes 1:1 and greater
Coir Mat 36+ months
Extended Term
Heavy flow on channels Severe Slopes
Jute 12-24 months
Temporary
Moderate Flows 2:1 or less
TRM 36+ months
Permanent
Heavy flow on channels velocity to 16’/s Severe Slopes

 

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Disclaimer: These guidelines are for informational purposes only and are intended as illustration or general information only and are not intended as a guarantee or warranty. IWT assumes no responsibilities in connection with the use of this information.