Erosion prevention practices - erosion control blankets and anchoring devices
This page is under development. We anticipate populating it in autumn, 2016.
Contents
Erosion Control Blankets
Definition
Erosion control blankets (ECBs) are typically biodegradable, open-weave blankets that provide temporary cover and support for establishing vegetation on bare soil areas.
Purpose and Function
ECBs provide cover for bare soil and support for emergent vegetation (i.e., typically grass) from the time of seeding until root density and top growth are capable of long-term erosion protection. ECBs function by shielding bare soil and newly seeded areas against raindrop and wind erosion, providing a dense matrix of biodegradable material (e.g., straw, coconut) that stabilizes and supports emergent vegetation and later decomposes to further aid in plant growth. They also help to increase precipitation infiltration and decrease soil crusting and compaction. ECBs are designed and fabricated in a variety of types that last from a few months to approximately three years. Temporary ECBs are grouped into categories based on functional longevity and according to the Erosion Control Technology Council (see Table 4 2) include:
- Category 1: Ultra short-term – typically 3 months
- Category 2: Short-term – typically 12 months
- Category 3: Extended term – typically 24 months
- Category 4: Long-term – typically 36 months
Applicability
Degradable ECBs are appropriate for any bare soil area where temporary protection from raindrop and wind erosion is needed, or where newly seeded grass requires short-term cover and support prior to germination, early growth, and full establishment.
Site Applicability
ECBs are typically used where vegetation requires only temporary support for establishment, such as flat upland areas and slopes less than 4H:1V. They are also effective in establishing vegetation on relatively flat shoreline areas, swales, ditches, and athletic fields, or grassy areas that will be mowed closely such as places where longer term plastic netting may cause a tripping hazard or be pulled up later by equipment. ECBs can also be used as temporary cover for small bare areas that are idle for a few weeks (i.e., time periods too long to remain unprotected, but too short to seed). In these cases, blankets can be unrolled on bare portions of the site for a short period, removed when work commences, and reused.