Construction BMPs: Temporary Stabilization

This straw mulch has been crimped into the ground for temporary stabilization.

Stabilization, or establishing ground cover to protect disturbed soils from erosion, is not only a good practice, it is required by law.  The Nebraska state Construction General Permit states that, with a few exceptions such as snow cover or frozen ground conditions, “stabilization measures  must be initiated as soon as practicable in portions of the site where construction activities have temporarily or permanently ceased, but in no case more than 14 days after the construction activity in that portion of the site has temporarily or permanently ceased.” Since it is unlikely that suitable vegetation can be established within 14 days, other methods of stabilization must be considered.  Covering exposed or disturbed areas protects the soil from raindrop impact, slows the flow of and infiltrates stormwater, and protects newly seeded areas.  It also helps retain soil moisture, which will help your vegetation become established more quickly.

One of the simplest methods of erosion control is mulching.  Straw or hay mulch should be applied at a rate of 2-3 tons per acre.  To provide good ground cover, at least 50% of the mulch should be ten inches in length or longer.  The mulch should be crimped using a weighted roller that anchors the mulch into the soil.  If the area is seeded before the mulch is applied, this can be a very simple and effective method of preventing erosion while vegetation is established.

Another method of erosion control is a rolled erosion control blanket.  These can be made from natural or synthetic materials and can be effective in protecting steeper slopes from erosion.  They are designed to be rolled onto the area and stapled into place.  Always follow installation specifications, as poor installation can cause these products to fail. 

This erosion contol blanket temporarily stabilizes the slope while vegetation is established.

If the blanket is not properly anchored and stapled, it can either be washed away or stormwater can wash out soil underneath the blanket, causing small gullies that are difficult to seed.  If the area is seeded and the erosion control blanket is installed correctly, grass will grow up through the blanket, and over time, the blanket will degrade.

For extremely steep slopes or areas with limited access, hydraulic mulching should be considered.  In this process, a slurry made up of mulch, seed, and a tackifying agent is sprayed onto the disturbed area.  There are also many other products and stabilization methods available.  Each site should be carefully evaluated to determine which product or combination of products is the most effective and economical way to achieve stabilization. 

 

 

 

 

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