Erosion control blankets (ECBs) are rolled mats of natural or synthetic fibers held together by netting or stitching. They protect bare soil from raindrop impact and runoff, hold seed and moisture in place, and break down as vegetation establishes. Turf reinforcement mats (TRMs) are permanent, non-degradable mats that reinforce vegetation in high-flow areas.
Types of blankets
| Type | Material | Typical use |
|---|---|---|
| Straw blanket | Agricultural straw | Gentle to moderate slopes, short-term protection |
| Straw/coconut blend | Straw and coir fiber | Moderate to steep slopes, longer service |
| Coconut (coir) blanket | Coconut fiber | Steep slopes and low-flow channels, longer service |
| Excelsior blanket | Curled wood fiber | Slopes and channels, good moisture retention |
| Synthetic blanket | Polymer fibers | Longer-lasting temporary protection |
| Turf reinforcement mat (TRM) | Permanent synthetic matrix | Channels, spillways, high-velocity areas where vegetation alone won't hold |
Manufacturers rate products by functional longevity, from a few months for light straw blankets to multiple years for coir and synthetic products, and by maximum slope and allowable shear stress or velocity for channels. The industry's Erosion Control Technology Council (ECTC) publishes standard categories that many specifications reference.
Choosing a blanket
- Slope steepness and length: steeper and longer slopes need heavier, longer-lasting products.
- Flow: channels need products rated for the design shear stress or velocity; high flows need TRMs or armoring.
- How long until vegetation is established: pick a longevity that outlasts the grow-in period.
- Wildlife: the EPA CGP encourages wildlife-friendly products, such as natural-fiber or fully biodegradable netting with a loose, movable weave, because plastic netting can trap snakes, birds and other animals.
Installing on a slope
- Prepare the seedbed: grade smooth, remove rocks and clods, add topsoil and amendments.
- Seed and fertilize first. The blanket goes over the seed.
- Dig an anchor trench at the top of the slope (commonly about 6 inches deep by 6 inches wide), lay the blanket end in, staple, backfill and compact.
- Roll the blanket down the slope in the direction of water flow. Don't run it across the slope.
- Overlap edges of adjacent rolls by several inches (commonly 4 to 6 inches), and shingle ends with the upslope roll over the downslope roll.
- Staple at the pattern and rate the manufacturer specifies for the slope, with more staples at overlaps, seams and the top.
- Make sure the blanket is in full contact with the soil. Gaps let water run underneath.
- Anchor the bottom at the toe or extend it onto flat ground.
Installing in a channel
Run blankets lengthwise in the direction of flow, start at the downstream end so upstream rolls overlap downstream rolls, add check slots (trenches across the channel) at intervals, and use the heavier stapling pattern for channels.
Inspection
Check for washouts under the blanket, displaced or torn sections, missing staples, and bare spots where seed didn't take. Re-seed and repair as part of routine maintenance.
Sources and official references
Last reviewed: October 25, 2026 · Free general education based on the Clean Water Act, EPA NPDES rules and the EPA Construction General Permit. Your governing permit (EPA, state, tribal or local) controls. This is not legal advice, not EPA-approved, and not a California QSP/QSD or other state credential, and it does not issue a certificate. Nothing you enter on this page is saved or sent.