Erosion control is the practice of keeping soil in place by covering it before it moves, using blankets, mats, mulch, or vegetation to prevent wind and water from carrying it away—rather than catching it after it has already washed down the slope.
If you’re looking at a bare slope on your property and wondering why the dirt keeps washing into the driveway after every rain, you need erosion control—not sediment control. The difference matters: erosion control stops soil from being dislodged in the first place, while sediment control (like a silt fence) only catches it after it has already moved. The single most effective principle is simple: keep the soil covered.
The right method depends entirely on how steep your slope is, how much water runs across it, and whether you need a temporary fix or a permanent solution. Here is what works for each situation.
How Slope Steepness Dictates Your Erosion Control Method
Steeper slopes need heavier, more aggressive cover because water moves faster and carries more force as the grade increases. The following table outlines the standard approach for each range.
| Slope Steepness | Recommended Methods | Key Installation Detail |
|---|---|---|
| Up to 33% | Mulch, crushed rock, grass seeding | A 2-inch layer of mulch is usually sufficient |
| 33% to 50% | Coco fiber mats, burlap, jute netting + seed mix | Trench top edge 6 inches deep; overlap adjacent blankets by 6 inches |
| Over 50% | Terracing with a retaining wall + matting | Consult a structural engineer for wall design |
For any slope that uses blankets or mats, installing them correctly is just as important as picking the right product.
Installation Steps That Actually Work
Proper installation is where most erosion control attempts fail. The sequence matters, and skipping steps creates weak points that wash out under the first heavy storm.
- Prepare the surface: Remove debris, large rocks, and vegetation to create a smooth, even soil surface. Do not drive equipment across the slope—compaction reduces infiltration and makes runoff worse.
- Trench the top edge: Dig a trench 6 inches deep across the top of the blanket or mat. Place the blanket’s top edge into the trench and staple it firmly to the bottom of the trench before backfilling.
- Overlap sections by at least 6 inches: Adjacent blankets should overlap—never leave gaps. If the blanket runs down the center of a channel, keep the seam out of the deepest part where water flows fastest.
- Install check strips: Every 25 to 30 feet down the slope, place a row of staples 2 to 4 inches apart across the full width of the blanket. This prevents water from lifting the blanket and running underneath it.
- Use correct staple length: Standard 6-inch staples work for most sites. In high-flow or loose-soil conditions, switch to 8-inch staples or wooden stakes driven deeper for more holding power.
- Seed properly: Drill seed or hydroseed the area—never broadcast seed on top of a blanket. Broadcast seeds wash through the mat’s holes and concentrate at the bottom of the slope, leaving the top bare.
For areas that stay saturated for weeks at a time, subsurface drainage must be installed before any surface erosion control goes on. Without drainage, no blanket or mat can handle the hydrostatic pressure from water building up underneath it.
What To Avoid: Common Erosion Control Failures
The mistakes that cause erosion control to fail are predictable and avoidable. Broadcast seeding is the most common—it looks like it worked for a week, then the first rain washes all the seed to the low spot. Placing blanket seams in the channel center is another frequent error: the seam is the weakest point, and concentrated flow tears it open quickly. On uneven ground, failing to add extra staples in pockets and depressions allows water to collect behind the blanket and lift it off the soil. And remember: a silt fence is not erosion control—it catches already-eroded soil, which means the soil on your slope is already gone by the time it works.
Biodegradable vs. Synthetic: Which Material Fits Your Timeline
Natural fiber mats—jute, straw, and coconut coir—are biodegradable and work best for temporary stabilization while vegetation establishes. Synthetic mats and turf reinforcement mats last much longer and are designed for permanent slope stabilization where high water flow or steep grades require structural reinforcement. The trade-off is cost: natural mats are cheaper and decompose naturally, but synthetic mats save labor over time because you do not have to re-apply them after they break down.
References & Sources
- USDA Natural Resources Conservation Service. “Controlling Soil Erosion: Small Scale Solutions for your Farm.” Covers ground cover thresholds and slope-based method recommendations.
- Texas Department of Transportation. “Erosion Control BMP Resources.” Details installation specifications for blankets, check slots, and staple patterns.
- University of Washington. “Erosion Control.” Explains the difference between erosion control and sediment control and lists common installation mistakes.