Sebastian County Conservation District
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Erosion Control on Steep Slopes

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Steep slopes are among the most challenging land management situations in Sebastian County — particularly on the Ouachita Mountain foothills where thin soils, high rainfall intensity, and frequent disturbance from roads and development create conditions for rapid erosion. Left unaddressed, a bare slope can lose inches of topsoil in a single storm event. The good news is that effective stabilization techniques are well-established and often surprisingly affordable.

Temporary Stabilization

When a slope has been disturbed — by grading, construction, or logging — temporary stabilization is the first priority. Erosion control blankets (ECBs) are woven or bonded mats of straw, coconut fiber, or wood excelsior that protect bare soil from raindrop impact and surface flow while vegetation establishes. They are stapled to the slope and seeded through or under them. For very steep slopes or areas with concentrated flow, heavier-duty turf reinforcement mats (TRMs) provide more durable protection.

Hydromulch and Tackifiers

Hydromulch — a slurry of wood fiber, seed, fertilizer, and tackifier sprayed onto bare slopes — is effective for large areas where blanket installation is impractical. The tackifier bonds the mulch to the soil surface, providing immediate protection while seed germinates. Hydromulch is particularly useful on road cuts and embankments. It is less effective than blankets on slopes steeper than 3:1 or in areas with concentrated flow.

Permanent Vegetation

Permanent stabilization requires deep-rooted vegetation that can anchor soil against both surface erosion and shallow mass movement. Native warm-season grasses — big bluestem, indiangrass, and switchgrass — are ideal for most slope situations in Sebastian County. Their root systems extend four to eight feet deep, far exceeding the depth of most erosion processes. For very steep or rocky slopes, native legumes like partridge pea and wild senna establish quickly and fix nitrogen to support subsequent grass establishment.

Terracing and Grade Breaks

On slopes longer than 100 feet, terraces or grade breaks interrupt the flow path and prevent runoff from accelerating to erosive velocities. Broad-based terraces — gentle, nearly level benches cut into the slope — are the most durable option and can be maintained with farm equipment. Simpler rock check dams or log wattles installed across drainage channels provide grade breaks at lower cost and with less disturbance, though they require more frequent maintenance.

Key Takeaways

  • Install erosion control blankets immediately after any slope disturbance
  • Native warm-season grasses root 4–8 feet deep — ideal for permanent stabilization
  • Terraces or grade breaks are essential on slopes longer than 100 feet
  • Hydromulch works well for large areas but is less effective on slopes steeper than 3:1