North Carolina NCDOT Erosion Control Products

Solmax DOT Standard Specification Product Chart (click image to expand)

North Carolina NCDOT - Erosion Control Methods

North Carolina projects cross loose Coastal Plain sands and tidal marshes, red Piedmont clays, and steep Blue Ridge corridors. Add hurricanes, tropical downpours, flashy streams, winter freeze–thaw in the mountains, and construction traffic, and freshly graded ground can ravel fast while ditches cut and deliver sediment to culverts and waters. NCDOT’s approach layers controls that (1) protect bare soil, (2) slow and spread runoff, and (3) capture sediment until vegetation takes over.

Rolled erosion control products (RECPs). On new embankments, slope repairs, and roadside swales, crews install straw, excelsior, coconut/coir, or blended blankets to shield soil and seed from rain splash and wind. Straw blankets suit short, gentle slopes and low-velocity swales; heavier coir or straw-coir mats handle longer grades and the higher shear typical of tropical storms. Blankets are trenched at the crest and toe, overlapped shingle-style downslope, and pinned to manufacturer patterns—often with extra anchoring on the coast where gusts and salt spray test fasteners. Along tidal creeks and lake margins, coir logs toe-in blanket edges and hold the line until roots knit the soil.

Turf-reinforcement mats (TRMs). Where velocities exceed blanket limits—steep ditches, culvert outlets, sharp bends, and drawdown zones—synthetic TRMs provide long-life reinforcement. Once vegetation roots through, the composite resists repeated storm events and tidal fluctuations better than bare soil and can reduce how much riprap is needed in constrained corridors, improving maintenance and appearance.

Hydraulic mulches and soil binders. Irregular cuts and broad slopes are stabilized with hydroseed plus hydromulch, bonded fiber matrix (BFM), or flexible growth media (FGM). BFMs form a breathable crust that resists sheet flow yet allows germination—ideal for quick cover between storm windows. On drought-prone or windy sites, straw mulch is crimped into the surface and locked with tackifier or polymer binder to prevent blow-off or float-off before roots establish.

Slope interrupters and perimeter controls. Fiber rolls (wattles) and compost filter socks placed on contour break long slope lengths, slow runoff, and trap sediment before rills form. At the disturbance boundary, silt fence excels in Piedmont clays when trenched and backfilled correctly; on sandy shoulders or tight urban footprints, heavier filter socks add stability and simplify maintenance. The goal is to intercept sheet flow high on the slope so water never builds erosive energy.

Check structures and channels. Temporary rock or wattle check dams in construction ditches reduce velocities and drop out sediment. Spacing is set so each crest ponds water to the toe of the next, creating stair-step energy dissipation. At culvert outlets, storm outfalls, and coastal transitions, crews pair RECPs or TRMs with riprap over an appropriate filter layer; coir logs keep toes tight until vegetation takes hold. In very high-shear zones or reversing-flow locations, articulated concrete block mats add durability while allowing vegetation in the cells.

Inlet protection and track-out control. Curb socks, drop-inlet inserts, and gravel rings around grates keep sediment out of storm systems during grading and paving. Stabilized construction exits—coarse stone over geotextile—limit mud tracked onto public roads; sweeping backs them up, especially where sticky clays cling to tires.

Basins, traps, stockpiles, and seasonal practice. Sediment basins or traps intercept runoff from disturbed areas and provide settling time before discharge. Topsoil stockpiles are promptly seeded and mulched or covered; perimeter wattles or fence contain fines during storms. Timing targets reliable moisture—dormant seeding in late fall in the mountains, spring windows in the Piedmont and coast. Native mixes are matched to ecoregion and aspect; coir-rich blankets and higher mulch rates help on sunny, wind-exposed slopes.

Inspection and maintenance. After major rains, crews repair tears, reset stakes, clean inlet devices, remove accumulated sediment (often at half-height), and reseed bare spots. Temporary controls are removed once vegetation is dense and slopes and channels prove stable.

Bottom line: on NCDOT projects, erosion control isn’t one product—it’s a layered system. Blankets, TRMs, hydraulic mulches, wattles, silt fence, check dams, inlet protection, basins, and stabilized exits work together to tame hurricanes and cloudbursts, protect waterways, and give vegetation the foothold it needs to lock North Carolina’s soils in place.

North Carolina NCDOT