Illinois IDOT Erosion Control Products

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

Illinois IDOT  - Erosion Control Methods

Illinois projects span dense glacial tills, lakebed clays along Lake Michigan, wind-blown loess in the west, and broad floodplains on the Mississippi, Illinois, and Ohio Rivers. Add intense summer thunderstorms, spring snowmelt, long freeze–thaw seasons, and heavy urban runoff, and freshly disturbed soils can ravel, gully, and load drainage systems with sediment. IDOT’s playbook layers products that (1) protect bare soil, (2) slow and spread water, 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 fit short, gentle slopes and low-velocity swales; heavier coir or straw-coir mats are used on longer grades and ditch reaches with higher shear. Blankets are trenched at the crest and toe, overlapped shingle-style, and stapled to manufacturer patterns—often with extra anchoring on open, windy corridors.

Turf-reinforcement mats (TRMs). Where velocities exceed what temporary blankets can handle—steep channels, culvert outlets, and tight bends—synthetic TRMs provide long-life reinforcement. Once vegetation roots through the mat, the composite withstands repeated storm events and drawdown better than bare soil and can reduce reliance on rock in constrained rights-of-way.

Hydraulic mulches and soil binders. Irregular cuts and rocky or compacted urban soils are treated with hydraulic applications: hydroseed with hydromulch, bonded fiber matrix (BFM), or flexible growth media (FGM). BFMs form a breathable crust that resists sheet flow yet allows germination, giving quick cover between storm windows. Where straw mulch is used, it’s crimped into the soil and locked with tackifier or polymer binder to prevent wind loss until roots knit the surface.

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 site boundary, silt fence excels in fine-grained tills when trenched and backfilled correctly; on stony shoulders or high-traffic zones, heavier filter socks offer stability and easier maintenance. Placement focuses on intercepting flow high on the slope so water never gains erosive energy.

Check structures and channels. Temporary rock or wattle check dams in construction ditches reduce velocities and drop sediment. Spacing is set so each crest ponds water to the toe of the next, creating a stair-step energy dissipator. At culvert outlets and storm outfalls, crews pair blankets or TRMs with riprap over an appropriate filter layer; coir logs at the toe keep edges tight until vegetation establishes. In very high shear, 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—especially important in dense urban corridors. Stabilized construction exits—coarse rock over geotextile—limit mud tracked onto public roads; sweeping backs them up where sticky clays cling to tires.
Basins, traps, and stockpiles. Sediment basins or traps intercept runoff from disturbed areas and provide settling volume before discharge. Topsoil stockpiles are promptly seeded and mulched or covered, with perimeter wattles or fence to contain fines.

Seasonal strategy, inspection, and maintenance. With long winters and shoulder-season storms, crews use dormant seeding, mulch plus tackifier, added anchoring on blankets, and quick temporary stabilization before shutdowns. After major rains or melt events, teams repair tears, reset stakes, empty inlet devices, remove accumulated sediment (often at half-height), and reseed bare spots. Temporary controls are removed once vegetation is established and slopes and channels prove stable.

Bottom line: on IDOT projects, erosion control isn’t a single product—it’s a layered system working together to tame stormwater, protect waterways, and give vegetation the foothold it needs to lock Illinois soils in place.

Illinois IDOT