Montana MDT Erosion Control Products

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

Montana MDT - Erosion Control Methods

Montana job sites span steep mountain cuts, glacial till plains, loessy benches, and wide alluvial valleys. Layer on long freeze–thaw seasons, snowmelt surges, rain-on-snow events, high-altitude UV, prairie winds, and post-wildfire debris flows, and freshly disturbed soils can ravel fast while ditches incise and deliver sediment to culverts and streams. MDT’s approach stacks 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, wind, and meltwater. Straw blankets suit short, gentle slopes and low-velocity swales; heavier coir or straw-coir mats handle longer grades and higher shear common during snowmelt and summer downpours. Blankets are keyed into anchor trenches at crest and toe, overlapped shingle-style downslope, and stapled to manufacturer patterns—with extra anchoring on windy passes and high plains. Along streams and lake shores, coir logs toe-in blanket edges, defend the line, and buy time for roots.

Turf-reinforcement mats (TRMs). Where velocities exceed what temporary blankets can handle—steep ditch reaches, culvert outlets, tight bends, and drawdown areas—synthetic TRMs provide long-life reinforcement. Once vegetation roots through, the composite resists repeated storm events and ice-out better than bare soil and can reduce how much riprap is needed in constrained corridors, improving access and aesthetics.

Hydraulic mulches and soil binders. Irregular cuts, talus-like slopes, and rocky shoulders 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—ideal for quick cover between storm windows. Where straw mulch is used, it’s crimped into the surface and locked with a tackifier or polymer binder so it won’t blow or float during spring runoff.

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 project boundary, silt fence works well in fine-grained tills when trenched and backfilled correctly; on stony shoulders or near traffic, heavier filter socks provide stability and easier maintenance. The goal is to intercept sheet flow high on the slope so water never gains erosive energy.

Check structures and channels. Temporary rock or wattle check dams in construction ditches cut velocities and settle suspended solids. Spacing is set so each dam’s crest ponds water to the toe of the next, creating a stair-step energy dissipator. At outfalls and culvert aprons, crews pair RECPs or TRMs with riprap over a proper filter layer; coir logs keep toes tight until vegetation takes hold. In very high-shear or fluctuating-stage zones, articulated concrete block mats add durability while supporting plant growth 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 rock over geotextile—limit mud tracked onto public roads; sweeping backs them up, especially during wet spring periods.

Basins, traps, stockpiles, and wildfire response. 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. On burn-scarred slopes above highways, MDT often layers BFM for immediate cover, wattles on contour to arrest rilling, and robust outlet armoring for ash-laden peaks.

Seasonal strategy and upkeep. With short growing windows, dormant seeding in late fall at elevation and early-spring seeding lower down are common. Cold-hardy native mixes are matched to aspect and moisture; coir-rich blankets and higher mulch rates help on sunny, wind-exposed slopes. After big storms, melt, or ice-out, crews repair tears, reset stakes, clean inlet devices, remove accumulated sediment (often at half height), and reseed bare spots. Temporary controls come out once vegetation is dense and slopes and channels prove stable.

Bottom line: on MDT projects, erosion control isn’t a single product—it’s a layered system that tames snowmelt and cloudbursts, protects waterways, and gives native vegetation the foothold it needs to lock Montana’s soils in place.

Montana MDT