Delaware DELDOT Erosion Control Products

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

Delaware DELDOT - Erosion Control Methods

Delaware work zones often sit on high-groundwater sands and silty clays that erode quickly when sheet flow concentrates. Storms can flip flow directions with tidal backwater, while tropical remnants dump short-duration, high-intensity rain. DelDOT’s playbook layers products that (1) protect bare soil, (2) slow and spread water, and (3) capture sediment before it reaches inlets, wetlands, and streams.

Rolled erosion control products (RECPs). On new embankments, slope repairs, and 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 handle longer grades and higher shear stresses common in stormwater ditches. Blankets are trenched at the crest and toe, lapped shingle-style downslope, and pinned to manufacturer patterns—extra anchoring is common near the coast where gusts and salt spray test fasteners. On steeper channels or high-flow bends, turf-reinforcement mats (TRMs) provide permanent reinforcement that, once vegetated, resists repeated storm events without resorting to continuous rock.

Hydraulic mulches and soil binders. For irregular cuts and sandy, drought-prone slopes, DelDOT uses hydroseed with hydromulch, bonded fiber matrix (BFM), or flexible growth media (FGM). BFMs form a breathable crust that resists sheet flow yet allows germination—useful when quick cover is needed between storm windows. Where straw mulch is used, it’s crimped into the soil and locked with a 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 project boundary, silt fence works well in finer soils if posts can be set firmly; on sandy shoulders or tight urban footprints, heavier filter socks provide stability and easier maintenance access. Placement emphasizes intercepting sheet flow early so water never gains erosive energy.

Check structures, channels, and outfalls. Temporary rock or wattle check dams in construction ditches reduce velocities and drop out sediment. Spacing is set so each dam’s crest backs water to the toe of the next, creating a stair-step energy dissipator. At culvert outlets and tidal outfalls, crews combine blankets or TRMs with riprap over a filter layer; coir logs at the toe keep edges tight until vegetation establishes. In very high energy or reversing-flow locations, articulated concrete block mats add durability while allowing some vegetation in the cells.

Inlet protection and track-out control. Curb socks, drop-inlet inserts, and gravel rings around grates keep sediment from entering storm systems during grading and paving. Stabilized construction exits—coarse stone over geotextile—limit soil tracked onto public roads; street sweeping and vacuuming backstop them in clayey districts where fines cling to tires.

Basins, traps, and stockpiles. Small sediment basins or traps intercept runoff from disturbed areas and provide settling volume ahead of discharge. Topsoil stockpiles are promptly seeded and mulched or covered; perimeter wattles or fence keep fines on site.

Seeding strategy near the coast. Timing targets reliable moisture: dormant seeding in late fall or windows ahead of spring rains. Salt-tolerant native mixes are matched to elevation and aspect; coir-rich blankets and higher mulch rates help conserve moisture and protect seedlings on sunny, wind-exposed slopes.

Inspection and maintenance. After storm or tidal events, crews repair tears, reset stakes, empty inlet devices, and remove accumulated sediment (often when it reaches half the device height). Temporary controls are removed once vegetation is established and slopes and channels prove stable.

Bottom line: on DelDOT projects, erosion control isn’t a single 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 stormwater and tides, protect sensitive marshes and streams, and give vegetation the foothold it needs to lock Delaware’s soils in place.

Delaware DELDOT