Erosion Control & Hydromulch in Sacramento, CA

Erosion control & hydromulch work in Sacramento is about the five months when it rains. From November through April the region gets nearly all of its yearly precipitation, and bare slopes, berms, ditch banks and swales that sat harmlessly all summer start to rill and slump with the first heavy storm. Our erosion control services, the core of what erosion control contractors do, cover that ground with sprayed mulch, bonded fiber matrix or rolled blankets, seeded with grass or native mixes that root in over the winter and hold the soil for good.

Where erosion shows up here

On the valley floor most lots are flat, so erosion problems tend to be smaller and local: the slope from a raised pad down to a backyard, the bank of a drainage swale, a berm along a fence line, a freshly trenched utility line. Toward the foothills in El Dorado Hills, Folsom, Cameron Park and Auburn, real slopes become the norm and the stakes rise. Bare soil on any of them moves the same way. Raindrops loosen the surface, sheet flow carries the fines, and small rills cut into gullies if nothing slows the water down. Soil that leaves your slope ends up in the street, the storm drain and eventually the river.

Matching the cover to the slope

The City of Sacramento's sediment control manual draws a useful line. Standard hydromulch, which is wood or paper fiber with a tackifier, is generally not recommended on slopes steeper than about 4 to 1. Bonded fiber matrix, a heavier fiber held together by a binder that dries into a continuous mat, can be used up to about 2 to 1. Steeper than that, or in channels where water concentrates, we turn to rolled erosion control blankets: straw blankets for short-term cover, straw and coconut for longer protection, and coir where flow is faster or the slope has to hold for more than a season. Blankets are stapled in place over seed, overlapping like shingles, with the top edge buried in a trench so water cannot get underneath.

Hydromulch on gentler ground

For most backyard berms and shallow banks, a heavy coat of hydromulch with seed is enough. It goes on quickly, covers irregular ground that blankets would bridge over, and needs no staples to pull out later. The manual asks for mulch to follow seed within a day when the two go on as separate passes, and for both to go down at least 24 hours before forecast rain so the binder can set. We follow that schedule and keep an eye on the forecast all fall.

Seed mixes for slopes

A slope that will be mowed can be seeded with the same fescue or Bermudagrass as the rest of the lawn, though mowing a slope is not much fun. A slope that will not be mowed usually does better with an erosion mix: annual cover for fast protection plus perennial or native grasses for long-term roots. On open ground that will not get summer water, native grass and wildflower seeding makes sense, since those mixes can be sown in fall and carried by winter rain, then go dormant in the dry season the way the surrounding hills do.

Soil and water on Sacramento slopes

Much of the valley's soil is loam over dense clay and hardpan, which the USDA describes as very slowly permeable with medium to very high runoff. On a slope that means more water runs off and less soaks in, so the cover has to stand up to sheet flow. Where a swale or downspout concentrates water onto a seeded area, we look at whether it needs a rock-lined outlet, a wider swale or a blanket rated for channel flow instead of just more mulch.

Homeowner slopes versus construction slopes

On a home, erosion control is usually about one problem area: a bank behind the fence, a slope that drops to the side yard, or soil washing out of a planting bed onto the patio. On construction ground the scale is larger and the stormwater plan spells out what goes where. Either way, the materials are the same, and so is the rule of thumb: the steeper the ground and the more water it carries, the heavier the cover needs to be. We size the job to the slope instead of selling the most expensive product on every bank.

Checking slopes after storms

The first big storm of the season is the real test. We look at slopes and swales after it, re-anchor any blanket that lifted, fill rills that started before vegetation took hold, and reseed spots that washed.

Timing and permits

The best time to seed and cover slopes is early fall, ahead of the rains, and the city manual names mid-October through mid-April as the optimum planting period. Some foothill counties set their own stabilization deadlines for bare ground going into winter, and we plan around them. Larger grading jobs may also need a permit and a stormwater plan, and we install what those documents call for. Call (916) 249-7160 to have us look at a slope.