Silt Fence & Inlet Protection in Los Angeles, CA

In Los Angeles, silt fence and inlet protection are the basic tools that keep a job site's dirt from ending up in the gutter, the storm drain and eventually the ocean. Runoff that enters a curb inlet heads into the flood control system, which includes 51 miles of concrete-lined Los Angeles River and smaller channels such as Ballona Creek running to Santa Monica Bay. As silt fence contractors, we set barriers around the downhill edges of a site, protect nearby inlets and keep the work zone from tracking mud onto the street. We also handle sediment control for homeowners doing remodels, pool digs and hillside additions.

Who needs sediment control

California's Construction Stormwater General Permit applies once a project disturbs an acre or more, including a lot that is only one phase of a bigger development crossing that line, and those projects need the controls their stormwater plan specifies. In the city, permitted grading over 200 cubic yards cannot begin between October 1 and April 15 until an approved erosion control system is in place. Smaller jobs are still bound by the building code rule that no excavation or fill may let soil or debris fall, slide or flow onto neighboring property. A pool dig, a hillside addition or a backyard regrade can all trigger a request from an inspector or an unhappy neighbor.

How silt fence works, and where it fails

The fence itself is woven geotextile, stapled or tied to stakes, with its bottom edge buried in a trench. It slows sheet flow so soil settles out on the uphill side. It is meant for sheet flow, not for channels or concentrated flows. Fence that is set without a buried toe, runs straight down a slope, or sits across a gully fails quickly. We trench the fabric in, follow the contour, curl both ends upslope so runoff cannot slip past the fence, and use stronger fence where the load is high.

Fiber rolls for tight lots

On small city lots, a full silt fence is not always practical, especially along a sidewalk or driveway. Fiber rolls, also called straw wattles, are tubes of straw or other fiber that lie flat on pavement or are staked into soil. They work well along curbs, at the base of stockpiles and across short slopes.

Storm drain inlet protection

Curb inlets and yard drains near the work need protection so sediment never gets in. Depending on the inlet and the traffic around it, we use gravel bags, fabric drop-in filters, fiber rolls or a silt fence barrier around field inlets. These need to be checked and cleaned after rain, because a clogged inlet guard can flood the street.

Stabilized entrances

Where trucks leave a site, a pad of coarse rock over fabric knocks mud off the tires before it reaches the street. We build entrances on larger jobs and can maintain them through the project.

Maintenance and removal

Sediment controls are only as good as their upkeep. After storms, fence gets undercut, wattles slip and inlet bags fill. We offer inspection and repair visits during the rainy season and remove and dispose of the controls when the ground is finally seeded and stable.

Stockpiles and small lots

A pile of soil or sand from a pool dig or a foundation trench can lose a surprising amount of material in a single storm. We ring stockpiles with fiber rolls, cover them when they will sit for a while, and keep them away from curbs and inlets. On tight city lots with no room for perimeter fence, a combination of wattles, gravel bags and covered piles usually does the job.

Getting ready for October 1

For projects that will still have bare soil when the rainy season starts, the best time to install sediment controls is late summer. Hillside owners with unfinished grading over 200 cubic yards have to file erosion control plans with their grading inspector before October 1, and controls installed in September go in on dry ground, which is far easier than trenching fence into mud. If your inspector has asked for controls by a certain date, tell us when you call.

Working from a stormwater plan

On projects covered by the state permit, the stormwater plan lists the controls and where they belong. We install to that plan and let your consultant know if field conditions call for a change.

Sediment control on remodels and additions

Homeowner projects are where controls most often get skipped. A backyard addition, a hillside deck foundation or a long sewer trench can leave a lot of loose dirt next to a driveway that slopes to the street. A few rolls along the curb, a guard on the nearest inlet and a covered spoil pile are usually enough, and they cost far less than cleaning a mud-filled gutter or answering a complaint.

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