Silt Fence & Construction BMPs in Denver, CO

Silt fence and construction BMPs (best management practices) are the sediment controls that keep soil from a Denver job site out of the street, the storm drains and the creeks. We install silt fence, inlet protection, wattles and related controls for builders, developers and general contractors, and we maintain them so the site still passes inspection after the third thunderstorm, not just the day it went in. If you are looking for silt fence contractors who will also seed and stabilize the site when grading is done, that is our whole job.

When controls are required

The City and County of Denver may require a Stormwater Management Plan and a Construction Activities Stormwater Discharge Permit for construction, including demolition, that disturbs one acre or more, for sites that are part of a larger development plan, for sites with significant erosion potential, and for work that disturbs contaminated soils or places fill in waters of the US. Developments over one acre, residential and commercial alike, need that permit. The plan shows where silt fence, inlet protection and other controls go, and inspectors check that they are in place and working.

Getting the fence to actually trap sediment

A silt fence does its job only when runoff pools behind it long enough for the sediment to drop out. That means the fabric is buried in a trench, not laid on the surface; posts are on the downhill side; the fence follows the contour so water does not run along it to one end; and the ends turn uphill. A fence installed straight up and down a slope, or with its bottom edge loose, becomes a channel. On Denver's clay-loam soils, a thunderstorm will find every gap.

Inlet protection

Storm inlets near a site get sediment barriers so runoff is filtered before it enters the system. The right type depends on whether the inlet is in a paved street or an unpaved area and how much flow it takes: silt fence rings, straw bale or sandbag barriers, gravel and mesh, or devices that sit inside the grate. Inlet protection in a street must not cause flooding, so we size and place it with that in mind.

Maintenance through the storm season

Sediment control is not install-and-forget. Denver gets most of its precipitation from April through August, much of it from afternoon thunderstorms, and each storm can fill a silt fence or bury an inlet filter. We offer inspection and maintenance visits: removing built-up sediment, resetting undermined fence, replacing torn fabric and swapping out spent inlet filters. When the site is stabilized, we pull the controls and seed the disturbed strip they leave behind.

Final stabilization

Controls come out only when the ground they protect is stabilized. Because we also do hydroseeding, erosion control blankets and grading, one crew can carry a site from perimeter control through final seeding.