Excess disturbance of the topsoil not only complicates efforts to restore worksites after construction activity has ceased, but it can also lead to severe pollution of the surrounding area.
Environmental consultants will likely recommend a mix of natural and artificial erosion barrier controls designed to reduce topsoil disturbance.
This guide will lay out five different erosion control barriers that are essential to every worksite.
The Importance of Erosion Control Barriers
Proper erosion control is essential for limiting the amount of pollution that can develop downstream from topsoil disturbance and potential sedimentation.
Loose sediments that leak out into running water will greatly impact local ecosystems and kill aquatic life due to excess turbidity and freshwater pollution.
As a result, erosion control via natural and artificial barriers is an essential part of any stormwater management plan and permitting requirements.
Furthermore, there are practical benefits to practicing proper erosion control, which can pay dividends long-term for your project:
- Investing in erosion control simplifies restoration efforts after construction activity has ceased.
- Investing in erosion control saves you money by avoiding erecting costly sediment barriers.
Practicing proper erosion control is not merely recommended by environmental consultants; it’s essential and often legally required.
Types of Erosion Control Barriers
The question then becomes, what erosion control barriers should my worksite erect? With a bevy of different erosion control barrier options available, we narrowed it down to five essential controls covering every topographical aspect of your operation.
Natural Vegetation
Natural vegetation, such as plants, flowers, and shrubs, not only protects native topsoil from erosion but also helps capture and trap sediment particles.
Natural vegetation–sometimes called riparian barriers–is often applied via hydroseeding or mulch to river banks to slow down stormwater runoff and trap heavy particles before they’re discharged into water systems.
Natural vegetation also helps increase soil infiltration, which allows the dirt underneath to absorb more water and slow the spread of stormwater runoff.
With all of those benefits listed, it’s important to preserve natural vegetation and restore any that’s been disturbed by construction activities. Tools, such as mulch and hydroseeding help accelerate the growth of new vegetation and protect the native topsoil while vegetation takes time to sprout.
Pros
- Affordable: You often don’t need specialized tools to help grow native vegetation.
- Multiple Benefits: Native plants help trap sediment, protect topsoil, and increase infiltration.
- Long-Term Protection: Natural vegetation acts as a natural erosion control barrier long after activity has ceased and artificial controls have been disbanded.
Cons
- Not the Most Sturdy: Vegetation can easily be displaced during severe storms or construction-related activity.
- Requires Active Care: Unlike some artificial controls, vegetation requires care, such as pruning and mowing, as well as active weed control.
Silt Fencing
Silt fences are artificial erosion control barriers made up of geotextile fabric tied to wooden posts. These fences slow the spread of stormwater runoff and trap sediment particles in the fabric, preventing them from being discharged into water systems.
For simple erosion control, silt fences can be used to slow runoff, divert water from vulnerable slopes, and trap abrasive particles that may lead to topsoil erosion.
Silt fences are best applied on slopes or highly graded hills where the flow of stormwater runoff is greater.
Installing each fence is easy, and they are typically sturdy enough to use on multiple jobs (depending on the quality of the geotextile material).
Pros
- Effective for Erosion and Sediment Control: Silt fencing serves dual purposes as an effective sediment and erosion control device.
- Easy-to-Install: Silt fencing can be installed without specialty equipment and often by hand.
- Affordable: Silt fencing ranges in price, but most rolls can be purchased at a hardware store for a decent price.
Cons
- Limited Lifespan: Depending on the material quality, silt fencing may require replacement after a few months or multiple jobs.
- Not Effective for High-Flow Areas: Silt fencing is strong but not powerful enough for high-flow areas, such as the bottom of slopes where unimpeded water flow occurs.
- Requires Active Maintenance: Silt fencing will require maintenance to clean the geotextile fabric to ensure it works its best.
Wattles and Logs
Like silt fences, wattles made of fiber rolls or natural logs serve as effective erosion and sediment control solutions. These thick logs help to slow and divert the flow of stormwater runoff while trapping heavy particles.
Apply wattles and logs on slopes and around discharge points to add another layer of filtration to your natural vegetative barriers and silt fencing.
Pros
- Biodegradable: Straw wattles, fiber wattles, and logs are biodegradable and safe for the environment.
- Promotes Plant Growth: Since each barrier consists of organic materials, they actually help promote plant growth by feeding nutrients into the soil.
- Easy Installation: Wattles are incredibly lightweight and easy to install, while logs don’t require specialized equipment.
Cons
- Limited Lifespan: Due to their biodegradable nature, wattles and logs are not designed for long-term usage and may only be suitable for one or two projects.
- Not Effective for High-Flow Areas: Like silt fencing, wattles and logs may need to be stronger to handle high-flow tasks independently.
- Requires Active Maintenance: Wattles can be more difficult to clean than silt fencing.
Erosion Control Matting
Composed of a synthetic, geotextile material, erosion control matting is simply a thin blanket applied to slopes and vulnerable areas that allow water to flow over topsoil undisturbed. Thanks to their flexibility, erosion control mats can be installed on slopes of varying shapes and sizes.
Unlike other barriers on this list, erosion control matting can be applied strategically to vulnerable areas where you’re trying to grow new vegetation.
Pros
- Flexible Material: Erosion control blankets can be installed on uneven terrain, making them versatile.
- Biodegradable: Erosion control mats are biodegradable and safe for the environment.
- Protects Slopes: Erosion control mats are specifically designed for vulnerable topsoil on slopes and areas with high water flow.
Cons
- Higher Upfront Cost: Erosion control blankets are a bit more expensive than other materials on this list, such as wattles or silt fences.
- Ongoing Maintenance: Geotextile blankets require active maintenance as sediment gets lodged in the material.
- Complex Installation: Installing an erosion control mat is a little more labor intensive, requiring you to dig trenches.
Riprap and Sea Walls
Combining riprap and seawalls serves the dual purpose of slowing down and trapping sediment before it’s discharged into river banks while protecting the surrounding area from riverbanks that flood. Ripraps are designed for the former, while sea walls are designed for the latter.
Seawalls are often just concrete walls constructed around river banks and oceans, while riprap barriers may consist of rocks and other artificial materials around river banks to slow down water flow.
Pros
- Flood Prevention: Sea walls can prevent construction sites from flooding concerns from rivers, creeks, and other water sources.
- Effective Erosion Control: Ripraps and sea walls control absolute erosion by disrupting and displacing stormwater runoff.
Cons
- Potential Permit Requirements: Depending on your location, permits may be required to erect such controls.
- Cost: Sea walls and ripraps can be highly expensive.
FAQs
Are silt fences suitable for all types of soil?
Silt fences are effective on most soil types, but their performance may vary. It’s essential to assess your specific soil conditions before choosing this barrier.
Can erosion control blankets be used on steep slopes?
Yes, erosion control blankets are suitable for steep slopes. They provide immediate protection and support vegetation growth on challenging terrain.
How often should I inspect my erosion control barriers?
Regular inspections should be conducted at least monthly or after significant weather events. Timely maintenance ensures the continued effectiveness of the barriers.