Erosion and sediment control is a meticulous process that goes beyond just setting up silt fences and erosion control blankets.
Site managers must account for on-site water buildup, vegetation, up-slope perimeters, site grading, and several other factors to ensure that worksites don’t pollute the surrounding ecosystem.
This guide will walk you through the basics of erosion and sediment control, including best practices and how to adopt these into your SWPPP plan.
What Is Erosion Control?
Erosion control is the active preservation of topsoil to prevent erosion, which can lead to several environmental effects.
Erosion control is considered the first priority of erosion and sediment control because it prevents sedimentation. Over time, repeated erosion can dislodge the top layer of soil or sedimentation, which, when mixed with water, leads to pollution via turbidity.
It is a legally required part of any SWPPP plan and is considered necessary for several reasons.
- Protects water systems from pollution
- Preserves natural vegetation and native landscapes.
- Makes revitalizing disturbed soil easier.
- Many erosion barriers reduce the risk of flooding by controlling the flow of stormwater runoff.
- Protects local infrastructure as much as surrounding water systems.
Some of the more common examples of erosion control include:
- Silt fences
- Erosion control blankets or matting
- Wattles
- Ripraps
- Natural vegetation and mulch
Learn More: Erosion Control 101: What Is Erosion Control?
What Is Sediment Control?
Sediment control is an extension of erosion control that seeks to reduce the spread of sediment particles once dislodged from the topsoil. Natural and artificial barriers and screens are erected to filter out and trap sediment particles so they can be reapplied to the dirt or disposed of properly.
Some examples of sediment control include:
- Silt fences
- Storm drain inlet barriers
- Sediment or retention basins
- Riparian Barriers
What’s the Difference Between Erosion and Sediment Control?
Erosion and sediment control are often used interchangeably, though they serve two different purposes. Erosion control is designed to prevent topsoil from dislodging sediment particles, while sediment control seeks to trap and control sediment particles once dislodged.
Many erosion and sediment controls often serve the same dual purpose of eliminating erosion and sedimentation, such as silt fences and wattles.
Creating an Erosion and Sediment Control Plan: 15 BMPs
To construct a proper SWPPP, you’ll need to combine the best practices of both erosion and sediment control into a single document.
We’ve laid out a few essential best practices of erosion and sediment control, which you can follow step-by-step to form your SWPPP.
Pre-Planning
- List all construction-related activities: Outline all potential construction-related activities and how they will disturb the surrounding landscape. Examples will include site grading, excavation, and land clearing.
- Perform a site assessment: Identify all water sources, potential sources of pollution, site-related activities, slope grades, and any sensitive areas where topsoil is vulnerable.
- Identify BMPs: Write down a list of BMPs and materials that will be needed to purchase in order to implement erosion and sediment controls properly.
General BMPs
- Grade slopes properly: Begin your project by grading slopes to reduce the velocity of stormwater runoff. While this requires more upfront work, this step will protect you from potential flooding, reduce the number of controls you’ll need to preserve slopes and prevent sedimentation of vulnerable areas.
- Preserve natural vegetation: Preserve and restore natural vegetation throughout your project to support additional erosion. Hydroseeding or mulch are particularly helpful at regenerating grass and other plants that are helpful to your efforts.
- Divert stormwater runoff (when possible): Silt fences, downpipes, and wattles are useful controls that can help divert and control the velocity of stormwater runoff to protect vulnerable areas. Use these tools to slow down runoff and divert it around slopes where topsoil is vulnerable.
- Erect slope barriers and covers: Where diversion is impossible, erosion control barriers may be erected. Silt fences, wattles, and erosion control mats are highly useful tools that help slow stormwater flow while preserving the topsoil underneath.
- Protect water beds: Erect another line of defense around river beds and streams to protect those water sources from pollution and your worksite from flooding. Ripraps (rock barriers), riparian (vegetation barriers), and sea walls composed of geotextile bags or concrete are highly effective barriers that slow the flow of stormwater runoff.
- Erect barriers around storm drains: Protect storm drains from loose sediment with filter fabric and filter socks that allow water to flow through and trap heavy particles.
- Construct a sediment retention basin (Optional): Retention ponds or sediment basins resemble man-made ponds and are designed to store water at the bottom of a slope to allow for sediment filtration to occur. There are several advantages and disadvantages to sediment basins, which is why we list them as optional.
Ongoing Maintenance
- Create an emergency spill response plan: Put in place an emergency response plan in case a spill or accident occurs, which may threaten the surrounding ecosystem. Make sure to create a special team with someone who is in charge of the plan if such a thing should ever occur.
- Employee training: Ensure BMPs are followed to the fullest letter of the law by constantly training and educating employees on proper procedures. This includes everything from equipment inspection to proper item storage.
- Subcontractor buy-in: Don’t just limit buy-in to your employees; make sure subcontractors are properly trained on all necessary BMPs.
- Routine inspection: Your erosion and sediment control plan doesn’t end at the first draft of your SWPPP; continue to perform inspections and make adjustments based on new data points and weather surveys.
- Record keeping: Be sure to record all data points of your SWPPP for regulatory and reporting purposes.
Learn More: Common Sediment and Erosion Control Solutions.
FAQs
What are the leading causes of erosion?
Erosion can be caused by factors such as heavy rainfall, strong winds, construction activities, deforestation, and improper land use.
How does sedimentation impact water quality?
Sedimentation can degrade water quality by depositing soil and debris in water bodies, affecting aquatic ecosystems and human use of water resources.
Why is site-specific assessment necessary for erosion and sediment control?
A site-specific assessment helps identify erosion-prone areas, soil types, and sediment sources, enabling the implementation of tailored control measures for effective environmental protection.