Silt fence

Types of Silt Fence

A silt fence is a temporary sediment control barrier used to protect water bodies from construction site runoff. It is designed to allow water to pass through while trapping sediment, making it an essential tool for erosion control during land-disturbing activities. Silt fences are made up of geotextile fabric, wooden posts, and support wires.

The main purpose of these barriers is to filter the water and trap sediments, but they can also help prevent flooding, control traffic, and divert water runoff. There are several types of silt fences, including:

• Woven Silt Fences

  Woven silt fences are made of textured, woven fabric. The fabric is usually made from high-density polyethylene (HDPE) or polypropylene. The woven nature of the fabric allows water to pass through the fence quickly. However, the fabric traps sediment effectively. Woven silt fences are suitable for sites with low to moderate sediment loads. They are popular for residential construction projects and small land-disturbing activities.

• Non-Woven Silt Fence

  These silt fences are made from non-woven geotextile fabric. The fabric is usually made from polypropylene. It is designed to provide a high level of filtration while allowing water to flow through. Non-woven silt fences are suitable for sites with high sediment loads. They are often used in commercial construction projects and large-scale land-disturbing activities.

• Permanent Silt Fence

  A permanent silt fence is a long-term sediment control barrier. It is designed to provide continuous sediment control for ongoing projects. The fence is constructed using robust materials, such as treated wood, vinyl, or heavy-duty wire mesh. It is usually supported by concrete footings. Permanent silt fences are installed in areas where ongoing water protection is necessary. For example, they can be placed along the boundaries of a site adjacent to water bodies.

• Regular Silt Fence

  This is the most common type of silt fence. It is suitable for temporary sediment control on most construction sites. A regular silt fence is made of lightweight, woven geotextile fabric. The fabric is supported by wooden posts and tension wire. It is installed along the perimeter of a construction site or disturbed area.

• Reinforced Silt Fence

  The reinforced silt fence is an upgraded version of the regular silt fence. It features additional support and filtration components. For instance, it has multiple layers of geotextile fabric and reinforced stitching. This type of silt fence is suitable for sites with high sediment loads and steep slopes. They are ideal for sites with high-traffic construction areas.

Functions and features of silt fence

• Erosion Control:

  The primary function of silt fences is to control erosion, especially on construction sites or areas with disturbed soil. By intercepting and filtering water runoff, they reduce the speed of water, allowing soil particles to settle and preventing sediment from flowing into nearby waterways or ponds.

• Sediment Retention:

  The woven geotextile fabric used in silt fences acts as a barrier, trapping and retaining sediment particles carried by stormwater. This retention is crucial for preventing sediment pollution in streams, rivers, and other bodies of water, which can harm aquatic ecosystems.

• Water Flow Regulation:

  Silt fences help regulate the flow of water on-site, directing it to designated drainage areas. This regulation prevents water from eroding gullies or channels forming in the landscape and maintains the integrity of the land.

• Environmental Compliance:

  Installing silt fences on construction sites is often a regulatory requirement to comply with environmental protection laws. Using these fences demonstrates a commitment to responsible land management and minimizes the project's environmental impact.

• Temporary Solution:

  Silt fences are designed as temporary erosion control measures to be used during construction or land-disturbing activities. Once the project is complete and vegetation is established, these fences can be removed.

• Material and Design Features:

  Silt fences are typically constructed from woven polypropylene fabric with wooden or metal support posts. Key features include easy installation, cost-effectiveness, and lightweight materials. The fabric is permeable, allowing water to pass through while trapping soil particles.

• Durability and UV Resistance:

  Many silt fences are made with UV-stabilized fabric for durability and longevity. This feature is particularly important for projects that last for months or years. The reinforced bottom hem adds strength and prevents soil undercutting.

Scenarios of Silt Fence

Silt fences are used in various applications, especially in construction sites. Here are some of their applicable scenarios:

• Construction Sites:

  During construction activities, soil erosion and runoff are usually high. This is because of land disruption by construction activities. Silt fences are installed around construction sites to prevent sedimentation. The silt fences trap sediments from stormwater before they are carried away. Additionally, silt fences help in water percolation. The stormwater collected in the sediment basin can be used for construction activities.

• Landscaping Projects:

  Land landscaping involves altering the natural vegetation and topography. This causes soil erosion and runoff. Installing silt fences at the site perimeters helps to control runoff and sedimentation. This ensures compliance with environmental regulations. It also reduces the costs incurred in restoration activities. The silt fences prevent sediments from entering water bodies. This protects aquatic life and the environment at large.

• Excavation Activities:

  The process of digging and removing large amounts of earth causes high soil runoff. This is due to the disturbance of the natural land. Silt fences are installed to minimize the effects of excavation on the environment. They reduce soil loss by trapping sediments. This ensures that the topsoil is preserved for use in reclamation and restoration.

• Utility Right-of-Ways:

  Utility right-of-ways involve clearing vegetation and altering land topography. This leads to soil erosion and increased runoff. Silt fences are installed along the disturbed areas to control sedimentation. They ensure that the disturbed areas are not washed away by water runoff.

• Agricultural Lands:

  In agriculture, silt fences are used to control water and soil conservation. They are used to divert clean water from agricultural lands. This reduces the effects of runoff and soil erosion in farms. Additionally, silt fences are used to direct water to areas of easy infiltration. This helps in reducing waterlogging in farmlands.

How to Choose a Silt Fence

When choosing a silt fence, there are several factors that should be considered. The type of project to be undertaken will determine the kind of silt fence to be installed. Other factors to consider are the topography of the area, the size of the construction site, and the budget available.

Some key factors that should be considered include:

• Evaluate the site conditions

  Before installing a silt fence, the site where it will be installed should be evaluated. This will ensure that the right type of silt fence is selected. When evaluating the site, factors like soil types, rainfall patterns, and topography should be considered. These factors influence the effectiveness of different types of silt fences.

• Determine project specifics

  For effective erosion control, the right silt fence should be installed. This involves determining the details of the project. This includes the size of the project, the duration of the project, and the expected water flow. This information will help in choosing the right type of silt fence that meets the needs of the project.

• Consider the budget

  Budget is an important factor when determining what type of silt fence to buy. There are different types of silt fences and they have different prices. A temporary silt fence is usually cheaper than a more robust and durable one. It is important to choose a silt fence that one can afford to buy and install.

• Consult with a professional

  It is recommended to seek help from someone who knows more about silt fences and how they work. A professional will charge a fee for their advice, but it will save one money in the long run. This is because they will assist in choosing a silt fence that is suitable for the site and project.

silt fence Q&A

Q1: What is the purpose of a silt fence?

A1: Silt fences are temporary barriers used to control sediment during construction projects. They help prevent the runoff of water carrying soil and sediment debris, protecting nearby water bodies and the environment.

Q2: What is a silt fence made of?

A2: A silt fence is typically made of geotextile fabric, wooden or metal stakes, and sometimes wire mesh. The fabric is porous, allowing water to pass through while trapping sediment particles.

Q3: How effective are silt fences?

A3: When installed and maintained properly, silt fences can be very effective at reducing sediment runoff during rainstorms. They are not meant to stop all water but to slow it down and capture sediment.

Q4: How long does a silt fence last?

A4: Silt fences are temporary structures meant to be used for the duration of a construction project or until disturbed areas are stabilized. Depending on the project and weather, they typically last a few months.

Q5: Do silt fences work in heavy rain?

A5: Silt fences can still work in heavy rain if properly installed and maintained. However, they may need additional support or reinforcement in extreme conditions. Regular monitoring is important.