Rarely is a worksite perfectly flat or free of sloping surfaces.
While grading and excavating land can help prevent some forms of sheet and rill erosion surrounding sloped surfaces, these hills often require additional controls to prevent water and wind damage from stripping the topsoil.
A temporary slope drain is one of the more effective solutions that can last for the length of your project.
These drains act as a conduit for stormwater, diverting water from the top of the slope to a basin or flat surface, thus protecting the slope from sheet erosion.
Temporary slope drains offer several benefits, from slope erosion control to flood prevention. This guide will discuss their individual uses and explain how our company employs them for various projects to provide sustainable erosion control.
What Are Temporary Slope Drains?
Temporary slope drains act as conduits for stormwater runoff, diverting it around the slope’s surface to prevent erosion. These drains are made of corrugated pipes or chutes that can be dug underneath a slope in a gully to bypass the slope.
Keep in mind that these drains are mostly temporary solutions that can help control water flow until permanent drainage systems are in place.
Due to their material composition, they were subject to damage and degradation over time if employed as a permanent solution without proper controls.
Benefits of Temporary Slope Drains
While only a temporary solution, slope drains can help ease additional stormwater management efforts and offer several benefits.
1. Erosion Control
One of the primary benefits of temporary slope drains is their ability to prevent soil erosion both at the top of slopes and on the slope’s surface. By safely channeling water down a slope, they reduce the impact of uncontrolled runoff, which can wash away valuable topsoil and disrupt construction activities.
2. Sediment Control
By directing stormwater through a designated path, temporary slope drains can direct sediment-laden runoff to a retention basin before being discharged into a nearby water source.
3. Protects Infrastructure
Uncontrolled runoff can weaken slopes, leading to landslides, flooding, road washouts, and foundation instability. Temporary slope drains help protect nearby infrastructure from excessive rainwater that can cause these issues.
4. Cost-Effective Solution
Temporary slope drains are relatively inexpensive compared to repairing eroded slopes or damaged infrastructure. Their simple installation and removal process make them a cost-effective choice for managing runoff in temporary situations.
5. Compliance with Environmental Regulations
Many construction and land development projects must adhere to environmental regulations regarding stormwater management. Temporary slope drains help meet these requirements by effectively controlling erosion and runoff.
Remember that temporary slope drains cannot discharge into an area greater than 5 acres.
6. Versatility in Different Conditions
Finally, temporary slope drains can be adapted to various site conditions, including steep slopes, uneven terrains, and different soil types. They can be easily repositioned or adjusted as construction progresses.
Uses of Temporary Slope Drains
We use temporary slopes for a number of different projects, including construction sites, highway projects, and more.
- Construction Sites: Temporary slope drains can help prevent slope erosion on active workzones and divert runoff to a controlled basin. Temporary slope drains can also help reduce the need to revitalize or restore old vegetation.
- Roadway and Highway Projects: Large-scale transportation projects often require slope stabilization, particularly around roadways where water naturally drains. Temporary slope drains ensure water does not accumulate on slopes and reduce the risk of landslides and washouts.
- Land Development: When preparing land for residential or commercial use, temporary slope drains help control water flow before permanent drainage infrastructure is completed.
- Stormwater Management: These drains assist in directing rainwater during heavy storms, preventing sediment-laden runoff from contaminating nearby water bodies.
- Agricultural Applications: Temporary slope drains are sometimes used in farming areas with sloped terrains to prevent topsoil erosion and improve water distribution.
How to Install Temporary Slope Drains
Temporary slope drains typically require professional assistance to ensure proper installation and discharge of the runoff. Here are some steps we follow to install temporary slope drains on sites properly.
Step 1: Site Assessment: Evaluate the slope’s gradient, soil type, and expected water flow to determine the optimal placement of the drain. You will need to account for multiple variables, including where the water will be discharged, taking care not to overwhelm erosion controls at the bottom of slopes or cause rill erosion.
Step 2: Select Drain Material: Choose a flexible pipe or chute that can handle the expected water volume and withstand site conditions. We work with a flexible but durable material that can handle extreme weather conditions.
Step 3: Excavate an Inlet Channel: Create a shallow trench at the top of the slope to direct water into the drain. This requires specialized equipment that your construction company may or may not have access to.
Step 4: Anchor the Drain: Secure the pipe with stakes or anchors to prevent displacement during heavy rain. This will also prevent erosion in the trench that you dig, which can compromise your erosion control efforts.
Step 5: Direct Water to a Stable Outlet: Ensure the drain leads to a designated discharge area, such as a sediment basin, to prevent erosion at the outlet point.
Be sure to inspect the drain periodically to clear any blockages and ensure it remains securely in place. Inspecting the drain should be a regular part of your SWPPP.
FAQs
How long can a temporary slope drain be used?
Temporary slope drains are typically used for the duration of a construction or land development project, usually lasting weeks to months. However, their lifespan depends on maintenance and environmental conditions.
Are temporary slope drains reusable?
Yes, many temporary slope drains, particularly flexible pipes, can be reused in multiple projects as long as they remain in good condition.
What is the best material for a temporary slope drain?
The best material depends on site conditions and expected water flow. Corrugated plastic pipes are commonly used due to their flexibility and durability, but metal or reinforced fabric chutes may be preferred in certain conditions.