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The Ultimate Guide to Understanding Soakaway Pits

The Ultimate Guide to Understanding Soakaway Pits, a soakaway pit is an essential component of many drainage systems. Understanding how they work and why they are important can help you make informed decisions about your property’s drainage solutions. This comprehensive guide will take you through everything you need to know about soakaway pits.

What is a Soakaway Pit?

A soakaway pit, also known as a soakaway or a drainage pit, is a simple yet effective method for managing surface water runoff. It is essentially a hole filled with gravel, rubble, or other coarse materials that allow water to percolate back into the ground slowly. This system helps prevent flooding and waterlogging by dispersing excess water into the surrounding soil.

How Does a Soakaway Pit Work?

A soakaway pit works by collecting water from roofs, driveways, and other hard surfaces through a network of pipes. Once the water reaches the pit, it seeps through the porous materials, filtering slowly into the surrounding soil. This process helps maintain the natural water table and reduces the risk of surface water flooding.

Components of a Soakaway Pit

  1. Inlet Pipe: The pipe that directs water from the source (e.g., roof gutters) to the soakaway pit.
  2. Soakaway Chamber: The main structure of the pit, often made of plastic crates or large perforated concrete rings, designed to store and disperse water.
  3. Filter Media: Layers of gravel or other permeable materials that surround the chamber, facilitating the slow release of water into the soil.
  4. Geotextile Membrane: A fabric layer that prevents soil from clogging the pit while allowing water to pass through.

Why are Soakaway Pits Important?

Prevents Flooding

One of the primary functions of a soakaway pit is to manage excess water and prevent flooding. By directing water away from hard surfaces and into the ground, soakaway pits reduce the risk of water accumulating and causing damage to properties.

Improves Soil Health

Soakaway pits help maintain soil health by ensuring that the ground remains well-drained. This is particularly important in areas with heavy rainfall, where poor drainage can lead to soil erosion and other issues.

Eco-Friendly Solution

Soakaway pits are an environmentally friendly way to manage water runoff. They help recharge groundwater levels and reduce the burden on public drainage systems, promoting a sustainable water management solution.

Installing a Soakaway Pit

The Ultimate Guide to Understanding Soakaway Pits,

Installing a soakaway pit requires careful planning and execution to ensure it functions correctly and efficiently. Here are the basic steps involved in the installation process:

Step 1: Site Assessment

Before installation, assess the site to determine the best location for the soakaway pit. The ideal site should be at least 5 meters away from any buildings to prevent water from seeping into foundations. Additionally, avoid areas with high water tables or impermeable clay soils.

Step 2: Excavation

Once the site is chosen, excavate a pit that is large enough to accommodate the expected volume of water. The size of the pit will depend on the area of the surface it will drain and the soil’s infiltration rate. A typical soakaway pit is about 1 cubic meter, but this can vary based on specific requirements.

Step 3: Lining and Filling

Line the pit with a geotextile membrane to prevent soil from clogging the drainage materials. Fill the pit with coarse materials such as gravel, rubble, or specialized soakaway crates. Ensure that these materials are evenly distributed to allow for maximum water infiltration.

Step 4: Connecting the Inlet Pipe

Connect the inlet pipe from the drainage source to the soakaway pit. Ensure the pipe has a slight gradient to encourage water flow into the pit. Secure the connection to prevent any leaks or blockages.

Step 5: Covering the Pit

Once the pit is filled and the inlet pipe is connected, cover the top with more gravel and soil. Ensure the surface is level with the surrounding ground. The area above the soakaway pit can be landscaped to blend seamlessly with the rest of your property.

Maintenance of Soakaway Pits

Regular maintenance is crucial to ensure the long-term effectiveness of a soakaway pit. Here are some maintenance tips:

Inspect Regularly

Check the inlet pipe and the pit itself periodically to ensure they are free from debris and blockages. Remove any leaves, twigs, or other materials that may obstruct water flow.

Clear Sediment

Over time, sediment can build up in the soakaway pit, reducing its efficiency. Clear out any sediment build up to maintain optimal performance.

Monitor Performance

After heavy rainfall, observe the area around the soakaway pit. If you notice pooling water or slow drainage, it may be a sign that the pit needs maintenance or that its capacity needs to be increased.

Common Issues and Troubleshooting


Blockages are a common issue with soakaway pits. They can occur due to debris buildup in the inlet pipe or sediment accumulation in the pit. Regular maintenance and inspections can help prevent and address blockages.

Poor Drainage

If your soakaway pit is not draining water effectively, it could be due to compacted soil, an undersized pit, or a high water table. In such cases, you may need to enlarge the pit, improve soil permeability, or install additional drainage solutions.


An overflow occurs when the soakaway pit cannot handle the volume of water it receives. This can be due to an undersized pit or excessive rainfall. Installing a larger pit or additional soakaway systems can help manage overflow issues.

Benefits of Installing a Soakaway Pit


Soakaway pits are a cost-effective drainage solution compared to other complex systems. They require minimal materials and maintenance, making them a budget-friendly option for homeowners and property managers.

Easy to Install

With proper planning and basic tools, a soakaway pit can be installed with relative ease. Many homeowners opt to install them as a DIY project, though professional installation is recommended for larger or more complex systems.

Long-Lasting Solution

When installed and maintained correctly, a soakaway pit can last for many years. The simplicity of its design and the use of durable materials contribute to its longevity, providing a reliable drainage solution for your property.

Enhances Property Value

Effective drainage solutions like soakaway pits can enhance the value of your property. Prospective buyers appreciate properties with well-maintained drainage systems that prevent flooding and water damage.

Regulations and Planning Permission

Before installing a soakaway pit, check local regulations and planning requirements. Some areas may have specific guidelines regarding the installation of drainage systems to protect the environment and public infrastructure. Obtaining the necessary permissions ensures that your installation complies with local laws and standards.

Choosing the Right Soakaway Pit

Soil Type

The type of soil on your property plays a crucial role in the effectiveness of a soakaway pit. Sandy and loamy soils are ideal because they have good drainage properties. Clay soils, on the other hand, have poor drainage and may require additional measures to improve water infiltration.

Size and Capacity

The size of the soakaway pit should match the area it drains and the volume of water it needs to handle. Consulting with a drainage expert can help you determine the appropriate size and capacity for your specific needs.


Choose materials that are durable and suitable for the expected load. High-quality gravel, rubble, or specialized soakaway crates are common choices. Ensure the materials used are compatible with the geotextile membrane to prevent clogging.

DIY vs. Professional Installation

The Ultimate Guide to Understanding Soakaway Pits,

While installing a soakaway pit can be a DIY project, there are benefits to hiring a professional. Professional installers have the expertise to design and implement a system that meets your specific requirements and complies with local regulations. They also have access to high-quality materials and equipment, ensuring a durable and efficient installation.


A soakaway pit is an invaluable solution for managing surface water runoff and preventing flooding. Understanding its function, installation, and maintenance can help you make informed decisions about your property’s drainage needs. Whether you opt for a DIY installation or seek professional help, a well-designed soakaway pit can provide long-lasting benefits for your home and the environment.

For a quote, contact VIV Construct Group. They offer expert advice and professional installation services to ensure your drainage system is efficient and compliant with local regulations.