Soakaway Installation


Soakaway installation is a crucial aspect of managing rainwater and preventing flooding in residential, commercial, and industrial properties. By effectively capturing and draining excess water into the ground, soakaways help prevent surface water runoff and recharge groundwater reserves. In this article, we will explore the importance of soakaway installation, the factors to consider before installation, the steps involved, different types of soakaways, associated costs, benefits, common issues, and frequently asked questions.

What is a Soakaway?

A soakaway, also known as an infiltration system or a soak pit, is an underground structure designed to collect and disperse excess rainwater or wastewater into the surrounding soil. It consists of a cavity filled with aggregate material, such as gravel or crushed stone, which allows water to infiltrate into the ground slowly. The aggregate acts as a filter, removing impurities before the water reaches the soil.

Why is Soakaway Installation Important?

Soakaway installation plays a vital role in managing stormwater runoff, especially in areas with high rainfall or poor drainage systems. It helps prevent waterlogging, erosion, and surface flooding by providing a controlled pathway for water to disperse naturally into the ground. Without proper soakaway installation, rainwater can accumulate, leading to water damage, soil erosion, and potential structural issues.

Factors to Consider Before Soakaway Installation

Before proceeding with soakaway installation, several factors need careful consideration to ensure an effective and efficient system. These factors include:

1. Site Assessment and Soil Analysis

A thorough site assessment is necessary to determine the suitability of the location for soakaway installation. Soil analysis helps understand the soil type, its permeability, and its ability to absorb water. This information is crucial in designing an appropriate soakaway system.

2. Legal and Regulatory Requirements

It is essential to research and adhere to local building codes, regulations, and permits related to soakaway installation. Failure to comply with these requirements can lead to legal complications and potential penalties.

3. Size and Design of the Soakaway

The size and design of the soakaway depend on various factors, such as the surface area draining into it, the intensity of rainfall, and the soil’s infiltration capacity. Calculations based on these factors help determine the optimal dimensions and capacity of the soakaway.

4. Water Flow and Drainage Calculations

Accurate calculations of water flow and drainage capacity are essential to prevent overwhelming the soakaway system. The capacity should be sufficient to handle peak rainfall events without causing flooding or backups.

5. Maintenance and Accessibility

Consideration should be given to the accessibility of the soakaway for inspection and maintenance purposes. Accessibility ensures regular upkeep, unclogging if necessary, and prolongs the lifespan of the system.

Steps for Soakaway Installation

The installation process of a soakaway involves several sequential steps. Following these steps ensures a proper and functional system. The steps include:

1. Determine the Location

Based on the site assessment and analysis, identify the most suitable location for the soakaway. It should be away from existing structures, trees, utility lines, and underground obstructions. The location should also consider the slope of the land for proper water flow.

2. Excavation and Preparation

Excavate the area to the required depth and dimensions, considering the soakaway design specifications. Remove any debris, vegetation, or rocks that may obstruct the installation.

3. Installation of Perforated Pipes

Place perforated pipes, also known as distribution pipes, at the bottom of the excavated area. These pipes distribute the water evenly throughout the soakaway system.

4. Filling the Soakaway with Aggregate

Fill the excavated area and the surrounding pipes with the chosen aggregate material. The aggregate allows water to infiltrate and prevents clogging by filtering out debris and sediment.

5. Backfilling and Compaction

Backfill the excavated area with soil, ensuring proper compaction to avoid settlement or subsidence. Compact the soil layer by layer, using suitable compaction equipment.

6. Surface Restoration

Restore the surface to its original condition, considering any landscaping or hardscaping elements that were disturbed during the installation process. Proper restoration ensures an aesthetically pleasing result.

Types of Soakaways

There are different types of soakaways available, each with its advantages and applications. The common types of soakaways include:

1. Traditional Soakaways

Traditional soakaways are simple, cost-effective systems that consist of a pit or trench filled with aggregate. They are suitable for smaller-scale applications and can be constructed using readily available materials.

2. Modular Soakaways

Modular soakaways consist of pre-formed plastic crates or chambers that interlock to create an underground storage system. These systems provide a larger capacity and are suitable for areas with limited space or high water volume.

3. Infiltration Trenches

Infiltration trenches are elongated excavated areas filled with aggregate, allowing water to infiltrate slowly into the ground along their length. They are effective in managing larger volumes of water and are commonly used in commercial and industrial settings.

4. Rainwater Harvesting Systems

Rainwater harvesting systems combine soakaway functionality with water storage capabilities. These systems collect and store rainwater for later use, reducing reliance on mains water supply and providing an eco-friendly solution.

Soakaway Installation Cost

The cost of soakaway installation can vary depending on various factors such as the size of the system, the complexity of the design, the type of soakaway chosen, and local labor and material costs. The cost components include:

1. Materials and Equipment

The cost of materials, including pipes, aggregate, geotextile fabric, and any additional components required for the installation.

2. Labor Costs

The cost of skilled labor for excavation, installation, and surface restoration.

3. Additional Expenses

Additional expenses may include obtaining permits, site preparation, soil testing, and any necessary landscaping adjustments.

It is advisable to obtain multiple quotes from reputable contractors to compare prices and ensure a reasonable cost estimate.

Benefits of Soakaway Installation

Soakaway installation offers several benefits for property owners and the environment. Some key benefits include:

1. Preventing Flooding

Soakaways efficiently manage excess water, preventing surface flooding, and reducing the risk of water damage to buildings and infrastructure.

2. Groundwater Recharge

By allowing water to infiltrate into the ground, soakaways contribute to recharging groundwater reserves. This helps maintain a healthy water table and sustains the local ecosystem.

3. Environmentally Friendly

Soakaways promote sustainable water management by reducing the strain on stormwater systems and preventing the discharge of pollutants into water bodies.

4. Cost-Effective Solution

Investing in a well-designed and properly installed soakaway can save property owners from costly repairs and damages caused by poor drainage or flooding.

Common Issues with Soakaway Installation

While soakaways offer effective water management, certain issues can arise if they are not installed or maintained correctly. Common issues include:

1. Clogging and Blockages

Soakaways can become clogged and have blockages over time due to the accumulation of sediment, debris, or tree roots. Regular maintenance, including cleaning and inspection, can prevent clogging issues.

2. Insufficient Drainage Capacity

If the soakaway system is undersized or poorly designed, it may not be able to handle the volume of water, leading to backups and ineffective drainage.

3. Poor Design and Installation

Inadequate design or improper installation can compromise the effectiveness of the soakaway system, leading to waterlogging or reduced lifespan.

4. Maintenance Neglect

Lack of regular maintenance, including inspections and cleaning, can lead to reduced functionality and potential issues with the soakaway system.

Frequently Asked Questions (FAQs)

1. How long does a soakaway installation take?

The duration of soakaway installation depends on various factors, including the size of the system, site conditions, and weather. On average, it can take anywhere from a few days to a few weeks to complete the installation.

2. Can I install a soakaway myself?

While it is possible to install a small-scale traditional soakaway with basic DIY knowledge, it is recommended to hire Bristol drain engineers in for larger or more complex installations to ensure proper design, adherence to regulations, and optimal functionality.

3. What happens if my soakaway gets clogged?

If a soakaway becomes clogged, it can lead to poor drainage and potential flooding. Regular maintenance, including cleaning and inspection, helps prevent clogging issues. If clogging occurs, professional drain unblocker assistance may be required to clean or repair the system.

4. Do I need planning permission for a soakaway installation?

The need for planning permission for soakaway installation may vary depending on local regulations and the scale of the project. It is advisable to consult with local authorities or a professional contractor to determine the specific requirements for your area.

5. How often should a soakaway be maintained?

Regular maintenance is essential to keep the soakaway system functioning optimally. It is recommended to schedule inspections and cleaning at least once a year, especially before the rainy season, to ensure any issues are addressed promptly.


Soakaway installation is a vital solution for managing stormwater runoff, preventing flooding, and promoting sustainable water management. By understanding the importance of proper installation, considering various factors, and choosing the right type of soakaway, property owners can effectively manage rainwater and contribute to a healthier environment. Regular maintenance and adherence to local regulations are crucial for long-term functionality and optimal performance. Soakaway installation provides a cost-effective and eco-friendly solution to address water drainage challenges while protecting properties from potential water damage.

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