Drainage · Practical advice
Soakaways: site suitability, design and installation
Why infiltration testing and location matter before buying drainage crates.
Understand what a soakaway does
A soakaway receives surface water and allows it to infiltrate into suitable surrounding ground. Storage and infiltration work together. It is not simply a hole that makes water disappear, and it is not suitable for every site. If the ground cannot accept water at the required rate, increasing the number of crates without a proper assessment may not resolve the problem.
Investigate before choosing the size
The contributing area, design rainfall and measured infiltration performance affect the required arrangement. Groundwater and other site constraints also matter. A competent assessment should determine what testing is appropriate and how the results inform the design. A casual bucket test or the fact that a neighbouring garden drains well does not provide a reliable specification for your property.
Choose the position carefully
The location needs to account for buildings, boundaries, services, slopes and other relevant constraints. Follow the applicable design and approval requirements rather than treating one online distance as the only test. Access for construction and future maintenance is also important. Establish suitability before finalising the surface layout around a chosen crate location.
Distinguish infiltration from storage alone
A crate system may form part of different drainage arrangements. An infiltration system and a lined attenuation system perform different functions and need different details. Ask which is proposed, what surrounds it and where the water ultimately goes. Product names or photographs of crates do not establish the purpose of the complete installed system.
Install to the assessed design
Excavation must be planned around services and ground stability. The selected system needs the specified support, wrapping or lining, connections and backfill, with the relevant loading considered. Do not enter an unsupported excavation to inspect it. Arrange the necessary checks and safe photographic record before covering, including how sediment is managed and maintenance access retained.
Maintain the upstream components
Keep gutters, inlets and any specified silt collection components maintained so avoidable debris does not enter the system. Retain the design information and installed location for future work. If performance deteriorates, investigate the whole route. A blocked inlet, sediment build-up or a wider groundwater issue can require a different response from simply replacing a visible pipe.
Can every driveway use a soakaway?
No. Suitability depends on the site and the proposed design. If infiltration is unsuitable, an appropriate alternative drainage arrangement needs to be assessed and any necessary permissions resolved.
Your project checklist
- Obtain the appropriate site assessment.
- Size and locate from the design.
- Identify infiltration or attenuation clearly.
- Protect access and upstream sediment control.
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