We offer an unrivaled, bespoke design service designed to help ensure you do not over or under provide soakaway capacity. Over provision means unnecessary cost and under provision could result in flooding. We will work out exactly how many you need and back this up with detailed calculations, which can be used to prove to building control or your planning officer, that the storm drainage is optimally sized.


Probably the most frequently asked question we hear is: "how big does my soakaway need to be? and how many crates do I need?" What our clients often don't realise is that in order for a soakaway to function properly and last for a significant number of years it is essential that is is designed and installed correctly. 
1.jpg *Soakaway crates provide a 95% void ratio compared to 30% provided by a traditional rubble filled soakaways. This results in better performance, a significantly longer service life and one third of the amount of excavation required to install.
To design a soakaway there are a number of key variables to consider. Key factors include:
  • The location of the project. Some areas of the UK receive far more annual rainfall than others.
  • The impermeable area to be drained to the soakaway. This includes areas such as roofs, driveways and patios etc
  • The infiltration properties of the soil. This is extremely important when designing a soakaway as certain soils are permeable (they allow water to pass through easily and are often referred to as 'Freely Draining') and others are impermeable (they don't allow water to pass through or of they do it can take a significant amount of time). 
Other factors may include:
  • Environment Agency Ground Water Source Protection Zones (Aquifers).
  • High or perched water table.
  • Distance from a structural foundation or property boundary.
2.jpg *Clay sub-soil particles are very cohesive making infiltration systems such as soakaways often unsuitable or difficult to achieve. We can adopt certain design techniques to combat this to an extent.
When installing a soakaway, whether it be at your own property or whether you are a builder installing a soakaway for one of your clients, or an Architect looking to discharge a client's drainage related planning conditions, you want the system to last for a very long time and be both hydraulically and structurally sound.
Sustainable Drainage Centre are able to help you:
  • Plan your soakaway.
  • Design your soakaway and provide drawings and calculations for Building Control if required.
  • Provide you with the products to construct your soakaway.
  • Provide support and assistance during the installation process.
We provide an excellent service and pride ourselves on delivering maximum customer support. 
Please contact us should you have any queries or wish to speak to one of our engineers. Alternatively, please consider our 'off the shelf' soakaway consultancy services.