Soakaway Design Packages

In addition to the broad range of civil engineering services we offer, we specialise in the design of surface water soakaways that meet the needs of our clients.

We appreciate that complying with modern day requirements for soakaway design can be a daunting task, especially for smaller builders or those wishing to install their drainage system themselves.

Soakaway Solutions can help you with your soakaway design from project conception to installation.

In order to assist with budget planning and providing up-front cost transparency, soakaway design packages can be purchased through our website based on the drainage area of your project.

We currently have five soakaway design packages to choose from:

We recommend you contact us from drainage areas exceeding 500m2 and these projects will require bespoke quotations.

What is your drainage area?

There are mainly two different types of surface within the built environment. These are permeable surfaces such as lawns, grass fields, shrub beds etc that allow rain water to pass through them, then there are impermeable surfaces such as roofs, driveways, roads and footways that won't allow rain water to pass through them. When rainfall lands on impermeable surfaces it needs to be drained or else it can cause flooding. Your drainage area is therefore any impermeable area within your project that will be drained to your new soakaway.

How to calculate your drainage area?

This is a simple calculation, it is determined by multiplying the length by the width of any new building or surface. For a simple square/rectangular building calculating the area is easy, it is also worth noting that taking plan view measurements are perfectly acceptable, you do not need to take into account roof pitches etc. Should you find that calculating your drainage area is more complex due to different shapes such as driveways etc please email your plans to us and we will work it out for you. We will accurately measure drainage areas when completing soakaway designs during the detailed design process so it does not matter if your figures are out slightly.

What to do next?

Once you have calculated your drainage area you can purchase the relevant soakaway design package through our website. We also accept BACS payment or we can send you a PayPal invoice to your chosen email address.

Each soakaway design package provides step by step guidance on what information we require to design your soakaway once we have received your payment. Details we require include:

  • Full address and postcode of the property
  • Plans or sketches of your proposal(s)
  • Confirmation of the design criteria. This is typically BRE-365 but your building control officer will confirm.
  • Soil infiltration rate. You can either request we look up the soil type at your project from published geology maps and use this to calculate a 'typical' infiltration rate or you can undertake a simple test on site. We can provide details on how to undertake a soakaway test if required. On site soakaway testing is a far more accurate method and we recommend you discuss this with your building control officer prior to determining which method you would like us to use.
  • Confirm if you are aware of any other site constraints such as high ground water or known areas of contamination.

Once we are in receipt of your documentation our qualified engineer will calculate the size of the soakaway required.

What will you receive? 

On completion of the soakaway design we will provide you with the following information:

  • Plan showing the designed configuration of your new soakaway. This can be incorporated into your site layout proposals or superimposed onto any sketches or drawings you have.
  • Detailed calculations for your soakaway that are used to determine the volume required. These can be passed to your building control/planning officer for approval.
  • Construction details providing details on how to install your new soakaway.

Please note that all our soakaway designs are based on using modern day soakaway crates that offer a 95% void ratio. Please advise if you wish to install a rubble filled soakaway prior to us commencing the detailed design. We must advise that rubble filled soakaways are an inefficient method of constructing soakaways as they only offer a 30% void ratio and some local authorities no longer permit their usage.

Why have your soakaway designed by us? 

  • Qualified staff with over 15 years industry experience.
  • Specialists in sustainable drainage systems and soakaway design.
  • Ensure that your soakaway is designed to modern day standards.
  • Comply with building regulations and planning requirements.
  • Have piece of mind knowing your soakaway is designed to an optimal size. This ensures you are not increasing your risk of flooding by installing an undersized soakaway or not paying additional costs by installing an oversized one.

Please don't hesitate to contact us with any questions or queries.