How deep does a soakaway need to be?

A soakaway is a type of drainage system optimised to deal with surface rainwater run-off, and is acknowledged as an ideal way to deal with excess water.

However, an oft-asked question is: ‘How deep should a soakaway be?’

The construction of a soakaway involves digging a large hole in the ground and filling it with crates. These crates typically have voids, permitting large volumes of water to seep back into the ground.

A soakaway needs to be built in a way that can support weight on top when it is filled in. It is better if a soakaway is deeper, because it will perform more efficiently and have an increased storage capacity.

For those wondering ‘How deep does a soakaway need to be?’, soakaways should be at least 5ft, and ideally 6ft5in, if possible.

In general, the depth of a soakaway depends on the size of the area that needs draining. The width and depth of the hole is assessed by the size of the crates you will be using. You should generally follow a rule of one cubic metre of a soakaway for 30 square metre of the roof. This is measured below the pipe invert, so it is advised to dig 1.3m deep and 1m x 1m.

However, the depth of a soakaway should not be as much of a priority as the volume of water it can hold. The speed at which water seeps into the ground should also be a factor taken into account.

Not only that, the location of the soakaway is also another critical component that needs to be carefully considered. A soakaway should be positioned at the lowest point in the rainwater drainage system.

As mentioned above, the depth of each soakaway varies according to the type. For instance, a driveway soakaway pit needs to be set deeper than a lawn soakaway. Moreover, if your roof or driveway is bigger, then your soakaway should be designed to deal with more rainwater.

For those considering installing a soakaway, consulting the experts at OMDI is a vital step in navigating the process from start to finish.

If you have any questions about the construction or maintenance of a soakaway such as ‘How deep does a soakaway have to be?’, we are happy to provide you with helpful advice.

Our years of experience in the field of off-mains drainage is exemplified in our extensive repertoire of installations for both commercial and domestic properties throughout the U.K.

So, why not give us your details via our contact form or give us a call on 01977 800 418?