We undertake all types of drainage work including residential, commercial, cesspits, soakaways and extension drainage throughout Sussex.


A cesspit is a large chamber for the waste coming from a property, this will be because the property is too far from the existing sewers or in an area where there is no sewerage system. Cesspits are designed to be emptied regularly, but still need the capacity and strength to hold months worth of waste.

Modern planning regulations have now started to dictate that cesspits are no longer acceptable when building a new property or when building an extension that requires additional drainage or capacity. The new stipulation is to install Sewage Treatment Plants. These are far more cost-effective, have lower maintenance and do not produce that smell normally associated with cesspits.

Extension drainage

When completing a new extension it is most likely you will need to at least re-route some of the existing drainage if not add in more drainage from the property to the sewers. This is usually if the new part of the property goes over existing drainage, if you are adding in a new bathroom or kitchen.

Soak aways

A soakaway is a large hole dug about 5 metres away from a property. They are backfilled with either debris or plastic crates and are a requirement by most local councils to facilitate the run-off of rainwater from the drainage on your property. Councils no longer allow rainwater to run into their drains unless you have special dispensation given for reasons such as insufficient drainage capacity of your soil. A soak away is so called as thats exactly what it is designed to do, soak your excess rainwater away into the ground.

You may hear a soak away being called a ‘Modular Cell Drainage System’, this image shows why.

Why Install a New Soakaway?

There are several reasons why you may want (or need) a new soakaway:

  1. Soakaways sometimes become blocked with roots, leaves, roof moss and mud. They occasionally collapse due to weight (cars, lorries, concrete, tarmac etc) placed above them.
  2. If you have an extension built on your house, the extra rainwater from the additional roof area may be too much for your existing soakaway to cope with.
  3. Current building regulations state that when having a new driveway or patio laid, you must allow for the adequate drainage of surface rainwater within the boundaries of your property. A soakaway is an answer to this.

How Are They Installed?

This schedule is for the removal of an existing soakaway and replacement with a crate based system, we assume the hole and pipework is through a lawn or flower bed and not a driveway.

  • Dig up existing drainage pipe from rainwater pipe to existing soakaway.
  • Lay gravel to base of pipe trench.
  • Dig up and excavate existing soakaway to a depth of 1.2 metres.
  • Perform a water permeable test to ensure water actually soaks through soil (clay based soil may prevent the soakaway from doing it’s job).
  • Lay gravel to base of hole.
  • Secure crates inside hole, lay new drainage pipe and connect to crates, lay membrane over and around crates and cover with top soil/turf etc.
  • Connect opposite end of drainage pipe to rainwater downpipe.

See our drainage gallery here. 


Contact us for a friendly chat about your project;

t: 01903 536587
m: 07886 310779
e: info@bvmhgroundworks.com