HWritten by a qualified plumbing and heating engineer·

Soakaway blocked or overflowing — causes and fixes

🔒 Written by a Gas Safe registered engineer
May Need Pro💷 £50£2000Varies
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Most likely cause & what to check

1

A soakaway is a pit filled with rubble or a plastic crate structure buried in the garden that allows rainwater or surface water to slowly drain into the ground. It will overflow when the surrounding ground is saturated.

2

First, check if it's just weather-related: after prolonged heavy rain, even a well-functioning soakaway will overflow temporarily. If water drains away within 12–24 hours of dry weather, it is working correctly.

3

If the soakaway remains waterlogged weeks after heavy rain, the surrounding soil has likely become clogged with fine silt over the years. This is normal degradation — soakaways typically last 10–30 years.

4

Check that surface runoff from neighbouring land isn't overwhelming your soakaway. If a new drive or extension nearby has increased runoff onto your land, this can overload a previously adequate soakaway.

5

A blocked access pipe leading to the soakaway can be rodded or jetter-cleared by a drainage contractor. This is often cheaper than replacing the soakaway itself.

6

Soakaway replacement involves excavating the old pit (typically 2–3m deep and 1–1.5m diameter) and installing new plastic crate systems or rubble fill. Cost varies widely with access and ground conditions.

7

Planning permission is not required for a soakaway, but building regulations may apply if it's connected to a new drainage scheme. Check with your local authority before installing a new one.

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