SuDS and Soakaways for Driveways: What They Actually Mean

Updated 14/09/2026 · 4 min read

"Permeable" and "SuDS" get used almost interchangeably in driveway quotes, but they're not quite the same thing, and understanding the difference helps you ask a contractor the right questions before work starts.

What SuDS actually means

Sustainable Drainage Systems (SuDS) is the general principle of managing rainwater close to where it falls, rather than sending it straight to the sewer or storm drain - mimicking natural drainage instead of overwhelming the drainage network during heavy rain. A driveway's drainage design is one small application of a much broader planning and engineering principle used across new developments.

The three main approaches for a driveway

• Permeable surfacing. Gravel, permeable block paving, or porous resin/asphalt that lets water pass through the surface itself into a permeable sub-base below, where it soaks away gradually.
• Directed run-off. An impermeable surface (standard tarmac or block paving) laid with a fall that directs water to a lawn, border or other permeable area on your own property, rather than to the road.
• A soakaway. A dug pit filled with rubble or a proprietary crate system, positioned to collect water (often from a permeable sub-base or a drainage channel) and let it disperse into the surrounding ground over time.

Why the choice matters beyond planning permission

Avoiding planning permission (see our planning permission guide) is one reason to choose a permeable design, but proper drainage also protects the driveway itself. Standing water sitting against a driveway edge or sub-base, especially on clay ground (see our clay ground guide), is a common cause of premature cracking and edge failure.

When a soakaway is the right call

A soakaway is worth considering where the natural ground doesn't drain well enough on its own to cope with a permeable surface's run-off, or where there isn't enough garden space to direct water to a border. A percolation test - checking how quickly water actually drains away in your specific soil - is the proper way to size a soakaway rather than guessing, and this matters more on Essex and East London's clay-heavy ground than on more free-draining soil.

Questions worth asking a contractor

• Is the proposed surface genuinely permeable, or does it rely on directed run-off to a border?
• If a soakaway is included, has a percolation test been done, or is the size just a standard assumption?
• Where does water go in a genuinely heavy downpour, not just typical rainfall?