Drains

Why Edinburgh Drains Block More in Autumn

Every autumn, our call volume for blocked drains and gullies rises sharply across Edinburgh. It's not a coincidence — the combination of falling leaves, heavier rainfall and Edinburgh's ageing Victorian drainage infrastructure creates near-perfect conditions for blockages. Here's what's actually happening, and what you can do about it.

Leaves are the biggest culprit

Edinburgh has a lot of mature trees, especially in areas like Morningside, Stockbridge and the New Town. As leaves fall through October and November, they collect over drain grates and gullies. A single heavy downpour can then wash a large volume of wet leaves straight into the drain, where they form a dense mat that traps grit, silt and debris behind it.

Older drainage systems have less capacity

Much of Edinburgh's tenement and Victorian-era housing sits on drainage systems that are well over a century old. Original cast iron and clay pipework has narrower bores than modern equivalents, more joints where roots and debris can catch, and in many cases has settled or shifted slightly over the decades — creating low points where water and debris collect rather than flow through freely.

Grease build-up meets colder pipes

Fat, oil and grease poured down kitchen sinks doesn't disappear — it coats the inside of pipes and solidifies as it cools. As outdoor and ground temperatures drop in autumn, pipes cool faster too, meaning grease solidifies more quickly and closer to the point it was poured in. Combined with reduced pipe capacity from years of gradual build-up, this is when a partially restricted pipe finally blocks completely.

What you can do to reduce the risk

• Clear leaves from drain grates and gullies near your property weekly during peak leaf fall
• Never pour fat, oil or grease down the sink — let it cool and put it in the bin instead
• Run hot water through kitchen sink pipes after washing up to help flush residue through
• If you have recurring blockages every autumn, book a CCTV drain survey to find out exactly where the restriction is rather than repeatedly clearing symptoms
• For shared tenement stacks, raise recurring issues with your factor — a joint CCTV survey can identify problems affecting the whole building

Related reading: What You Can (and Can't) Flush Down the Toilet · Signs You Have a Hidden Water Leak