Which places flood: ramblas, barrancos and low-lying towns

Key rules

• Dry is not safe: A dry rambla or barranco can fill within minutes, with no rain where you are.
• Most exposed area: The Mediterranean coast and the Balearics see the most flash floods.
• Flat beds: Wide, flat channel beds look safe but are the most dangerous place to park, camp or walk.
• Warnings: Follow warnings for the whole catchment, not just your local weather.

The short answer

Dry ramblas, barrancos and floodplain towns can fill with fast, violent water within minutes, even when it is not raining where you are. Rain that fell kilometres upstream is enough. Treat any dry watercourse as dangerous.

What a rambla and a barranco are

A rambla is a wide, usually dry watercourse in the Mediterranean area. A barranco is a ravine or gully. Both carry water only after heavy rain, so most of the year they look like empty ground.

Why they are dangerous when dry

Rain falling upstream, possibly many kilometres away, runs down the channel. It can arrive downstream in minutes to a few hours, carrying mud and debris. You get no rain at your spot to warn you.

The wide, flat bed looks like a safe place. That is why roads, car parks and campsites are often put there. A sunny sky tells you nothing. If you are near a watercourse, follow the warnings for the whole catchment, not just the weather where you stand.

Where it happens most

The most exposed area is the Mediterranean arc:

• the Valencian Community, including Valencia and Alicante provinces
• Murcia
• eastern Andalucía (Almería, Granada, Málaga)
• Catalonia
• the Balearic Islands

Albacete and parts of Aragón can also be hit. Inland and Atlantic areas are affected less often, but not never.

How to spot risky ground

• A wide, flat, gravel or sand bed running through a town or valley.
• A road that dips to cross a dry channel.
• A home, car park or campsite built beside or inside a channel.
• A town sitting on low, flat land next to a river or rambla.

The checklist below shows how to look up official flood maps for any address. Do this before you rent, buy, park long-term or camp.

Checklist

• Open the national flood-zone viewer (SNCZI), run by the Ministry for the Ecological Transition.

• Search for the address or municipality you are considering.

• Switch on the flood-prone layers for return periods of 10, 50, 100 and 500 years.

• Check your region's own viewer, such as PATRICOVA in the Valencian Community or the ACA viewer in Catalonia.

• Look on the ground for any rambla or barranco near the home, road, parking spot or campsite.

What to watch out for

• Dry ramblas and barrancos fill fast: A dry rambla or barranco can carry a violent flow of water, mud and debris within minutes, even with no rain where you stand. Rain falling many kilometres upstream is enough. Never camp, park or walk in a dry watercourse, and leave the bed at once if heavy rain is reported anywhere in the catchment.

• Wide flat beds look safe: The wide, flat floor of a rambla looks like solid ground and is often used for roads, parking and camping. Treat any gully or dry riverbed as a flood path and choose higher ground.

• A sunny sky is not a safe sign: Floods can reach towns on a floodplain where it is not raining, arriving in minutes to a few hours after upstream rain.

• The Mediterranean coast is most exposed: The Valencian Community, Murcia, eastern Andalucía, Catalonia and the Balearic Islands face the most flash-flood risk. Look up any address you plan to rent or buy in the flood-zone viewer before you commit.

Frequently asked questions

Which parts of Spain are hit most often by DANA flash floods?

The Mediterranean arc is hit most often: the Valencian Community, Murcia, eastern Andalucía (Almería, Granada, Málaga), Catalonia and the Balearic Islands.

How can I check if my street is in an official flood zone?

Open the national flood-zone viewer (SNCZI), which is free and online, and search for your address or municipality.

Can a flash flood reach me if the sky above me is sunny?

Yes, a flash flood can reach you under a sunny sky if rain falls upstream in the same catchment. The water can arrive downstream in minutes to a few hours. Follow warnings for the whole catchment, not just your own spot.

Why do people park or camp in ramblas if they are dangerous?

Their wide, flat, dry beds look safe, so they are often used for roads, parking and camping. Rain many kilometres upstream can still send a fast flow of mud and debris through within minutes. Park and camp on higher ground away from any gully.