Why some parts of Spain run drier than others

Key rules

• Most exposed: The Segura basin has a structural water deficit, and the Júcar, Guadalquivir, Andalusian Mediterranean, Catalan internal basins and both island groups are also exposed.
• Check by basin: Find the river basin that covers your town, then read its indicator and drought scenario.
• Year to year: Exposure varies by year, so one wet year does not remove a long-term shortage.
• Outlook: Projections point to lower water resources, with the biggest falls in the south and southeast.

The short answer

Water stress is structurally higher in the southeast, Andalusia, Catalonia and the islands. Northern and Atlantic Spain is generally less exposed. "Structural" means the shortage is a long-term feature of the area, not just a bad year.

Which areas are most exposed

• Southeast: the Segura basin has a structural deficit. It uses more water than it naturally receives, and it is the standard example of a stressed area. The Júcar basin is also under pressure.
• Andalusia: the Guadalquivir basin and the Andalusian Mediterranean basins.
• Catalonia: the internal basins, which serve Barcelona and the surrounding coast.
• The islands: the Balearic Islands and the Canary Islands.

The ranking comes from official water-scarcity indices, including the explotación index, which compares how much water is used with how much is available. Exposure changes from year to year, so a wet year can ease the pressure without removing it.

How to check your own exposure

Do it in this order:

1. Find which river basin your town sits in. Each basin has a confederación hidrográfica, the public body that manages it. It publishes maps of its water systems.
2. On the national environment ministry's website, find the monthly drought and scarcity reports. The same site has the hydrological plan and the special drought plan (PES) for your basin.
3. Read the indicator and the scenario for the system that covers your area. The scenario tells you whether the area is in normal conditions, alert or emergency.
4. Look at the current reservoir levels in the Boletín Hidrológico and the Embalses reservoir figures.
5. For climate data and drought indices, use the national weather agency, AEMET.

The FAQ below covers the same checks as short questions.

What to expect in the coming years

National adaptation studies project lower water resources: reductions of about 10% by 2040, and up to 20% or more by 2100 under high-emissions scenarios. The falls are larger in the south and southeast. They also project longer and more frequent droughts, more heat and evaporation, and more intense rainfall.

The size of the change depends on the emissions scenario. For your decision, this means a stressed area is likely to stay stressed. An area that is fine today in the south or southeast may become less so.

Using this when you choose where to live

If you are looking at a stressed area, check its drought scenario before you sign or buy. Ask your town hall or the basin body whether there are current water restrictions. Plan for the possibility of restrictions in a dry year.

Frequently asked questions

How do I check how dry my own area is over the long term?

Find the river basin or water system that covers your town, then read its indicator and scenario in the official reports. The environment ministry publishes monthly drought and scarcity reports, the hydrological plans and a drought plan for each basin. Each basin authority (confederación hidrográfica) also publishes maps of its water systems.

Where can I see current reservoir levels for my area?

You can see reservoir storage in the national hydrological bulletin and the reservoir level (Embalses) tables. Look up the reservoirs in your basin rather than the national average, because levels differ a lot between basins. Spain's weather agency adds climate data and drought indices for your area.

Will drought get worse in Spain in the coming years?

Yes, official projections expect water resources to fall by about 10% by 2040 and by 20% or more by 2100 under high-emissions scenarios. The falls are larger in the south and southeast. Droughts are also expected to be more frequent and longer, with more heat and evaporation.

Is the Segura basin the most exposed area in Spain?

Yes, the Segura basin has a structural water deficit, which makes it one of the most exposed areas. The Júcar, Guadalquivir, Andalusian Mediterranean basins, Catalonia's internal basins and the Balearic and Canary Islands also rank high. The official scarcity indices show how the ranking shifts from year to year.