Buying a property on the Costa Blanca South: earthquakes, floods and new builds
Torrevieja, Orihuela Costa and the Vega Baja are among the busiest places in Spain for foreign buyers, many of them buying off-plan. The area has two risks that brochures rarely mention: it is one of the most seismically active zones in Spain, and the lower Segura floods.
Check a specific property →Costa Blanca South by town: official data
Town-level figures from official sources. They describe the area, not your house: a villa on high ground in a town with floods can be safe, and the opposite. The Hogarfax report checks the exact plot.
| Town | Population | Urban plots in 100-year flood zone | Forest fires 2006–2015 | Seismic acceleration (ab) |
|---|---|---|---|---|
| Torrevieja | 98,533 | 0.0% | 12 (+26 small) | 0.14 g |
| Orihuela | 84,560 | 2.1% | 3 (+28 small) | 0.16 g |
| Pilar de la Horadada | 24,316 | 4.2% | 1 (+5 small) | 0.12 g |
| San Miguel de Salinas | 7,177 | 0.0% | 2 (+6 small) | 0.15 g |
| Guardamar del Segura | 18,564 | 0.0% | 5 (+43 small) | 0.15 g |
| Rojales | 17,652 | 0.8% | none recorded | 0.15 g |
| Santa Pola | 39,709 | 3.4% | 6 (+24 small) | 0.15 g |
| Almoradí | 22,965 | 0.0% | none recorded | 0.16 g |
Sources: population, INE municipal register (2025); flood, share of urban cadastral plots inside the 100-year river flood zone (SNCZI, MITECO; it does not cover rain or sea flooding, nor the Canary Islands); fires, municipal forest fire statistics (EGIF, MITECO, CC-BY 4.0); seismic, basic acceleration of the Spanish seismic building code NCSE-02.
The most seismic coast in Spain
In 1829 an earthquake destroyed Torrevieja and much of the Vega Baja. Today the Spanish seismic building code (NCSE-02) assigns Orihuela and Torrevieja some of the highest basic accelerations on the Spanish coast. Modern buildings must be designed for it; for older ones, ask about the structure and look for cracks. See our earthquake hazard map.
The Segura and the 2019 DANA
In September 2019 a DANA (cut-off low) flooded Orihuela, Almoradí, Dolores and much of the Vega Baja. River flood maps (SNCZI) cover the Segura; heavy rain can also flood streets and ground floors far from any river. Check the exact plot, and ask the seller whether the house has flooded and whether insurance paid out.
Off-plan and new builds
If you buy off-plan, your deposits must be guaranteed by a bank guarantee or insurance for each payment (Ley 38/1999, Ley de Ordenación de la Edificación). Ask for the building licence, the guarantee certificates and the developer's details before paying. Check what is around the plot: a petrol station, a motorway or a future building can change the value.
Real square metres
Listings often add terraces, solariums and common areas to the floor area. Compare the advertised size with the Cadastre's built area; we explain how in our buying guides.
41 things to check before buying a home in Spain
Many buyers think they can check it all themselves. In practice the data is spread across the Cadastre, the Land Registry, the Ministry for the Ecological Transition, the Nuclear Safety Council, the National Geographic Institute, regional planning and town halls, each with its own maps and its own language. Missing just one can cost far more than the house's renovation.
Legal status and land
- Cadastral use (is it legally a home?)
- Planning classification of the land
- Urban, developable or rustic land
- Livestock trails (vías pecuarias)
- River public domain (DPH)
- Coastal public domain and easements (Costas)
- Minimum habitable floor area
- Building inspection status (ITE/IEE)
- Land Registry: owner, mortgages, seizures, easements (Land Registry Study)
Natural hazards
- River flooding (100-year flood zone)
- Sea and coastal flooding
- Wildfire: forest next to the house
- Wildfire history of the area
- Areas burned in recent fires
- Active fires detected by satellite
- Earthquake hazard
- Radon gas
- Dams upstream
Installations and surroundings
- High-voltage power lines
- Electrical substations and energy plants
- Wind farms
- Solar farms
- Nuclear power plants
- Thermal power plants
- Macro-farms (intensive livestock)
- Factories and industrial land
- Landfills and incinerators
- Petrol stations next to the home
- Vacant plots next door (what will be built?)
- Noisy roads and motorways
- Railways
- Airports
The house and the price
- Real square metres vs the listing
- Age of the building and its parts
- Estimated renovation cost
- Asking price vs real sales nearby
- Indicative price range
- Estimated rent
- Real buying costs (taxes, notary, registry)
- Annual costs (IBI, community, waste)
- Facade photo and official record
The one you forget is the one that matters: a power line behind the garden, a macro-farm just down the road, a vacant plot next door where a block will go up, a ravine that floods once every few years, or a "villa" that the Cadastre doesn't record as a home. Hogarfax checks all of them for the exact property, with the official source of each one.
Before you pay a deposit in Costa Blanca South
- Check the exact plot, not the town: flood zone, distance to forest, planning classification and what is planned around it.
- Check it is legally a home: the cadastral use, the Land Registry description (nota simple) and the occupancy licence.
- Compare the real square metres with the listing and the price with real sales nearby.
- Make the deposit conditional on anything that doesn't add up, and have a lawyer review the contract.
Check the house you like in Costa Blanca South
The Hogarfax report checks the specific property against 30+ official sources — legal use, flood zone, wildfire, planning, real size and price — in English, reviewed by a person and emailed within 24 hours. €24.90 VAT included. Add the Land Registry Study (€89) and we request and explain the nota simple for you.
Find the property →Free: check the flood zone of an address on the flood zone page or the wildfire history on the wildfire map.
Frequently asked questions
Is Torrevieja at risk of earthquakes?
It is in one of the most seismically active areas of Spain: an earthquake destroyed the town in 1829, and the seismic building code (NCSE-02) gives it a basic acceleration of 0.14 g. Modern buildings must be designed for it.
Does Orihuela Costa flood?
The river flood zone of the Segura mainly affects the inland Vega Baja (Orihuela, Almoradí, Dolores), which flooded in the 2019 DANA. On the coast, heavy rain can flood streets and ground floors; check the specific plot and its history.
What should I check before buying off-plan in Spain?
The building licence, a bank guarantee or insurance for every payment (Ley 38/1999), the developer's records in the Land Registry and what is planned around the plot.
Other areas
Are you a lawyer, agent or adviser working with buyers here? See our partner programme. Written by Diana Popescu, Hogarfax. This guide is general information, not legal advice.