Administrative boundary determination, the Spanish Coastal Act and compulsory purchase: the complete 2026 guide for Costa Blanca owners

Published on 9 September 2026 · Bufete Padilla · Administrative and Planning Law · Torrevieja, Elche and Moraira

One day a registered letter arrives, or a notice appears in the Spanish Official State Gazette, and the message is brutal: the authorities are going to carry out a deslinde — an administrative boundary determination — of public land adjoining your property. On the Costa Blanca this happens far more often than people think: front-line plots in Torrevieja, villas in Orihuela Costa, country houses beside a drovers' road inland from Elche, homes in Moraira fifty metres from the sea.

The typical reaction of a foreign owner is always the same: *"Am I being expropriated?"*. The short answer is no: a boundary determination and a compulsory purchase are two very different things, with radically different financial consequences. And that difference is exactly what decides whether you are paid fair value or simply lose a strip of land with no compensation at all.

> 30-second summary. The administrative boundary determination is the procedure by which the Administration itself fixes the physical limits of its public-domain assets against neighbouring private land (arts. 50 to 54 of Law 33/2003 on Public Administrations' Assets, and arts. 61 to 67 of Royal Decree 1373/2009). It is declaratory: it acquires nothing new, it declares what was already public. That is why it carries no right to compensation. Compulsory purchase, by contrast, is transfer-based: it takes something private and therefore must pay fair value. The coastal boundary determination under the 1988 Coastal Act is the variant that destroys most wealth on the shoreline, because your house stops being yours and becomes an administrative concession. The deadlines are brutally short: twenty days before the on-site survey to make submissions, ten days after the survey record, one month to appeal and two months to go to court.

1. What exactly is an administrative boundary determination?

It is the procedure by which the Administration determines, unilaterally, declaratorily and enforceably, the physical limits of its assets — especially public-domain assets — against adjoining private properties.

The key word is self-enforcement. In a civil boundary dispute, two neighbours arguing about where one plot ends and the other begins go to court as equals. In an administrative determination they do not: the Administration investigates, decides and enforces by itself, without needing any court's prior permission. You are not defending yourself before a neutral judge; you are defending yourself inside the file of the very body that will decide, and only afterwards can you go to court.

In theory the purpose is not to acquire new land but to pin down how far an already existing public title extends. In practice, when that theoretical line is drawn on the ground with GPS and a scale plan, some owners discover that their pool, their wall or their entire plot is on the wrong side of it.

2. The legal framework: which rules will apply to you

It matters which regime applies, because not all boundary determinations are governed by the same rules:

| Type of asset | Main legislation | Usual competent body |
|---|---|---|
| Public assets generally | Arts. 50-54 Law 33/2003 (LPAP) and arts. 61-67 RD 1373/2009 | The owning administration (State, region, town hall) |
| Coastal public domain (maritime-terrestrial) | Coastal Act 22/1988, as amended by Law 2/2013, and RD 876/2014 | Directorate-General for the Coast; Alicante Provincial Coastal Service |
| Public forests | Forestry Act 43/2003 and regional legislation | Regional environment department |
| Drovers' roads | Act 3/1995 on Drovers' Roads and Valencian rules | Generalitat Valenciana |
| Water public domain (rivers, ramblas, ravines) | Consolidated Water Act and its Regulation | Segura or Júcar River Basin Authority |
| Roads and railways | Roads Act 37/2015 and sector rules | Ministry, Provincial Council or regional government |

In Alicante province the two that cause foreign owners most trouble are, by a distance, the coastal boundary determination and the water public domain determination affecting ramblas and ravines that look like dirt tracks in summer and become watercourses in September.