Short answer. Possibly. An island formed by alluvial accumulation in a non-navigable, non-floatable river belongs to the owners of the nearest banks. If the island sits in the middle, it is divided lengthwise between both sides; if it is closer to one bank, the owner of that nearer bank owns the whole island.
What the law says
Islands which through successive accumulation of alluvial deposits are formed in non-navigable and non-floatable rivers, belong to the owners of the margins or banks nearest to each of them
Civil Code, Article 465 — Islands on Non-navigable Rivers. Read the full provision →
The kind of island this article covers
Article 465 applies specifically to islands "which through successive accumulation of alluvial deposits are formed in non-navigable and non-floatable rivers." Two conditions have to be met together: the island has to form gradually through the buildup of alluvial deposits — sediment accumulating over time — and the river it forms in has to be non-navigable and non-floatable. An island formed some other way, or one that appears in a navigable or floatable river, is not what this article is describing. The rule does not address what happens if the river later becomes navigable, or if the alluvial buildup instead attaches the new land directly to an existing bank rather than forming a distinct island — those are different factual scenarios this article does not reach.
Why the river's character decides everything
The two conditions are not technicalities; they are the whole of it. Article 464 provides that islands formed on the seas within the jurisdiction of the Philippines, on lakes, and on navigable or floatable rivers belong to the State. That is the other half of the same scheme: if the river is navigable or floatable, no bank owner takes the island at all, however close it lies. So the first thing to establish is not where the island sits but what the watercourse is, because that single fact decides whether Article 465 is in play or whether the land is public. The mode of formation matters just as much — the article is about deposits accumulating gradually, not about ground left dry when a river shifts or divides its course, which the Code treats separately.
Ownership starts with the nearest bank
The general rule the article states is that such an island "belong[s] to the owners of the margins or banks nearest to each of them." Ownership is not determined by who first claims the new land or by proximity to the riverbed generally — it is tied specifically to which bank or banks are nearest to the island once it has formed.
When the island sits in the middle
The article addresses the situation where the island is equidistant from both banks: it belongs "to the owners of both margins if the island is in the middle of the river, in which case it shall be divided longitudinally in halves." So a centrally located island is not awarded entirely to one side — it is split lengthwise, giving each bank owner a portion running the length of the island rather than a share of the whole as an undivided unit.
When the island is closer to one side
Where the island is not centered, the article resolves it differently: "if a single island thus formed be more distant from one margin than from the other, the owner of the nearer margin shall be the sole owner thereof." In that case, there is no splitting at all — the owner of whichever bank the island sits closer to takes the entire island, and the more distant bank's owner gets nothing from that particular formation.
Related provisions
- Civil Code, Article 465 — Islands on Non-navigable Rivers
- Civil Code, Article 464 — Islands on Seas and Navigable Rivers