Short answer. The moment the water leaves your land. Article 507 of the Civil Code allows you to use spring water freely while it flows within your property, but once it crosses the boundary and flows onto or past other land, it becomes public. You have no proprietary claim over water that has left your property.
What the law says
The owner of a piece of land on which a spring or brook rises, be it continuous or intermittent, may use its waters while they run through the same, but after the waters leave the land they shall become public
Civil Code, Article 507 — Spring Or Brook On Private Land. Read the full provision →
Two distinct zones: private while on your land, public once it leaves
Article 507 of the Civil Code draws a precise geographical line. The owner of land on which a spring or brook rises has full use of the water while it runs through the same — that is, while it flows within the boundaries of their property. The article applies whether the spring is continuous or intermittent. But the moment after the waters leave the land they shall become public. The transition is automatic and location-based. No government act, no declaration, no registration is needed to trigger it. The water becomes public by operation of law as soon as it crosses the boundary.
What you can do with the water on your land
Within your property, the law gives you free rein. You can use the spring water for irrigation, domestic purposes, livestock, bathing, or any other use you see fit — subject only to other applicable laws. You can divert it, channel it, collect it in tanks or ponds, or redirect its flow within your land boundaries. What you cannot do is permanently intercept or divert the water in a way that prevents it from eventually leaving your property and continuing its natural course into public waterways. Taking all the water for yourself and causing the spring to run dry before it exits your land may affect downstream users and could raise issues under water law.
After it leaves: governed by public water law
Once the water is public, its use is regulated by the applicable water laws of the Philippines. No individual landowner — not you, not a downstream neighbor — has a private right to that water as property. Third parties seeking to use public water for irrigation or other purposes must comply with the rules governing public water use. This transition protects downstream communities, agriculture, and the general public from any single landowner monopolizing a water source by virtue of owning the land where it originates.
Practical notes for landowners with springs
If you are planning to develop or use the spring on your property, think about the scope of your use within your boundaries and how it affects the water that leaves. If your development requires capturing or substantially reducing the spring's outflow, there may be regulatory requirements or neighbor concerns to address. Springs that feed into rivers, irrigation systems, or community water sources are particularly sensitive. If you are in a dispute over spring water use — with a neighbor, a local government unit, or a downstream user — a lawyer can help you understand the boundaries of your rights under Article 507 and applicable water legislation.