Short answer. If a water-use question is not expressly answered by the Civil Code's chapter on waters, Article 518 directs you to the Special Law of Waters of August 3, 1866 and to the Irrigation Law. These older statutes fill the gaps the Code leaves open; wherever the chapter directly addresses a point, the Code's own rule controls instead.
What the law says
All matters not expressly determined by the provisions of this Chapter shall be governed by the Special Law of Waters of August 3, 1866, and by the Irrigation Law.
Civil Code, Article 518 — Suppletory Law On Waters. Read the full provision →
What "suppletory" means here
"Suppletory" is the operative word in this article. It does not mean the 1866 Special Law of Waters and the Irrigation Law sit alongside the Code as equal, competing sources. It means they only step in for matters the Code's chapter on waters does not expressly settle. Where the codal provisions on waters speak to an issue — for example, ownership of a particular class of water or the rules on easements affecting it — those provisions govern, and the older statutes are simply irrelevant to that point.
Why the Code incorporated an older law by reference
This arrangement reflects how the Civil Code was drafted generally: rather than rewriting every specialized body of law that already existed, it absorbed some subjects by direct restatement and left others to be governed by reference to prior legislation. Waters were treated this way because a detailed, technical statute on water administration and irrigation already existed before the Code took effect, so the drafters incorporated it by reference for whatever the codal articles did not cover.
A signpost, not a full answer
For someone dealing with a dispute over water use, distribution, or irrigation rights, this article is a signpost rather than a complete answer. It tells you that if the specific Civil Code articles on waters do not resolve your situation, the analysis does not stop there — it continues into the older Special Law of Waters and the Irrigation Law, which may contain the more detailed rule that actually applies to the facts at hand.
Reading both sources together
Because these are older, specialized statutes layered underneath the Code rather than restated within it, working out which rule governs a particular water dispute often requires reading the codal chapter on waters together with the referenced legislation side by side. A lawyer handling a property or agricultural water dispute will typically need to check both sources before advising on how a specific water-use question is actually resolved.
Check the modern context too
Water disputes also frequently overlap with other special legislation on irrigation administration and natural resources that has developed since 1950, so a suppletory reference in the Civil Code is rarely the last word on a modern water-use question. Treating Article 518 as a starting point for research, rather than a complete answer on its own, is the safer way to approach a real dispute over water rights.
Related provisions
- Civil Code, Article 518 — Suppletory Law On Waters
- Civil Code, Article 517 — Sharing The Cost Of Works
- Civil Code, Article 519 — Mining Governed By Special Laws