Short answer. Yes. Article 643 of the Civil Code requires you to show that the proposed right of way for a water easement is both the most convenient and the least onerous to third persons, not merely convenient for you. If a less damaging route exists elsewhere, the law expects you to use that route instead.
What the law says
One desiring to make use of the right granted in the preceding article is obliged
Civil Code, Article 643 — Conditions for the Easement of Aqueduct. Read the full provision →
What the law says
To show that the proposed right of way is the most convenient and the least onerous to third persons
Civil Code, Article 643 — Conditions for the Easement of Aqueduct. Read the full provision →
What the law says
To indemnify the owner of the servient estate in the manner determined by the laws and regulations.
Civil Code, Article 643 — Conditions for the Easement of Aqueduct. Read the full provision →
The route must be both convenient and least onerous, together
Article 643 sets a two-part standard for the route, not a one-part one. Someone seeking a water easement is obliged: to show that the proposed right of way is the most convenient and the least onerous to third persons. Convenience for you alone does not satisfy this condition. The route also has to be the one that burdens third persons the least, so a more convenient path that causes more damage elsewhere does not meet what the article demands.
This is one of three obligations imposed on you
The route requirement sits alongside two other conditions article 643 imposes: one desiring to make use of the right granted in the preceding article is obliged to meet all three, not just the one about the path. You also have to prove you can dispose of the water and that it is sufficient for its intended use, and you have to indemnify the owner of the servient estate. Choosing the least onerous route does not by itself complete what the article requires.
"Third persons" is broader than just your immediate neighbor
The article does not limit the least-onerous requirement to the owner of the land your pipe crosses. It speaks of third persons generally, which covers whoever is affected by the route you propose, not only the one property owner you may be negotiating with directly. A route that is convenient for you but shifts the burden onto other landowners is exactly what this condition is meant to rule out.
Indemnity still applies even on the least onerous route
Meeting the route condition does not remove the third obligation the article imposes: to indemnify the owner of the servient estate in the manner determined by the laws and regulations. Picking the least damaging path reduces the burden you impose, but it does not exempt you from compensating the owner of the land the water actually crosses under the route you have chosen.