Short answer. Yes, within limits. Article 636 says legal easements established for private use are governed by the Civil Code but may be modified by agreement of the interested parties, provided the law does not prohibit it and no third person is injured. So the parties can adjust the terms of such an easement between themselves.
What the law says
These easements may be modified by agreement of the interested parties, whenever the law does not prohibit it or no injury is suffered by a third person.
Civil Code, Article 636 — Easements for Private Use. Read the full provision →
Legal easements for private use
Not every easement imposed by law serves the general public; some are established by law in the interest of private persons or for private use, such as certain rights of way or water easements between neighbouring estates. Article 636 provides that these are governed by the Civil Code's provisions on easements, without prejudice to general or local laws and ordinances for the general welfare. But because their purpose is private rather than public, the law gives the parties more room to shape the easement to their own needs than it would for one that protects a public interest.
The parties may modify by agreement
The heart of the article is its flexibility. It states that these easements may be modified by agreement of the interested parties, whenever the law does not prohibit it or no injury is suffered by a third person. So the dominant and servient owners are not locked into the exact terms the law would otherwise supply; they can agree to adjust how the easement is exercised, its route, extent, or conditions, to suit their circumstances. The private character of the easement is what makes this bargaining possible, since the interest being served is chiefly their own.
The two limits on modification
The freedom to modify is bounded by two conditions built into the article. First, the change must be one the law does not prohibit; the parties cannot agree to something the law forbids. Second, the modification must not injure a third person; the parties may reshape the easement between themselves, but not at the expense of someone outside their agreement whose rights would be prejudiced. Within these limits, their agreement controls; beyond them, it cannot, because private convenience does not license breaking the law or harming outsiders.
Putting it to use
For neighbours living with a legal easement for private use, Article 636 is an invitation to cooperate. Rather than being rigidly held to statutory defaults, they can negotiate practical terms, perhaps relocating a path, sharing maintenance, or clarifying limits, and put them in a clear written agreement. The prudent course is to confirm that the arrangement breaks no legal prohibition and prejudices no third party, then record it, so that the modified easement is both valid under Article 636 and easy to enforce between them later.