Short answer. Yes. Article 517 obliges all owners who participate in the benefits of these works to contribute to the construction expenses in proportion to their respective interests. Anyone whose fault caused the damage the works address is separately liable for the resulting expenses.
What the law says
All the owners who participate in the benefits arising from the works referred to in the two preceding articles, shall be obliged to contribute to the expenses of construction in proportion to their respective interests.
Civil Code, Article 517 — Sharing The Cost Of Works. Read the full provision →
What the law says
Those who by their fault may have caused the damage shall be liable for the expenses.
Civil Code, Article 517 — Sharing The Cost Of Works. Read the full provision →
Benefiting owners share costs proportionally
Article 517 answers your question directly, tying the obligation to contribute to whether an owner actually benefits. All the owners who participate in the benefits arising from the works referred to in the two preceding articles, shall be obliged to contribute to the expenses of construction in proportion to their respective interests. If several landowners benefit from river-control or drainage works, each one who shares in that benefit is obligated to help pay for it — not equally across the board, but in proportion to their respective interest in the works.
Proportional, not equal, contribution
The article specifically calls for contribution in proportion to their respective interests, rather than splitting the cost evenly among every benefiting owner. A landowner who benefits substantially from the works is expected to contribute more than one whose benefit is comparatively minor, which means the actual cost-sharing arrangement depends on assessing how much each owner's land genuinely benefits, not simply counting heads among the participating owners.
A separate rule for whoever caused the underlying damage
The article adds a distinct rule alongside the general cost-sharing principle: those who by their fault may have caused the damage shall be liable for the expenses. If the need for the works arose because of some owner's fault — for example, conduct that caused or worsened flooding or erosion that the works are now meant to address — that owner bears liability for the resulting expenses, on top of or instead of the ordinary proportional-benefit sharing that otherwise applies.
What this means for landowners facing a shared project
If you are one of several landowners benefiting from river-control or drainage works, you can expect to be asked to contribute to the construction costs, and the fair share you owe should track your proportional interest in the works rather than an equal split. If a particular owner's fault caused the damage the works are addressing, that fact changes who is separately liable for the resulting expenses under this article, apart from the general proportional-sharing rule.