DR1 Daily News - Dominican Republic

The reappearance of an intense olive-green hue in the waters of the Hatillo Dam has reignited a wave of alarm across the Sánchez Ramírez province and the Northeast region. Local residents and civil society groups are demanding “credible and convincing” explanations for the phenomenon affecting the largest freshwater reservoir in the Dominican Republic.

The discoloration, which first emerged in early December 2025, has caused widespread uncertainty in communities along the Yuna River, including San Francisco de Macorís, Pimentel, and Nagua. The Yuna serves as the primary artery feeding the dam and a vital water source for the region.

While government authorities have attributed the change to a natural “algal bloom,” a significant portion of the local population suspects a more industrial cause. Historically, the Yuna River has been a catch-basin for runoff from mining operations in Bonao, Maimón, and Cotuí.

Specific concerns have been raised regarding inactive mining...