Overview
- Exceptional rainfall from storm Leonardo and runoff from the Sierra de Grazalema filled the reservoir for the first time, sending water over the crest overnight into Friday.
- Operators opened the spillway gates at 8:42 a.m. Friday and began discharge at 9:02 a.m., initially releasing about 345 m3/s before stabilizing near 200 m3/s.
- Andalusian government delegate Patricia Navarro said the spillway and long-dormant siphons are working properly and that previously evacuated families downstream remain safe.
- The 83.75‑metre double‑curvature arch dam, built in 1924 under engineer Henri Edwuard Gruner and the firm Electrowat, had never functioned due to persistent leakage.
- Set on karstic limestone connected to the Hundidero‑Gato cave system, the structure is under unprecedented hydraulic pressure, with authorities continuing close monitoring.