Following the wildfire that affected the Sierra Oeste—the largest in Spain—the San Juan Reservoir remains closed to swimming, boating, and any recreational water activities. The closure is particularly notable because the San Juan Reservoir is the only reservoir in the Community of Madrid where swimming is officially permitted during the summer season, in designated areas such as Virgen de la Nueva and El Muro. Precisely for this reason, it typically attracts thousands of weekend visitors from the capital, including swimmers, canoeists, boaters, and patrons of local restaurants.
The recommendation from the Community of Madrid and emergency services remains to avoid the area this weekend, respect the checkpoints, and not attempt to access the affected recreational areas.
The measure remains in effect as a preventive and temporary measure. Although the fire has been extinguished in most areas, firefighting and monitoring teams remain deployed to prevent flare-ups, and they need to keep roads and access points clear for fire trucks and emergency vehicles.
Swimming, boating, and recreation: all prohibited
Swimming, boating, using watercraft, and engaging in recreational activities in the reservoir’s waters are not permitted. The ban affects the most frequently visited areas, including El Muro and Virgen de la Nueva, as well as Playa del Alberche in Aldea del Fresno—three of the only five natural beaches in the Community of Madrid.
The Tagus River Basin Authority and the Community of Madrid have imposed the restriction for safety reasons, not only due to the possible deterioration of water quality following the fire. Ash and debris can alter conditions in the reservoir, and the authorities have temporarily suspended the tests used to ensure the water is safe for swimming.
Why You Shouldn’t Go There
The problem isn’t limited to the water. The fire has left trees and infrastructure damaged, as Carlos Sevillano, owner of one of the reservoir’s boat docks, explained to Madrid Secreto. There are still potential hot spots and unstable terrain around the reservoir; approaching the area could put visitors at risk and hinder the work of firefighters, forest rangers, and the Civil Guard.
The M-957 highway remains closed between kilometers 0 and 5, one of the main access routes to the area. In San Martín de Valdeiglesias, the El Muro recreational area remains completely closed; in Aldea del Fresno, security has been stepped up to prevent access to the water at Playa del Alberche.
No date has been announced yet for reopening the reservoir to swimming or water sports.The lifting of restrictions will depend on experts certifying that there is no risk of the fire reigniting, that access points are safe, and that environmental and water conditions allow for the resumption of activities. The announcement will be made in coordination with the affected municipalities.