San Rafael Reservoir, reservoir in Colombia

San Rafael Reservoir is located near Bogotá in the town of La Calera and forms part of the Chingaza system that supplies water to the city. The dam stands approximately 60 meters high and extends over 680 meters long, holding around 75 million cubic meters of water within a natural landscape of green hills and open spaces.

Construction began in the late 1980s and the reservoir opened in 1996 as part of the city's water infrastructure. It became crucial during a 1997 crisis when a tunnel in the Chuza system failed, and the reservoir took on the responsibility of supplying the city while repairs were undertaken.

The reservoir takes its name from the San Rafael hacienda on whose land it was built, and its water reaches Bogotá, La Calera, Sopó and Guasca. Every two years, when the Chingaza tunnels close for maintenance, it again carries the city's supply, so its level is watched as a gauge of how much water the capital has in reserve.

The reservoir is not open to visitors; it is a working water-supply structure of the Chingaza system, encircling the Francisco Wiesner treatment plant. It lies in La Calera municipality, about 12 km from Bogotá, on the río Teusacá. Views of the dam, 59.6 m high and 680.36 m long, are from surrounding roads; there is no trail access to the water.

In 1997, the reservoir unexpectedly became the sole water supplier to Bogotá when a tunnel in the Chuza system collapsed, revealing how a single structure could save an entire city. This crisis demonstrated its hidden importance to the urban water system.