Guavio Reservoir, Hydroelectric reservoir in Cundinamarca Department, Colombia

Guavio Reservoir is the impoundment created by the 243-metre-high Alberto-Lleras rockfill dam, which holds back the Guavio, Batatas and Chivor rivers in the municipalities of Gachetá, Gachalá, Gama and Ubalá, Cundinamarca. The reservoir has a usable volume of 950 million m³ and lies at 1,619 metres above sea level. Its irregular shoreline forms several inlets, with a rounded point of land jutting into the opaque green water on the left and a small landmass at the lower centre; the far shore shows a band of exposed greyish-brown rock and earth below slopes covered in dense green vegetation.

The reservoir was created by the Alberto-Lleras dam, a 243 m rockfill structure that impounds the Guavio, Batatas and Chivor rivers in the municipalities of Gachetá, Gachalá, Gama and Ubalá. At the time of its construction it was the third-highest dam in the world; by 2012 it ranked twelfth. Its bottom outlet was badly damaged on the day of the first spillway overflow, when onlooking politicians demanded more water.

The reservoir was formed by damming the Guavio, Batatas and Chivor rivers, and the Batatas and Chivor are diverted into it through tunnels of 2,330 and 2,190 metres. After the water rose, people in Gachetá, Gachalá, Gama and Ubalá took up fishing and water sports on the lake.

The reservoir lies about 70 km east of Bogotá in Cundinamarca, at 1,619 m above sea level. The dam stands in the municipalities of Gachetá, Gachalá, Gama and Ubalá, and the town of Gachalá sits on its shore. The water body measures roughly 8.8 km north to south and 9.9 km east to west.

The dam's bottom outlet, built to flush out sediment, was badly damaged on the day of the reservoir's first overflow, when politicians watching the event demanded more water. The reservoir lies about 70 km east of Bogotá, and the town of Gachalá, with roughly 1,660 residents, sits on its shore.