Lake Arenal is an artificial lake in Costa Rica, located in the northern highlands of the country. It was enlarged to its present size as a part of a 1979 hydroelectric project by the Costa Rican government to provide electricity to the country.
Geography Lake Arenal is situated in the northern highlands of Costa Rica, in the provinces of Guanacaste and Alajuela. It is located in the Arenal Tilaran Conservation Area, and is close to the Arenal Volcano and Monteverde cloud forest.The lake is approximately 30 km long and almost 5 km at its widest point, making it the largest lake in Costa Rica at 85-square-kilometre (33 sq mi). Its depth varies between 30 and 60 meters (100–200 feet) depending on the season.The town of Arenal was relocated to higher ground when the lake was expanded in 1979. The old towns of Arenal and Tonadora now lie abandoned at the bottom of the lake, with the new town of Arenal existing to the northeast on the lake.
Hydroelectricity Lake Arenal was tripled in size with the construction of the Arenal dam in 1979, which exists at the eastern end of the lake. This hydroelectric project is hugely important to Costa Rica, initially generating 70% of the country’s electricity, now closer to 17%, and was also a driving force behind Costa Rica’s green energy policy