Lake Cachí
| Lake Cachi Represa de Cach | |
|---|---|
View of Lake Cachi | |
| Location | Costa Rica |
| Coordinates | 9°49′38″N 83°49′0″W / 9.82722°N 83.81667°W |
| Type | Artificial reservoir |
| Primary inflows | Reventazon River |
| Primary outflows | Reventazon River into Atlantic Ocean |
| Catchment area | 919 square kilometres (355 sq mi) |
| Basin countries | Costa Rica |
| Max. length | 70 metres (230 ft) |
| Surface area | 324 hectares (800 acres) |
| Average depth | 69 metres (226 ft) |
| Max. depth | 80 metres (260 ft) to deepest foundation |
| Water volume | 51 million cubic metres (41,000 acre⋅ft) |
| Surface elevation | 970 metres (3,180 ft) |
Lake Cachi (Spanish: Lago de Cachí) is an artificial lake in central Costa Rica created by the Cachí Dam (Represa de Cachí), an arch dam north of Tapantí National Park, to the east-southeast of Cartago in Cartago Province. The main town is Cachí, away from the east bank of the lake. Built in the 1970s, it was one of the first hydroelectric projects in Costa Rica. It has an installed capacity of 102 MW with three units of 34 MW capacity each (Vertical Francis turbines).
The project became operational with the first unit commissioned in 1966, the second unit in 1967, and the third unit in 1978. The Reventazon River provides multiple benefits through the three dams built on it. Out of the three dams, Cachi Dam, not only provides power generation benefits but also controls floods, and offers recreational facilities in the Lake Cachi. The Rio Macho project on the upstream provides hydroelectric power and the downstream Birris power project also provides drinking water (40% of the metropolitan city's water supply needs).
The reservoir, in the Rio Reventazón, is an important supplier of electrical power to Costa Rica. It is operated by Instituto Costarricense de Electricidad (ICE).