It forms Lake Apanás, the largest reservoir in the country.

The primary purpose of the dam is hydroelectric power generation and it supports the 50 MW Centro América Plant.

To generate power, water from the southwestern end of the Lake Apanás flows along a 4,000 m (13,000 ft) long channel before it enters a series of headrace pipes and a penstock.

About 3.4 km (2.1 mi) to the south west the penstock meets Centro América Plant where it turns two 25 MW Francis turbines.

The Virgen Dam downstream on the Viejo River was destroyed but later rebuilt.