The Virgen Dam is an embankment dam on the Viejo River near the town of El Hato de La Virgen in Matagalpa Department, Nicaragua.

The primary purpose of the dam is hydroelectric power generation and it supports the 50 MW (67,000 hp) run-of-the-river Carlos Fonesca (Santa Barbara) Plant.

Water from the dam is diverted along the left bank of the river through a 2.7-kilometre (1.7 mi) long channel before being piped underground over 4.8 km (3.0 mi) to the power plant near Santa Barbara on the Viejo River.

[1] The difference in elevation between the dam and power station affords a hydraulic head (water drop) of 187 metres (614 ft).

[2] In 1998 heavy rains and flooding from Hurricane Mitch severely damaged the Mancotal and El Dorado Dams, over-topping their spillways and nearly destroying the dams.