Rio Hondo Dam, hydroelectric power station in Argentina

Rio Hondo Dam is a large water control structure in Santiago del Estero that spans over 4,300 meters, holding back the Dulce River with both earth and concrete sections. The structure rests on a clay foundation and includes turbines and valves in the concrete section on the right bank, with protective rock and gravel layers that shield against water pressure.

Construction began in the late 1950s and finished in the late 1960s, with the goal of preventing floods, supplying water for farming, and generating electricity for the region. This major project took years of planning and labor and became essential to local development and water management.

The reservoir is called Lago El Frontal, and its warm water holds dorados, bogas, bagres, tarariras, sábalos and pejerreyes. Motorboating, water skiing, rowing and fishing take place on it, with national and international competitions held each year. The left bank has a beach, campsites and a four-star hotel with a nautical club for sailing, regattas, canoeing, windsurf and freshwater diving.

The dam lies about 2 km southwest of Termas de Río Hondo and is reached from the RN 9 bridge, from which the 206 m concrete section with its buttresses can be seen. The reservoir's left bank has a beach, camping areas and a 4-star hotel. The dam is a state-owned operating plant, so the crest, valves and powerhouse are not open to visitors.

Sediment buildup over the years has gradually reduced the water storage capacity, though scientists continuously monitor these changes to preserve function. This challenge shows how natural forces shape even major engineering works and highlights why ongoing maintenance is critical.