The natural hazard occurred in December 1999 in northern region of Venezuela is considered as the most destructive of South America in 20th century. This tragedy encroached 8 northern states of Venezuela, including the state of Vargas wherein debris flows, landslides and floods caused severe property damages and loss of human lives.
According to (Lopez, et al., 2007), December 1999 tragedy caused an estimated death toll of 15 000 to 20 000 people and property damages evaluated in more than 4 billion dollars. Vargas state for itself registered 2 billion dollars losses.
The mass movement events (mostly debris flows and landslides) occurred on December 15-16th had been triggered by high intensity rainfall over previously saturated soils due to fourteen days of continuous rainfall. The high intensity rainfall resulted into extreme surface runoff with a huge transport capacity (Lopez & Courtel, 2008). According to (Genatios, 2012) the extreme exceptional meteorological event, namely the high intensity rainfall recorded can be assigned to a 500 years return period event.
The volume of sediment transported in December 1999 tragedy was estimated to be about 20 million cubic meters, including large boulders with more than 10 meters. This aspect irreversibly changed the morphology of the northern coastal range (Genatios, 2012). The urban regions settled on alluvial fans were severely damaged by debris flows events. In fact, the disaster was aggravated by man’s unregulated occupation and urban development on the alluvial fans, canyons and slopes of the coastal range.
After the 1999 tragedy, government authorities initiated an intensive development plan focusing on structural mitigation measures employment of various types. For instance, thirty five (35) retention dams had been build. Accordingly it was funded a public authority exclusively driven for state of Vargas reconstruction and development – CORPOVARGAS (Corporación para la Recuperación y Desarrollo del Estado Vargas).