Vega de Tera disaster

The Tera River basin located within Sanabria Lake Natural Park, is a geological horst, uplifted by the Cabrera Valley Fault in the north, and the Las Portillas Fault in the south. The horst is part of the Montes de León mountain range. The range consists of granite, gneiss and volcanic rocks. The dam was constructed over the Tera River. Construction of the dam began in 1954 and ended in 1956, with the dam wall high and spanning across. It had a maximum capacity to hold of water. It formed part of a larger system of artificial lakes and canals. The dam was managed by Hidroeléctrica Moncabril, a hydroelectric company. ==Flood==

Before the dawn of 9 January, a section of the dam's retaining wall measuring in dimension collapsed. The collapse released of water from the Vega de Tera reservoir. At an initial peak discharge of , the flood traveled downstream towards Ribadelago. More than 1,500 domesticated animals also died. Recovery teams were only able to recover 28 bodies from the lake. Given the remote location of the town and time of incident, the first assistance did not arrive until the following morning. Sanabria Lake rose by after floodwater and sediments entered. Only 10–20% of the total sediment volume was deposited into the lake; most of it was deposited along the floodway in the Tera River gorge. Damage was minor downstream as the force of the flood weakened when it entered the lake. ==Aftermath==

The disaster led to the creation of Instruction for the Project, Construction and Exploitation of Large Dams by the Ministry of Public Works in 1962. A modified version of the law was introduced in 1967. The Dam Surveillance Service was also formed for the purpose of ensuring dam safety and regulations. In December 1959, seven workers from Hidroeléctrica Moncabril, and three from the company that constructed the dam were indicted by the Court of Valladolid. Eventually, only five individuals were convicted for reckless negligence without circumstances. A trial was held in March 1963 in Zamora concluded that Hidroeléctrica Moncabril was to pay 19,378,732 pesetas. In a report published during the trial, a failure in the design of the dam led to disaster. The Hidroeléctrica Moncabril was eventually absorbed by Unión Fenosa. The court of justice sentenced the then managing director of the company, two engineers and an expert as directly responsible for the works to one year in prison for the crime of reckless negligence. Subsequently, the sentence was appealed and the convicted were finally acquitted or pardoned by the state. Over a period of several days after the flood, donations amounted to 12 million pesetas. Families of the dead were compensated with varying amounts of money depending on ages of the victims. For each deceased adult, €600 equivalent was the compensation. €450 for victims over the age of 16, and €300 for children below 10 years. Those who were injured received €18 equivalent. Many survivors migrated to Zamora and Benavente. The Instituto Nacional de Colonización received €7,500 equivalent in compensation as well. ==See also==