Environmental Impacts
It has been estimated that about 40% of the houses in Valdivia were destroyed, leaving 20,000 people homeless. The most affected structures were those built of concrete, which in some cases collapsed completely due to lack of earthquake engineering. Traditional wooden houses fared better; although in many places, they were uninhabitable, they did not collapse. Houses built upon elevated areas suffered considerably less damage compared to those on the lowlands, which absorbed great amounts of energy. Many city blocks with destroyed buildings in the city center remained empty until the 1990s and 2000s, with some of them still used as parking lots. In terms of urban development, Valdivia suffered the loss of the minor but significant Cau-Cau bridge, a bridge that has not been rebuilt. The other bridges suffered only minor damage. Land subsidence in Corral Bay improved navigability as shoal banks, produced earlier by sediments from Madre de Dios and other nearby gold mines, sank and were compacted. As the earthquake destroyed Valdivia's flood barriers, general land subsidence exposed new areas to flooding. The earthquake created several landslides which were so great that they changed the course of some rivers.