The bursting of a dam on the Guadalupe river in Texas shows the problems of aging infrastructure in the US. The Lake Dunlap dam was built in the 1920's to generate electricity for rural homes in the state, and is one of six dams on the Guadalupe river. There are 91,815 dams in the US with an average age of 61 years, according to the US Army Corps of Engineers. It would cost $157 billion to repair and build new dams to replace these aging dams.