According to The Los Angeles Times on February 16, 2015:

The water main break that flooded Nowita Place in 2013 fit an increasingly common pattern for L.A.’s aging waterworks: The pipe was more than 80 years old. It was rusted out. And it was buried in corrosive soil.

About one-fifth of the city’s water pipes were installed before 1931 and nearly all will reach the end of their useful lives in the next 15 years. They are responsible for close to half of all water main leaks, and replacing them is a looming, $1-billion problem for the city.

We must do something about our infrastructure and we must make the necessary investment,” said H. David Nahai, former head of the Department of Water and Power. “If we don’t act now, we’ll simply pay more later.”