Water pipe breaks and leaks occur several times a day in L.A., but none in recent memory was as serious as the flooding near UCLA in July 2014. A 90-year-old water main burst under Sunset Boulevard on Tuesday, producing a raging geyser that sent 8 to 10 million gallons of water onto the UCLA campus, flooding several buildings, including the famed Pauley Pavilion. It took the Los Angeles Department of Water and Power about four hours to fully shut off the 30-inch-diameter line as water inundated athletic fields, underground garages filled with cars and various campus walkways.

But this incident merely pointed to a much bigger problem lying under the surface of Los Angeles: the city's water infrastructure is crumbling. Large sections of the water system are old and corroded, and the city has struggled to find the money to replace them. A series of major breaks in 2009—including one in which a sinkhole partly swallowed an L.A. Fire Department truck—generated outrage and calls for action.

Utility officials warned in 2012 that 1 million feet of pipeline—or 20 percent of the system -had been in service for 100 years or more. The utility predicted that by 2014, more than 1.4 million feet of pipeline—or 27 percent of the total—would be at least a century old.

The city is slowly swapping out the old lines, but it would take several lifetimes to replace the entire system at the current pace, and sadly, for many people, what lies under the surface isn't a high priority for repairs.