The bridges that span the Los Angeles River offer a history lesson of how Los Angeles became a modern city.
There's the Cesar Chavez Bridge, with its colossal porticoes, embellished with spiral columns and a replica of the city seal. The bridge, decorated with elements of the Spanish Baroque style, is an architectural nod to the historic El Camino Real, of which it is a part, and to the city's Spanish heritage.
The beaux-arts North Broadway Bridge, originally named the Buena Vista Viaduct, is one of the river's older structures and was the state's longest and widest concrete arch bridge when it opened in 1911.
Then there is the 6th Street Viaduct, a streamline-moderne monolith of steel arches and concrete towers built in 1932.
The city wants to replace the span with a spare, modern cable-stayed bridge. Officials released new design plans for the bridge in recent days that were met with criticism from those who say that the modern look has no place amid the ornate spans.
"I said as far as I am concerned, if you are going to put this bridge with cables there, you might as well not put a bridge there at all. I would rather not see one there," said Victoria Torres, a board member of the Boyle Heights Historical Society. "It's very disappointing when the city is trying to push something on you that you didn't agree with."
At two-thirds of a mile long, the Sixth Street Viaduct is the largest and longest span across the Los Angeles River. Known for its two sweeping steel arches and a rather notable curve in the middle, the viaduct is punctuated at either end by decorative pylons with fluted, zigzag designs. Railroad tracks run underneath on both banks of the river.
When the viaduct was built, masons used concrete from a plant that had been constructed on site at the river's edge for the building of the bridge. The practice was revolutionary at the time -- but an aggregate used in the making of the concrete caused it to have a high alkali content. As water has seeped into the concrete over time, the concrete has begun to erode. The rare degenerative condition is called alkali-silica reaction, and officials say it has weakened the viaduct to the point that officials say it has a 70% chance of collapsing in a major earthquake within 50 years. It is the only span along the river to have such a condition.
"It is an irreversible chemical erosion," said Department of Public Works spokeswoman Tonya Durrell. "We describe it as a pretty sick bridge, like a cancer."
