The Arroyo Seco Parkway article on Wikipedia (link) was featured on their main page today, so took a look, and saw the photo above. The big "50 year" flood of 1938 (link) started February 28, so certainly this photo predates it, and there is no apparent flood damage in the photo.
The bridge was demolished last year: http://la.streetsblog.org/2014/08/06/nelas-historic-riverside-figueroa-bridge-being-demolished/
|Bridge goes bye-bye, but the octagonal phone booth remains!|
(Image sourced from link above. Link to photographers Instagram Feed.)