California Code, Streets and Highways Code - SHC § 5614

The notice shall particularly specify what work is required to be done, and how it is to be done, and what materials shall be used in the repair and shall further specify that if the repair is not commenced within two weeks after notice is given and diligently and without interruption prosecuted to completion, the superintendent of streets shall make such repair, and the cost of the same shall be a lien on the property.