California Code, Labor Code - LAB § 1193.6

(a) The department or division may, with or without the consent of the employee or employees affected, commence and prosecute a civil action to recover unpaid minimum wages or unpaid overtime compensation, including interest thereon, owing to any employee under this chapter or the orders of the commission, and, in addition to these wages, compensation, and interest, shall be awarded reasonable attorney's fees, and costs of suit.  The consent of any employee to the bringing of this action shall constitute a waiver on the part of the employee of his or her cause of action under Section 1194 unless the action is dismissed without prejudice by the department or the division.

(b) The amendments made to this section by Chapter 825 of the Statutes of 1991 shall apply only to civil actions commenced on or after January 1, 1992.