Cal. Sts. & High. Code § 27188

The board of directors shall, for the protection of a bridge and highway district, insure any bridge or other facility constructed or acquired under the provisions of this act against all risks to such extent as it deems necessary. In case of damage or destruction, the proceeds of such insurance shall be applied to the restoration of such bridge or facility. Any such bridge or facility may be insured, irrespective of the retirement of all indebtedness incurred for its construction or acquisition, and the cost of such insurance shall be paid from any funds available to the district.