If any bridge, bridges, approach, approaches, culvert or culverts, may need immediate repairs on account of the same having broken down, or on account of high water, or fire, or if for other cause an emergency shall exist, the county board shall have the power to declare that the public good requires immediate action to prevent inconvenience and damage, and may proceed to enter into a contract under the provisions of sections 39-810 to 39-826 for such bridge, bridges, approach or approaches, culvert or culverts, or may buy material and hire labor and repair any such bridges, approaches or culverts.