If the proposed watershed management authority lies in more than one soil and water conservation district, the petition shall be presented to the board of supervisors of all such soil and water conservation districts, and the supervisors of all such districts shall act as a joint board of supervisors in the formation of the watershed management authority.

Pursuant to the provisions of this chapter, whenever it is necessary for a joint board of supervisors to convene, said meeting may be called by a majority of the members of the several boards of supervisors comprising the joint board of supervisors.

A majority of the joint board of supervisors shall constitute a quorum. All actions taken by the joint board of supervisors shall require a majority vote of all members comprising the joint board of supervisors who are voting on said action.