Whenever any civil action is commenced in the district court involving fewer than 10 water claimants or less than the major part of the rights to the use of water from any river system, lake, underground water basin, or other source, the court in its discretion may, if a general determination of the rights to the use of water from said water source has not already been made, proceed, as in this chapter provided, to make such a general determination. In any such action for the determination of water rights the state of Utah shall be joined as a necessary party.