Within five days after an election held under the provisions of RCW 53.04.020, the board of county commissioners shall canvass the returns, and if at such election a majority of the voters voting upon the proposition shall vote in favor of the formation of the district, the board of county commissioners shall so declare in its canvass of the returns of such election, and the port district shall then be and become a municipal corporation of the state of Washington and the name of such port district shall be "Port of . . . . . ." (inserting the name appearing on the ballot).