At its first regular meeting or at a special meeting thereafter, the board of supervisors shall examine the returns of the board of election commissioners, and if the board of supervisors finds that a majority of the votes cast at the election was in favor of organizing the district, it shall make and spread such finding upon its minutes and by resolution declare the district duly organized. By a separate resolution the board of supervisors shall define the boundaries of the district, and the clerk of the board shall immediately file a certified copy of the resolution in the office of the county recorder. When such certificate is recorded, the district and its officers shall at once proceed with the business of the district, and carry out the purposes for which it was created.