Unless otherwise specifically required by law, the board of supervisors of any county shall upon the filing of a petition touching any matter affecting the entire county and over which it has jurisdiction, signed by twenty-five per cent. of the qualified electors of the county, either pass an order putting said proposition in force and effect or immediately submit the same to a vote of the qualified electors of the county, after giving thirty days’ notice of said election, said notice to contain a statement of the proposition to be voted on at said election. If said election shall result in favor of the proposition petitioned for, the board of supervisors, shall pass the necessary order, to put the said proposition in force and effect. In the event the election shall result against the proposition submitted, no other election shall be held on the same, or substantially the same proposition within twelve months of the date of the prior election. This section shall not, however, apply to the creation of taxing districts.