In the event that it appears from the returns that a majority of the qualified electors of the district have voted in favor of the ballot question, the district shall then be authorized to incur the indebtedness or the obligations, enter into the contract or issue and sell the bonds of the district, as the case may be, for the purpose and object provided for in the proposition submitted under the provisions of the Water and Sanitation District Act and in the resolution for them and in the amount so provided and at a rate of interest not exceeding the rate of interest recited in the resolution. Submission of the proposition of incurring such obligations or bonded or other indebtedness at an election shall not prevent or prohibit submission of it or other propositions at subsequent elections called for that purpose.