Every municipality may borrow money and issue municipal obligations thereof for the purpose specified and by the procedure provided in this chapter, and for no other purpose and in no other manner, except as otherwise provided in section 21-03-02. No municipality may incur indebtedness in any manner or for any purpose in an amount which, with all other     outstanding indebtedness of the municipality, exceeds five percent of the assessed value of the taxable property therein, except:

1. Any incorporated city, by a two-thirds vote of the qualified voters thereof voting upon said question at a general or special election, may increase such limit of indebtedness three percent on such assessed value beyond said five percent limit, and a school district, by a majority vote of the qualified voters thereof voting upon said question at a general or special election, may increase such limitation of indebtedness five percent on such assessed value beyond the said five percent limit.

2. Any county or city, when authorized by a majority vote of the qualified voters thereof voting upon said question at a general or special election, may issue bonds upon any revenue-producing utility owned by such county or city, for the purchase or acquisition of such utility, or the building or establishment thereof, in amounts not exceeding the physical value of such utility, industry, or enterprise.

3. Any incorporated city, if authorized by a majority vote of the qualified voters thereof voting upon said question at a general or special election, may become indebted in any amount not exceeding four percent of such assessed value, without regard to the existing indebtedness of said city, for the purpose of constructing or purchasing waterworks for furnishing a supply of water to the inhabitants of such city or for the purpose of constructing sewers, and for no other purposes whatever, but the aggregate of such additional indebtedness for waterworks and sewers never may exceed such four percent over and above the limitations of indebtedness in this section heretofore prescribed.

All bonds or obligations in excess of the amount of indebtedness permitted by this chapter, given by any municipality as herein defined, are void.