A district may borrow money and incur or assume indebtedness therefor, as provided in this chapter, so long as the total of all such indebtedness (but excluding revenue bonds, special assessment bonds, and other securities constituting special obligations which are not debts) does not exceed an amount equal to 50 percent of the total of the last assessed valuation of taxable property (excluding motor vehicles) situated within such district.
NRS 318.277