must be voted upon at a special election, district election or primary or general state election in the same manner as for the issuance of district bonds.
but the sum of the amounts which the district is obligated to pay pursuant to those contracts, excluding payments out of the revenue of the project, and any bonds issued must not exceed the amount of the bonds approved in the election and interest thereon at a rate not exceeding 5 percent above the Index of Revenue Bonds which was most recently published before the contract is executed, bids are received or a negotiated offer is accepted.
NRS 539.240