A mosquito control district shall have the power to issue general obligation bonds and to pledge the full faith and credit of the district to the payment thereof, for authorized capital purposes of the mosquito control district, and to provide for the retirement thereof by excess property tax levies whenever a proposition authorizing both the issuance of such bonds and the imposition of such excess levies has been approved by the voters of the district, at an election held pursuant to RCW
39.36.050, by three-fifths of the persons voting on said proposition at said election at which such election the total number of persons voting on such bond proposition shall constitute not less than forty percent of the total number of votes cast within the area of said mosquito control district at the last preceding county or state general election. Mosquito control districts may become indebted for capital purposes up to an amount equal to one and one-fourth percent of the value of the taxable property in the district, as the term "value of the taxable property" is defined in RCW
39.36.015.