The principal and interest of such general bonds shall be paid by levying each year a tax upon the taxable property within the district sufficient, together with other revenues of the district available for such purpose, to pay said interest and principal of said bonds, which tax shall be due and collectible as any other tax. All bonds and warrants issued under the authority of this chapter shall be legal securities, which may be used by any bank or trust company for deposit with the state treasurer, or any county or city treasurer, as security for deposits, in lieu of a surety bond, under any law relating to deposits of public moneys.