If bonds are authorized and are issued or are expected to be issued on behalf of any district which is organized pursuant to this article, the governing body of the initiating city shall, on or before the 15th day of July of each year, certify to the board of supervisors of the county in which the district is located, the amount to be raised for the payment of the principal of and interest on the bonds in accordance with Section 4638 and, if applicable, Section 4639.5. The county auditor shall determine the rate of taxation which shall be clearly sufficient to raise such amount. The county auditor shall compute and enter in a separate column in the county assessment roll the respective sums to be paid as the district tax on the taxable property in the district. The board of supervisors of the county in which the district is located shall, at the time of fixing the general county tax levy and in the manner which is provided for such tax levy, levy and collect each year upon all of the taxable property in the district a tax in accordance with Section 4638 and, if applicable, Section 4639.5. The taxes so levied shall be in addition to all other taxes levied for county or city purposes and in addition to taxes levied pursuant to Section 4614.14 and shall be collected at the same time and in the same manner as county taxes are collected. When such taxes are collected they shall be paid to the county treasurer who shall forthwith remit them to the city treasurer of the initiating city. The taxes are a lien on all taxable property in the district and shall be of the same force and effect as the lien for county taxes. Their collection shall be enforced by the same means as provided for the enforcement of the lien of county taxes. The city treasurer of the initiating city shall hold such taxes in trust, separate and apart from all other city funds and use and apply them solely to the payment of bond principal and interest.