In the same manner as provided for the adoption of an original general comprehensive plan, a plan providing for additions and betterments to the original general comprehensive plan may be adopted. Without limiting its generality "additions and betterments" shall include any necessary change in, amendment of, or addition to the general comprehensive plan.
The district may incur a general indebtedness payable from annual tax levies to be made in excess of the constitutional tax limitation for the construction of the additions and betterments in the same way that general indebtedness may be incurred for the construction of the original general comprehensive plan after submission to the voters of the entire district in the manner the original proposition to incur indebtedness was submitted as provided in RCW
57.20.105. Upon ratification the additions and betterments may be carried out by the commissioners to the extent specified or referred to in the proposition to incur the general indebtedness.
The district may issue revenue bonds to pay for the construction of the additions and the betterments pursuant to resolution of the board of commissioners.