The city council is authorized to issue bonds, as in this section provided, for the purpose of improving lands, lots, or grounds purchased, appropriated or acquired for parks, parkways, boulevards or playgrounds. Bonds so issued shall be known as park bonds and the issuance thereof except as herein provided shall be governed by the general provisions of section 14-515. The city council may issue in any one year and without a vote of the electors one hundred thousand dollars of such bonds. The city council may issue bonds if the same are authorized by a majority vote of the electors of the city voting on the proposition at a general city election or a special election called for that purpose. A part of the proceeds from the sale of such bonds may be used to pay for improvements upon streets, sidewalks or thoroughfares abutting upon or immediately adjacent to parks, parkways, boulevards, and playgrounds when such costs would otherwise be chargeable to the city.