Whenever the public peace, health, safety, convenience, interest, or general welfare may require, the planning commission shall recommend, and the city council shall adopt, specific plans and regulations, including setback lines, based on the general plan.

Specific plans and regulations shall be adopted and amended in accordance with the provisions of the Government Code of the state except as modified by this title.

A proposed specific plan or regulation or a proposed amendment to an adopted specific plan or regulation may be initiated in any of the following ways:

Upon the initiation of a proposed specific plan or regulation or amendment, the same shall be set for hearing before the planning commission. If the planning commission fails, within sixty days after the close of the public hearing to recommend or disapprove such proposed plan or regulation or amendment, such failure shall be deemed to be the adoption of a resolution recommending the proposed plan or regulation or amendment; provided, that this time limitation may be extended with the consent of the petitioners.

Any person may appeal the disapproval of a proposed plan or regulation or amendment to the city council at any time within ten days after the decision of the planning commission. A notice of appeal must be filed with the city clerk, with a copy to the planning director. Within ten days after such filing, the planning director shall transmit to the city clerk all exhibits, notices and other documents on file with the planning commission, together with the report of the planning commission. The city council shall conduct a public hearing on the appeal and shall render a decision on the appeal after the conclusion of the hearing. If a proposed plan or regulation or amendment is disapproved by the planning commission, the same shall not be adopted except by a plurality of concurring votes of the city council.

The provisions of this title relating to withdrawal and renewal of rezoning applications shall apply to petitions for specific plans and regulations and amendments thereto. Fees for petitions and appeals shall be established by resolution of the city council.

From and after the taking effect of any ordinance establishing any specific plan which includes setback lines, all required yard areas shall be measured from the setback lines established by the specific plan.

From and after the taking effect of any ordinance establishing any specific plan which includes setback lines, no person shall erect, construct or establish any building, structure or improvement within the space between the street line and the setback line or the building line established by a required yard area measured from the setback line. No permit shall be issued for any such building, structure or improvement within such setback space, or required yard area; except, that permits may be issued for the erection, construction or establishment of temporary structures or improvements in such setback space or required yard area; provided, that the owner or owners of any property proposing to erect or establish such temporary structures or improvements shall first file with the city a written guarantee and bond, in an amount to be fixed by the city council, that he or they will remove such structures or improvements from such setback space or required yard area at his or their own expense at such time as the city shall declare its intention of acquiring the setback space for street widening purposes; providing, that in the event of sale or lease of such temporary structures or improvements, the city shall be put to no additional expense for the acquirement of said setback space for street widening purposes by reason of such temporary structures or improvements thus erected in said setback space or required yard area and that any additional expense thus caused shall become a lien against the property, including such setback space.