SECTION 18. DIVIDING THE CITY INTO WARDS.
   (a)    Upon the adoption of this Charter and at least 45 days prior to the filing date of the nominating petitions for the terms beginning on January 1, 1968, the present Council shall divide the City into four wards upon the basis of one ward for each seven thousand population or major portion thereof. Wards so formed shall be as nearly equal in population as may be composed of contiguous and compact territory, and bounded by natural boundaries or street lines. In the event Council shall not have fixed the division of wards herein prescribed, the Mayor shall cause such division to be made at least thirty days prior to the filing date herein provided. If, and when any particular territory is annexed to the City, the Council shall by ordinance declare it a part of the adjacent ward or wards. If the total population in any ward or wards exceeds the seven thousand or more, then the ward or wards shall be realigned.
   (b)    The Council, not later than the year 1971 and each five years thereafter, shall restudy the then existing wards relative to the equality of their population. If, in the opinion of Council, the population of the several wards becomes out of balance, a redivision of the City into wards shall be made in the same manner as provided for in paragraph (a) of this section