Section 11.6  Limitations on Contractual Power.
   (a)   The Council shall only have power to enter into contracts which by the terms thereof will be fully executed within a period of ten (10) years, unless such contract shall first receive the approval of the majority of the qualified electors voting thereon at a regular or special election. This qualification shall not apply to any contract for services with a public utility, or one (1) or more other governmental units, or to contracts for debt secured by bonds or notes which are permitted to be issued by the City by law.
   (b)   Except as provided by ordinance authorized in this Charter, each contract for construction of public improvements or for the purchase or sale of personal property shall be let after opportunity for competition.
   (c)   All bids shall be opened and read aloud in public by the City Clerk or his authorized representative at the time designated in the notice of letting, and shall be reported by him to the Council at its next regular meeting. The Council may reject any or all bids if deemed advisable. If, after ample opportunity for competitive bidding, no bids are received, or such bids as are received are not satisfactory to the Council, the Council may either endeavor to obtain new competitive bids or authorize the City Clerk, or other proper officials of the City, to negotiate or contract on the open market.