181.05 PAYMENTS, PARTIAL PAYMENTS.
   (a)    The unit or lump sum price stated in the contract shall be used in determining the amount to be paid and shall constitute full and final compensation for all the work.
   (b)    Partial payment to the contractor for work performed under the lump sum price shall be based on a schedule prepared by the contractor and approved by the City Engineer who shall apportion the lump sum price to the major components entering into or forming a part of the work under the lump sum price. Partial payment to the contractor for work performed under the unit price shall be based on work completed and material incorporated into the project as certified by the contractor and approved by the City Engineer.
   (c)    Partial payments to the contractor for labor performed under either a unit or a lump sum price contract shall be made at the rate of ninety percent (90%) of the amounts submitted by the contractor and approved by the City Engineer.