None of the facilities or services afforded by the sewer system shall be furnished without a charge being made therefor. In the event the city or any department, agency, or instrumentality thereof shall avail itself of any of the facilities or services so afforded, the reasonable value thereof shall be charged against the city, or such department, agency or instrumentality, and shall be paid for as the charges therefor accrue. The revenues so received from the city shall be deemed to be revenues from the operation of sewer system, and shall be used and accounted for in the same manner as any other revenues derived from its operation; provided, however, that nothing in this section shall be construed as requiring the city, or any department, agency, or instrumentality thereof to avail itself of the facilities or services afforded by the sewer system. (Ord. 311 § 19, 1982)