Whenever, in the determination of the approving agency, it is necessary that oversize conveyance facilities for storm drainage and/or sanitary sewers be installed by the developer which can or will be used for the immediate or future benefit of property not within the development, the developer shall be required to install such facilities in addition to the infrastructure requirements for the subject development, and the developer may be eligible for credits under Section 3.891 (Storm Drain SDC Credits), or Section 3.835(2) (Sanitary Sewer SDC Credits) of the Medford Code.