An indenture may include a clause relating to the bonds issued pursuant to the indenture requiring the regents to fix, prescribe, and collect rates, rentals, or other charges in connection with the services and facilities furnished from the project acquired, constructed, or purchased from part or all of the proceeds of the bonds, sufficient to pay the principal of, and interest on, the bonds as they become due and payable, together with such additional sums as may be required for any sinking fund, reserve fund, or other special fund provided for the further security of such bonds or as a depreciation charge or other charges in connection with such project.