Any lease of a mass transit facility entered into pursuant to the provisions of ORS 267.227 and 391.500 to 391.660 shall be for a term not shorter than the longest maturity of any bonds issued to finance such mass transit facility or a portion thereof and shall provide for income, revenues and rentals from all sources pledged to the payment of such bonds adequate to pay the principal, interest and premiums, if any, on such bonds as the same fall due and to create and maintain such reserves and accounts for depreciation, if any, as the board in its discretion shall determine to be necessary.
ORS 391.560