The city shall have a lien for delinquent and unpaid water charges against the premises for which the water has been furnished, provided that the owners of a delinquent mortgage on the premises may give written notice to the water department to cut off services to the premises and from and after the giving of such notice and the payment or tender of the then delinquent and unpaid charges against the premises for such services and the cut-off charge, the city shall have no lien on the premises for such services thereafter furnished, nor shall the owner or the owner of the delinquent mortgage on the premises be held for the payment thereof; provided, further, that such liens not be for more than four months’ charges due or to become due nor for any charges which have been due for more than four months. Nothing herein, however, shall be construed as impairing any vested rights or liens which have accrued to the city prior to December 19, 1968. The lien as herein provided may be enforced by cutting off the service until the delinquent and unpaid charges are paid (Ord. 104 §1(G), 1968).