During the time that the revenue bond and debt service cost, including principal and interest, assumed by the city at the time of taking control of such system, are being paid the township board of any such township shall levy an annual tax sufficient to raise an amount equal to thirty-five dollars ($35) for each fire hydrant remaining in any such township, and pay such amount annually to any such city of the first class or its board of public utilities for fire protection.
K.S.A. 13-1278