The total amount of capital allocated to irrigation shall be shared between the State Governments as follows, namely:--
     (1) the Government concerned shall be responsible for the capital cost of the works constructed exclusively for irrigation in its State; and
     (2) the balance of capital cost under irrigation for both the States of Bihar and West Bengal shall be shared by the State Governments in the proportion to their guaranteed annual off-takes of water for agricultural purposes:
     Provided that the divisible capital cost under this clause shall be provisionally shared between them in accordance with their previously declared intentions regarding their respective guaranteed off-takes and any payments made accordingly shall be adjusted after the determination of the guaranteed off-takes.