(3) For the flood control provided by Canada under Article IV (2) (b) the United States of America shall pay Canada in United States funds in respect only of each of the first four flood periods for which a call is made 1,875,000 dollars and shall deliver to Canada in respect of each and every call made, electric power equal to the hydroelectric power lost by Canada as a result of operating the storage to meet the flood control need for which the call was made, delivery to be made when the loss of hydroelectric power occurs.
(4) For each flood period for which flood control is provided by Canada under Article IV (3) the United States of America shall pay Canada in United States funds:
(a) the operating cost incurred by Canada in providing the flood control, and
(b) compensation for the economic loss to Canada arising directly from Canada foregoing alternative uses of the storage used to provide the flood control.