Upon the assessment by the board or court of the amount of damages to which the respective owners of land which may be damaged by the construction of a flood irrigation project may be entitled, and upon the assessment by the board or court of the amount of damages to which the respective owners of the right of way may be entitled, the board of flood irrigation shall issue warrants in sums sufficient to pay the damages so assessed, drawn upon the proper county treasurer and payable out of any funds in the hands of the treasurer for the construction of such flood irrigation project. Such warrants shall be negotiated at not less than their par value and the proceeds thereof paid to the owners of the land entitled thereto, according to such assessments of damages. The surplus, if any, shall be paid to the county treasurer, who shall place the same to the credit of the proper flood irrigation project fund.