In the event that any such tracts of land so included within any irrigation district are leased from the state board of land commissioners, then all such lessees, in addition to the rental paid to said state board of land commissioners, shall pay such an additional amount to said board as will equal the district assessments levied upon such lands for the year in which such rental shall be paid; and such moneys, when so received by the register of the state board of land commissioners, shall be turned in to the state treasurer and kept in a separate fund for the payment of such assessments.
C.R.S. § 37-43-117