An annual rate, in respect of such scheme, may be charged, according to rules to be made by the State Government, on the owners of all lands which shall, in the manner prescribed by such rules, be determined to be so chargeable.
     Such rate shall be fixed, as nearly as possible, so as not to exceed either of the following limits :--
         (1) six per cent. per annum on the first cost of the said works, adding thereto the estimated yearly cost of the maintenance and supervision of the same, and deducting therefrom the estimated income, if any, derived from the works, excluding the said rate:
         (2) in the case of agricultural land, the sum which under the rules then in force fo r the assessment of land-revenue, might be assessed on such land on account of the increase of the annual value or produce thereof caused by the drainage -work.
     Such rate may be varied from time to time, within such maximum, by the State Government.
     So far as any defect to be remedied is due to any canal, water-course, road or other work or obstruction, constructed or caused by the State Government or by any person, a proportionate share of the cost of the drainage -works required for the remedy of the said defect shall be borne by such Government or such person, as th e case may be.