If any drainage district shall contract with the United States for the construction of drainage works, it shall be within the powers and the duties of the board of directors on or before September 1st next preceding the initial payment for such works under contract with the United States, to fix and determine the rate or percentage of the benefits from the proposed works for all real property within the district to be affected by said works, subject to judicial confirmation as by this act N.M. Stat. Ann. § 73-8-1 to 73-8-60 hereinafter provided. The board shall also assess the damages inflicted upon any real property by any such works of the district, and such amount shall be deducted from the assessments payable by each owner of the lands damaged, until compensation for the damages shall have been fully made. If the damage shall be found to exceed the benefits as regards any parcel of real property or any easement, a cash award of the difference shall be made. In thus fixing and determining the rate or percentage of benefits and assessing damages as aforesaid, such board shall determine the amount of money required to meet all obligations and all maintenance, operating and current expenses of the district during the ensuing year for properly carrying out the purposes of this act, all of which shall be taken into consideration in determining the rate or percentage of benefits and assessing damages as aforesaid; and the amount necessary for all of the aforesaid purposes shall thereafter be ascertained and determined by such board in like manner on or before September 1st of each year. The said rate of benefits shall be subsequently used as the basis for annual assessment; but such rate may be changed from time to time by the board of directors as new or changing conditions may, in their judgment, require, subject to judicial confirmation as aforesaid. Drainage districts organized under this act may assess realty within the district boundaries owned by all classes of persons and corporations, to the same extent as now permitted by the laws of this state to drainage districts.