Colorado Revised Statutes Title 37. Water and Irrigation § 37-23-101. Assessments according to benefits

(1) As soon as the plans for a drainage system have been determined and before the actual work of drainage is begun or bonds voted, the board of directors shall proceed to make special assessments for benefits by classifying the lands in the district in tracts of forty acres, more or less, according to the legal or recognized subdivisions on a graduated scale to be numbered according to the benefits to be received by the contemplated drainage. The tracts of land which will receive most and about equal benefits shall be marked one hundred, and such as are adjudged to receive less benefits shall be marked with a lesser number denoting its percent of benefit. This classification when established shall remain as a basis for the levy of taxes as may be needed for the lawful and proper purposes of the drainage district.

(2) In any district where a classification has once been made and the board of directors believes from experience and results that such former classification is not fairly adjusted on the several tracts of land according to benefits which may be adjusted by new or additional assessments, then the board of directors shall disregard such former classification and make a new classification in accordance with justice and right. When the classification is completed it shall be properly tabulated or shown by a map, or both, and filed in the office of the secretary of the district for inspection.