(1) Contain provision for notice to property owners of intention to make the assessment and improvement.
(2) Provide that notice shall be not less than 20 days before action is taken thereon.
(3) Provide an opportunity for property owners to appear before the board for the purpose of remonstrating against assessments.
(4) Provide for the general method of assessing the property directly benefited and of the recording of liens against the property directly benefited, and of making supplementary assessments and rebates.