(1) "Drainage assessment" means any tax, assessment, or charge levied on account of the construction, maintenance, and operation of the drainage project.
(2) "Drainage district" means an organization formed under the drainage district law of this state.
(3) "Drainage project" includes legally organized drainage districts and enterprises of persons, corporations, or associations having for their object the drainage of land.
(4) "Treasurer" means the proper officer of the drainage project authorized to receive payments of drainage assessments.