In this title the following words have the meanings indicated. “Board of drainage commissioners” means the board of drainage commissioners of a drainage district. “Board of viewers” means the board of viewers of a drainage district established under this title. “Designated officer” means: the clerk of the county commissioners for a code county or commission county if there is a clerk for the county; or an employee or official of a county who is designated by the county commissioners or county council to perform the responsibilities of the designated officer under this title. “Drainage district” means a drainage district established under this title. “Landowner” means a person who owns land located in a drainage district or proposed drainage district.