A more thorough explanation:

A drainage district is a type of political subdivision that has the authority to levy assessments for making drainage improvements within its area. This means that they can collect money from people who live in the area to pay for projects that will improve drainage in the area.

For example, if a drainage district is formed in a rural area that is prone to flooding, they may use the money collected from assessments to build drainage ditches or install drainage pipes to help prevent flooding.

Drainage districts are usually formed after a local election or petition showing consent of a majority of affected landowners. The projects are usually publicly financed, and assessments are made against all property benefited, whether or not all individual landowners have consented.

Overall, drainage districts can help improve the agricultural capacity of drained lands and provide new land for buildings and other improvements. However, if private property rights are taken or if others are damaged, compensation must be paid.