A stormwater control facility is a facility or improvement that is constructed or acquired to protect life or property from storm, waste, or flood water.  Counties may acquire, construct, and improve storm control facilities within the county.  This can be done in conjunction with other government agencies.

A county may assess rates and service charges for properties served or benefiting from the stormwater control facility or contributing to surface water runoff.  In fixing the rates, the county can consider the service provided, the benefits received, the character and use of the land, whether the ratepayer is a public benefit nonprofit corporation, the income level of the ratepayer, and any other matters that are a reasonable ground for determining rates and charges.  The revenue from the rates and service charges must be placed in a special fund and only used for maintaining, operating, acquiring, constructing, or improving stormwater control facilities.

When a county proposes to construct or improve a stormwater control facility within a city or town (city), the county must first obtain the consent of the city.  A county and a city may agree that, upon completion, any facility or portion of a facility within the city will be operated and maintained by the city as a part of the city's stormwater control system.

Diking districts, drainage districts, and sewerage improvement districts are special purpose districts.  From the end of the nineteenth century to the 1930s, they proliferated, and there were multiple permutations of diking, drainage, or sewerage improvement districts authorized.  The various districts were standardized to some extent in the 1980s and 1990s.  In general, each type of district has authority to engage in flood control activities, stormwater control, drainage control, and to construct and maintain the facilities necessary to do so.  To fund their activities, the districts are authorized to impose rates and charges on property within their districts.

A county that intends to extend or improve a stormwater control facility that is within an operating diking or drainage district, and that interacts with or changes water movement within the district, must notify and consult with the diking or drainage district.

A county and a diking or drainage district may enter into an agreement that, upon the completion of a stormwater control facility constructed by the county within a diking and drainage district, the diking and drainage district will operate and maintain the facility, and that it will become part of the diking and drainage district's system.

A diking district that maintains and operates a stormwater control facility may, in order to pay its operating and administrative costs, receive a portion of the stormwater rates and service charges collected by the county for stormwater control.

Beginning in 2024, service charges rates collected by the county for stormwater control facilities operated and maintained by a diking or drainage district may be deposited into the revenue account for that district.