Fla. Stat. § 298.353
The board of supervisors of the district may designate areas or parts of the district as separate administrative and financial "units." Units must be created or modified as a part of and through the adoption of a water control plan or plan amendment as provided in this chapter. The units into which the district is divided must be given appropriate numbers or names by the board of supervisors so that the units can be readily identified and distinguished. The board may fix and determine the location, area, and boundaries of the lands to be included in each unit, the type and amount of work required in the unit and the order of development, and the method of carrying on the work in each unit. The unit system provided by this section may be conducted, and all the proceedings by this section and this chapter authorized in respect to such unit or units may be carried on and conducted, whenever the board of supervisors finds that it is appropriate. If the board finds that it is advisable to implement the district infrastructure and service plans by units, as authorized by this section, the board shall, by resolution duly adopted and entered upon its minutes, declare its purpose to conduct the work accordingly, and shall proceed through the water control plan adoption or amendment process described in s. 298.301 to fix the number, location, boundaries, and description of lands within each unit or units and give them appropriate numbers or names. All provisions of this chapter shall apply within all units, and the enumeration of or reference in this section to specific powers or duties of the supervisors does not limit or restrict the application of any and all of the proceedings and powers in this chapter within all units. For water control plans applicable to one or more units, but to less than the entire district, the notices to district landowners or municipalities required under s. 298.301 need be provided only to owners of lands within the affected unit or units and municipalities within whose boundaries unit lands are located. All assessments, levies, taxes, bonds, and other obligations made, levied, assessed, or issued for or in respect to any unit or units constitute a lien and charge solely and only upon the lands in the unit or units, respectively, for the benefit of which the same have been levied, made, or issued, and not upon the remaining units or lands in the district. However, bonds may be payable from assessments imposed on more than one unit. The board of supervisors may at any time amend the location and description of lands in any unit or units by proceeding in accordance with the provisions of this section for the original creation of the unit or units. If, after the approval of the engineer's report of benefits in any unit or units or the issuance of bonds or other obligations that are payable from taxes or assessments for benefits levied upon lands within any unit or units, the board of supervisors finds that the infrastructure or service plan for the unit or units is insufficient or inadequate for efficient development, the plan may be amended or changed and the unit or units may be amended or changed as provided in this section, by changing the location and description of lands in the unit or units, by detaching lands therefrom, or by adding lands thereto pursuant to this chapter. However, a change or amendment to a designated unit is not authorized if it has the effect of impairing a debt or other obligation of the unit or the district.
Fla. Stat. § 298.353