Annexation of Properties

The City of Johnston continues to consider annexation of properties to allow for the orderly expansion and growth of the community. In addition, developed properties outside the Johnston city limits wishing to connect to Johnston city services are required to annex to the city.

Annexation Process

The annexation procedure, while quite complex, is relatively easy for property owners.

Voluntary Annexations

The City of Johnston generally only completes annexations that are considered voluntary. Annexations are considered voluntary when 80% or more of the area being annexed has petitioned for annexation by signing an annexation application (PDF).

Involuntary Annexations

Areas up to 20% of the annexation area can be annexed without the consent of the owner only to prevent the creation of an unincorporated island or to create more uniform boundaries. These regulations are specified by state law.


Once the annexation area is determined, appropriate notices are sent to all of the property owners and the City Council conducts a public hearing and approves the annexation.

Following approval, the annexation is sent to the City Development Board, a State of Iowa board appointed by the governor to review all annexations. The City Development Board again sends notices and conducts a public hearing on the annexation. Upon approval by the City Development Board, the annexation is complete.

Length of Process

For a standard annexation, this process takes anywhere from three to six months.