Territory may be added to an existing district upon filing a petition as in the case of formation with the commission by twenty percent of the voters of the affected area to be included. The same procedure shall be followed as for the creation of the district.

As an alternate procedure, the commission may upon the petition of a majority of the voters in any one or more districts or in unorganized territory adjoining a conservation district change the boundaries of a district, or districts, if such action will promote the practical and feasible administration of such district or districts.

Upon petition of the boards of supervisors of two or more districts, the commission may approve the combining of all or parts of such districts and name the district, or districts, with the approval of the name by the secretary of state. A public hearing and/or a referendum may be held if deemed necessary or desirable by the commission in order to determine the wishes of the voters.

When districts are combined, the joint boards of supervisors will first select a chair, secretary, and other necessary officers and select a regular date for meetings. All elected supervisors will continue to serve as members of the board until the expiration of their current term of office, and/or until the election date nearest their expiration date. All appointed supervisors will continue to serve until the expiration of their current term of office, at which time the commission will make the necessary appointments. In the event that more than two districts are combined, a similar procedure will be set up and administered by the commission.

When districts are combined or territory is moved from one district to another, the property, records, and accounts of the districts involved shall be distributed to the remaining district or districts as approved by the commission. A new certificate of organization, naming and describing the new district or districts, shall be issued by the secretary of state.