The membership and functions of a board of city park commissioners may be combined with one or more boards of city park commissioners or with one or more boards of county park commissioners pursuant to a plan adopted pursuant to this chapter. This chapter does not supersede the procedure and requirements of chapter 11-28 with respect to the creation of a joint county park district. A proposal for combining boards of park commissioners may be initiated:

1.    By execution of a joint powers agreement between participating city or county boards of park commissioners incorporating a plan for combining boards of park commissioners; or

2.    By a petition, signed by ten percent or more of the total number of qualified electors of each affected city park district or county voting for governor at the most recent gubernatorial election and submitted to the city park district or county, incorporating a plan for combining boards of park commissioners.