(1) Within a Nebraska planning and development region, a development district may be formed as a voluntary association by agreement pursuant to the Interlocal Cooperation Act in one of the following ways if the combined membership of the association includes at least fifty-one percent of the local governments in the region:

(a) By local governments within the region; or

(b) By two or more regional councils, each of which is a voluntary association of local governments in the region formed by agreement pursuant to the act between the governing bodies of such governments, the membership of which association does not include at least fifty-one percent of the local governments located in the region.

(2) For purposes of this section and sections 13-1903 to 13-1906, local government shall mean a county, city, or village.