Any ordinance or resolution adopted by a board of county commissioners may be referred to a vote of the qualified voters of the county by the filing of a petition signed by five percent of the registered voters in the county, based upon the total number of registered voters at the last preceding general election, except such ordinances and resolutions as may be necessary for the immediate preservation of the public peace, health, or safety, or for the support of the county government and its existing public institutions.
SDCL 7-18A-15