The county planning commission may prepare and adopt regulations governing the subdivision of land, which regulations may provide for the proper location and width of streets, building lines, open spaces, minimum width and area of lots, street grading and paving, sewers, water and other utilities, which are necessary to avoid the congestion of population and to protect the public health, safety or the general welfare. Such regulations shall be adopted only after public hearing has been held thereon at any one place in the county, public notice of which shall be given in the same manner as provided for hearings in section 64.040. Such regulations shall become effective after their approval and adoption by order of the county commission and may after their adoption be amended by the county commission. In lieu of the immediate completion or installation of the improvements required under the regulations adopted, the county zoning enforcement officer shall accept bond for the county in an amount and with surety and conditions prescribed by the county general attorney and approved by the county commission. Such bond shall provide and secure to the county the actual construction of such improvements and utilities within the period prescribed by said regulations.