From and after the adoption of the official master plan or portion thereof and its proper certification and recording, thereafter no improvement of a type embraced within the recommendations of such official master plan or part thereof shall be constructed or authorized without first submitting the proposed plans thereof to the county planning commission and receiving the written approval or recommendations of said commission. This requirement shall be deemed to be waived if the county planning commission fails to make its report and recommendations within forty-five days after receipt of the proposed plans. In the case of any public improvement sponsored or proposed to be made by any municipality or other political or civil subdivision of the state, or public board, commission or other public officials, the disapproval or recommendations of the county planning commission may be overruled by a two-thirds vote, properly entered of record and certified to the county planning commission, of the governing body of such municipality, or other political or civil subdivision, or public board, commission or officials, after the reasons for such overruling are spread upon its minutes, which reasons shall also be certified to the county planning commission.