When the agency has caused such maps and plans to be prepared, it shall transmit them to the governing body, together with a report of its proceedings and its recommendations, including a recommendation as to what officer, board or body should be the administrative head or body of the proposed district. Such report may further include the recommendations relating to the establishment of two or more zones of assessment within the proposed district and the estimated initial allocation of the cost of the construction of the facilities as between such zones to be assessed, levied and collected in each zone in the same manner and at the same time as other county charges. Upon receipt of the report and the maps and plans, the governing body shall call a public hearing upon a proposal to establish a county district, to comprise the area or areas described and defined in said maps and plans. The clerk of the governing body shall cause a notice of the public hearing to be published at least once in the official newspapers of the county and in such other newspapers having a general circulation in the proposed district as the governing body may direct, the first publications thereof to be not less than ten or more than twenty days before the day set therein for the hearing. The notice of hearing shall contain a description of the area or areas to be included within the proposed district, and if the report shall have recommended the establishment of zones of assessment, a description of the area or areas to be included within each zone of assessment, the improvements proposed, the maximum amount to be expended for the improvement, the allocation of such maximum amount as between the zones of assessment recommended, if any, the proposed method of assessment of the cost and shall specify the time when and place where the governing body will meet to consider the matter and to hear all parties interested therein concerning the same. In the event that zones of assessment are provided for and an allocation of cost of the facilities between such zones of assessment, said notice shall further state that said zones of assessment and said allocations of cost may be changed from time to time by resolution of the governing body adopted after a public hearing whenever said governing body shall determine that such changes are necessary in the public interest.