At the time set for the hearing of the petition as provided in Kan. Stat. Ann. § 24-129, it shall be the duty of the board of county commissioners to first ascertain and determine whether notice has been given of the time of hearing as required by this act, and, if it shall be determined that such notice has been given, to make a declaration and finding of that fact and cause the same to be entered upon its records, and thereupon to hear all persons in favor or opposed to granting the prayer of said petition and all other evidence that it may desire to hear for the purpose of ascertaining whether the statements in said petition are true; and if upon such hearing it shall be found that such petition is in conformity to the requirements of this act, and that the allegations thereof are true, then such board of county commissioners shall make a finding and decision to that effect, and shall thereupon declare the territories described in the petition to be detached from the one drainage district, naming it, and to be attached to the other drainage district, naming it, and shall fix the date that such transfer shall become effective; and if such board of county commissioners upon such hearing finds that such petition is not in conformity to this act or that the statements in such petition are not true or that said transfer should not be made then such board of county commissioners shall make a finding and decision to that effect and reject that petition. Such affirmative decision and order of the board of county commissioners may provide for the transfer of all or part of the territory described in the notice of hearing, but shall not include any territory not so described.