That it shall be the duty of the board of county commissioners incorporating any drainage district under the provisions of this act to cause an entry to be made upon its records showing all of its declarations, findings, decisions and orders made pursuant to the preceding sections, which entry shall define the limits of the drainage district to be so incorporated in conformity to the description contained in the petition, and such entry shall fix the time and place of holding the first election to choose such officers of such drainage district as are hereinafter required to be elected, and designate five taxpayers residing within said district, three to act as judges and two to act as clerks of such election; and all declarations, determinations, findings, decisions and orders of such board of county commissioners so entered of record shall be conclusive on all persons, so that no matter or fact so determined shall ever be disputed by anyone, and such record, or a properly authenticated copy thereof, shall be conclusive evidence in all courts of the matters therein recited and of the corporate existence of such drainage district: Provided, That the fact that the lands described in drainage districts heretofore incorporated under the provisions of said chapter 215 are described by sections or subdivisions of sections, according to the government survey, or as lots or blocks or parts of lots or blocks, by their appropriate number, shall not invalidate said petitions or invalidate the orders of the board of county commissioners incorporating such districts.