Each county mosquito control commission shall, on or before the first day of November in each and every year, file with the state health officer a detailed estimate of the moneys required for the ensuing year, and a plan of the work to be done and the methods to be employed. The said state health officer shall have the power to approve, modify, or alter the said estimates, plans and methods. The estimate, plan and method finally approved by him shall be forwarded to the county board of supervisors in each county on or before the first day of December following its receipt.