Whenever the governing body of a city of the second class shall by ordinance declare and establish a sewer district composed of the territory as in Kan. Stat. Ann. § 14-516 provided necessary, they shall at the same time as far as may be divide the territory adjacent to said main intercepting sewer into sewer districts, and after constructing the said main sewer as hereinafter provided, or in connection with the construction thereof, if they deem it advisable, proceed to have surveyed, mapped, located and platted said main sewer and lateral sewers, and advertise and let the contract for the building of said main sewer and lateral sewers as well, if in their judgment they so elect.