Section 88.71 - Enlarging or supplementing existing drains(1) Whenever the board is petitioned by the owners of one-tenth of the lands in a district to enlarge existing drains or to lay out and construct new drains in such district, or whenever the board is of the opinion that the plan of drainage of the district is or will be insufficient to effect a thorough drainage of such district or any portion thereof, and that enlarged or supplemental drains are required to effect such drainage, the board shall cause to be prepared plans and specifications for the enlargement of existing drains or for the construction of sufficient supplemental drains to complete the drainage of such district.(1m) If the drainage board is satisfied that the public health or welfare will be promoted by the enlarged or supplemental drains and that the benefits from the drains will exceed the cost of construction, the drainage board shall order the construction of the enlarged or supplemental drains.(2) The board shall estimate the cost of construction of the enlargements or supplemental drains together with the cost of all additional bridges that the district must build and shall assess the costs against the lands benefited, as provided in ss. 88.35 and 88.36 and in this subsection. The board shall award to each parcel of land the damages caused to the land by the supplemental work and shall assess benefits against the lands benefited by the supplemental work. The benefits shall be apportioned and assessed so that all assessed lands are required to pay a sum total for the construction of the total drainage proportionate to the actual benefits received by the lands from the total drainage.