If in its opinion it is expedient, the board of trustees of a regional water and sewer district may provide for the construction of main sewers and drains and branch sewers and drains connecting therewith without previously adopting any plan of sewerage or division of the area or any part thereof into districts, and may assess the cost and expense of such construction upon such lots and lands as are designated in the resolution to improve, or such cost and expense may be paid from the general fund of the district, as the board determines. Such proceedings shall be had in respect to such improvements and assessments as are provided for in sections 6119.01 to 6119.42, inclusive, of the Revised Code, for the construction of main or branch sewers according to a previously adopted plan.