A. An estimate to be made of the cost and expense of the proposed improvements, together with all papers and information in their possession touching the proposed improvement;

B. A description of the boundaries of the district;

C. A statement of what portion of the cost and expense of the improvement should be borne by the property within the proposed district;

D. A statement in detail of the local improvement assessments outstanding and unpaid against the property in the proposed district;

E. A statement of the aggregate actual valuation of the real estate including 25 percent of the actual valuation of the improvements in the proposed district according to the valuation last placed upon it for the purposes of general taxation.

If the proceedings were initiated by petition, the city engineer shall also determine the sufficiency of the petition and whether the facts set forth therein are true. If the petition is found to be sufficient and in all proceedings initiated by resolution of the city council, a diagram shall be filed with the city engineer of the lots, tracts and parcels of land and other property which will be specially benefited by the proposed improvements and the estimated amount of the cost and expense thereof to be borne by each lot, tract, parcel of land or other property; provided, that no such diagram shall be required where such estimates are on file in the office of the city engineer, together with a detailed copy of the preliminary assessment roll and the plans and assessments map of the proposed improvement. (1957 code § 8.02.010.)