Specifications include, but are not limited to: The County requests the designer analyze the condition of the structure and provide feasible options for structure replacement or perpetuation, including culvert lining, should those options be hydraulically acceptable and constructible. It is anticipated that construction will occur in 2028, with full road closure and detour around the work zone. The structure may be one (1) or more spans as determined by hydraulic modelling. The CTH XX roadway will remain two (2) twelve-foot lanes designed to 6-foot gravel shoulders given design standards for the existing AADT. The design process will determine if a recoverable slope or beam guard will be necessary. The new structure shall convey the 50- year return interval discharge with a check of the 100-year return interval to check for roadway overtopping. The backwater shall not be raised greater than 0.01 feet for any structure selection. Land acquisition is not anticipated for completion of this project, however; additional right of way or easements will be acquired, if needed. Beam guard replacement shall be investigated and likely deemed necessary. The new structure shall convey the 50-year return interval discharge with a check on the 100-year return interval to check on roadway overtopping. The backwater shall not be raised more than 0.01 feet for any structure selection. Land acquisition is not anticipated for completion of this project, however; additional right of way or easements will be acquired, if needed. A detailed discussion of the scope of services and special provisions for the project are contained in the proposed Contract for engineering services in 2024025 Prof Design Srvcs CTH XX – Mill Brook Structure Attachment A - Proposed Contract.
