7.7.3 Final Drainage Report

A final drainage report must be prepared and submitted along with finalized hydraulic calculation sheets to the District for review and then submitted to DES – H&H section for review and approval before the Final (90%) milestone submittal. The final drainage report should be signed and sealed
by the drainage engineer of record.

The drainage report and H&H calculations should be retained in the District project File of Record for permanent reference (refer to the HDM for more information on specific documentation retention requirements). Retaining these records provides many benefits, including:

Ease of reference for future alteration or rehabilitation of the subject drainage structure;

Justification of design decisions in case of future challenges or litigation;

Valuable reference information for the design of other structures that cross the same stream or are in the same watershed; and

Proof of intended compliance with regulations such as NFIP rules.

7.7 Drainage Design