This document provides guidance in the methods, procedures, policies, and criteria that must be followed, and the information that is to be developed during a drainage study and hydraulic design. It is not intended to be an all inclusive document on the practice of hydraulic engineering, and the designer must reference other materials and use good judgment in its application to ensure that the design is complete and appropriate for the site. The AASHTO Highway Drainage Guidelines (1)and Model Drainage Manual (2)are recommended as primary references for drainage design.

The engineer is encouraged to apply ingenuity and consider new and differing concepts and procedures in the design process. However, all specified methods, procedures and criteria presented in this guideline must be followed unless approval for variance is given by the State Hydraulics Engineer or his delegated representative.

All referenced design forms, reports and check lists are to be completed and included with the Hydraulics Design Package. The Hydraulic Design Documentation Summary Sheet(Appendix Item A) is to front the design package and must include the seal of the engineer performing or directly responsible for the work. All Bridge and Culvert Survey and Hydraulic Design Reports will be individually sealed by the responsible engineer.

Additional documents required for implementation of procedures, or suggested as further informational resources, are noted as references within the guideline text and listed in the reference section.