diegopuj95,
Are you having a specific problem or just don't know how to do the analysis? If it is a specific problem or issue please clarify your question. If you don't know how to start, I think that the agency or your client would expect that you have some expertise before designing a drainage system based on teaching yourself from a book. If you haven't done this type of engineering analysis before you should be working under the supervision of a licensed engineer, who should be able to help you, or hire a qualified consultant. HEC-22 is a great reference, but here in Washington (and I assume the other states as well) our state code requires that engineering analyses are supposed to be overseen by a qualified (i.e. experienced) and licensed engineer.
Good luck!