Utilizing fish swimming power and energy capabilities and the hydraulic properties of culverts in those locations within culverts where fish actually swim, the writers have prepared a detailed manual of culvert design procedures for culverts which must provide safe passage of upstream moving, weak swimming fish. The design procedures utilize hydraulic formulae for profile drag, non-Archimedean buoyant forces, and virtual mass force to quantify the hydraulic conditions within a culvert that the design fish can sustain without exhaustion for various time durations. Final culvert design may then be selected on economic or other bases from the full range of trial designs that are hydraulically suitable for fish passage. This paper provides an overview of the analytical and biological methods used in the preparation of the design procedures and its associated software.