HIGHWAY HYDROLOGY: HYDRAULIC DESIGN SERIES NO. 2

This manual is a revision of Hydraulic Engineering Circular No. 19. The manual discusses the physical processes of the hydrologic cycle that are important to highway engineers and the methods that are used in the design of highway drainage structures. Hydrologic methods of primary interest are frequency analysis for analyzing gaged data, empirical methods for peak discharge estimation, and hydrograph analysis and synthesis. The peak discharge methods discussed include regression equations, the rational method, and the SCS Graphical method. Assessment of the effects of urban development is discussed. Hydrologic methods used in arid lands are presented. Methods for the planning and design of detention basins are detailed. Channel and storage routing procedures commonly used in hydrologic analyses for highway drainage are presented. The basics of geographic information systems (GISs) are presented in support of the increased use of GIS on highway projects. All computations are performed in SI units.