Purpose: This manual describes the development and use of response spectra for the seismic analysis of concrete hydraulic structures. The manual provides guidance regarding how earthquake ground motions are characterized as design response spectra and how they are then used in the process of seismic structural analysis and design. The manual is intended to be an introduction to the seismic analysis of concrete hydraulic structures. More detailed seismic guidance on specific types of hydraulic structures will be covered in engineer manuals and technical letters on those structures.