The basics and analysis of seepage effects on open channel flow which are needed for the planning, design and operation of water-resource project are presented. Features: 1. Concerns to understand the literature by focusing the attention towards the problem definition. 2. A new resistance equation and a governing equation relating critical stream power is developed for little or no transport beds. 3. The change in stream power induced by seepage is quantitatively estimated using spatially varied flow analysis. 4. Numerical model for spatially varied flow is developed with the help of seepage governing equations developed in this text. 5. Deals with the geometry of channel cross section with seepage. Regime conditions for the prediction of channel geometry in alluvial channel affected by seepage (downward seepage) are presented in the form of regression equations. An approach is developed based on the application of functional analysis of the salient variables that control the channel behavior.