In studying “modern” water hydraulics, it is important to remember that the science of water hydraulics is the direct result of two immediate and enduring problems: The acquisition of freshwater and access to continuous strip of land with a suitable gradient between the source and the destination. In water hydraulics, water balance or water budget can be used, in equation form, to describe the flow of water in and out of a system. Water exerts force and pressure against the walls of its container, whether it is stored in a tank or flowing in a pipeline. There is a difference between force and pressure, though they are closely related. When the source of water for a water distribution system is from a groundwater supply, knowledge of well hydraulics is important to the operator. In hydraulics, the flow of water is analogous to the flow of electricity. The primary parameters used in open-channel flow are hydraulic radius, hydraulic depth, and slope.