The simplest form of control for a spillway is the free, or uncontrolled, overflow crest, which automatically releases water whenever the reservoir water surface rises above crest level.

Freeboard is the vertical distance between the crest of the embankment and the reservoir water surface. Free board can be defined in different terms such as:

There are very few stilling basins with horizontal aprons for its larger dams. It has been the consensus that the hydraulic jump on a horizontal apron is very sensitive to slight changes in tail water depth.

A side channel spillway is one whose control weir is placed alongside and approximately parallel to the upper portion of the spillway discharge channel. Flow over the crest falls into a narrow trough opposite the weir, turns approximately 90 degree and then continues into the main discharge channel.

For the design of earth fill dams, presented the flow of seepage through the foundation and abutments be controlled so that no internal erosion occurs and there is no sloughing in the area where the seepage emerges.

Mass concrete can be defined as any large volume of cast-in-place concrete with dimensions large enough to require measures to cope with the generation of heat and attendant volume change to minimize cracking.

Spillways are structures constructed to provide safe release of flood waters from a dam to a downstream are, normally the river on which the dam has been constructed. Spillways can be controlled or uncontrolled.

Earth dams are generally built of locally available materials in their natural state with a minimum of processing.

A small scale power plant that generates electricity using the energy potential of water. Microhydro power plants convert the energy of flowing water into electrical energy. The energy produced by them is renewable & the process does not emit polluting gasses.