Location of Powerhouse in Hydro-Electric Plant

The location of the powerhouse is determined by the overall project development. The factors affecting the location include:

(1) Location of the spillway (when powerhouse is located adjacent to the dam).
(2) Location of navigation locks (on navigation projects).
(3) Foundation conditions.
(4) Valley width.
(5) River channel conditions below dam.
(6) Accessibility.
(7) Location of switchyard and transmission lines.

Local conditions

At projects where the powerhouse is located at the dam adjacent to the spillway, local condition such as width of flood plain, accessibility, and depth of foundations will usually govern the location. On projects which will include a navigation lock, the powerhouse is preferably located at the opposite end of the spillway from the lock. Where the river channel below the dam has an appreciable fall, economic studies should be made to determine whether a remote powerhouse location downstream from the dam is justifiable.

Sub-structures

At low-head projects, the substructure of the powerhouse may be wholly or partially incorporated into the design of the intake structure. At medium-head plants, the substructures of the generating units and the upstream generator room wall should be separated from the toe of a concrete dam, and any part of the powerhouse supported thereon, by a formed joint.

 The amount of separation between the powerhouse substructure and the toe of the dam at, or below, the elevation of the generator room floor may be dependent upon the foundation conditions, but the separation is frequently as much as 10 feet or more to provide adequate space to install service facilities.