16.13. OUTLETS An outlet in a dam is a combination of structures and equipment required for the safe operation and control of water released from a reservoir to serve different objectives. Outlets are classified according to the purpose they serve. River outlets regulate flows to the river and control the water level in the reservoir. Besides, the river outlets may be useful for increasing the flow downstream of the dam alongwith the normal spillway discharge. In addition, river outlets may also act as a flood control regulator to release waters temporarily stored in flood control storage space or to evacuate storage in anticipation of flood inflows. Further, river outlets may also serve to empty the reservoir for inspection, repair, and maintenance of the upstream face of the dam and other structures which are normally inundated.
560 IRRIGATION AND WATER RESOURCES ENGINEERING
Irrigation, municipal water supply, and industrial outlets control the flow of water into a canal, pipeline, or river to satisfy specified needs. The design of these outlets will depend primarily on irrigation, commercial, industrial, and residential water needs and also on the capacity requirements with the reservoir at a predetermined elevation as well as the amount of control required as the elevation of the reservoir fluctuates.
Power outlets provide passage of water to the turbines for generation of hydropower. The power outlets should be so designed as to minimise hydraulic losses and to obtain the maximum economy in construction as well as operation.
