SR-43 : Spillway gate regulation

Abstract

Storage structures are constructed to equalize the natural streamflow. Spillway is pro- vided at the dam site to dispose off the surplus water from the upstream of the reservoir to the downstream without causing any harm to the dam structure. Spillway gates (movable crest) are provided to head up the water level for specified purposes like water supply for domestic and industrial use, irrigation, hydropower generation and flood control. So gate operators require gate opening, the straight line distance (cord length) from the gate seat to the downstream side of the gate lip, to serve the purposes. The aim of this report is to review different types of spillways and gates, various discharge equations for each type of spillway, different modes of operation, general considerations for selection of spillway and to present a generalised computer program which can give précised ratings table to operate either tainter gate or sluice gate. The HEC(July 1966) program is modified with the addition of précised sluice gate equations (P.K.Swamee) to prepare ratings table with any number of reservoir level and gate opening intervals according to the prevailing condition in the reservoir.