Question

Morning glory is the _____________________________

(a) special flared inlet of the shaft spillway of a dam of very small height

(b) special flared inlet of the shaft spillway of a large dam project

(c) a horizontal tunnel constructed in a shaft spillway across the body of a gravity dam to carry surplus reservoir water to the d/s river

(d) a horizontal tunnel constructed in a shaft spillway of an earthen dam through its foundation to carry surplus reservoir water to the d/s river

The question was asked by my school teacher while I was bunking the class.

Origin of the question is Shaft Spillway in chapter Spillways, Energy Dissipators and Spillway Gates of Irrigation Engineering

Answer 1

Right option is (b) special flared inlet of the shaft spillway of a large dam project

To explain: In shaft spillway of large heights, RCC may be used and for smaller heights, no special inlet design is necessary. A flared inlet called morning glory is often used in large projects. The horizontal tunnel is either taken through the dam body or below the foundations.