The R.L. of ground water table on the sides of a valley is 1505 m whereas R.L. of the stream water is 1475 m. If 60° slope consists of pervious soil between R.L. 1485 m to 1500 m, the gravity spring may be expected at the point of reduced level

Water Supply Engineering is a branch of engineering concerned with the development of sources of supply, transmission, distribution, and treatment of water.

The term is commonly used for municipal (city) water works, but applies also to water systems for industry, irrigation, wastewater reuse, and other purposes.