Q is the discharge from an unconfined tube well with depression head s through its pipe of radius rw. If the radius of influence is R, the length of the required strainer, is

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.