Ratio of actual drainage modulus to needed drainage modulus

Yangtze River Drainage Changjiang Drainage

branch sewer

building storm sewer

clay sewer pipe

Combined Intercepting Sewer

Combined intercepting sewer system

Combined Sewer

Combined sewer overflow

Combined Sewer Overflow Pollution

Combined Sewer Overflows

Combined Sewer System

common sewer

communal foul sewer

communal sewer

covered sewer

deep tunnel intercepting sewer system

depressed sewer

domestic sewer