Gb500 14-20 16 code for outdoor drainage design.

Legal analysis: 1, this specification is formulated to make the design of drainage engineering in China implement the concept of scientific and technological development, conform to national laws and regulations, promote the construction of sponge city, achieve the requirements of preventing and controlling water pollution, improving and protecting the environment, improving people's health level and ensuring safety.

2. Design flow and design water quality

3. Rainfall

Legal basis: Regulations on Urban Drainage and Sewage Treatment

Article 1 These Regulations are formulated for the purpose of strengthening the management of urban drainage and sewage treatment, ensuring the safe operation of urban drainage and sewage treatment facilities, preventing and controlling urban water pollution and waterlogging disasters, ensuring the safety of citizens' lives and property and protecting the environment.

Article 2 These Regulations shall apply to the planning of urban drainage and sewage treatment, the construction, maintenance and protection of urban drainage and sewage treatment facilities, the drainage and sewage treatment of urban drainage facilities, and the prevention and control of urban waterlogging.