(Issued on September 12, 2014 in accordance with Decree No. 107 of the People’s Government of Guangzhou Municipality, amended for the first time on September 30, 2015 in accordance with Decree No.132 of the People’s Government of Guangzhou Municipality and amended for the second time on November 14, 2019 in accordance with Decree No. 168 of the People’s Government of Guangzhou Municipality)

　　Article 1 In order to control and reduce rainwater runoff, improve urban and rural flood control and drainage capacity, and safeguard the life safety and property safety of citizens and public safety, these Measures are formulated in accordance with the Law of the People's Republic of China on Flood Control, Regulations on Urban Drainage and Sewage Treatment, Regulations of Guangzhou Municipality on Water Affairs Management and other laws and regulations and on the basis of the actual conditions of this Municipality.

　　Article 2 The Measures shall apply to the rainwater runoff control and supervision and management activities of newly built, rebuilt and expanded construction projects within the administrative area of this Municipality.

　　Article 3 The rainwater runoff control of construction projects shall follow the principles of urban and rural overall coordination, unified planning, source control and low-impact development, so that the rainwater runoff after construction does not exceed the rainwater runoff before construction.

　　Article 4 The municipal drainage authority shall be responsible for the management of rainwater runoff control of construction projects in this Municipality, and shall be responsible for organizing the implementation of these Measures.

　　District drainage authorities shall be responsible for the management of rainwater runoff control of construction projects within their respective administrative areas ex officio.

　　The authorities in charge of urban and rural planning, urban and rural construction, landscaping, transportation and comprehensive law enforcement shall cooperate in rainwater runoff control and the relevant work ex officio.

　　Article 5 In the overall drainage plans and the detailed drainage plans, rainwater permeation and retention, collection, regulation and storage, storage, utilization, discharge and other facilities shall be reasonably planned; impervious areas shall be reduced; rainwater regulation and storage and permeation and retention capacity shall be improved; rainwater runoff shall be reduced.

　　Article 6 The rainwater runoff control facilities of construction projects are components of their drainage facilities, which shall be designed, constructed and used simultaneously with the main works of construction projects, and their construction expenditures shall be included into the project construction investment.

　　The municipal drainage authority shall formulate technical guidelines, which shall be implemented after public consultation, and guide relevant entities to design, construct and use rainwater runoff control facilities.

　　Article 7 When handling the planning conditions, the urban and rural planning authorities shall inform the construction developers to take rainwater runoff control measures in accordance with the relevant provisions of these Measures, making the rainwater runoff after construction not exceeding the rainwater runoff before construction.

　　Article 8 The rainwater runoff before the construction of construction projects shall be determined by the construction works design entities in the design stage according to the 1: 500 or 1: 2000 topographic map of the original plot and by counting the rainwater runoff coefficient tables corresponding to different underlying surfaces.

　　After the construction of construction projects, the rainwater runoff is calculated and determined by the construction works design entities in the design stage according to the relevant provisions of the Code for Design of Outdoor Wastewater Works (GB50014-2006).

　　Article 9 Rainwater runoff control of construction projects shall meet the following requirements:

　　(1) An integrated system of seepage and drainage shall be established for the drainage and reduction of rainwater on urban public roads;

　　(2) On the hardened ground of the new project, except for urban public roads, the outdoor permeable ground rate of buildings is not less than 40%; permeable pavement facilities shall be set up on sidewalks, outdoor parking lots, pedestrian streets, bicycle lanes and external courtyards of construction projects, and the permeable pavement rate shall not be less than 70%;

　　(3) For construction projects involving the requirements of the green space rate index, at least 50% of the green space except parks shall be used as sunken green space for stranded rainwater. The green space for stranded rainwater shall be 50 mm lower than the surrounding ground, and the top surface elevation of the gutter inlet located in the green space shall be more than 20 mm higher than the green space; facilities that can drain accumulated water within 24 hours may be set up;

　　(4) The daily permeability of permeable facilities shall not be less than the total daily rainwater design runoff with a recurrence period of 2 years on their catchment surface, and the permeable time shall not exceed 24 hours;

　　(5) In addition to surface infiltration, the horizontal distance between rainwater infiltration facilities and building foundation shall not be less than 3 meters;

　　(6) When seepage and drainage sheets or seepage and drainage pipes are set up on the top surface of the underground building covered with soil, the top surface of the underground building may be used as a permeable layer;

　　(7) The plants configured on the surface infiltration site shall be water-resistant plants. It is encouraged to provide construction projects with roof regulation and storage facilities or landscaping facilities.

　　Article 10 For a new construction project with a hardened area of more than 10,000 square meters, except for urban public roads, every 10,000 square meters of the hardened area shall be equipped with rainwater regulation and storage facilities of not less than 500 cubic meters.

　　Rainwater regulation and storage facilities may be combined with ecological landscape ponds, circulating pools, etc. for comprehensive utilization. They shall be capable of reducing rainwater peak runoff, and can be discharged to the lowest water level within 12 hours. Their external discharge shall not exceed the drainage capacity of public drainage pipes.

　　Article 11 The design scheme of public drainage facilities submitted by the construction developer to the drainage authority for examination shall include the rainwater runoff control contents.

　　The contents of rainwater runoff control shall be included into the drainage works design, which presents in the design documents of construction projects submitted by the construction developer to the urban and rural construction authority for examination. The urban and rural construction authorities shall consult the drainage authority on the drainage work designs of construction projects.

　　The rainwater runoff control contents specified in the preceding paragraph shall include the calculation sheet of rainwater runoff coefficient before and after development, the calculation sheet of rainwater discharge, rainwater runoff control facilities, scale and layout, etc.

　　Article 12 For the construction of supporting drainage facilities for newly built, rebuilt or expanded construction projects, the urban and rural planning authority shall, when issuing the planning permits for construction lands according to law, consult the drainage authority in accordance with the provisions of Regulations on Urban Drainage and Sewage Treatment. The drainage authority shall give comments on whether the drainage design scheme conforms to the urban drainage and sewage treatment plan and relevant standards.

　　Article 13 Rainwater runoff control facilities of construction projects shall meet the following requirements:

　　(1) Constructing in accordance with the replied comments and drawings of the authorities in charge of urban and rural planning, urban and rural construction and drainage;

　　(2) The quality meets the requirements of relevant standards or specifications for drainage works;

　　(3) Rainwater runoff control facilities are in good condition and the trial operation is normal.

　　If the rainwater runoff control facilities do not meet the requirements prescribed in the preceding paragraph, the construction developer shall organize repair or reconstruction.

　　Article 14 The owner or manager of rainwater runoff control facilities shall be responsible for the maintenance, repair and daily management in accordance with the relevant provisions of Measures of Guangzhou Municipality for Drainage Management.

　　The owner or manager of the rainwater runoff control facilities shall timely advise and stop the acts of obstructing or hindering the management, protection, maintenance and repair of the runoff control facilities or damaging the rainwater runoff control facilities, and report to the drainage authority.

　　Article 15 Relevant entities and individuals shall use rainwater runoff control facilities according to the requirements stipulated in these Measures, and shall not use rainwater runoff control facilities for other purposes or obstruct/hinder the management, protection and maintenance of rainwater runoff control facilities.

　　The following acts damaging rainwater runoff control facilities are prohibited:

　　(1) Block rainwater runoff control facilities and hinder drainage;

　　(2) Unauthorized occupation, dismantling or landfill of rainwater runoff control facilities;

　　(3) Dump garbage and other wastes into rainwater runoff control facilities;

　　(4) Dump and discharge excessive sewage and corrosive, radioactive, flammable, explosive, toxic and other hazardous substances into rainwater runoff control facilities;

　　(5) Other acts that damage rainwater runoff control facilities.

　　Article 16 In the flood season, the owner or manager of rainwater runoff control facilities shall undertake flood control obligations according to law and obey the unified command and dispatch of flood prevention, drainage and emergency rescue.

　　Article 17 The drainage authorities shall establish an inspection system for rainwater runoff control facilities, regularly inspect rainwater runoff control facilities, and supervise the maintenance, repair and daily management of the owner, manager and the organization responsible for maintenance and repair of facilities.

　　The supervision and management information of rainwater runoff control facilities shall be regularly announced to the public.

　　Article 18 If the authorities in charge of drainage, urban and rural planning, urban and rural construction and their staff violate the provisions of these Measures by failing to perform their duties according to law, the competent authority shall order them to make corrections, and the responsible leaders and directly responsible personnel shall be punished according to law; if a crime is constituted, criminal responsibility shall be investigated according to law.

　　Article 19 If rainwater runoff control facilities are not conforming to the provisions of Article 13 herein by failing to meet the prescribed requirements, and the construction developer does not organize repair or reconstruction, the drainage authority shall order it to make corrections within a time limit and deal with it as follows:

　　(1) For the rainwater runoff control facilities serving as public drainage facilities, a fine of 2% to 4% of the project contract price shall be imposed;

　　(2) For the rainwater runoff control facilities not prescribed in Item (1) of this article, a fine of RMB 20,000 to RMB 50,000 shall be imposed.

　　Article 20 If the owner or manager of rainwater runoff control facilities violates the provisions of Article 14 herein by failing to maintain, repair and daily manage the facilities as required, the drainage authority shall deal with them in accordance with the provisions of Article 38 of the Measures of Guangzhou Municipality for Drainage Management.

　　Article 21 Those who violate the provisions of Paragraph 1 of Article 15 herein by failing to use rainwater runoff control facilities as required, diverting rainwater runoff control facilities for other purposes or obstructing/hindering the management, protection, maintenance and repair of rainwater runoff control facilities shall be ordered by the drainage authority to make corrections, and a fine of not less than RMB 500 but not more than RMB 1,000 shall be imposed on individuals, or a fine of not less than RMB 20,000 but not more than RMB 50,000 shall be imposed on entities.

　　Those who violate the provisions of Paragraph 2 of Article 15 herein by damaging rainwater runoff control facilities shall be handled by the drainage authority or the comprehensive law enforcement organ in accordance with the provisions of Article 57 of the Regulations of Guangzhou Municipality on Water Affairs Management.

　　Article 22 If the owner or manager of rainwater runoff control facilities violates the provisions of Article 16 herein by failing to perform flood control obligations, which seriously affects flood control and constitutes an illegal act against public security, the public security organ shall deal with it in accordance with the Law of the People's Republic of China on Penalties for Administration of Public Security; if a crime is constituted, criminal responsibility shall be investigated according to law.

　　Article 23 The term "rainwater runoff" herein refers to the water flow that does not enter the soil but flows along the earth surface after the atmospheric precipitation falls to the ground.

　　The term "outdoor permeable ground rate" herein refers to the proportion of the sum of permeable ground area to the total outdoor ground area. The permeable ground includes natural bare grounds, public green space, green grounds, hollow pavement with a hollow area greater than or equal to 40% (e.g. grass planting bricks), permeable bricks, permeable asphalt and permeable concrete.

　　The term “hardened area” includes the hardened area of roofs, roads, squares, courtyards and other parts within the scope of construction land, calculated as per the formula "hardened area = construction land area-green space area (including the roof greening area)-permeable pavement land area". The calculation of the hardened area of the roof shall be based on the projected area of the roof (excluding the roof greening area).

　　Article 24 These Measures shall come into force on November 1, 2014.