Abstract: According to design hydrological conditions and water quality targets, the water environment capacity of control sections of Guanlan River in Shenzhen was calculated with COD as the calculation index, and the monthly environment capacity was allocated. Furthermore, based on pollution source investigation and the handling ability of ewage treatment plants, the total amount of pollutants discharged into the river was obtained and was compared with the environment capacity. Results show that the environmental capacity is very small compared with the amount of pollution into the river, which far exceeded the maximum carrying capacity of river. Especially in dry season in December, the total amount of pollutants into the river is 62.2 times the water environmental capacity. On this basis, a comprehensive plan of water pollution control is put forward: pollution discharge reduction, pollution dredging, clean water recharge, and ecological restoration.

Key words: Guanlan River, environment capacity, control section method, water pollution, comprehensive control