Abstract:So far,the water quality model based on the hydraulic model is static which assumes that the decay parameters of the residual chlorine of the pipes to be constant.Therefore,the model is not fit for the multisources water distribution system whose chlorine decay parameters are different.This paper presents a new water quality model adaptable to the real network more, which is solved by the genetic algorithm,and the optimized result which satisfies the requirement of the residual chlorine concentration at each junction is obtained.The model is applied to the real network and obtains the valuable information on the water quality operation.