Analysis of the water environmental impacts of the construction of the central Yunnan water diversion project on the Qingshuihai reservoir

Long-distance water diversion projects have become an important part of urban water supply planning. Meanwhile the ecological impacts of long-distance water diversion projects are attracting increasing attention. In 2007, the Qingshuihai water supply project was launched with the purpose of meeting the water demand of the new development zone in Kunming city. During the construction phase, a series of mitigation measures were adopted by the Kunming municipal government to protect the environment. This article focuses on the 4-year monitoring of the water quality of the Qingshuihai reservoir. The analysis has shown that the water quality of the reservoir is better in the dry season than the raining season when the water quality was affected primarily by polluting sources in the reservoir catchment and by the construction activities. The study has also concluded that the implementation of the environmental mitigation measures during the construction phase has played an important role in protecting the water quality of the Qingshuihai reservoir. As the construction activities are near completion, rural non-point sources, sewage and upstream flow will become the major factors affecting the water quality of the reservoir.