China's south-to-north water transfer project has reached its "overall" targets on water quality, with "certain" pollution being treated, an official said Tuesday.

"For the central line, media reports and our probes have spotted pollution, but it did not affect the overall situation," said Gao Juncai, head of the Department of Rural Economy under the National Development and Reform Commission, China's top economic planner.

For the east line, water pollution treatment has showed remarkable progress, he said at a press conference.

"Currently, water quality in both central and eastern lines have reached designed overall water quality targets," Gao said.

"Some problems showed up in certain regions, pollution spots and tributaries. We and other involved departments are paying much attention to them. More anti-pollution measures will be made."

Gao did not specify any pollution issues in the project.

The project, South-to-North Water Division, has three lines. The east line is located in the eastern region where water must be heightened to go north. The central line starts from Danjiangkou Reservoir to supply water for regions along the Yellow River, Huaihe River and Haihe River. The west line, located at the Qinghai-Tibet Plateau, has not broken ground yet.