Up to 9.5 billion cubic meters of clean water will be supplied to 19 large and medium-sized cities in arid North China every year through the South-to-North Water Diversion Project's middle route from next year, authorities said. Construction on the first phase of the middle route, which brings water from the Danjiangkou Reservoir in Central China's Hubei province to four provinces and municipalities, including Beijing, Tianjin, Hebei and Henan, was completed on Wednesday, the State Council's Office of the SNWD Project Commission said.

The water diversion will commence after the 2014 flood season, the office said, without providing any specific dates.

The middle route is expected to transfer about 1.24 billion cu m of water to Beijing and 1.02 billion cu m of water to Tianjin, it said.

More than 340,000 people have been relocated to make way for the 10-year construction of the middle route, the office said.

The SNWD project, the world's largest water diversion program, is designated to divert water from the Yangtze River in the south via an eastern, middle and western route to satisfy the water demands in the arid northern regions of China.

The first phase of the east route, completed in March, had brought water from the Yangtze River in Jiangsu province's Jiangdu to Shandong province along the Beijing-Hangzhou Grand Canal during its first use in November.

The western route, which will replenish the Yellow River with water diverted from the upper reaches of the Yangtze River, is still in the planning stage.