WUHAN -- Water from China's longest river, the Yangtze, was routed to the drought-struck Hanjiang River on Friday to supply China's ambitious south-north water diversion project.

The Hanjiang, the Yangtze's largest tributary, has suffered a severe drought since winter, which has caused a test run of the south-north water diversion project planned for June 1 to be postponed until September.

The Yangtze River has fed back to the Hanjiang through a 67.23 km-long canal to offset the effects of the drought and water diversion to the north.

Operators decided to begin routing water through the canal 51 days ahead of the planned September start date due to the severity of the drought lingering in the reaches of the Hanjiang.

The Hubei meteorological department put the Hanjiang on its highest drought alert earlier this month as parts of the river ran dry and agriculture was affected.

Xu Mingxiang, chief engineer of the Yangtze Water Resources and Hydropower Planning Survey and Design Institute, which designed the Yangtze-Hanjiang water diversion project, said the canal was built with an investment of 8.4 billion yuan (1.36 billion U.S. dollars). It runs through four cities in Hubei Province.

Water from the Yangtze flowed through a sluice gate into the canal at a rate of 100 cubic meters per second on Friday morning and is expected to reach the Hanjiang in 24 hours.