NANNING/CHANGSHA - Shipping traffic remains paralyzed along the drought-stricken Xijiang and Xiangjiang rivers running through south China as authorities work to preserve drinking water for the region's households.

As of Sunday, more than 900 vessels remained stuck on a section of the Xijiang River that runs through the city of Wuzhou in the Guangxi Zhuang autonomous region.

A lack of rain decreased the river's runoff by more than 30 percent in December.

The Pearl River flood control and drought relief headquarters said Saturday that the Changzhou Reservoir, the river's primary water control facility, will not discharge water until Wednesday.

Water must be stored in the reservoir in order to ensure sustainable drinking water supplies for the city of Zhuhai and the Macao special administrative region in January. Otherwise, supplies will only last for 12 days, according to the headquarters.

Xijiang is a major tributary of the Pearl River. As the river's runoff shrank, seawater flowed back into the river, triggering a severe salt tide earlier this month.

Water management departments in the cities of Zhuhai and Zhongshan in Guangdong province have detected excessive salinity levels in water samples taken from pump stations along the river.

The river's low water level has been attributed to a lingering drought along its upper reaches in the provinces of Guizhou, Yunnan and Guangxi.

Meanwhile, water levels on a section of the Xiangjiang River that runs through Changsha, the capital of Hunan province, reached a historic low on Thursday.