China’s National Meteorological Center has renewed its blue weather alert for central and southern China after days of continuous torrential rain.

The center says heavy rain is expected in Hubei, Anhui, Jiangsu, Hunan, Jiangxi, Sichuan and Yunnan provinces, as well as in the Guangxi Zhuang Autonomous Region. The center has told officials to be on alert for landslides and floods. China has a four-tier color-coded system for severe weather, with red being the most serious, followed by orange, yellow and blue.

This year’s first typhoon—Nepartak—is expected to bring even more gales and downpours to China’s east coast Wednesday night. Chinese authorities say 11 provinces have already been hit by extreme weather this year.

Heavy rains have become a familiar sight in China over the past few days. In eastern China, dams and reservoirs are being put to the test. Authorities say 117 rivers nationwide are close to overflowing, including China's biggest fresh-water lake—Poyang Lake—and Taihu Lake.

“It has been raining for about 20 days. The water levels of the river that flows into Taihu has risen a lot,” said a fisherman.

Officials in the area have detained over 400 ships as a security precaution and triggered a level two warning for emergency-flood-control response teams across the south.

Water-gates have been closed to prevent flooding downstream in Nanjing. Flood waters are being diverted to a wetland park to ease pressure on dams. Residents have been told to stay clear of the park.

The measures have helped keep the Qinhuai River from overflowing. The river runs through the heart of Nanjing—a city that is home to more than 8 million people.

Workers are reinforcing dams along the Yangtze River in preparation for even more rain.

Roads are waterlogged. Like here in Tongren, a city in southwest China’s Guizhou province. In one of the hardest hit areas, more than 300 millimeters of rain fell within one day.

“The water rose so quickly that it flooded my car’s engine. Traffic police and passengers helped me get the car out of the water,” said Lu Tingqing, a local resident.

Eastern China’s Anhui province was one of the worst-hit provinces. Severe landslides triggered by heavy rainfall damaged the main road leading to Anhui’s Jinzhai county. The government sent hundreds of emergency crew to the scene to provide support.

The heavy rain and floods have destroyed around 22,000 houses across China—in the provinces of Jiangsu, Hubei, Henan and Sichuan. Total direct economic losses have reached almost 25 billion yuan. Tens of thousands of people have joined disaster relief efforts in rain-affected regions.