Torrential rain has poured across the Sichuan province over the last few days, leaving seven people dead and 48 others missing.
The rain has poured across the region for several days, washing away buildings, bridges and triggering landslides.
The situation has been made worse by the huge Qionglai Mountains, which tower over 3,000m (9,800ft).
The water has gushed down the mountainsides, forming fast-flowing torrents of water.
Deforestation has also exacerbated the problems, increasing the likelihood of landslides.
Beichuan County has been badly hit. The flooding destroyed buildings and wrecked a memorial for the 2008 earthquake, which claimed the lives of almost 90,000 people. The museum was only opened in May this year.
In the nearby city of Dujiangyan, a massive landslide left two people dead and 21 missing.
Across the region, bridges have been closed and train services suspended.
More than 2,000 people had to be rescued after being trapped for several hours in a highway tunnel between Dujiangyan and Wenchuan.
Mudslides and flooding are common in China's mountainous areas, killing hundreds of people every year, but the rains in the Sichuan province are the worst in half a century.
The wet season is expected to run until September.