Read this: Wang Mang initiated a series of major reforms that were ultimately unsuccessful. These reforms included outlawing slavery, nationalizing land to equally distribute between households, and introducing new currencies, a change which debased the value of coinage. Although these reforms provoked considerable opposition, Wang's regime met its ultimate downfall with the massive floods of c. 3 AD and 11 AD. Gradual silt buildup in the Yellow River had raised its water level and overwhelmed the flood control works. The Yellow River split into two new branches: one emptying to the north and the other to the south of the Shandong Peninsula, though Han engineers managed to dam the southern branch by 70 AD.

What caused the end of Wang Mang's regime?
What is the answer? (If it cannot be answered, return "unanswerable")
massive floods