Taiwan's Zengwen Reservoir hit full capacity after heavy rain and is now releasing water, a routine but disruptive move that keeps flood risk down while putting riverbanks downstream off limits.

• The reservoir filled to its maximum level early Tuesday, and the spillway was opened to let water out.
• Another 50 million cubic meters of water is still expected to flow in from the surrounding hills.
• Water managers are clearing space ahead of Typhoon Sadel, which may bring more rain to Taiwan.
• The release also flushes built-up mud down the river and out to sea, which extends the reservoir's useful life.
• People are being warned to stay out of the riverbed and off the banks while flows are high.

Outlook: Release volumes will be adjusted day by day depending on how much rain the typhoon delivers.