Southern Taiwan's biggest reservoir is almost full after days of heavy rain, good news for a region that has struggled with water shortages.

• Zengwen Reservoir is sitting just under its full level, with storage close to 99%.
• A low-pressure system and southwest winds have dumped heavy rain on the catchment area since the 19th.
• The inflow so far is roughly the size of an entire Sun Moon Lake, and rain is still falling.
• Water officials are now weighing when to start releasing water to keep the reservoir from overtopping.
• Combined with the nearby Wushantou Reservoir, usable storage is over 530 million cubic meters.

Outlook: If the rain keeps up, controlled water releases are likely in the coming days.