What's the maximum amount of rain Seoul can handle?

The amount of rain Seoul can handle is set at 100mm per hour. This number isn't just a guess; it's a probability derived from rainfall records accumulated at observation stations nationwide. It's calculated based on rainfall that occurs once every 30 years, with a little extra buffer added to set the current standard. The problem is that this number is both a promise and a declaration of limits. In the summer of 2022, Dongjak-gu experienced 141mm of rain per hour, when Seoul's standard was 95mm. Therefore, instead of grouping the entire city under one number, Seoul has opted to set different standards for each neighborhood and channel excess rain into deep underground tunnels.