9.6mm/hr is an order of magnitude lower than what this Japanese reservoir is expected to handle. It would be considered heavy rain, but not at all unusual, for

9.6mm/hr is an order of magnitude lower than what this Japanese reservoir is expected to handle. It would be considered heavy rain, but not at all unusual, for monsoon season in East Asia. It happens a few times every summer, so most cities in Japan and Korea are equipped to handle it just fine. If such events were more common in Colorado, they would have been better prepared, too.