[Tinordi]

https://www.washingtonpost.com/news/...=.4defdef41458

Hurricane Harvey has brought “500-year” rainfall and flood conditions to the Houston area, according to officials at the Harris County Flood Control District.

By the time the storm finally leaves the Houston area the true magnitude may be even greater than that, surpassing 1,000-year thresholds -- potentially even more.

But 500-year floods, as it turns out, happen more frequently than you might expect. The Houston area alone has seen no fewer than three such events in the past three years, according to local officials: Memorial Day floods in 2015 and 2016, followed by Hurricane Harvey's torrential rains this year.