Facilities are often built for the “10-year” or 10% storm. Harvey has dropped a much larger amount of rain, comparable to a “500-year” storm. These large deluges are happening every year.
All the rain that’s fallen over Houston so far, in one massive water drop. Source: Javier Zarracina / Vox.
About 9 trillion gallons of rain has fallen across southwest Texas. If that water were collected into a cube, it would be four miles square and two miles tall.
Contamination Risks at low elevation (EPA data via Climate Central) – hover or click on the points to identify individual facilities.