Subject to where you are from, different countries have different terms for "storm drain".
Depending on where you are from, different countries have (link removed) for "storm drain".
Accordingly to Wikipedia, a storm drain is essentially a tunnel that carry runoffs (rain) from urban areas. For a layman, it helps to think along the line of sewage system that operates beneath our cities.
In the US, this is actually best known "storm drain" or "sto