Cool, but how was Chris, the maker, able to seal the area which the spigot is out from ?

The City of Philadelphia has set a goal to reduce the rainwater runoff that pollutes local rivers and causes flooding. They are focusing on measures to create places where rain is quickly absorbed into the ground, rather than sheeting off pavement.

figuring out the amount of rainwater you can collect from your roof, given you know how much rain is coming down, of course.