The title of the article assumes a drought. The sentence in question is arguing that there is enough water, using the word drought casually (I don't think the writer is arguing whether technically a drought exists).
The basic point is that if people collected rainwater instead of channeling it into the ocean they could have more than enough water. Don't argue at the margins and ignore the main point.
The basic point is that if people collected rainwater instead of channeling it into the ocean they could have more than enough water. Don't argue at the margins and ignore the main point.