How much effort would you be willing to invest in diverting a single raindrop? None of course. You wouldn't get yourself out of your chair to go divert a raindrop unless you thought you had a plan to divert lots of raindrops.

You could go outside with pots and pans to collect all the raindrops that you could, so that the water could be slowly released at a safer dryer time, but even those thousands or millions of raindrops wouldn't be worth the effort. If you had a bulldozer and found a strategically located ravine, you might actually bother to construct an earthen damn. That might actually make a difference.