Invention needed - for inground sprinklers!

Did you ever notice that inground sprinklers seem to be set on timers and work just fine.

Great!

However, if it has rained 3 inches the day before, don't you think that the inground sprinkler system shouldn't really be needed for maybe the next couple of days?...

Wouldn't it be great if someone could invent an inground sprinkler system that sensed when it needed to turn on? So much more efficient! So much less waste!

Quick, someone smarter than me get on this! And if you already invented it, let my neighbors know!

I am a Putnamaniac that knows smart enough people to come up with this much needed invention!