Strictly speaking British people don't need a licence to own a TV, just to watch the BBC. Its a tax or subscription, not a licence except by an accident of nomenclature.
Several court cases have been won by "licence-dodgers" on the basis that their TV was for watching non-BBC products. I will be joining their ranks when I've adequately researched the subject.
Then why do you need a license for a lawn sprinker? What special interest does that serve?