No expert here either, but as I understand it, at least some of the reason for tiling is because of people wanting to put up houses right next to farm land. Perhaps a bit is to try to improve the land for farming as well?

Anyways, I am always skeptical about putting mandates on any consumer driven industry as that very often translates into increased cost to the consumer. Have you seen the prices of groceries lately?! With four kids and a six person household, I can tell you that I feel every little increase multiplied by six.

That said, I understand the problem, but how to reduce run-off without a great cost is very perplexing.