The many and varied agricultural magazines of the 19th century have articles on them. Also, when googling them, be aware that the Brits have called them mole drains.

From what I've seen, they're laid out at anywhere from 50 foot centers on up to 150 feet. Depth is sub-plowzone obviously.

Lyle Browning


On Oct 29, 2012, at 2:06 PM, Pentney, Sandra wrote:

> Has anyone done any research on agricultural drainage tiles? How much of an agricultural field is disturbed from the installation of drainage tile? Are/were the tiles installed at an average depth? Does anyone know of any reference material on this topic?
> 
> Thank you,
> Sandra.