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C IL | I would answer yes, yes, and that's probably the purpose of your district, depending on your bylaws.
1. Pattern tiling the upper areas will definitely remove some 'pressure' from overland flow during a rainfall event. Like, maybe soaking up the first inch or two of water if the tiled zone has had time to remove all of the free water. But probably not much more than that. The famed 3/8" drainage coefficient is a standard that basically says your tile can remove water as fast as a steady rainfall of 3/8" per day. So the 3-4' of empty soil can soak up an inch or 2, but the tile can't remove water very fast in comparison to a toad-strangler dumping an inch or two per hour. Also, the surface of the soil will seal off under those conditions, slowing the infiltration rate.
So, you win and lose, depending on scenario. 3" over a day. Pattern tiling big winner.
8" over a day. Everyone loses. Pattern tile just exacerbates the flooding downstream, because it gets the water off of your farm faster but helps flood that guy.
2. Sizing mains is a science. You can calculate the recommended diameter of main based on the ground slope and receiving area.
An undersized main will still pull out a lot of water, depending on the ratio of how small it is compared to desired design flow. If you have grade breaks in the tile main, you can figure out if an undersized main is at risk of a blowout or will just drain more slowly. A fully sized tile main only runs full for a short time after a storm before flow starts to decline. It's a marginal return economics problem to figure out how much main to add to get up to tolerable amount.
3. Clearly, the tiled landowner receives most of the benefit with neighboring landowners receiving much less. Of course, the shoe was on the other foot when the downstream landowner wanted the ditch dug out so his field didn't flood so much or wanted help paying for the big main through his field to solve all the clay breaks. (hypothetical examples).
Good luck with your project. | |
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Pattern Tiling and Drainage District Tile
