North Central Illinois | KDD - 3/14/2024 19:56
Soilnotdirt: NO, the areas closest to the outlet does NOT drain first, if it is being overloaded by water coming from upstream.
Think about two tanks connected, one being higher than the other, with the outlet in lowest one. Open the outlet on the bottom tank, does it drain out before any water flows in from the tank above?? Of course not...the water draining out below just gets replaced by water from the higher tank, until the higher tank is empty. Only then does the lower tank start to empty out.
If you think the lower ground would drain first, what, exactly would hold back the water from above while the lower ground drains out????
That's like saying a tank empties from the bottom up!
That is a really good explanation.
I'll add that it is possible to build a drainage system where the lower ground drains first, but that requires significant tile capacity increases as the system gets closer to the ditch. Very rarely the care. It'd be akin to your two tank example, but a case where the bottom tank has a much bigger drain port than the top one. |
Adding tile
