from The Century Dictionary.
- To drain by forming channels under ground.
- noun A drain or trench placed under ground.
from the GNU version of the Collaborative International Dictionary of English.
- noun An underground drain or trench with openings through which the water may percolate from the soil or ground above.
- transitive verb To drain by forming an underdrain or underdrains in.
from Wiktionary, Creative Commons Attribution/Share-Alike License.
- noun An
underground drainor trenchwith openingsthrough which the watermay percolatefrom the soilor ground above.
- verb transitive To
drainby forming an underdrain or underdrains in.
from Wiktionary, Creative Commons Attribution/Share-Alike License
So we captured all of that in what we call underdrain pipe.
If the depression holds water for more than four hours, dig 10 to 15 inches deeper and provide an underdrain of gravel.
As it approaches the project, it will be funneled into underdrain piping systems so that it runs underneath the road through those systems.
Shock drainage is achieved by a fast opening and closing of the valves or gates connected to the underdrain system of the filter.
The filtered water is then collected by an underdrain system and conveyed to the clear water tank.
Support layer and underdrain: gravel covered by perforated metal tray.
A very wide range of materials are used for underdrain construction.
If the land is wet on which we design making a lawn, we should first thoroughly underdrain it by laying tiles two rods apart, and two feet below the surface.
The best way undoubtedly is to underdrain the land, and then to distribute the sewage on the principle of intermittent downward filtration.
We must underdrain all the land we cultivate, that Nature has not already underdrained, and we shall cease complaints of the seasons.