босоо шүүрүүл
вертикальная дрена
A drain constructed at the upper end of the area to be drained, to intercept surface or ground water flowing toward the protected area from higher ground, and carry it away from the area. Also called an Intercepting Drain.
Source http://www.nws.noaa.gov/om/hod/SHManual/SHMan014_glossary.htm