олон зорилгоор нэгдмэлээр ашиглах усан сан
водохранилище комплексного назначения
Storage of water for later release for usual purposes such as municipal water supply, power, or irrigation in contrast with storage capacity used for flood control..
Source http://www.nws.noaa.gov/om/hod/SHManual/SHMan014_glossary.htm