Human beingstry to control water by examining many ways and methods. One of them has been building dam. Relying on their skills and facilities the people of every region have been building dams. One of these dams that was used in Saqez region to control the water of rivers in spring to autumn was the construction of a dam with a kind of wooden structure called Wlyr. The purpose of this study is how people make Wlyr and what the functions of Wlyrdam are. In fact, this researchwas a case study. Data were collected by an observation and interview with people in Seifabad village in region. The data showed that the people have been building the dam in every spring with foliage and grass and wood. The dam conducts the water through the creeks to irrigate potato and alfalfa and the like. This damwas destroyed by flood in every autumn. Now a day, this construct ruined and displaced by water pump and pollution of environment. Rethinking in imposed modernity, returning to ethics and altruism is one of the suggested ways of the research.