In order to make full use of water and sand resources, dam system which can control the flood water, retain sand and silt
up cropland, is a kind of engineering system with large, medium and small size of dams at the bottom of gully as a unit of small watershed.
Dam system construction is a check dam engineering system for building cropland which can distribute reasonably large, medium and small size of dams in the small watershed, whose main purpose is to control flood when it's flooding, irrigate crops when drought, silt up cropland, drain water in the flood season, control flood and get harvest. In order to sum up the experiences and morals of the dam
Construction, and to direct future construction of gully and dam system, the relevant problems of dam system construction are analyzed based on the comprehensive investigation on typical cases of dam system in the small watershed. In order to ensure dam system safety, and make the best benefit from the dam system, the reasonably determining dam system scale, construct dams density, time and order, and proportion of large, medium and small check dams for building cropland should be considered.