Drainage refers to a slot drainage system
https://vodaland.ca/collections/slot-drains for diverting excess moisture that accumulates during precipitation from a residential building. In most cases, it consists of a system of pipes through which water resources are diverted outside the garden plot or in a specially arranged place for this purpose. Among homeowners there is a common misconception that for the protection of a country house is quite enough to qualitatively concrete footing, and drainage is a waste of time and money. But experts strongly recommend to equip the system, the diversion of precipitation, which will protect the building from excess rainwater.