She would be closed in the superior part, with cover removable with height of 10 cm, on the level of the ground. All water precipitated on the building or covered areas would be directed for two pipes of entrance of six counts each one, 20 centimeters below of the airly-tight closed cover. 20 centimeters below of these pipes, more two pipes also of six counts for draining or outflow of the exceeding water of the storage capacity, directly for the street or pluvial, if necessary net, being, therefore, 40 centimeters of internal space inaproveitveis. 3.2? How much to the capacity of temporary storage, we would have: – Ray of 50 centimeters of the cylinder multiplied for PI (3, 1416) multiplied by the useful height of 2,60 mts, would result in 2,04 cubical meters of restrained water at moment of peak of the precipitation in each house or construction. Obviously the sizing of the container will be defined in ratio with the constructed area or cemented common area of where, for pipes of captation or small lateral canals, it will be all volume of water directed for the two pipes of entrance. Important also it will be a statistical precipitation study in millimeters for specific region, what already it comes being mensurado. 3.3? For determination of the thickness of the plastic material to be used in the relation WEIGHT x VOLUME, is of if considering that one centimeter cubical of distilled water and the four degrees of temperature, condition well next to the situation of rain water, WEIGHS a GRAMO, also having been this the paradigm for the determination of the kilo. 3.4? Obviously, being this one arcabouo of a final project, always would be opened the modification possibility in order to diminish costs and to maximize resulted, always and when such modifications do not modify substantially the project as a whole.