Stormwater management system with water storage and vegetation

Abstract

“Stormwater management system with water storage and vegetation device” The system (1) comprises on the surface a multi-layer complex (2) on a soil (3) and a water storage and vegetation device (1) with a lower part in the soil (3) and an upper part in the open air, the complex (2) comprises from top to bottom a surface coating (20, 24) and at least one porous layer (21), the device (1) comprising a reservoir (10) and a vegetable part comprising a substrate (11) separated from each other by a separator (12), the reservoir (10) having at its upper part a collection inlet (15) to the surface water reservoir runoff (7) on the surface coating (20, 24), the system (1) comprising fluidic communication means (4) between the reservoir (10) and water that may be located under the surface coating (20, 24) and in particular in said at least one porous layer (21),the fluidic communication means allowing the passage of liquids and preventing the passage of solids, and in which system the permeability of the soil (3) to water is less than the permeability of said at least one porous layer (21). Figure 1,

Description

Description Title of the invention: Stormwater management system water storage and vegetation system technical field

[0001] — The present invention relates generally to the field of civil engineering. It relates, more specifically, to a stormwater management system in multi-layered complex, including a pavement, and water storage and Greening. It is applicable to the construction of roads and similar structures. Technological background

[0002] = Stormwater management structures with water storage devices are known and vegetation for roadways, such as the one revealed in the documents CN208748468U or CN113006252A or CN1851162A or CN213142689U.

[0003] The present invention proposes a distinct solution that is optimized by means of the socket taking into account the hydrological properties of the soil on which the system is implemented stormwater management and which also allows for the optimization of water management rainwater by allowing its infiltration and retention in the multi-layered complex. Description of the invention

[0004] — According to the invention, a stormwater management system is proposed, comprising on the surface a multi-layered complex arranged on a floor and a storage device water and vegetation storage system comprising a lower part set in the ground and an upper part set in sealed to the open air, the multilayer complex comprising from top to bottom a re- surface garment and at least one porous layer, the lower part of the device water storage and vegetation being lower than the lowest point of the a multi-layered complex, the water storage and revegetation system comprising a prefabricated structure made up of walls and including a storage area water forming a reservoir and a vegetable area comprising a substrate, a face with the upper part of the substrate exposed to the air, the vegetated part the talizable being separated from the reservoir by a separator allowing water to pass through and retaining in the vegetable part of the substrate, so that plants can be installed in the substrate are moistened by the water that can be stored in the reservoir, the reservoir of the water storage and vegetation system comprising at its upper part a surface water collection inlet intended to collect water into the reservoir rain running off the surface coating of the multi-layered complex, the reservoir of water storage and vegetation system comprising at its lower part a fundamentally, the system includes fluidic communication means between the reservoir of the water storage and vegetation system and of the waters which may be found under the surface coating and in particular in said at least one porous layer, the means of fluid communication allowing the passage of liquids and preventing the passage of solids, the means of fluid communication opening into the reservoir at a determined height above the bottom of the reservoir by passing through the wall of the reservoir, and in which system the permeability of the soil to water is less than the permeability of said at least one porous layer. Other non-limiting and advantageous features of the system according to the invention, taken individually or in all technically possible combinations, are as follows: - depending on the embodiments, the maximum height of water stored in the tank may be above the determined height at which the fluid communication means open into the tank, or this maximum height of water stored in the tank may be just below or slightly below the determined height at which the fluid communication means open into the tank. This can be achieved by implementing or not implementing an overflow outlet intended to evacuate excess water from the tank, and depending on the height of this overflow outlet relative to the height at which the fluid communication means open into the tank. - Fluidic communication methods allow the passage of liquids and prevent the passage of macroscopic solid materials. - Fluidic communication systems include at least one permeable filtering membrane to prevent the passage of macroscopic solid matter, - the multilayer complex is adjacent to the water storage and vegetation system, - the multilayer complex is in contact with the water storage and vegetation system, - in the system, a channel is arranged along the contact zone between the multilayer complex and the water storage and vegetation device, - in the system, a channel is arranged perpendicular to the contact zone between the multilayer complex and the water storage and vegetation device, - The surface water collection inlet is designed to directly receive rainwater running off the surface coating of the multi-layered complex, - the surface water collection inlet is arranged to receive, via a gutter, rainwater running off the surface coating of the multi-layer complex, - the multi-layered complex is a pavement, - The multi-layer complex is a roadway for motor vehicle and heavy goods traffic. heavy, - the multi-layered complex is a roadway for light vehicle traffic, particularly vehicles with two wheels or less. - the multi-layered complex is a pedestrian roadway, - the multi-layered complex is a roadway for light vehicles, - the multi-layered complex is a pathway for soft mobility, including a cycle path, a sidewalk, a pedestrian walkway, - a geosynthetic layer separates said at least one porous layer and the soil, - the lower part of the water storage and vegetation system reservoir is positioned lower than the lowest point of the geosynthetic layer separating said at least one porous layer and the soil, - The geosynthetic layer allows liquids, particularly water, to pass through. - The geosynthetic layer is liquid-proof. - the geosynthetic layer is a geotextile, - The substrate is separated from the separator by a geosynthetic layer that allows liquids, particularly water, to pass through, while stopping solid matter. - the fluid communication means include at least one through-hole in the tank wall allowing fluid communication between the tank and said at least one porous layer and / or a drainage zone under or within said at least one porous layer, - said at least one through-hole in the tank wall has an opening suitable for the passage of a pipe for indirect passage of water / liquid between the tank and said at least one porous layer and / or a drainage zone under or within said at least one porous layer, - the fluid communication means include at least one orifice passing through the tank wall and at least one element from the following: a drainage zone in the lower part of the multilayer complex, a perforated drainage pipe, a permeable filtering membrane, - Fluidic communication methods implement indirect fluidic communication via a pipe, in particular a perforated drainage pipe, - the fluidic communication means include, around the perforated drainage pipe, a sock made of a permeable filtering membrane in order to prevent the passage of macroscopic solid matter into said pipe, - the pipe is a perforated drainage pipe, - the perforated drainage pipe has at least one non-perforated section, - The perforated drainage pipe is used in combination with a permeable filter membrane to prevent the passage of solid elements into said pipe. Perforated drainage - the perforated drainage pipe is placed in said at least one porous layer, - the perforated drainage pipe is placed in the drainage area, - the geosynthetic layer separating said layer from at least one porous layer and the soil passing under the drainage zone, - said at least one porous layer includes the drainage zone, the drainage zone being in the lower part of said at least one porous layer, - the perforated drainage pipe and / or the drainage zone is / are in a trench made in the ground forming a low zone below the general plane of the multi-layer complex, - the perforated drainage pipe and / or the drainage zone is / are in a trench made in the ground forming a low zone of the multilayer complex, below the general plane of the multilayer complex, - the fluidic communication means comprise a perforated drainage pipe extending into said at least one porous layer, the perforated drainage pipe opening into the reservoir, - the fluidic communication means include a perforated drainage pipe extending into a drainage zone, the perforated drainage pipe opening into the reservoir. - the fluidic communication means comprise a perforated drainage pipe extending into a drainage zone belonging to said at least one porous layer, the perforated drainage pipe opening into the reservoir, - said at least one porous layer and / or the drainage zone includes a granular drainage structure, - said at least one porous layer comprises a bed of sand, - the drainage zone comprises a granular drainage structure, - The drainage zone includes a bed of sand, - the fluid communication means include at least one drainage zone in the lower part of the multilayer complex and at least one perforated drainage pipe disposed in the drainage zone and opening into the tank, the tank wall having at least one through-hole adapted for the passage of the perforated drainage pipe(s), - the passage of solid matter into the perforated drainage pipe is further prevented by a permeable filtering membrane, - the fluidic communication means include a drainage zone in the lower part of the multilayer complex and a permeable filtering membrane, the tank wall having a set of orifices passing through opposite the drainage zone, the permeable filtering membrane separating the tank wall from the drainage zone, - The permeable filtering membrane is of the same type as the anti-contamination layer that allows liquids to pass through. - The permeable filtering membrane and the anti-contamination layer that allows liquids to pass through are one and the same film. - the soil has a permeability coefficient between 105 and 107 cm / s and the surface coating of the multilayer complex is a permeable coating and in which the system is configured to ensure drainage of water from said at least one porous layer towards the reservoir, the fluidic communication means being arranged to allow gravity flow of at least part of the water having passed through the surface coating towards the reservoir, - The fluid communication system includes a non-return device preventing water from the reservoir from passing into the multilayer complex. -the non-return device is chosen from one or more of the following devices: a valve, an overflow outlet of the tank intended to evacuate excess water from the tank and which is at a height less than or equal to the determined height at which the fluid communication means open into the tank, an inclined perforated drainage pipe whose lowest point is on the side of the tank, an inclined drainage zone whose lowest point is on the tank side, - the non-return device is the implementation of an overflow outlet of the tank intended to evacuate excess water from the tank and which is at a height less than or equal to the height of the water level drained in said at least one porous layer and possibly in the draining zone by means of fluidic communication, - the surface coating of the multilayer complex is impermeable and the system is configured to ensure water retention in said at least one porous layer, the fluidic communication means being arranged to allow gravity flow of excess water from the reservoir to said at least one porous layer, the excess water from the reservoir being the water whose level is higher than the determined height at which the fluidic communication means open into the reservoir, - The fluidic communication system includes a perforated drainage pipe inclined with a high point on the side of the tank. - the fluidic communication system includes a drainage zone located in the lower part of the multilayer complex and inclined with a high point on the reservoir side. - the tank includes an overflow outlet designed to evacuate excess water from the tank and located at a height greater than the determined height at which the fluid communication means open into the tank, - The tank does not have an overflow outlet. - The excess water from the tank is discharged through the overflow outlet into a reservoir of another water storage and vegetation system, - The stormwater management system includes a set of water storage and vegetation devices, the reservoirs of which have overflow outlets, and the overflow outlets are interconnected. - The overflow outlet is designed to evacuate excess water to an outlet chosen from: a stormwater management network, the ground, the natural environment, a retention basin, another water storage and vegetation system, or a water storage method. - The stormwater management system comprises a set of water storage and vegetation devices placed side-by-side along one lateral side of the multi-layered complex, - the stormwater management system comprises two sets of water storage and vegetation devices arranged laterally, on both lateral sides of the multilayer complex, on either side of said multilayer complex, the water storage and vegetation devices of one set being joined together along the lateral side of the multilayer complex, - in the case of two sets of water storage and vegetation devices arranged on either side of the multilayer complex, in each set the reservoirs have overflow outlets and the overflow outlets are connected to each other, and the two sets are fluidly connected to each other by at least one fluidic link, - the fluid connection opens into the level tanks with overflow outlets - the fluid connection opens into the reservoirs lower than the overflow outlets. Brief description of the drawings [Fig.1] represents a first schematic example of a stormwater management system of the invention, in which the surface coating of the multi-layer complex is permeable and in which water is provided to infiltrate the soil under the multi-layer complex, the water stored in the reservoir of the water storage and vegetation device not being able under normal conditions to pass into the multi-layer complex, [Fig.2] represents a second schematic example of a stormwater management system of the invention, in which the surface coating of the multi-layer complex is impermeable and in which water is provided to infiltrate the soil under the multi-layer complex, the water stored in the reservoir of the water storage and vegetation device being able to pass into the multi-layer complex, [Fig.3] represents a third schematic example of a stormwater management system of the invention, in which the surface coating of the multi-layer complex is permeable and in which no infiltration of water into the soil under the multi-layer complex is provided, a sealing membrane being disposed under the multi-layer complex. Detailed description of an example of implementation The description that follows, with regard to the attached drawings, given by way of non-limiting examples, will make it clear what the invention consists of and how it can be carried out. In principle, the system of the invention can include numerous functional variants due to the possible combinations of at least one of the following different characteristics: - surface coating 20, 24 of the multilayer complex 2 which can be permeable (20) or impermeable (24), - the water stored in the reservoir 10 of the water storage and vegetation device 1 may or may not pass back to said at least one porous layer 21 of the multilayer complex 2, - said at least one porous layer 21 of the multilayer complex 2 being separated from the ground by a waterproofing membrane 25 or by a geosynthetic layer 22 that is not waterproof or by no membrane, - the structure of said at least one porous layer 21 of the multilayer complex 2 which may be simple / uniform or complex / multilayer and which is advantageously, in some embodiments, a (single) granular drainage layer forming overall a drainage zone or, in other embodiments, a multilayer complex 2 comprising in its lower part, under said at least one porous layer 21, a specific drainage zone 23 which may comprise materials possibly different from said at least one porous layer 21. Moreover, if the basic aim is to manage rainwater, it is understood that once this rainwater has passed through said at least one porous layer 21 of the multilayer complex 2, either directly by passing through the surface coating 20 or indirectly after passing through the reservoir 10 of the water storage and vegetation device 1 according to the embodiments. In [Fig. 1], the surface coating 20 of the multilayer complex 2 is permeable. Under these conditions, a portion 8 of the rainwater falling 6 towards the ground can pass through the surface coating 20 and thus enter at least one porous layer 21, and another portion 7 of the rainwater falling 6 towards the ground can run off the surface coating 20 and pass, through the collection inlet 15 of the water storage and vegetation device 1, into the reservoir 10 of the water storage and vegetation device. Vegetation 1. Reference 7 therefore corresponds to runoff rainwater. Reference 8 therefore corresponds to rainwater infiltrating the surface coating 20 to pass through at least one porous layer 21. Part of the water that has passed through, or was present in, at least one porous layer 21 is drained towards the reservoir 10, and another part 9 passes into the soil 3. Reference 9 therefore corresponds to rainwater infiltrating into the soil 3. It is understood that these phenomena depend on the groundwater level, and for this description, it is assumed that this level is sufficiently low in the soil for this other part 9 of the water to pass into the soil 3. It is also understood that this is possible because the soil has a certain permeability, reduced in this case, and that there is no waterproof membrane between the multilayer complex 2 and the soil 3. Still on [Fig.1], the water storage and vegetation device 1 includes a part that can be vegetated and includes a substrate 11 in and on which plants 13 can grow. The substrate 11 and the water from the reservoir 10 are separated by a separator 12 allowing the passage of water in order to hydrate the plants 13 but preventing the passage of the substrate 11 towards the reservoir, a permeable filtering membrane possibly being used for this purpose, at the bottom of the substrate against the separator. Still in [Fig. 1], the at least one porous layer 21 is separated from the soil 3 by a permeable geosynthetic filter membrane 22. The permeable geosynthetic filter membrane 22 prevents the passage of macroscopic solids but allows water to pass between the at least one porous layer 21 and the soil 3. The at least one porous layer 21 includes a drainage zone 23 in the lower part of the multilayer complex. This drainage zone 23 forms a lower zone of the multilayer complex, extending into the soil, and may or may not be composed of materials identical to those of the rest of the at least one porous layer 21. A perforated drainage pipe 4 is placed in the drainage zone 23. It may be advantageous to place the perforated drainage pipe 4 in a "sock" of the permeable filter membrane in order to prevent the passage of macroscopic solids towards the perforated drainage pipe 4. This drainage zone 23, located in the lower part of the multilayer complex, allows for the collection of water present in at least one porous layer 21 and its transfer, via the perforated drainage pipe 4, to the reservoir 10. Preferably, the reservoir wall has a through-hole adapted for the passage of the perforated drainage pipe 4. The perforated drainage pipe 4 has, at its end on the reservoir 10 side, a non-return valve 5 preventing the passage or return of water from the reservoir 10 to the multilayer complex 2; water can only be drained from the multilayer complex to the reservoir. It can be noted that in [Fig.1], the perforated drainage pipe 4 is inclined with a low point on the reservoir side, which is part of a non-return means preventing or limiting the passage of water from the reservoir 10 to the multilayer complex 2. It is understood that the perforated drainage pipe 4 can extend in multiple ways within at least one porous layer 21 and / or the drainage zone 23, under the surface covering 20 of the multilayer complex 2, and may even include branches whose final common trunk opens into the reservoir and / or form a mesh or drainage network therein. The same applies to the drainage zone 23, whether or not it is associated with the perforated drainage pipe 4; this drainage zone can also extend in multiple ways. As can be seen in [Fig. 1] and [Fig. 2], there is an overflow outlet 14 of the tank designed to discharge excess water from the tank. This outlet is located at a height greater than the predetermined height at which the fluid communication means, which extend between the multilayer complex 2 and the tank 10, discharge into the tank. In this particular case, the overflow outlet 14 is at a height greater than the predetermined height of the tank-side end of the perforated drainage pipe 4. In alternative configurations, the overflow outlet 14 of the tank may be at the same height as, or lower than, the predetermined height of the tank-side end of the perforated drainage pipe 4.This last possibility is advantageous for guaranteeing the direction of water flow from the multilayer complex 2 to the tank 10 even in the absence of a non-return valve, as the water in the tank cannot normally rise above the overflow level allowing any excess water to be evacuated. In [Fig. 2], the surface coating 24 of the multilayer complex 2 is impermeable. Under these conditions, rainwater falling 6 towards the surface runs 7 over the surface coating 20 and passes through the collection inlet 15 of the water storage and vegetation device 1 into the reservoir 10 of the water storage and vegetation device 1. Therefore, no rainwater falling 6 towards the ground can pass through the surface coating 24. Beneath the surface coating 24 of the multilayer complex 2, at least one porous layer 21 is placed, resting on the soil 3 via a permeable filter membrane 22, which is, for example, a geotextile. A perforated drainage pipe 4 is extended between the reservoir 10 of the water storage and vegetation unit 1 and a drainage zone 23 arranged in the lower part of the multilayer complex 2. In this case, the perforated drainage pipe 4 is inclined so that its end on the reservoir side is a high point, allowing water in the reservoir to flow from the reservoir 10 to the multilayer complex 2 and the soil 3. Since the soil has a certain permeability, reduced in this case, water can infiltrate 9 into the soil 3. No check valve is implemented in this embodiment of [Fig.2]. As in [Fig. 1], the overflow outlet 14 in [Fig. 2] is at a height greater than the determined height of the tank-side end of the perforated drain pipe 4. This configuration is advantageous for allowing water to flow from the tank 10 to the multilayer system 2. In less advantageous variants, which do not facilitate water flow from the tank to the multilayer system, the tank overflow outlet 14 may be at the same height as, or lower than, the determined height of the tank-side end of the perforated drain pipe 4. In [Fig.3], the surface coating 20 of the multilayer complex 2 is permeable. Under these conditions, a portion 8 of the rainwater falling 6 towards the surface can pass through the surface covering 20 and thus partially enter said at least one porous layer 21, and another portion 7 of the rainwater falling 6 towards the surface can run off the surface covering 20 and partially enter the collection inlet 15 of the water storage and vegetation device 1 into the reservoir 10 of the water storage and vegetation device 1. A waterproof membrane 25 is placed between the multilayer complex 2 and the soil 3, and no water can pass between the multilayer complex 2 and the soil 3. The rainwater that has infiltrated 8 into the surface covering 20 to pass through said at least one porous layer 21 can be collected in the drainage zone 23 to pass into the reservoir 10. It can be noted that because the surface coating 20 of the multilayer complex 2 is permeable, water can evaporate through the surface coating 20, which can contribute to a cooling effect. As shown in [Fig. 2], a perforated drainage pipe 4 extends between the reservoir 10 of the water storage and vegetation device and a drainage zone 23 in the lower part of the multilayer complex 2. Figures 1 to 3, which are two-dimensional, show a water storage and vegetation system 1 on the left side of a multilayer complex 2. However, it is clear that it is also possible to implement a water storage and vegetation system 1 on the right side of the multilayer complex 2 to create a substantially symmetrical system. In this latter case, direct water communication via a pipe can be provided between the reservoirs of the water storage and vegetation systems on both lateral sides of the multilayer complex to equalize their water storage levels. Furthermore, if overflow outlets are present in the reservoirs of the water storage and vegetation systems, these outlets can be connected by one or more pipes between the water storage and vegetation systems on both lateral sides of the multilayer complex. The multi-layered complex can, for example, be a traffic pavement. The tomobile and the water storage and vegetation devices separate this roadway from other types of urban infrastructure, including sidewalks, tram tracks, cycle paths, pedestrian walkways, etc. It is understood that this two-dimensional extension can also be applied to the three dimensions of space, in a direction perpendicular to the plane of representation shown in Figures 1 to 3. This means that water storage and vegetation systems can be placed side by side along one or both lateral sides of the multilayer complex. If overflow outlets 14 are present in the reservoirs, these outlets are connected to each other between the adjacent water storage and vegetation systems. This alignment can also be achieved along one or both lateral sides of the multilayer complex, sometimes using non-vegetated water storage systems to free up space for certain uses, such as pedestrian and / or disabled access, or building entrances. The system of the invention is particularly interesting when the permeability of the soil to water is less than the permeability of said at least one porous layer. In particular, when the soil has a permeability coefficient between 10⁷ and 10⁻⁷ cm / s, it is advantageous to implement a permeable surface coating for the multilayer system and a permeable contaminant barrier or permeable filter membrane between the multilayer system and the soil. Conversely, if the soil has a very high permeability coefficient, it may be advantageous to implement an impermeable surface coating for the multilayer system and / or an impermeable contaminant barrier between the multilayer system and the soil, in order to collect rainwater in the reservoir before the excess infiltrates the soil. It is understood that it is possible to combine these various possibilities according to the needs and a local context and for example to implement an impermeable surface coating and a permeable anti-contamination layer or permeable filtering membrane between the multi-layer complex and the ground.

Claims

Demands

1. Stormwater management system, comprising on the surface a multilayer complex (2) disposed on a floor (3) and a device of water storage and revegetation (1), the water storage and of vegetation (1) comprising a lower part arranged in the ground (3) and an upper part opening to the open air, the multilayer complex (2) comprising from top to bottom a coating of surface (20, 24) and at least one porous layer (21), the lower part of the water storage and vegetation system (1) being lower than the lowest point of the multilayer complex (2), the water storage and revegetation system (1) comprising a prefabricated structure consisting of walls and including a part of water storage forming a reservoir (10) and a vegetated area comprising a substrate (11), an upper face of the substrate of the part being suitable for planting in the open air the vegetable part being separated from the reservoir by a separator (12) allowing water to pass through and retaining the substrate in the vegetable area (11), so that plants installed in the substrate are moistened by the water that can be stored in the reservoir (10), the reservoir (10) of the water storage and vegetation system (1) comprising at its upper part a water collection inlet (15) surface intended to collect rainwater in the reservoir (10) flowing (7) on the surface coating (20, 24) of the mul- complex ticlayer (2), the reservoir (10) of the water storage and vegetation system (1) comprising a base at its lower part, the system comprising fluidic communication means (4) between the reservoir (10) of the water and vegetation storage device lisation (1) and waters that may be found under the surface coating (20, 24) and in particular in said at least one porous layer (21), the fluidic communication means allowing the passage of liquids and preventing the passage of solid matter, the means of communication fluidic deniation opening into the reservoir at a height de- finished above the bottom of the tank by passing through the wall of the reservoir, in which system the permeability of the soil (3) to water is less than the permeability of said at least one porous layer (21).

2. System according to claim 1, wherein a geo syn- layer thetic(22) separates said at least one porous layer (21) and the soil (3).

3. System according to claim 1 or claim 2, wherein the Fluidic communication means include at least one orifice passing through the tank wall and at least one element among the following: a drainage zone (23) in the lower part of the mul- complex ticouche, a perforated drainage pipe, a permeable membrane filtering.

4. System according to claim 3, wherein the means of communication Fluidic nication includes at least one drainage zone (23) in lower part of the multilayer complex and at least one drainage pipe (4) perforated, arranged in the drainage zone (23) and opening into the reservoir, the wall of the reservoir having at least one opening a through-hole adapted for the passage of the perforated drainage pipe(s) (4).

5. A system according to claim 4, wherein the passage of materials solids in the perforated drainage pipe {4} is further prevented by a permeable filtering membrane.

6. System according to claim 3, wherein the means of communication Fluidic nication includes a drainage zone (23) in the lower part of the multilayer complex and a permeable filtering membrane, the wall of the reservoir comprising a set of through orifices opposite the drainage zone (23), the permeable filtering membrane separating the wall of the reservoir in the drainage zone (23).

7. A system according to any one of claims 1 to 6, wherein the soil (3) has a permeability coefficient between 10⁷ and 10⁷ cm / s and the surface coating of the multilayer complex is a coating permeable (20) and in which the system is configured to ensure a drainage of water from said at least one porous layer (21) towards the reservoir (10), the fluidic communication means being arranged in order to allow gravity flow of at least part of water having passed through the surface coating (20) towards the reservoir (10).

8. System according to claim 7, wherein the means of communication Fluidic systems include a non-return device preventing the water from the reservoir (10) to pass into the multilayer complex (2).

9. System according to claim 8, wherein the non-return device is chosen from one or more of the following devices: a flap, a tank overflow outlet designed to drain excess water from reservoir and which is at a height less than or equal to the height of the- completed, to which the means of fluidic communication lead in the reservoir (10), a perforated inclined drainage pipe (4) whose the lowest point is on the side of the reservoir, a sloping drainage zone (23) of which the lowest point is on the tank side (10).

10. A system according to any one of claims 1 to 6, wherein the The surface coating of the multilayer complex is waterproof (24) and the system is configured to ensure water retention in said at minus a porous layer {21), the means of fluidic communication being arranged to allow a gravity flow of excess water dental reservoir towards said at least one porous layer (21), the water excess water from the reservoir (10) being the water whose level is higher than the determined height at which the means of fluidic communication flow into the reservoir.

11. | System according to claim 10, wherein the means of communication Fluidic nication include a perforated inclined drainage pipe (4) with a high point on the side of the tank (10).

12. System according to claim 10, wherein the means of communication Fluidic nication includes a drainage zone (23) located partly base of the multilayer complex (2) and inclined with a high point side of the tank.

13. System according to any one of claims 10 to 12, wherein the reservoir (10) includes an overflow outlet for discharging excess of water from the reservoir and located at a height greater than the height of- completed, to which the means of fluidic communication lead in the tank.