GB2613921A - Rainwater flow braking system - Google Patents

Abstract

The flow moderation system 1 comprises at least one concrete casting 2, which may be in the form of a channel, having a lower part which has at least one opening 220. At least one removable porous concrete component 3 covers the opening to form two longitudinal channels in the internal volume of the casting. The porous component is in the form of a block which makes up between 20-50% of the internal volume of the casting. The system acts to slow the flow of rainwater runoff from roads and pavements and can be placed in trenches, ditches or excavations. The system provides a water collection capacity whilst providing a controlled discharge of water through the porous block, out the openings and into the ground. The casting may be provided with a cover plate and the ends of the casting may include connection pieces for connection to further systems or a filtration or decantation module. An adjustable weir may be provided.

Description

System for moderating rainwater flow The invention relates to a flow moderation system for at least collecting rainwater and at least partially slowing down the water flow, the said system being suitable for construction in a ditch or stream or river or excavation.

Rainwater collection systems are known from the documents EP-A-1234913, FR-A-2713254 and KR-A-200403213.

Construction of weirs in a ditch or stream to slow down the water flow in the said ditch or stream is already known.

Drainage systems enabling water contained in the ground to be drained are likewise known.

The invention relates to a system which can be constructed in a ditch, stream, river, trench, underground passage or excavation, and which has multiple functions and so is advantageous in dealing with many problems involving water Due to climate change, there are spells of extreme drought and spells of extreme rainfall (storm rainfall) that can have disastrous effects on nature, human beings and agriculture. The invention at least partially remedies these problems with flow moderation systems that are quick to instal and can serve as basic support elements for the construction of roads, pavements, cycle tracks, etc. All components of the flow moderation systems can be produced at one production unit. Quality checks can be carried out at the production unit before the components are transported on ordinary lorries to the ditch, stream, river, trench, underground passage or excavation.

The subject-matter of the invention is a rainwater flow moderation system for at least receiving rainwater and at least partially slowing down the flow of rainwater, the said flow moderation system being suitable for placing in a ditch, stream, river, trench, underground passage or excavation in which at least the floor and two opposite sides of the ditch, stream, river, trench, underground passage or excavation are formed by the terrain, wherein the rainwater flow moderation system comprises at least one concrete casting which is composed of at least: -two opposite concrete side parts, preferably consisting substantially of non-porous concrete, capable of at least partially reinforcing the sides formed by the terrain, the said concrete side parts having a minimum height of 50 cm, and -a concrete lower part, preferably a lower part consisting of substantially non-porous concrete, extending between, and interconnecting, the two opposite concrete side parts, the said concrete lower part having an upper face at least partly located substantially in a horizontal plane, wherein the said upper face defines an upper area between the two concrete opposite side parts, this upper area having a minimum width of 50 cm, wherein an internal volume is defined within the flow moderation system above the upper face of the concrete lower part and between the concrete opposite side parts.

The flow moderation system according to the invention possesses the following features: -the concrete lower part is provided with one or more openings with an open area of more than 10 cm2, the total area of the opening or openings in the concrete lower part being equal to or more than 50%, preferably between 55% and 75%, of the upper area of the upper face.

-the flow moderation system is provided with one or more components made of porous concrete which are removably mounted on the upper face of the concrete lower part so as to at least partly cover one or more openings in the concrete lower part -the one or more porous concrete components are in the form of a porous elongated protruding block which rests on the concrete lower part and extends between two longitudinal ends, this porous elongated protruding block having between its longitudinal ends an upper face and two at least partially porous lateral faces, wherein the porous elongated protruding block is made with a minimum width of 30 cm along the concrete lower part and with a minimum height of 20 cm to form a first channel and a second channel within the flow moderation system along the concrete lower part, the first channel facing towards a first concrete side part of the concrete casting and the second channel facing towards the second concrete side part of the concrete casting, the porous elongated protruding block located within the internal volume of the flow moderation system defining a protruding volume between 20 and 50 cro of the part of the internal volume located between the substantially vertical planes in which the two longitudinal ends of the porous elongated protruding block extend.

-the said first and second channels have a minimum width of 10 cm and a minimum depth of 20 cm, the said first and second channels defining a free volume (VK1 + VK2) of between 30 and 60 % of the protruding volume of the porous elongated protruding block.

-the porous elongated protruding block is made of hardened porous draining concrete with an open pore volume of 8 to 12 % The porous elongated protruding block is preferably made of hardened porous water-draining concrete prepared by curing a mixture of at least cement, aggregates with a particle size of 6 mm to 14 mm and water to form an open pore volume of 8 to 12 % in the hardened porous draining concrete, wherein the hardened porous draining concrete has a perviousness to water (along its lower face resting on the upper face of the lower concrete part of the concrete casting) of from 0.05 litre/m2/s to 5 litres/m2/s inclusive, preferably from 0.1 litre/m2/s to 3 litres/m2/s, and [most] preferably between 0.5 litre/m2/s and 1.5 litre/m2/s, where the said perviousness to water of the porous elongated protruding block is measured by placing the porous elongated protruding block on the bottom of a receptacle with a bottom opening (with an open area equal to 50% of the lower area of the porous elongated protruding block), filling the receptacle with water to maintain a water level in the receptacle that is twice the mean height of the porous elongated protruding block, and then determining the (maximum stable) quantity of water that runs off through the part of the lower face of the porous concrete protruding block during a period of 30 seconds into a receiving chamber located undemeath the bottom opening of the receptacle (after a period of immersion of the porous concrete block to allow the said body [sic] to be filled, e.g. an immersion period of 15 to 30 minutes). The bottom opening of the receptacle is covered by the central part of the lower face of the porous elongated protruding block.

Thus the flow moderation system according to the invention possesses the following advantages: -ensuring a sufficient controlled drainage of water from the flow moderation system into the layer of ground under the concrete lower part of the moderation system; -ensuring a sufficient controlled flow of ground water into the flow moderation system. Ground water can therefore be drained.

-positioning the flow moderation system in a stream, ditch, excavation or river is simple and straightforward.

-a large water collection capacity of the porous elongated protruding block and hence a large buffering capacity (a large quantity of water can be released slowly during a dry spell, or stored during a rainy spell).

-a controlled delayed discharge of the water collected by the porous elongated protruding block to the side channels of the flow moderation system and/or to the underlying ground (controlled percolation).

-the side channels are designed to handle a high velocity of water, particularly in case of heavy rainfall or storms, which means that these channels and also the sides of the porous [elongated protruding block] can be cleaned by a rapid water current.

-high stability of the system once installed in the ground, as the water (ground water or water entering the system) is able to run through the lower part in the longitudinal direction of the system. The zone affected by the percolated water or drained water is substantially horizontal.

In advantageous embodiments, the flow moderation system according to the invention possesses one or more of the following additional features: -the concrete casting (preferably at least both of the concrete side parts) and the porous component are provided with attachment points that can be attached to lifting gear or a crane to place the concrete casting in an excavation or ditch or stream and to place the porous component on the bottom of a concrete casting of the system according to the invention.

-the concrete side parts of the concrete casting are adapted to form a support for a cover plate or a cover plate [sic] suitable for the passage of vehicles (e.g. bicycles) and/or people, the said cover plate preferably being adapted at least for the passage of people and bicycles. The flow moderation system according to the invention may form a substructure for the construction of a road, footpath or cycle track above an existing ditch, stream, excavation or river.

-at least one concrete side part has an upper edge, the said upper edge being provided with a plurality of open notches, the said notches forming passages for water when the concrete casting is covered by the cover plate. These notches allow rainwater to run into the interior of the flow moderation system. The said notches are also suitable for inserting dogs of lifting gear, facilitating raising of the cover plate e.g. for maintenance and/or inspection purposes.

-the flow moderation system is provided with at least one removable partition wall with or without one or more openings and/or with or without one or more overflow openings, the said removable partition wall preferably resting on the upper face of the porous elongated protruding block. The partition wall may serve as an additional means of retarding the flow or as a dam (e.g. for temporary interruption of the flow), and/or as a means of forming a decantation zone. The partition wall preferably rests on the upper face of the protruding block. The partition wall may serve as an additional support for a cover plate forming part of a pedestrian or cycling zone. The openings may be provided with a filter element. The filter element is preferably adapted to retain particles deposited as sediment, as well as floating particles. The partition wall may also be provided with attachment points.

-the concrete casting defines an elongated channel with a length of 1 m to 5 m, the ends (entry end and exit end) of this elongated channel being open. Thus water can enter via the entry end and exit via the exit end. The elongated channel preferably has a substantially rectangular and/or trapezoidal cross-section. Preferably, the lower part defines a substantially rectangular upper face, while one or more openings are substantially rectangular elongated openings with a width of more than 30%, preferably more than 50%, of the width of the said substantially rectangular upper face.

-the concrete lower part has a substantially central axis, the concrete lower part being provided with two or three substantially rectangular elongated openings juxtaposed in the direction of the substantially central axis, with a transverse component extending between adjacent elongated openings. The transverse component may serve as a means of support for a transverse plate or weir plate -The elongated openings preferably [have] a length of at least 80 cm, said length preferably being less than 250 cm. Water passing through the porous protruding block is distributed to the underlying ground in the longitudinal direction of the flow moderation system, which is advantageous for the stability of the flow moderation system in the event of a change in ground water level.

-[if] the concrete casting has a length of less than 3 m, the upper face has a single substantially rectangular elongated opening, the length of the single substantially rectangular elongated opening being between 70 and 90 % of the length of the concrete lower part.

-the flow moderation system is provided with at least one porous elongated protruding block covering at least one substantially rectangular elongated opening, wherein preferably each substantially rectangular elongated opening is covered by a single porous elongated protruding block.

-the porous elongated protruding block is in the form of a beam with a cross-section that is substantially rectangular or trapezoidal, and preferably square, the beam advantageously being provided with attachment points at both ends.

-each opening in the lower part is covered by a single porous elongated protruding block.

-the flow moderation system is provided with a weir, preferably an adjustable weir. Using an adjustable weir is advantageous during maintenance work on at least one flow moderation system.

-the ends of the concrete casting are provided with means for one or more connecting pieces for connecting the flow moderation system to an adjacent flow moderation system or to a filtration or decantation module.

-the flow moderation system is provided with means forming a weir, preferably an adjustable weir -part of the flow moderation system is not provided with a porous concrete component, [the concrete lower part in this part of the flow moderation system combining] with a partition wall to define a decantation zone in the aforesaid flow moderation system, and/or with a filter element for removing particles deposited as sediment and hydrocarbons before the water can percolate through a porous concrete component.

-a combination of two or more of these features.

Another subject-matter of the invention is a complete flow moderation layout comprising a series of flow moderation systems according to the invention. The flow moderation systems may be placed side by side in a ditch, stream, river, trench or excavation, before being covered if required. The flow moderation systems according to the invention may be placed one after another with one or more interposed intermediate components, e.g. one or more intermediate components made of concrete or partly of concrete. The flow moderation layout may control the water flow over a length of 100 m or more, advantageously over a length of 1000 m or more, according to the number of flow moderation systems employed. Where the ditch, stream or river is unduly wide, moderation systems can be placed so as to form parallel flow channels.

The layout according to the invention preferably comprises one or more pairs of adjacent flow moderation systems wherein at least one porous concrete component at least partly covers the upper face of the concrete lower part of two adjacent flow moderation systems. This is advantageous for improving the stability of flow moderation systems which are arranged side by side.

In certain embodiments, the flow moderation layout according to the invention possesses one or more of the following features: -part of a flow moderation system is not provided with a porous concrete component, the concrete lower part in this [part of the] flow moderation system combining with a partition wall to define a decantation zone in the aforesaid flow moderation system, and/or with a filter element for removing particles deposited as sediment and hydrocarbons before the water can percolate through a porous concrete component of a flow moderation system according to the invention.

-the flow moderation layout is provided with a filter element or filtration module for removing particles deposited as sediment and hydrocarbons before the water can percolate via at least one flow moderation system according to the invention.

-the flow moderation layout comprises a decantation module locatable between a water inlet means and a water outlet means, wherein at least one of the means selected from the water inlet means and the water outlet means appertains to a flow moderation system according to the invention.

Advantageously, at least the means of discharging the water cooperate with at least one flow moderation system according to the invention, though preferably, both the water inlet means and the water discharge means each cooperate with at least one flow moderation system according to the invention. The decantation module is preferably also a filtration module.

-the decantation module is in the form of a chamber for receiving water from the water intake means or from the latter's water flow moderation system so that as soon as the level of water in the chamber is above an outlet level, water runs from the decantation module into the water discharge means or into the latter's flow moderation system, the said chamber having a bottom that is below the level of the upper face of the lower part of the water intake means or of the latter's flow moderation system, and below the level of the upper face of the lower part of the water discharge means or of the latter's flow moderation system, wherein the decantation chamber comprises an at least partly flexible filter container, pervious to water, removably installed in the decantation chamber.

-the at least partly flexible water-pervious filter container or reservoir has a bottom and at least one side wall with a free upper edge, wherein the side wall has an upper part along the free upper edge, and the upper part of the at least one side wall is more pervious to water than the bottom and than a lower part of the at least one side wall near the bottom.

-the flow moderation layout comprises a weir, preferably an adjustable weir, the said weir preferably forming part of a decantation module placed between two flow moderation systems and/or between a flow moderation system and a decantation module.

- the at least partly flexible water-pervious filter container or receptacle and the flow moderation system at the inlet are contrived so that the water coming from the flow moderation system at the inlet runs into the at least partly flexible water-pervious filter container or receptacle at least when the water level in the decantation chamber is below the level at the outlet of the decantation chamber.

- the porous elongated protruding blocks of one or more flow moderation systems are spaced apart from one another so as to define a free zone between adjacent porous elongated protruding blocks. This free zone is advantageous for the creation of a mixing zone for water flowing [through] the channels of a flow moderation system at a first rate of flow, and also for the creation of a water distribution zone for supplying water to the first and second channels of another flow moderation system at a second rate of flow different from the said first rate of flow.

* the flow moderation system is provided with a weir, preferably an adjustable weir, the said weir preferably forming part of a module placed between two flow moderation systems and/or alongside a decantation module of the flow moderation layout. The adjustable weir can be used to raise the water level in a decantation module. By opening the weir, a surge of water can be released into the channels of one or more flow moderation systems: this is advantageous for cleaning these channels.

* combination of one or more of these features.

Yet another subject-matter of the invention is the use of a flow moderation layout according to the invention to slow down the flow of rainwater, wherein the flow moderation layout has at least the following functions: -at least partially collecting and storing the water passing through the flow moderation layout in the porous protruding blocks of the flow moderation systems; -at least partially infiltrating the water collected/stored in the porous protruding blocks into the layer of ground under the concrete lower parts of the flow moderation systems; -in the event of an unduly high level of ground water, partially collecting the ground water in porous protruding blocks, with the possibility of storing the collected ground water in the porous protruding blocks and/or discharging it via the channels in a controlled manner; -delayed discharge of the ground water collected in the porous protruding blocks and/or of collected runoff rainwater for infiltration into the ground and/or for discharge via the flow moderation systems.

Features of advantageous embodiments of this use include: -one or more flow moderation systems are combined with cover plates and/or removable cover plates to form a road or highway or a part thereof, - preferably in the case of two adjacent flow moderation systems, one cover plate at least partly covers the two adjacent flow moderation systems, -the flow moderation system is adapted for the construction of a path, footpath and/or cycle track, preferably above a ditch, canal, stream or river, or above a trench or excavation or a part thereof.

-the flow moderation system is adapted for the reinforcement of existing banks of ditches, canals, streams, trenches, excavations or rivers, or a part thereof, and/or - the flow moderation system is adapted for raising the banks of canals, streams, canals [sic] or rivers, or a part thereof, or for forming an embankment e.g. along a canal or river Embodiments of the invention will now be described with reference to the accompanying drawings. These embodiments are given solely by way of example.

In these drawings, -Figure 1 shows a perspective view of a flow moderation system according to the invention, made up of at least three distinct main components which are shown separated from each other; -Figure 2 is a view in section along the line II-II of the flow moderation system of Figure 1; -Figure 3 is a view in section along the line Ill-Ill of the flow moderation system of Figure 1; -Figure 4 is a view in section of two flow moderation systems adjacent to each other, -Figure 5 is a view in section along the line V-V of Figure 4; -Figure 6 is a view in section of another embodiment of a flow moderation system; -Figure 7 is a view from above of the flow moderation system of Figure 6 without a cover plate; -Figure 7A is a view from above of the flow moderation system of Figure 6 without a cover plate and with a weir plate; -Figure 8 is a view in section of a decantation module cooperating with an intake flow moderation system and a discharge flow moderation system; -Figure 9 is a view in cross-section of a stream or ditch or excavation provided with a flow moderation system of a layout according to the invention; -Figure 10 shows a view in cross-section of a ditch which extends alongside a canal and which is provided with a flow moderation system used to raise a bank of the canal; -Figure 11 is a view of the system for measuring the perviousness to water of the porous elongated protruding block.

Figure 1 shows a flow moderation system 1 for at least collecting rainwater and for at least partially slowing down the rainwater flow. The flow moderation system 1 is suitable for placement, at least in part, in a ditch or stream or river or excavation G (see Figure 9). The ditch or stream or river or excavation G has a floor GB formed by the terrain, and two opposite sides GZ which are also formed by the terrain.

The flow moderation system 1 comprises at least one concrete casting 2 which is made up of at least: -two opposite concrete side parts (preferably practically non-porous) 20, 21 (side parts substantially vertical), capable of at least partially reinforcing the sides GZ formed by the terrain, these side parts having a minimum height H20, H21 of 50 cm (e.g. a height of from 100 cm to 150 cm), and -a concrete lower part 22 (substantially horizontal), preferably a lower part consisting of substantially non-porous concrete (lower part made substantially from non-porous concrete), extending between, and interconnecting, the two opposite side parts 20, 21. The concrete lower part 22 has an upper face 22B which is at least partially located substantially in a horizontal plane. The upper face 22B defines an upper area between the two opposite side parts 20, 21, this upper area having a minimum width B22B of 50 cm, for example from 75 cm to 200 cm, e.g. 100 cm or 150 cm.

An internal volume VOL1 is defined within the flow moderation system 1 above the upper face 22B of the lower part 22 and between the opposite side parts 20, 21.

By way of example, the concrete side parts 20, 21 and the concrete lower part 22 have a thickness of more than 5 cm, preferably more than or equal to 8 cm, more preferably more than or equal to 10 cm, and still more preferably more than or equal to 15 cm, e.g. 20 cm or 25 cm. The thickness may be varied to suit the height and width of the concrete casting. The side parts 20, 21 and lower part 22 may contain metal reinforcement. The concrete casting 2 defines a substantially U-shaped channel. Other sections are possible. Fixing points 200 are provided along the internal faces of the side parts 20, 21.

The flow moderation system of Figure 1 possesses the following features: -the lower part 22 is provided with an opening 220 with an open area of more than 1000 cm2, the total area of the opening or openings 220 in the lower part 22 being between 55% and 75% of the upper area 22B. This opening 220 reduces the weight of the concrete casting 2, which is advantageous for construction and handling.

-the flow moderation system 1 is provided with, or cooperates with, a component 3 made of porous concrete which is removably mounted on the upper face 22B of the lower part 22 so as to cover the centre opening 220 in the lower part. The porous concrete component 3 rests on strips of the upper face 22B along the edges of the central rectangular opening 220, the width of the said strips being from 3 to 10 cm. The porous concrete component 3 takes the form of a porous concrete beam with metal reinforcement and with attachment points 310 (along the ends 30E1, 30E2 of the beam 30). These attachment points can be connected to a crane or lifting gear to shift the porous concrete component 3 in relation to a concrete casting 2.

-the porous concrete component 3 is in the form of a porous elongated protruding block 30 which rests on the lower part 22. Between its ends 30E1, 30E2, this porous elongated protruding block 30 has an upper face 30B and two at least partially porous side faces 30L1, 30L2, the elongated protruding block 30 having a minimum width B30 of 30 cm along the concrete lower part 22 and a minimum height H30 of 20 cm to form a first channel K1 and a second channel K2 within the channel defined by the flow moderation system 1 along the lower part 22. The first channel K1 faces towards a first side portion 20 of the concrete casting 2, and the second channel K2 faces towards the second side portion 21 of the concrete casting 2, the [porous] elongated protruding block 30 located within the internal volume VOL1 of the flow moderation system defining a volume of between 35 and 50 % of the part of the internal volume located between the vertical planes of the ends 30E1, 30E2 of the protruding block 30. The channels K1, K2 are substantially similar The face 30Z of the protruding block 30 covers the opening 220 and partly covers the upper face 22B.

-the first and second channels K1, K2 have a minimum width BK1, BK2 of 10 cm and a minimum depth of 20 cm, the first and second channels K1, K2 defining a free volume (VK1 + VK2) of between 40 and 50 % of the volume of the protruding block 30.

-the elongated protruding block 30 is made of hardened porous draining concrete with an open pore volume of 8 to 12 %.

The porous elongated protruding block 30 is made of hardened porous draining concrete prepared by curing a mixture of at least cement, aggregates with a particle size of 6 mm to 14 mm and water to obtain an open pore volume of 8 to 12 % in the hardened porous draining concrete, wherein the hardened porous draining concrete has a perviousness to water (along its lower face resting on the upper face 22B of the lower part 22) of from 0.05 litre/m2/s to 5 litres/m2/s inclusive, preferably from 0.1 litre/m2/s to 3 litres/m2/s, and most preferably between 0.5 litre/m2/s and 1.5 litre/m2/s. The perviousness to water of the protruding block 30 is measured by placing the protruding block 30 on the bottom 101 of a receptacle 100 with a (preferably adjustable) bottom opening 102 (with an open area equal to 50% of the porous surface area of the lower face of the protruding block 30). The central part of the porous lower face 30Z of the protruding block 30 covers the bottom opening 102 and shuts this bottom opening 102. The reservoir 100 is then filled with water W to maintain a water level 100P in the reservoir 100 corresponding to a depth of water in the reservoir that is twice the mean height H30 of the protruding block 30. Then, after a 30-minute period of immersion of the porous body [sic] 3 in the reservoir 100, the (maximum stable) quantity of water running out in 30 seconds through the bottom opening 102 into a receiving chamber 105 located underneath the bottom opening 102 is determined.

The perviousness to water On 1/m2/s) is then equal to: ( ( HW/ 30)! Opv) with HW: the quantity of water which runs out in 30 seconds On litres) Opv: the area of the bottom opening 102 On m2) The quantity of water running out through the bottom opening 102 can also be measured by determining the quantity of water that needs to be added to maintain the water level 100P for 30 seconds.

Thus, the flow moderation system of Figure 1 possesses the following advantages: -ensuring a sufficient controlled drainage of water W1 from the flow moderation system into the layer of ground under the lower part 22B through the opening 220; -ensuring a sufficient controlled flow of ground water (W2) into the flow moderation system (for example if the level of the ground water is above the level of the bottom of the porous component 3) -installing the flow moderation system in a stream, ditch, excavation or river is simple (dig, put casting 2 in place, then put porous component 3 in place and put on cover plate 5) -a large water collection capacity of the porous protruding block 30 and hence a large buffering capacity -a controlled time-lagged discharge W3 of the water collected by the porous protruding block to the side channels K1, K2 of the flow moderation system and/or to the underlying ground (controlled percolation).

-the side channels are designed for a high velocity of water, particularly in case of heavy rainfall, enabling these channels and also the sides of the porous protruding block to be cleaned.

-high stability of the system once installed in the ground, as the water (ground water or water entering the system) is able to run off through the lower part in the longitudinal direction of the system. The zone affected by percolation is substantially limited horizontally to the area close to the lower part 22.

In the embodiment shown in Figure 1, the flow moderation system according to the invention possesses one or more of the following additional features: " the concrete side parts 20, 21 of the concrete casting 2 are adapted to form a support for a cover plate 5 or a cover plate suitable for the passage of vehicles and/or people, or adapted to form a pedestrian zone (with attachment points 500), the cover plate preferably being adapted for the passage of people and bicycles. The flow moderation system according to the invention may form a substructure for the construction of a road, footpath or cycle track above an existing ditch, stream, excavation or river * at least one side part (20, 21) has an upper edge (20R, 21R), the said upper edge (20R, 21R) being provided with a plurality of open notches 201, 211, the said notches forming open passages when the concrete casting 2 is covered by the cover 5. These notches allow rainwater W4 (e.g. from the path or thoroughfare 5) to run into the internal volume VOL1 of the flow moderation system 1. The notches 201, 211 are also designed to facilitate raising of the cover plate 5 e.g. for maintenance and/or inspection purposes. The said notches may be fitted with grilles 90 to prevent solid particles from getting into the internal volume VOL1.

* the flow moderation system is designed to cooperate with at least one removable partition wall 4 (with upper openings 40 and/or lateral overflow openings 41) (the partition wall 4 may serve as an additional means of slowing down the discharge of water The partition wall 4 forms a dam or weir in the flow moderation system.). The partition wall 4 preferably rests on the upper face 30B of the protruding [block] 30. The partition wall 4 may serve as an additional support for the roadway cover plate 5.

* the concrete casting 2 defines an elongated channel with a length of 1 m to 5 m, the ends (entry end 2E1 and exit end 2E2) of this elongated channel being open. Thus water can enter the internal volume of the casting 2 via the entry end and exit from the channel via the exit end.

* the lower part 22 defines a substantially rectangular upper face 22B, and the lower part 22 has one or more substantially rectangular openings 220 with a width of more than 30%, preferably more than 50%, of the width of the upper face.

* the openings 220 have a length of at least 80 cm, said length preferably being less than 250 cm. Water passing through the porous elongated protruding block 30 is distributed to the ground beneath the flow moderation system in the longitudinal direction or axial direction AR of the flow moderation system or of the lower part 22, which is advantageous for the stability of the flow moderation system e.g. in the event of a change in ground water level, and also to ensure that the part of the ground which is situated underneath the moderation system is sufficiently moist, which is advantageous for preventing ground movements and for ensuring that this part of the ground is sufficiently pervious.

" the concrete casting 2 has a length of less than 3 m, and the upper face 22B has a single substantially rectangular opening 220, the length of the single substantially rectangular opening being between 70% and 90% of the length of the lower part 22.

" the ends 2E1, 2E2 of the concrete casting 2 are provided with means 80 for one or more connecting pieces 81 for connecting the flow moderation system to an adjacent flow moderation system and/or to a filtration module and/or a decantation module (BZM).

* the flow moderation system is provided with a weir 4, preferably an adjustable weir 44. Using an adjustable weir 44 is advantageous during maintenance work on at least one flow moderation system downstream of the weir. The adjustable weir 44 is e.g. a platelike element that can be slipped into a slot in the cover 5 or into the slot between two adjacent covers 5. Movement of this plate element 44 may if required be controlled remotely by suitable means. The weir 4 may be provided with openings 40, 41, the said openings 40, 41 operating in conjunction with a filter element 41F, 40F for removing solid particles (see Figure 1). The weir 4 may also be provided with two legs 4P which are designed to block the side channels K1, K2.

* the cover plate 5 may be provided with a manhole 55 with a removable cover 56.

In the embodiment shown in Figure 4, a removable transverse support element 22X is placed in the opening 220 to divide this opening 220 into two open zones (2201, 2202). The embodiment shown in Figure 4 comprises a fixed upper weir element 4 (which rests on top of the porous protruding block 30) and a movable weir plate 44 which can be slipped between two adjacent porous protruding blocks. The said movable plate 44 can cooperate with the said weir element 4 to form a dam from the lower part 22 to the outlet openings 41 of the upper weir element 4. The movable weir plate 4 can be inserted between two protruding blocks 30 through a slot in the cover plate or traffic plate 5, but preferably through a slot 5G formed between two lids or cover plates 5.

The porous protruding block 30 is designed to be supported partly by the lower part 22 (upper face 22B) of a first flow moderation system 1 and partly by the lower part 22 (upper face 22B) of a second flow or discharge moderation system 1 adjacent to the first. The porous protruding block 30 is arranged so that it covers the first open zone 2201 of the lower part 22 of a first flow moderation system and the second open zone 2202 of the lower part 22 of a second flow moderation system adjacent to the first system. This is advantageous for maintaining the positioning of two adjacent flow moderation systems. The cover plate 5 is supported by part of a first flow moderation system 1 and by part of a second flow moderation system 1. A groove 5G may be formed between adjacent cover plates through which rainwater can run into the interior of a flow moderation system.

Adjacent porous components 30 form guide means for moving a cleaning device into adjacent flow moderation systems. A road plate 5 must be removed before inserting an inspection and/or cleaning device into the interior of a flow moderation system. The cleaning device is then able to move inside the flow moderation systems with the road covering plate 5 in position covering the flow moderation system 1. The cleaning device may for example have wheels which run on the upper face of one or more porous components 3.

In the embodiment shown in Figure 6, the concrete casting 2 is provided with a lower part with two openings 2201, 2202 separated by a cross piece 22E. Each opening 2201, 2202 (see Fig. 7) is covered by a porous protruding block 3. A diaphragm 300 may extend between the adjacent porous protruding blocks 30. The gap between the two porous protruding blocks 30 can also be used for insertion of a weir element.

The cover plate 5 may also be in two separate parts.

In Figure 7A, one opening 2201 is covered by a porous protruding block 30. The other opening 2202 is not covered, and provides a well for [??forme le fond lit "forms the bottom of..." -Translator] a decantation zone BZK behind a weir element 44 with one or more overflow openings.

Figure 8 shows part of a flow moderation system with a decantation module BZM located between water inlet means WIM and water outlet means WAM, wherein at least the outlet means WAM appertains to at least one flow moderation system according to the invention. The said decantation module BZM also functions as a filtration module for removing particles deposited as sediment and hydrocarbons before the water can percolate through the porous component 3 of at least one flow moderation system according to the invention.

The decantation module BZM is in the form of a collecting chamber 70 for collecting water from the (intake) flow moderation system 1 so that as soon as the level of water in the chamber 70 is above an overflow level UP, filtered water can run from the decantation module BZM (decantation zone BZK) into the discharge flow moderation system 1, the said chamber 70 having a bottom 71 that is below the level of the upper face 223 of the lower part 22 of the incoming flow moderation system 1 (WIM) and below the level of the upper face 22B of the lower part 22 of the discharge flow moderation system 1 (WAM), the decantation chamber having an at least partly flexible filter receptacle 72, which is pervious to water, removably installed in the decantation chamber 70.

The lid 78 of the decantation module BZM may be provided with two slots for insertion of a weir plate 44. Preferably, slots 5G are formed between the lid 78 of the decantation module BZM and the lid 5 of a flow moderation system. By inserting the said weir plates 44, both the inlet opening and the outlet opening of the decantation module can be at least partially shut so that practically no water is able to enter the chamber 70 during maintenance operations, e.g. lifting of the filter container 72 out of the chamber 70 through the opening 79 after removal of the plate 790.

The bottom 73 of the filter container rests on a support 76 resting on the bottom 71 of the decantation chamber BZM or decantation zone BZK.

The at least partly flexible water-pervious filter container or receptacle 72 has a bottom 73 and at least one side wall 74 with a free upper edge 75, wherein the side wall 74 has an upper part 74B along the free upper edge 75, and the upper part 74B of the at least one side wall 74 is more pervious to water than the bottom 73 and than a lower part 740 of the at least one side wall 74 near the bottom 73.

Water from the intake flow moderation system 1 (WIM) runs into the filtration and decantation receptacle 72 through the lateral opening 720, via a flexible [ramp] 77. The opening 720 is situated at a higher level than the discharge level UP of the decantation zone BZK.

To retain hydrocarbons in the container 72 in the event of heavy rain, the container is capped with a lid 72D provided with an overflow opening 72D1 with a tube 72B extending into the interior of the container 72.

Figure 9 is a view in cross-section of a stream or ditch or excavation provided with a flow moderation system 1 of a layout according to the invention. The lateral faces GZ of the stream, ditch or excavation are reinforced by the side parts 20, 21 of the concrete casting 2 of the system 1. Adequate drainage of water into the ground beneath the lower part 22 is guaranteed, which is advantageous for horizontally limiting the zone affected by the percolation. This is advantageous for ensuring the stability and positioning of the systems 1 over a long period of time.

Figure 10 is a view in section of a canal KA (shown only in part) provided with a flow moderation system used to raise a bank KB (with a ground level PG). A ditch G with vertical sides GZ extends into the bank KB and runs alongside the canal KA. A part of the flow moderation system is situated above the ground level (PG) of the bank KB. Cover plates 5 forming a thoroughfare (for pedestrians or bicycles) are situated at a level P5 above the ground level PG of the bank. In the event of a flood, the thoroughfare 5 can still be used; and the flow moderation system can serve as a conduit for evacuation of storm rainwater The flow moderation system can also be used as a component of a barrier or levee. If the side part 20 of the concrete casing 2 is inundated, the flow moderation system 1 can stem the flow of water along the other side part 21. The flow moderation system can thus form a raised levee for a canal.

The flow moderation system can thus serve as a climatic tool for countering the effects of climate change.

Flow moderation systems according to the invention may also be placed in one or more excavations e.g. close to a building, or under a parking area or terrace, to gather rainwater and partially store it and allow it to soak away.

Claims (20)

1. Claims 1. Rainwater flow moderation system (1) adapted for at least receiving rainwater and for at least partially slowing down the rainwater flow, the said moderation system (1) being suitable at least for placing in a ditch, stream, river, trench, underground passage or excavation (G), wherein the ditch, stream, river, trench, underground passage or excavation (G) has at least a floor (GB) and two opposite sides (GZ) formed by the terrain, wherein the rainwater flow moderation system comprises at least one concrete casting (2) which is composed of at least: -two opposite concrete side parts (20, 21), preferably consisting substantially of non-porous concrete, capable of at least partially reinforcing the sides (GZ) formed by the terrain, the said two concrete side parts (20, 21) having a minimum height (H20, H21) of 50 cm, and -a concrete lower part (22), preferably a substantially non-porous concrete lower part, extending between, and interconnecting, the two opposite concrete side parts (20, 21), the said concrete lower part (22) having an upper face (22B) at least partly located substantially in a horizontal plane, wherein the said upper face (22B) defines an upper area between the two concrete opposite side parts (20, 21), this upper area having a minimum width (B22B) of 50 cm, wherein an internal volume (VOL1) is defined within the flow moderation system (1)above the upper face (22B) of the concrete lower part (22) and between the concrete opposite side parts (20, 21), characterized in that the concrete lower part (22) is provided with one or more openings (220) with an open area of more than 10 cm2, the total area of the opening or openings (220) in the concrete lower part (22) being equal to or more than 50%, preferably between 55% and 75%, of the upper area of the upper face (22B), the flow moderation system (1) is provided with one or more components (3) made of porous concrete which are removably mounted on the upper face (22B) of the concrete lower part (22) so as to at least partly cover one or more openings (220) in the concrete lower part (22), the one or more porous concrete components (3) are in the form of a porous elongated protruding block (30) which rests on the concrete lower part (22) and extends between two longitudinal ends (30E1, 30E2), this porous elongated protruding block (30) having between its longitudinal ends (30E1, 30E2) an upper face (30B) and two at least partially porous lateral faces (30L1, 30L2), wherein the porous elongated protruding block (30) is made with a minimum width (B30) of 30 cm along the concrete lower part (22) and with a minimum height (H30) of 20 cm to form a first channel (K1) and a second channel (K2) within the flow moderation system (1) along the concrete lower part (22), the first channel (K1) facing towards a first concrete side part (20) of the concrete casting (2) and the second channel (K2) facing towards the second concrete side part (21) of the concrete casting (2), the porous elongated protruding block (30) located within the internal volume (VOL1) of the flow moderation system defining a protruding volume between 20 and 50 % of the part of the internal volume (VOL1) located between the substantially vertical planes in which the two longitudinal ends (El, E2) of the porous elongated protruding block (30) extend, the said first and second channels (K1, K2) have a minimum width (BK1, BK2) of 10 cm and a minimum depth of 20 cm, the said first and second channels (Ki, K2) defining a free volume (VK1 + VK2) of between 30 and 60 % of the protruding volume of the porous elongated protruding block (30), and the porous elongated protruding block (30) is made of hardened porous draining concrete with an open pore volume of 8 to 12 %.
2. 2. Flow moderation system according to Claim 1, characterized in that the concrete side parts (20, 21) of the concrete casting (2) are adapted to form a support for a cover plate (5) or a cover plate (5) [sic] suitable for the passage of vehicles and/or people, the said cover plate (5) preferably being adapted at least for the passage of people and bicycles.
3. 3. Flow moderation system according to Claim 2, characterized in that at least one concrete side part (20) has an upper edge (20R), the said upper edge (20R) being provided with a plurality of open notches (201), the said notches (201) forming passages for water when the concrete casting (2) is covered by the cover plate (5).
4. 4. Flow moderation system according to any one of Claims 1 to 3, characterized in that the flow moderation system (1) is provided with at least one removable partition wall (4) with or without one or more openings (40) and/or with or without one or more overflow openings (41), the said removable partition wall (4) preferably resting on the upper face (30B) of the porous elongated protruding block (30).
5. 5. Flow moderation system according to any one of the preceding claims, characterized in that the concrete casting (2) defines an elongated channel with a length of 1 m to 5 m, the ends of this elongated channel being open, wherein preferably, the lower part (22) defines a substantially rectangular upper face (22B), while one or more openings (220) are substantially rectangular elongated openings with a width of more than 30%, preferably more than 50%, of the width of the said substantially rectangular upper face (22B).
6. 6. Flow moderation system according to Claim 5, characterized in that the concrete lower part (22) has a substantially central axis (AR), the concrete lower part (22) being provided with two or three substantially rectangular elongated openings (2201, 2202) juxtaposed in the direction of the substantially central axis, wherein a transverse component (22E) extends between adjacent elongated openings (2201, 2202), the elongated openings (2201, 2202) preferably having a length of at least 80 cm, said length preferably being less than 250 cm.
7. 7. Flow moderation system according to any one of the preceding claims, characterized in that the concrete casting (2) has a length of less than 3 m, the upper face (22B) has a single substantially rectangular elongated opening (220), the length of the single substantially rectangular elongated opening (220) being between 70 and 90 % of the length of the concrete lower part (22).
8. 8. Flow moderation system according to either of Claims 6 and 7, characterized in that the flow moderation system (1) is provided with at least one porous elongated protruding block (30) covering at least one substantially rectangular elongated opening (220), wherein preferably each substantially rectangular elongated opening (220) is covered by a single porous elongated protruding block (30).
9. 9. Flow moderation system according to any one of the preceding claims, characterized in that the ends (2E1, 2E2) of the concrete casting (2) are provided with means (80) for one or more connecting pieces (81) for connecting the flow moderation system (1) to an adjacent flow moderation system or to a filtration or decantation module (BZM).
10. 10. Flow moderation system according to any one of the preceding claims, characterized in that the flow moderation system (1) is provided with means (4, 44) forming a weir, preferably means (44) forming an adjustable weir.
11. 11. Flow moderation system according to any one of the preceding claims, characterized in that part of the flow moderation system (1) is not provided with a porous concrete component (3), wherein the concrete lower part (22) [in this part] of the flow moderation system (1) in conjunction with a partition wall (4) defines a decantation zone (BZK) in the aforesaid flow moderation system (1), and/or with a filter element for removing particles deposited as sediment and hydrocarbons before the water can percolate through a porous concrete component (3).
12. 12. Flow moderation layout comprising a plurality of flow moderation systems (1) according to any one of the preceding claims, wherein preferably, for one or more pairs of adjacent flow moderation systems (1), at least one porous concrete component (3) at least partly covers the upper face (22B) of the concrete lower part (22) of two adjacent flow moderation systems (1).
13. 13. Flow moderation layout according to Claim 12, characterized in that part of a flow moderation system (1) is not provided with a porous concrete component (3), the concrete lower part (22) in this [part of the] flow moderation system (1) combining with a partition wall (4) to define a decantation zone (BZK) in the aforesaid flow moderation system (1), and/or with a filter element for removing particles deposited as sediment and hydrocarbons before the water can percolate through a porous concrete component (3) of a flow moderation system (1) according to any one of Claims 1 to 11.
14. 14. Flow moderation layout according to either of Claims 12 and 13, characterized in that the flow moderation layout is provided with a filter element or filtration module for removing particles deposited as sediment and hydrocarbons before the water can percolate via at least one flow moderation system (1) according to any one of Claims 1 to 11.
15. 15. Flow moderation layout according to any one of Claims 12 to 14, characterized in that the flow moderation layout comprises a decantation module (BZM) locatable between water inlet means (WIM) and water outlet means (VVAM), wherein at least one of the means selected from the water inlet means (WIM) and the water outlet means (WAM) appertains to a flow moderation system (1) according to any one of Claims 1 to 11, wherein advantageously, at least the water discharge means (WAM) appertains to least one flow moderation system (1) according to one of Claims 1 to 11, and wherein preferably, both the water inlet means (WIM) and the water discharge means (WAM) each appertain to at least one flow moderation system (1) according to one of Claims 1 to 11.
16. 16. Flow moderation layout according to Claim 15, characterized in that the decantation module (BZM) is in the form of a chamber (70) for receiving water from the water intake means (WIM) or from the latters water flow moderation system (1) so that as soon as the level of water in the chamber (70) is above an outlet level (UP), water runs from the decantation module (BZM) into the water discharge means (WAM) or into the latter's flow moderation system (1), the said chamber (70) having a bottom (71) that is below the level of the upper face (22B) of the lower part (22) of the water intake means (WIM) or of the latter's flow moderation system (1), and below the level of the upper face (22B) of the lower part (22) of the water discharge means (WAM) or of the latter's flow moderation system (1), wherein the decantation chamber (70) comprises an at least partly flexible filter container (70), pervious to water, removably installed in the decantation chamber (70).
17. 17. Flow moderation layout according to Claim 16, characterized in that the at least partly flexible water-pervious filter reservoir (72) has a bottom (73) and at least one side wall (74) with a free upper edge (75), wherein the side wall (74) has an upper part (74B) along the free upper edge (75), wherein the upper part (74B) of the at least one side wall (74) is more pervious to water than the bottom (73) and than a lower part (740) of the at least one side wall (74) near the bottom (73).
18. 18. Flow moderation layout according to either of Claims 16 and 17, characterized in that it comprises a weir (4), preferably an adjustable weir (44), the said weir (4) or adjustable weir (44) preferably forming part of a decantation module (BZM) located between two flow moderation systems (1) and/or between a flow moderation system (1) and a decantation module (BZM).
19. 19. Use of a flow moderation layout according to any one of Claims 12 to 18 to slow down the flow of rainwater, wherein the flow moderation layout has at least the following functions: -at least partially collecting and storing the water passing through the flow moderation layout in the porous protruding blocks (30) of the flow moderation systems (1) ; -at least partially infiltrating the water collected/stored in the porous protruding blocks (30) into the layer of ground under the concrete lower parts (22) of the flow moderation systems (1) ; -in the event of an unduly high level of ground water, partially collecting the ground water in porous protruding blocks (30), with the possibility of storing the collected ground water in the porous protruding blocks (30) and/or discharging it via the channels (K1, K2) in a controlled manner; -delayed discharge of the ground water collected in the porous protruding blocks (30) and/or of collected runoff rainwater for infiltration into the ground and/or for discharge via the flow moderation systems (1), wherein advantageously, one or more flow moderation systems (1) are combined with cover plates and/or removable cover plates (5) to form a road or highway or a part thereof, wherein preferably, in the case of two adjacent flow moderation systems (1), one cover plate (5) at least partly covers the two adjacent flow moderation systems (1).
20. 20. Use according to Claim 19 for the construction of a path, footpath and/or cycle track, preferably above a ditch, canal, stream or river, or above a trench or excavation or a part thereof, and/or to reinforce the banks of ditches, canals, streams, trenches, excavations or rivers, or a part thereof, and/or to raise the banks of canals, streams, canals [sic] or rivers, or a part thereof.