GB2529648A

GB2529648A - A flood barrier device

Info

Publication number: GB2529648A
Application number: GB1415167.4A
Authority: GB
Inventors: John Hadden
Original assignee: Individual
Current assignee: Individual
Priority date: 2014-08-27
Filing date: 2014-08-27
Publication date: 2016-03-02
Anticipated expiration: 2034-08-27
Also published as: GB2529648B; GB201415167D0

Abstract

A folding flood barrier comprising a base 10 and a hinged platform 18 adapted to move between a flat, horizontal position and a raised position, a flexible bag 22 attached to the lower surface of the platform which has an interior space for receiving and retaining water through an inlet 30. The bag is adapted to fold from a collapsed configuration to an inflated configuration wherein water is introduced into the interior space of the bag whilst folding the platform. The bag comprises 3 side portions (32, 34, 36, Fig. 4) one attached to the upper surface of the base, one attached to the lower surface of the platform and one extending between the first two side portions and two end portions 38 to form a closed interior. The bag also comprises at least one preformed folding region (42, Fig. 4) adapted to cause the side portions to fold. The bag may have a triangular profile. The barrier may further comprise control means to pump water into the bag.

Description

A flood bairier device

Field of the Invention

The present invention relates to flood barrier devices adapted to be raised from a lowered position to a raised position to hold back floodwater.

Background

Numerous flood barrier devices are described in the prior art, generally falling into the categories of fillable containers, rising barriers than may be driven by buoyancy of the barrier itself or a flat attached to it, or devices driven by pumped fluid, for example air into airbags or water into bags or bladders that then expand either to form a barrier themselves or to lift a barrier formed of a rigid material. Some of these devices are suited for permanent installation at a location, such as on a riverbank, and some are transportable. In particular, to handle large amounts of floodwater, a robust system is needed that is adapted to permanent or semi-permanent placement and is capable of being deployed rapidly in response to flood warnings, and of being restored easily to its normal, storage configuration once the flood warning or event has passed. Such barriers may be deployed several times per year, for example if installed on the banks of a river that tends to flood, and on these occasions they may not actually be used -rather the provide protection against the possibility of a flood that does not arise. For such circumstances it is essential that the device be easy to deploy automatically, and also to return reliably and automatically to its storage configuration with certainty that is will be ready for the next deployment. While the prior art provides devices that may be deployed rapidly, it is in the return to the storage position that they are most deficient. The present invention remedies these shortcomings by providing a flood barrier device that may be deployed and returned to a storage configuration reliably.

Prior Art

Accordingly a number of patent applications have been filed in an attempt to resolve the problem or similar, including the following: W02013163763 discloses a unique water containment wall or barrier employs a flexible envelope that is extendable in a longitudinal direction from a collapsed condition for storage and transport into an expanded position for use. Support ribs disposed at spaced apart positions along the longitudinal direction provide support and shape retention to the envelope, the interior of which is fillable with water to weigh down the envelope down against oncoming or expanding waters. A unique fastening mechanism attaches a pair of wail or barrier sections together by using an inflatable member to force apart a pair of profiled ribs on the two sections into engagement with matching-profile walls of a channel member that bridges together the two sections over the ribs. A bumper mechanism rises and falls with water levels to protect the wail or barrier against impact by floating debris.

This device is a portable flood defence means that is fillable with water to hold it in place, and expandable laterally parallel to its base in a concertina-like manner from a collapsed configuration to an unfolded configuration, and has support ribs to hold the flood defence elements in place.

US201301 08372 discloses a portable, water-filled barrier emulates a sandbag dike or wall without requiring sand or intensive labor to install. The barrier is made of a light, flexible material that can include nanofiber. Some embodiments are formed from a plurality of interlocked water-filled cells, with a forward-facing water barrier sheet.

Other embodiments are unitary shells that are internally divided into cells, with internal openings that permit water to flow between cells. Automatic valves can seal the filled cells, so that a punctured cell will not cause cells below and behind to deflate. A row or rows of cells can project below the base into a stabilizing trench.

Cells can include internal or external rods or plates that support the horizontal structure. Embodiments can be initially filled with air, positioned, and then filled with water while the air escapes through a pressure valve. Barrier end structures can enable interlocking of adjacent units.

This device is a shell that contains a series of internal cells that can be filled with water with valves between them inside the shell. It is typical of a class of devices that resemble water-filled sandbag defences, many of which have an interior filling such as an absorbent polymer or fibrous material.

CN202509445U discloses: The utility model relates to a double-layer flood prevention wall which is automatically lifted and tilted by an inflation air bag, which belongs to the field of a water conservancy engineering technology. The double-layer flood prevention wall mainly comprises an inflation air bag, a tilting steel deck, a connection rotating shaft, an automatic charging apparatus, a flexible stay cable, a reinforced concrete based wall, water sealing apparatuses and interboard serial fasteners. The air bag is charged and discharged to provide buoyancy for controlling the elevation of an upper plate. According to the utility model, floods at different water levels can be withstood, the plate is light and thin, elevation is automatic, usage is convenient, a certain economic benefit is provided, and the double-layer flood prevention wall can be widely applied for protecting cities and important buildings from floods.

This device is typical of a class of devices having air bag floatation means that lift a flood defence barrier when they are immersed in floodwater. In this case the air bag lifts a hinged barrier means.

US2O1 10268506 discloses: A flood defense apparatus including a channel having a base and side walls, extending downwardly from a surface level opening to the base so as to be adapted to collect and transfer surface liquid, a channel dividing formation extending generally downwardly from the opening of the channel towards but not to the base, so as to divide the channel into a drainage portion open for the access flow of surface liquid and a chamber portion and to define a liquid communicating portion 24 between the drainage portion and the chamber portion below the dividing formation, and at least one buoyant barrier member received in the chamber portion to be selectively moveable between a first position within the channel and a second position where the barrier member at least partially extends from the channel. The level of liquid in the drainage portion follows the level of liquid in the chamber portion to allow, in use, varying levels of liquid in the channel to move the barrier member reversibly between the first position and the second position.

This device is typical of a class of devices comprising floating barrier elements that are themselves buoyant and rise up when water enters a channel in which they stand.

W02009148434 discloses: A portable, inflatable flood wall is characterized by a sheet of synthetic plastic material which is folded back on itself to define a chamber between bottom, rear and front portions of the sheet and within which at least one inflatable bladder is secured. When the bladder is inflated, the rear portion of the sheet is erected to a vertical position which prevents water from passing beyond the sheet. The front portion preferably contains a plurality of openings to allow water to enter the chamber. The weight of the water on the bottom portion of the sheet serves to hold the wall in place. A plurality of such walls may be connected in end-to-end relation to construct a wall of a desired length.

In this device a gas-inflatable bladder lifts a separate plastic barrier face. Flood water bears down on a base plate to anchor it to the ground.

DE20300565 discloses: The device has a water protecting element comprising a storage container, a bag-like hollow body and a cover plate supported at a hinge in a pivotable manner. A pump system fills and drains the hollow body. The hollow body is attached to the plate and arranged in an inner side of the container, such that the plate is folded till to an angle of 90 degrees in a water-barricading manner by a water-protected folding system after filling the hollow body with water, where the plate, hollow body and the container represent a flood water-sided, elastic seal.

In this device a hinged barrier is supported by a bag that may be filled with water.

The bag expands to force the barrier into an angled position. However, no means to control the configuration and in particular the folding of the bag when the bag is emptied again, so that the bag risks becoming trapped when the hinged barrier lowers. The device is therefore poorly suited for autonomous action, and is likely to prove unreliable in repeated use.

Sum mary of the Invention According to the present invention there is provided a foldable flood barrier device comprising: a base having an upper surface and a lower surface, a front and a rear edge; a platform hingably connected to the front edge of the base by means of a hinge mounted on a front edge of the platform and the front edge of the base, the platform being moveable between a first folded position in which it lies substantially flat on the base and a second raised position in which the platform extends at an angle to the upper surface of the base; a flexible bag mounted on the upper surface of the base and attached to the lower surface of the platform, the bag having an interior space configured to receive and retain water and an inlet into the interior space; and a water inlet means to supply water to the interior space, wherein the bag is foldable from a first collapsed configuration to a second inflated configuration when water is introduced into the interior space while moving the platform from the first folded position to the second raised position, the bag comprising: a first side portion attached to the upper surface of the base; a second side portion attached to the lower surface of the platform; a third side portion extending between the first and the second side portions, and first and second end portions joined to the side portions to form a closed interior; and one or more preformed folding regions provided in the third side portion adapted to cause the third side portion to fold between the first and second portions when the bag is in the first collapsed configuration.

Herein a preformed folding region is a region of the third side that is adapted to fold preferentially over other regions of the third side as the third side folds. In some embodiments the folding region is more flexible than other regions of the third side.

A preformed folding region may comprise a thinner region of the third side, a crease, a living hinge formed within the material of the third side, or may be defined by one or more stitched layers adjacent to the folding region, or may be defined by a join to a further component of the bag as described in more detail below.

In some embodiments the device is configured such that when inflated the bag has an approximately triangular profile, with the first and the second sides held substantially planar by means of their attachment to the base and to the platform respectively, and the third side forms a substantially planar sheet between them.

It will be understood that according to the nature of the folding region, the third side may have a convex curved profile, a concave curved profile, or a profile comprising two or more planar regions, when viewed in cross-section.

In this way the device may provide a flood barrier that may be positioned so as to resist floodwaters, for example along a river bank, and may be raised into position by inflating the bag with water. The device may be placed with the platform facing the floodwater, the platform thereby providing a barrier against debris etc that might puncture the bag. When not in use the device may provide a flat platform folded down onto the base, which in some embodiments is adapted to be sunk into the ground to provide a fixed base for the device. The platform may therefore form a walkway or a raised platform. The base in some embodiments is heavy, for example adapted to be mounted in or anchored to the ground, for example adapted to be mounted in concrete, on in some embodiments formed itself from concrete, to hold it in position against the force of floodwater. The platform is preferably foimed from a rigid, load bearing sheet material such as metal, for example aluminium alloy or steel.

The device preferably comprises means to release water from the interior of the bag, in some embodiments comprising a release valve and a drain channel or pipe. In some embodiments the release valve is connected to the inlet to the bag.

When the bag is emptied of water, the folding region of the bag allows the bag to fold into the base in a predictable and repeatable way, in contrast with prior art devices comprising bags that do not have such features, and in which no means are provided to control such folding with the result that the bag risks begin trapped as it deflates and consequently damaged.

In some embodiments the said preformed folding region comprises one of a fold or a corrugated region formed in the third side portion and extending substantially parallel to the axis of the hinge.

In some embodiments the said preformed folding region is defined by an internal member within the interior space attached to the interior of the third side portion at the folding region.

In some embodiments the said internal member is attached at its other extremity to the internal side of one of the first side portion, the second side portion or a joining region between them.

In some embodiments the internal member is attached to the interiors of the two end portions of the bags, so forming a partition within the interior of the bag dividing the interior space into a lower compartment defined by the first side portion, the lower part of the third side portion and the paitition, and an upper compartment defined by the second side portion, the upper part of the third side portion, and the partition.

Such an embodiment is described in more detail below and shown in the figures. In some such embodiments the upper and lower compartments may have separate inlets. In some such embodiments the water supply means may be configured to supply water to both compartments simultaneously and in some embodiments separately.

In this way in some embodiments the device comprises a bag having two compaitments and an internal partition that joins a folding region on the third side portion with a region between the first and the second side portions, so forming two compaitments that when filled together form a body substantially in the form of a triangular prism having its base on the base of the device, its second side attached to the platform and so holding it at an angle to the base, that angle being the angle of the prism, and a third side that according to the length of the partition may be substantially planar, or may comprise two planes joined at the folding region and meeting at an angle determined by the length of the paitition. In some embodiments the partition is sized such that the angle is less than 180 degrees, such that the two planes of the third side portion tend to fold towards one another when the bag is deflated.

In some embodiments a folding region comprises a weight configured to pull the folding region downwards towards the base when the bag is emptied and moves towards the collapsed configuration. For example one or more masses may be disposed on the third side portion along the length of the fold, so causing the fold to fall downwards as the bag deflates, so causing a predictable folding behaviour to guide the bag into a recess within the base as the device is moved to the folded configuration. Such folding may be assisted by the mass of the platform.

The means to supply water to the interior of the bag is preferably a pump and in some embodiments a non-return valve is provided in the water supply line from a water source via the pump to the bag, for example between the source and the pump, or between the pump and the bag.

The device is intended form part of an extended barrier and so is configured such that the end portion of a bag in a first device may be butted up against the end portion of a bag in a second device. In some embodiments the bag is adapted such that when filled the end portions of the bag bulge outwards with respect to the base and the platform. In this way if two devices are aligned such that their bases are touching, when the bags are inflated their side portions will extend to touch and form a compliant seal between them, so acting in use to prevent floodwater from leaking between them. In some embodiments the bags may comprise sealing means to allow adjoining bags to be joined and sealed to one to another. Such a sealing means may comprise a flap extendable from a first bag and joinable to a second.

The device may be provided in a permanently fixed form in which it is mounted in a fixed position, for example sunk into a chosen flood barrier position, such as a river bank, or in a portable form in which the device may be moved into position and then fixed to the ground. The weight of water within the device will in large measure prevent floodwater from moving it, but in some embodiments the base comprises fixing means to fix it to the ground, such as ground screws or fixing means such as shackles or reinforced apertures to allow it to be fixed to piles driven into the ground.

In some embodiments the device further comprises a control means to control a pump configured to pump water into the bag. In some embodiments the control means comprises a sensor means adapted to sense water level and the control means is configured to actuate the pump in response to signals from the sensor. In some embodiments the sensor comprises two or more water level sensing means provided vertically separated. In this way the control means may raise the barrier to a height determined by the signals from the two or more sensors, for example to a first height when the water level reaches the first, lower sensor and a second, greater height when the water level reaches the second, higher sensor. In some embodiments the control means is configurable to raise the barrier automatically in response to a sensor signal. In some embodiments the device comprises a light source to indicate the edge of the platform, and optionally to indicate that the platform is moving, or is about to move.

Brief Description of Figures

Figure 1 shows a front isometric view of an embodiment of a device according to the invention with the platform in a raised position.

Figure 2 shows a rear isometric view of the embodiment as shown in figure 1.

Figure 3 shows a side elevation of the embodiment as shown in figure 1.

Figure 4 shows a cross section of the embodiment as shown in figure 3.

Figure 5 shows a top view of the embodiment as shown in figure 1.

Figure 6 shows a front isometric view of the embodiment as shown in figure 1 with the platform in a lowered position.

Figure 7 shows a rear isometric view of the embodiment as shown in figure 5.

Figure 8 shows an embodiment of a sensor housing adapted for use with a device according to the invention.

Detailed Description of Figures

Referring to figures 1 to 8, an embodiment of the present invention comprises: A base 10 having an upper surface 12 and a lower surface, a front edge 14 and a rear edge 16, A platform 18 hinged to the front edge 14 of the base by means of a hinge 20 mounted on a front edge of the platform and the front edge of the base, the platform being adapted to move between a first folded position in which it lies substantially flat on the base and a second raised position at an angle to the upper surface of the base, A flexible bag 22 mounted on the upper surface 12 of the base 10 and attached to the lower surface 24 of the platform, the bag having an interior space 26 configured to receive and retain water and an inlet 28 into the interior space, A water inlet means 30 to supply water to the interior space, Wherein the bag is adapted to fold from a first collapsed configuration to a second inflated configuration when water is introduced into the interior space while moving the platform from the first folded position to the second raised position, the bag comprising: a first side portion 32 attached to the upper surface of the base, a second side portion 34 attached to the lower surface of the platform, a third side portion 36 extending between the first and the second side portions, and first 38 and second 40 end portions joined to the side portions to form a closed interior, and one or more preformed folding regions 42 provided in the third side portion adapted to cause the third side portion to fold between the first and second portions when the bag is in the first collapsed configuration.

In this embodiment the device is configured such that when inflated the bag has an approximately triangular profile, with the first and the second sides held substantially planar by means of their attachment to the base and to the platform respectively, and the third side forms a substantially planar sheet between them, in this embodiment the third side has a profile comprising an upper planar region 44 and a lower planar region 46.

Referring to figure 1, the device provides a flood barrier that may be positioned so as to resist floodwaters, for example along a river bank, shown in figure 1 raised into position by inflating the bag with water. The device is placed with the upper surface 25 of the platform facing the floodwater, the platform thereby providing a barrier against debris etc that might puncture the bag. Referring to figure 6, when not in use the device provides a flat platform folded down onto the base, which in some embodiments is adapted to be sunk into the ground to provide a fixed base for the device. The platform may therefore form a walkway or a raised platform. The base 10 in this embodiment is formed from a metal such as steel and comprises a frame 48 defining a recess 50 into which the bag may fold when the barrier is not in use, and having a front flange 52 and a rear flange 54 to define a stable position in the ground when the base is in position. In this embodiment the base is adapted to be mounted in a poured concrete foundation such that the flanges are level with the upper surface of the foundation. The platform is preferably formed from a rigid, load bearing sheet material such as metal, for example aluminium alloy or steel.

The device comprises means to release water from the interior of the bag, comprising a release valve 56 connected to the inlet to the bag and a drain pipe 58.

When the bag is emptied of water, the preformed folding region 42 of the bag allows the bag to fold into the base in a predictable and repeatable way into the recess 50, so avoiding the risk of the bag begin trapped as it deflates and consequently damaged.

In this embodiment the said preformed folding region 42 comprises a fold extending substantially parallel to the axis of the hinge 20.

In this embodiment the preformed folding region 42 is defined by the junction of the third side portion with an internal member 60 attached to the interiors of the two end portions of the bag and to the internal side at a joining region 66 between the first side portion and the second side portion, so forming a partition within the interior of the bag dividing the interior space into a lower compartment 62 defined by the first side portion, the lower part of the third side portion and the partition, and an upper compartment 64 defined by the second side portion, the upper part of the third side portion, and the partition. In this embodiment the water supply means is configured to supply water to both compartments simultaneously.

In this way the embodiment comprises a bag having two compartments and an internal partition 60 that joins a folding region 42 on the third side portion with a region 66 between the first and the second side portions, so forming two compartments that when filled together form a body substantially in the form of a triangular prism having its base on the base of the device, its second side attached to the platform and so holding it at an angle 68 to the base, that angle being the angle of the prism, and a third side that comprises two planes 44, 46 joined at the folding region 42 and meeting at an angle 70 determined by the length of the partition. In this embodiment the partition is sized such that the angle 70 is less than 180 degrees as shown in figures 1 to 4, such that the two planes 44, 46 of the third side portion tend to fold towards one another when the bag is deflated.

The means to supply water to the interior of the bag comprises a pump 72 and a non-return valve 74 is provided in the water supply line 76 leading to a water source.

The device in this embodiment is intended form part of an extended barrier and so is configured such that the end portion of a bag in a first device may be butted up against the end portion of a bag in a second device. In this embodiment the bag 22 is adapted such that when filled the end portions 38, 40 of the bags bulge outwards with respect to the base and the platform as shown in figure 5. In this way if two devices are aligned such that their bases are touching, when the bags are inflated their side portions will extend to touch and form a compliant seal between them, so acting to prevent floodwater from leaking between them.

This embodiment is adapted to be permanently fixed in position, for example sunk into a chosen flood barrier position, such as a riverbank. It will be understood that with minor modification to the base 10 the embodiment may be provided in a portable form suitable be moved into position and then fixed to the ground. The weight of water within the device will in large measure prevent floodwater from moving it, but in some embodiments the base comprises fixing means to fix it to the ground, such as ground screws or fixing means such as shackles or reinforced apertures to allow it to be fixed to piles driven into the ground.

In some versions this embodiment further comprises a control means (not shown) to control the pump 72. In some embodiments the control means comprises a sensor means 80 adapted to sense water level and the control means is configured to actuate the pump in response to signals from the sensor. As shown in figure 8, the device may comprise a probe 82 adapted to be mounted in or near a river, comprising a metal tube 84 having a spiked end suitable to be inserted into the ground or a riverbed and one or more open mesh areas 86 to allow water to enter the interior of the tube. The sensor 80 is provided within the tube -the top portion of the sensor is shown in figure 8 supported by the upper end 88 of the tube -to sense the water level within the tube. The sensor may be for example a conductivity sensor, and is connected to the control means by cable 90.

In some versions of this embodiment the device comprises a light source 92, for example a LED source extending along the rear flange region 54, to indicate the edge of the platform, and optionally to indicate that the platform is moving, or is about to move.

The invention has been described by way of examples only and it will be appreciated that variation may be made to the above-mentioned embodiments without departing from the scope of invention. Firstly it will be understood that any features described in relation to any particular embodiment may be featured in combinations with other embodiments.

With respect to the specification therefore, it is to be realised that the optimum dimensional relationships for the parts of the invention, to include variations in size, materials, shape, form, function and manner of operation, assembly and use, are deemed readily apparent and obvious to one skilled in the art, and all equivalent relationships to those illustrated in the drawings and described in the specification are intended to be encompassed by the present invention.

Therefore, the foregoing is considered as illustrative only of the principles of the invention, with variation and implementation obvious and clear on the basis of either common general knowledge or of expert knowledge in the field concerned. Further, since numerous modifications and changes will readily occur to those skilled in the art, it is not desired to limit the invention to the exact construction and operation shown and described, and accordingly, all suitable modifications and equivalents may be resorted to, falling within the scope of the invention as set out in the accompanying claims.

Claims

Claims 1. A folding flood barrier device comprising: a base having an upper surface and a lower surface, a front and a rear edge, a platform hinged to the front edge of the base by means of a hinge mounted on a front edge of the platform and the front edge of the base, the platform being adapted to move between a first folded position in which it lies substantially flat on the base and a second raised position at an angle to the upper surface of the base, a flexible bag mounted on the upper surface of the base and attached to the lower surface of the platform, the bag having an interior space configured to receive and retain water and an inlet into the interior space, and a water inlet means to supply water to the interior space, wherein the bag is adapted to fold from a first collapsed configuration to a second inflated configuration when water is introduced into the interior space while moving the platform from the first folded position to the second raised position, the bag comprising: a first side portion attached to the upper surface of the base, a second side portion attached to the lower surface of the platform, a third side portion extending between the first and the second side portions, and first and second end portions joined to the side portions to form a closed interior, and one or more preformed folding regions provided in the third side portion adapted to cause the third side portion to fold between the first and second portions when the bag is in the first collapsed configuration.
2. A device according to claim 1 configured such that when inflated the bag has an approximately triangular profile, with the first and the second sides held substantially planar by means of their attachment to the base and to the platform respectively, and the third side forms a substantially planar sheet between them.
3. A device according to claim 1 configured such that when inflated the third side has a convex substantially curved profile.
4. A device according to claim 1 configured such that when inflated the third side has a concave substantially curved profile.
5. A device according to claim 1 configured such that when inflated the third side has a profile comprising two or more planar regions.
6. A device according to any preceding claim comprising a release valve connected to the inlet to the bag to release water from the interior of the bag.
7. A device according to any preceding claim wherein the said preformed folding region comprises one of a fold or a corrugated region formed in the third side portion and extending substantially parallel to the axis of the hinge.
8. A device according to any preceding claim wherein the said preformed folding region is defined by an internal member within the interior space attached to the interior of the third side portion at the folding region.
9. A device according to claim 8 wherein the said internal member is attached at its other extremity to the internal side of one of the first side portion, the second side portion or a joining region between them.
10. A device according to any preceding claim wherein the internal member forms a partition within the interior of the bag dividing the interior space into a lower compartment and an upper compartment.
11. A device according to claim 10 wherein when inflated the bag has a third side that comprises two planes joined at the folding region and meeting at an angle less than 180 degrees.
12. A device according to any preceding claim wherein the folding region comprises a weight configured to pull the folding region downwards towards the base when the bag is emptied and moves towards the collapsed configuration.
13. A device according to any preceding claim wherein the water inlet means comprises a non-return valve.
14. A device according to any preceding claim wherein the bag is adapted such that when filled the end portions of the bag bulge outwards beyond the sides of the base and the platform.
15. A device according to any preceding claim further comprising a control means to control a pump configured to pump water into the bag.
16. A device according to claim 15 comprising a sensor means adapted to sense water level and the control means is configured to actuate the pump in response to signals from the sensor.
17. A device according to claim 16 comprising two or more water level sensing means adapted to be mounted in a vertically separated configuration.Amendments to the claims have been made as foliws: Claims 1. A folding flood barrier device comprising: a base having an upper surface and a lower surface, a front and a rear edge; a platform hinged to the front edge of the base by means of a hinge mounted on a front edge of the platform and the front edge of the base, the platform being adapted to move between a first folded position, in which, the platform lies substantially flat on the base; and a second raised position at which the platform is arranged at an angle with respect to the upper surface of the base; a flexible bag mounted on the upper surface of the base is attached to a lower surface of the platform, the bag comprising: a first side portion attached to the upper surface of the base, a second side portion is attached to the lower surface of the platform, a third side portion extends between the first and the second side portions, first and second end portions joined to the side portions to form a closed interior volume which is configured to receive and retain water; the third side portion has a profile comprising two or more planar regions providing preformed LI') folding regions that are adapted to cause the third side portion to fold between the first and second portions when the bag is in a first collapsed configuration; an inlet into the interior volume of the bag permits the supply T" 20 water to the interior volume of the bag, wherein the bag is adapted to expand C from a first collapsed configuration to a second inflated configuration when water is introduced into its interior volume while displacing the platform from the first (folded) position to the second (raised) position.2. A device according to claim 1 configured such that when inflated the bag has a triangular profile.3. A device according to claim 1 configured such that when inflated the third side has a convex curved profile.4. A device according to claim 1 configured such that when inflated the third side has a concave curved profile.5. A device according to any preceding claim comprising a release valve connected to the inlet to the bag to release water from the interior of the bag.6. A device according to any preceding claim wherein the preformed folding region comprises one of either a fold or a corrugated region formed in the third side portion and extending substantially parallel to an axis of the hinge.7. A device according to any preceding claim wherein the said preformed folding region is defined by an internal member within the interior space attached to the interior of the third side portion at the folding region.8. A device according to claim 7 wherein the said internal member is attached at its other extremity to the internal side of one of the first side portion, the second side portion or a joining region between them.9. A device according to any preceding claim wherein the internal member forms LI') a partition within the interior of the bag dividing the interior space into a lower compartment and an upper compartment. rr" 20 10. A device according to claim 9 wherein when inflated the third side portion C comprises two planes joined at the folding region and meeting at an angle less than 180 degrees.11. A device according to any preceding claim wherein the folding region comprises a weight configured to pull the folding region downwards towards the base when the bag is emptied so as to move towards the collapsed configuration.12. A device according to any preceding claim wherein the water inlet means comprises a non-return valve.13. A device according to any preceding claim wherein the bag is adapted such that when filled end portions of the bag bulge outwards beyond its sides of the base and the platform.14. A system according to the device of any preceding claim further comprising a control means to control a pump configured to pump water into the bag.15. A system according to claim 14 comprising a sensor means adapted to sense water level and the control means is configured to actuate the pump in response to signals from the sensor.16. A system according to claim 15 comprising two or more water level sensing means adapted to be mounted in a vertically separated configuration.17. A device as substantially herein described with reference to the Figures. IC) r rC r