Patent Application
20220268008
The present invention relates to rain gardens, which are used to intercept, attenuate and temporarily store rain water runoff, usually in urban areas having impervious surfaces such as roads, driveways, pavements, roofs and the like.
Storm water drainage in cities is a current challenge for urban planners and engineers. In many urban areas, the existing drainage infrastructure was built for a different era and population. The need for car parking for example, results in many suburban front gardens being paved over, adding to water runoff in storm events to an already overburdened drainage system.
Scientists also predict an increase in heavy rain fall events in the coming decades, raising the likelihood of severe and damaging flooding in cities.
Current initiatives to reduce run off tend to be bespoke, are limited in impact, and expensive to install, requiring considerable engineering input. Replacing underground drainage pipes for larger higher capacity pipes can be highly disruptive to communities, and prohibitively expensive.
Excavating small rain gardens in paved surfaces, to intercept, attenuate and store rain water in engineered surrounds is problematic due to the load bearing and structural requirements of such surfaces. Rain gardens in soft landscape areas can also cause problems with soil erosion and ground stability.
At the same time, there is great resistance from the highways engineering profession for water to be collected within the soil adjacent to highways, due to the potential for destabilisation of the road kerbs and edgings. Those approving new build schemes, also express concerns over the potential desiccation of soils where trees are planted in relatively close proximity to buildings, and have imposed onerous standards that restrict or prohibit their use.
A need exists for an improved design of rain garden which can be mass-produced, which is scalable for different sites, and which can be simply and comparatively easily installed within both new developments and existing streets as well as domestic gardens to help intercept, attenuate and store water runoff, thus easing pressure on the drainage systems in the vicinity, and reducing the potential incidence of surface water flooding.
At the same time, the ability to maximize the benefits of ‘managing water on the surface’ (to fulfil a need for development to be more sustainable) requires all parts of water management schemes to also improve water and air quality, provide a more biodiverse system and contribute to the visual amenity of urban spaces.
According to the invention, a modular rain garden system is provided comprising a plurality of modules, each in the form of a channel section, at least one end of the channel section having an engaging profile configured to engage with a part of another like module so that the modules are configured to be assembled to one another to define an elongate trough for receiving rainwater runoff, and end panels arranged to close the ends of the trough.
The channel section is preferably of substantially U-shaped section.
In one preferred embodiment, one end panel is formed integrally with the respective channel section and the other end panel is formed separately from the respective channel section and engageable with the respective channel section to form the trough. In another embodiment, both end panels are formed separately from the channel section.
In either case, the end panel which is formed separately from the channel section preferably has an engaging profile configured to engage with the channel section. The engaging profile of the channel section and/or the end panel may comprise a simple overlap joint, a flange joint or any other suitable form of joint. Preferably, the engaging profile comprises an interlocking profile to form an interlocking joint with the other component. In a preferred embodiment, the interlocking profile comprises corresponding vertically-running grooves/projections which engage with one another by relative vertical movement.
The system preferably further includes a perforated drainage pipe to receive and transport the rainwater runoff out of the trough. At least one of the end panels may be provided with a removable section to provide an aperture for the drainage pipe to exit the trough.
In preferred embodiments, the channel section and/or the end sections are provided with a horizontal flange on the upper edge for bedding into surround material in use.
As mentioned above, the channel section is preferably substantially U-shaped. Preferably, the channel section comprises a bottom wall and two side walls projecting upwards from the bottom wall. The side walls may project perpendicularly to the bottom wall or they may project at an angle greater than 90 degrees relative to the bottom wall. This will facilitate stacking of a plurality of identical channel sections.
Preferably, the side walls are corrugated (e.g. by means of grooves or projections) to provide increased load-bearing strength. The end sections may be similarly corrugated.
The bottom wall is preferably provided with inwardly-extending projections to provide a void space between the projections which acts as a reservoir at the bottom of the trough.
The projections will serve to space the material above in the trough from the bottom wall so that the space can be filled with water. The system is configured so that this reservoir is not drained from the trough (e.g. by the perforated pipe, which in preferred embodiments will rest on the projections also) but will instead be available to sustain plant life in the trough in dry spells.
The modular rain garden system may further include one or more divider panels to separate the trough into compartments. The projections on bottom wall of the channel section mentioned above may be used to locate and retain the divider panels in position. The divider panels preferably slot into grooves provided in the side walls of the channel sections.
Divider panels may be employed to provide additional strength or rigidity to the trough. They may also or instead be employed to control or limit the flow of water between compartments, for example if the trough is employed on sloping ground. In one embodiment, the divider panels are permeable and are provided with apertures to permit the flow of water between compartments. Such divider panels may be employed when the trough is used on level ground. In another embodiment, the divider panels are substantially impermeable and act as weir walls between compartments. These may be used when the trough is employed on sloping ground. In either embodiment, the divider panels may be corrugated by means of grooves or projections to provide increased load-bearing strength.
Weir plates may also be employed at the joint of two channel sections to provide unimpeded water storage capacity above the top of the trough in most sloping ground applications. Such weir plates would sit above the internal weir walls, and in most applications be fixed within the surrounding walls.
The modular system preferably comprises a plurality of preformed channel sections and two end plates. The system is therefore readily configurable into a trough of the desired length and capacity for the particular installation. Preferably, the plurality of preformed channel sections are identical in all significant respects and are configured to be nestable/stackable to reduce the volume required for transportation and storage. Similarly, the end panels may be configured to be nestable/stackable.
The various components of the modular rain garden system may be formed from any suitable material. The material is preferably generally impermeable, and at least in the case of the modules and end plates will typically be a plastics material. Preferably, the components are formed from recycled and/or recyclable material.
No proprietary product currently exists for this application. This invention is designed to create a “plug and play” rain garden for retro-installation in existing locations or incorporated into plans for new-build areas. The invention allows engineers to fit rain gardens more quickly, with predictable results, be easy to maintain, and provide a beautiful and functional aesthetic in-street and in-garden designs.
The modular rain garden system may be supplied with specific soil mixture and plants for planting within the rain garden, suited to the application. Such planters would have many advantages beyond their primary purpose as it is well known that soft planting in urban areas has multiple beneficial impacts on surrounding communities.
As discussed above, the modular rain garden system may optionally incorporate an integral storage reservoir and wicking to provide reserve irrigation, to sustain plant life in dry spells. The main channel section may be capable of being used individually or be locatable with other body sections with a joining mechanism and will allow for suitable interfaces with existing drainage pipes. The modular rain garden system may be formed with reinforceable walls and allow for drop in weir plates and storm water baffles, allowing the system to be used in sloping applications. The design may incorporate provision for adjacent kerb support. The modular rain garden system is designed with the horticultural requirements of resilient plant material in mind.
At least in preferred embodiments, the invention may provide:
Embodiments of the invention will now be described by way of example only and with reference to the accompanying drawings, in which:
With reference to
A forebay 15 is provided to control the flow of water into the trough 100 and act as a silt and debris filter. A pre-cast concrete kerb 16 provides an overflow lip (75 mm in this example), over which the water W passes when there is a high enough flow of water into the forebay, for example during persistent or heavy rain. Water W may also pass into the trough from other routes, such as from the footway or from roadside inlets where the number of units is greater. The water incident on the trough is initially collected on the surface, and within the aggregate 14, then flows down through the bioretention media 13 and grid layer 12 to the perforated pipe 11, from which it flows out of the trough into a non-perforated pipe for onward connection to the drainage system. Paving stones 17 and kerbs 18 are provided around the edge of the trough 100 to protect the trough and provide an appropriate solid surface.
The use of a pipe 240 to conduct water to a remote location may not always be required. Depending upon the underlying geology, perforations may be provided in the bottom wall of the trough 200 through which water can escape for infiltration into the ground.
End panels 420 and divider plates 430 are provided with removable sections or blanking panels 423 and 433 respectively which can be selectively removed to provide apertures to accommodate a drainage pipe (not shown).
The join between the channel sections 410 is an interlocking joint of the type described below. Grooves 413 and short grooves 414 are provided in channel section side walls 412, similar to the
These figures also show the method of interlocking engagement between the end panel 320 and the channel section 310. End panel 320 is provided with a projection profiles 324 which engage with the reinforcing grooves shown specifically as 317. The end panel 320 is slid down vertically into engagement with the channel section 310 and this makes a sufficiently water-tight join without the need for sealant.
In the arrangements described hereinbefore, the upper edge of the trough is intended to be located below the level of the surrounding ground surface. By way of example, one or more layers of bricks, kerbstones or the like may surround the periphery of the trough. A void is thus defined above the trough. In use, in the event of heavy rain or the like a quantity of rainwater will collect within the void defined above the trough.
As shown in
It will be appreciated that the weir plates of
Channel sections 210, 310 and 410 as well as unitary channel section and end panel 510 are designed to be stackable within each other to reduce the volume required for transportation and storage. Similarly, the same design of end panel may be stackable.
| Number | Date | Country | Kind |
|---|---|---|---|
| 1910568.3 | Jul 2019 | GB | national |
| Filing Document | Filing Date | Country | Kind |
|---|---|---|---|
| PCT/EP2020/070792 | 7/23/2020 | WO |
