High-capacity rain garden system for maximum attenuation within constrained urban environments
HydroPlanter MAX is an enhanced version of the HydroPlanter modular rain garden system, engineered to deliver significantly increased stormwater attenuation where space is limited and runoff volumes are high.
Designed for highways, public realm and development projects, HydroPlanter MAX combines a planted bioretention system with a large internal storage void beneath the soil profile. This creates a high-capacity attenuation system while maintaining the water quality, amenity and biodiversity benefits associated with rain gardens.
With 1.7x the storage capacity of the original HydroPlanter, the system allows designers to maximise catchment area without increasing the surface footprint. Its modular design allows performance to be tailored to site constraints, hydraulic requirements and local authority standards.
HydroPlanter MAX is designed for projects where available space is limited but stormwater storage requirements are high. The increased internal storage volume provides substantial attenuation capacity without requiring additional land take.
The system is particularly suited to retrofit projects, constrained urban environments and developments where traditional SuDS solutions may not provide sufficient storage within the available footprint.
By combining a planted rain garden with high-volume subsurface storage, HydroPlanter MAX helps projects deliver attenuation, treatment, amenity and biodiversity within a single piece of infrastructure.
1.7x greater storage capacity than HydroPlanter
Large internal attenuation void beneath the soil zone
Maintains bioretention treatment through the planted soil profile
Modular and modellable design
Manufactured in the UK from 100% recycled plastic
Suitable for highways, public realm and development projects
HydroPlanter MAX builds on the proven HydroPlanter rain garden concept by incorporating a large internal attenuation void beneath the planted soil profile. The result is a modular system that delivers enhanced hydraulic performance while maintaining the environmental benefits of a planted SuDS feature.
HydroPlanter MAX combines stormwater storage, treatment and planting within a single system, helping projects maximise hydraulic performance without compromising landscape quality.
Choosing the correct configuration helps maximise attenuation performance while maintaining the water quality, amenity and biodiversity benefits of a planted SuDS feature.
HydroPlanter MAX forms part of GreenBlue Urban’s wider HydroPlanter rain garden range, providing the highest attenuation capacity within the family of systems.
HydroPlanter provides a cost-effective modular bioretention solution focused on water quality treatment, amenity and source control, while HydroPlanter Flex delivers a fully integrated, shape-adaptive rain garden system for projects requiring greater flexibility of layout and design.
HydroPlanter MAX builds on the proven HydroPlanter concept by introducing significantly greater storage capacity where hydraulic performance is the primary requirement.
Access detailed guidance covering HydroPlanter MAX design, installation, specification and application within SuDS and urban drainage projects, with practical information to support successful delivery from design through to construction.
CPDs, design guidance and technical documentation used during specification and project delivery.
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HydroPlanter MAX is a high-capacity modular rain garden system designed for projects where runoff volumes are high but surface space is limited. It combines a planted bioretention soil profile with a larger attenuation void below. This allows the system to retain rain-garden treatment, biodiversity and amenity benefits while providing substantially more temporary stormwater storage within the same visible landscape footprint.
HydroPlanter MAX provides 1.7 times the storage capacity of the original HydroPlanter by adding a large internal attenuation void beneath the soil zone. The standard system is suited to modular source control and bioretention applications, while MAX is intended where attenuation is the primary constraint. Both retain a planted treatment profile, but their hydraulic capacities and suitable catchments differ.
It is most relevant where the available footprint is constrained, the contributing catchment is larger or the required storage cannot be achieved efficiently with a standard rain garden configuration. Typical settings include highways, public realm, retrofit and development schemes. Selection should follow hydraulic modelling and site assessment, including levels, outlet control, utilities, structural conditions, planting and future maintenance.
Yes. Its modular and modellable design allows storage and layout to be developed around the site’s catchment, hydraulic targets and available space. The designer should confirm inflow, storage, outlet, drawdown and exceedance alongside landscape and construction requirements. Tailoring the configuration does not remove the need to use the current product data and coordinate the final arrangement with the wider drainage model.
No. The increased storage sits beneath the planted soil profile, so runoff can still pass through bioretention media that supports filtration and planting. HydroPlanter MAX is designed to combine attenuation, water-quality treatment, amenity and biodiversity in one system. These benefits depend on correct soil, planting, inlet and maintenance design; additional storage does not compensate for a poorly configured treatment layer.
