R-Tank
R-Tank
R-Tank maximizes underground storage volume with modular, lightweight design for efficient stormwater management.
Underground Stormwater Storage and Infiltration
Nexterra's R-Tank Stormwater Modules provide a flexible, high-capacity underground storage solution designed for today's stormwater management needs. With five available configurations ranging from 2 inches to more than 7 feet tall, the system adapts easily to site-specific requirements. Applications include green infrastructure, permeable paver systems, detention, infiltration, and even water reuse when paired with pump integration.
R-Tank is a modular underground stormwater storage system that delivers high capacity in a compact footprint while supporting detention, infiltration, and rainwater harvesting strategies. With configurable heights, high void space, and traffic load capacity for surface use, R-Tank helps projects reduce surface storage needs, maximize developable land, and meet site-specific stormwater objectives.
Strength and Flexibility in Design
R-Tank modules are engineered to perform under the heaviest demands, providing durability that supports both infrastructure and long-term stormwater goals. Their versatility in construction makes them an asset on projects where conditions can vary dramatically. Benefits include:
- Engineered to withstand HS-20 and HS-25 traffic loads.
- Handles cover depths from 6 inches up to 16 feet.
- Modular components simplify design and installation across a wide range of projects.
R-Tank combines high storage efficiency with traffic load strength and rapid installation to lower construction cost and preserve surface area. Lightweight modular units stack and interlock to create the required detention or infiltration volume, and can be shipped preassembled or assembled on site for flexibility.
Each unit provides approximately 95% open space for water storage and can be wrapped for infiltration or lined for detention and water reuse. These features make R-Tank an effective alternative to large surface basins and many traditional underground systems.
Performance Built for Every Site
Underground storage from R-Tank delivers dependable functionality while giving project teams freedom to optimize land use above. Each installation can be tailored to match specific performance goals, from flood control to water reuse. Applications include:
- Geosynthetic wrap allows for multiple functions: infiltration, detention, or water harvesting depending on fabric choice.
- Maximizes available site space by moving storage underground.
- Reduces surface-level impacts while meeting stormwater regulations.
R-Tank functions as a configurable subsurface storage array that detains stormwater and, when permitted, allows infiltration back into the ground. Water moves through the system in a defined sequence that protects capacity and promotes long-term reliability:
- Runoff enters the R-Tank array and is detained within the modules to provide storage between storm events.
- Where designed for infiltration, geotextile wrapping or configured voids allow exfiltration to surrounding soils.
- For detention or harvesting use, collected water is routed to outlet piping, pumps, or controlled discharge structures as required by design.
- Overflow and bypass provisions are provided to safely route excess flows during peak events and protect the system.
Specifications and Design Options
R-Tank provides flexibility across site conditions by offering multiple configurations and structural strengths. Designers can match hydraulics, cover depth, and loading requirements without excessive excavation while maintaining high storage efficiency.
- Five standard module heights from 2 inches to more than 7 feet.
- Supports HS-20 and HS-25 vehicular loads with cover depths from 6 inches to 16 feet.
- Approximately 95 percent void space to minimize required footprint.
- Fabric wrap for infiltration, liners for detention or reuse, and pump integration for harvesting.
- Available preassembled for rapid install or as components for reduced freight and staging.
Best-Fit Environments
R-Tank is a smart choice whenever underground storage, infiltration, or rainwater harvesting helps make better use of land than traditional surface ponds. It adapts well to new construction, retrofits, and even sensitive sites where space and disturbance must be carefully managed.
- Stormwater detention in urban or suburban areas where every square foot of surface space counts.
- Infiltration systems in soils and locations where releasing water back into the ground is safe and permitted.
- Rainwater harvesting setups combined with pumps and treatment for non-potable reuse like irrigation or cooling.
- Retrofit projects limited by shallow depth, existing utilities, or tight site constraints.
- Parking decks, roadways, and other developments that need underground storage beneath traffic-ready surfaces.
- Large developments requiring high-capacity storage with minimal aboveground impact.
- Environmentally sensitive projects near wetlands, waterways, or conservation land where surface disturbance must be minimized.
Performance Highlights
R-Tank delivers measurable outcomes for storage efficiency, constructability, and long-term site value. Its engineering characteristics are proven in a wide range of installations and documented case studies.
- High void space provides industry-leading storage per cubic foot so designers can reduce the size of subsurface systems compared to older modular approaches.
- Configurable heights and stackable modules allow designers to avoid utility conflicts and adapt to variable subsurface conditions.
- Structural capacity to support HS-20 and HS-25 traffic loads enables installation under roadways, parking areas, and other driven surfaces with appropriate cover.
- Lightweight construction and modular assembly reduce installation time and lower construction costs relative to cast-in-place alternatives.
Upstream and Downstream Integration
R-Tank is designed to integrate seamlessly within the broader stormwater system, connecting with both upstream pretreatment measures and downstream discharge or reuse components. This ensures that the storage modules function efficiently as part of a complete hydraulic network that protects capacity, promotes infiltration, and supports water quality goals.
Typical upstream and downstream elements include:
- Pretreatment structures: such as hydrodynamic separators, filter cartridges, or catch basins to remove sediment and debris before entering the R-Tank array.
- Flow control devices: like orifices, weirs, or valves to regulate inflow rates and prevent surges during peak storm events.
- Downstream conveyance systems: that route treated water to infiltration zones, controlled discharge points, or reuse systems such as pumps and storage tanks.
- Overflow bypasses: that provide additional protection during extreme rainfall by safely directing excess flow around the system.
By connecting upstream treatment and downstream management components, R-Tank becomes a fully integrated stormwater solution that enhances performance and simplifies compliance across a wide range of site designs.
Additional Resources
Design assistance, specification sheets, assembly guidance, and case study summaries are available to support hydraulic sizing, geotechnical checks, and installation planning. Nexterra can provide cartridge counts, fabric recommendations, and pump integration guidance upon request.
Support Material
Nexterra Environmental partners with leading manufacturers to deliver the industry’s most trusted solutions.