BARR Plastics · GRAF EcoBloc
Underground Stormwater Detention Systems
Control peak stormwater flows without sacrificing valuable surface space. Discover modular GRAF EcoBloc detention systems for commercial, residential, industrial and municipal projects.
Design assistance · Product supply · Installation guidance
Concept illustration. Final layout, liner, cover depth and outlet controls depend on engineered project requirements.
Understand the solution
What is stormwater detention?
Stormwater detention temporarily holds excess runoff during a storm and gradually releases it at a controlled rate.
As paved surfaces increase, rainwater reaches drainage systems faster. Underground detention provides storage during peak flows while keeping land available for parking, landscaping and other site uses.
Detention versus infiltration: A detention configuration typically uses an impermeable liner and a controlled outlet. Infiltration systems allow suitable runoff to soak into surrounding soil where site conditions permit.
Collect runoff
Stormwater enters the system from roofs, roads, parking lots and other drainage areas.
Store it underground
Interlocking EcoBloc modules create a reservoir sized for your project requirements.
Release at a controlled rate
An engineered outlet limits discharge to the approved downstream drainage system.
Featured system · GRAF EcoBloc
Modular underground storage, tailored to your site
GRAF EcoBloc uses lightweight, interlocking plastic modules to form a high-capacity underground reservoir. Configure the footprint and depth for your available space, hydraulic requirements and structural loading.
BARR Plastics supports your project with system selection, reservoir configuration, product supply and installation guidance.
Illustrative module assembly, not a dimensional or installation drawing.
High storage efficiency
EcoBloc Inspect SMART offers a 96% storage coefficient, helping maximize capacity within a compact footprint.
Modular configuration
Arrange interlocking cells to suit site dimensions, specified storage volume and installation depth.
Inspectable access
Inspection channels and suitable access components support system monitoring after installation.
High-pressure cleanable
Compatible inspection channels allow maintenance using approved jet-cleaning methods.
Traffic-load applications
Selected variants can be specified beneath vehicle areas when cover and structural design requirements are met.
Lightweight modules
Stackable plastic components support efficient transport, handling and installation logistics.
Specifications vary by EcoBloc model and must be checked against current manufacturer documentation and site-specific engineering.
System overview
How an EcoBloc detention system works
An underground detention system combines modular storage, appropriate lining, inspection access and flow control.
Concept only. Pretreatment, lining, outlet structures and inspection configuration must be designed for each project.
Collected runoff enters through the designed connection and any required sediment-control components.
A liner surrounds the configured EcoBloc modules to retain stormwater temporarily.
Accessible channels allow inspection and appropriate maintenance of the reservoir.
An engineered outlet releases detained water according to the project's permitted discharge rate.
Where it fits
Stormwater detention for a wide range of projects
Make productive use of surface space while providing underground storage for peak stormwater flows.
Commercial developments
Underground detention for shopping centres, offices and other projects with extensive roofs or paved surfaces.
Residential developments
Flexible configurations for townhome communities, multi-family sites and subdivision drainage.
Industrial and logistics facilities
Storage for warehouses, distribution centres and industrial sites with large runoff-generating areas.
Municipal infrastructure
Detention solutions for roads, public spaces and stormwater upgrades in developed areas.
Design & project support
Designed around your site requirements
Every detention project has different storage, loading and discharge requirements. BARR Plastics helps engineers, developers and contractors identify a suitable EcoBloc configuration and plan for installation.
- Required detention volume and site footprint
- Depth of installation, soil conditions and structural loading
- Inlet, outlet, pretreatment and inspection access
- Appropriate liner and backfill requirements
- Module selection, product supply and installation guidance
Continue your research
EcoBloc technical resources
Frequently asked questions
Underground stormwater detention FAQs
How does an underground stormwater detention system work?
It receives runoff from a drainage network, temporarily holds it in an underground reservoir and releases it through a controlled outlet. The system is designed around the required storage volume, peak inflow and permitted discharge rate.
What is the difference between detention and infiltration?
Detention temporarily stores runoff before controlled discharge, typically using an impermeable liner. Infiltration allows runoff to soak into surrounding soil, subject to soil conditions, groundwater constraints and applicable approvals.
Can EcoBloc be installed beneath parking lots?
Some EcoBloc variants support traffic-load applications when specified with appropriate burial depth, earth covering, loading assumptions and structural engineering. Your project design must verify the selected system's suitability.
How do I determine the required detention volume?
A qualified designer sizes storage using local rainfall data, contributing drainage area, runoff characteristics, allowable discharge and local stormwater requirements. BARR can assist with reservoir configuration once project criteria are available.
Can EcoBloc detention systems be inspected and cleaned?
EcoBloc Inspect configurations provide inspection access and channels that support camera inspection and high-pressure cleaning when the correct access components and approved methods are included in the design.
What should I include in a project inquiry?
Send your project location, proposed development type, storage volume or drainage calculations if available, site drawings, traffic-loading requirements and expected installation timeline. You can contact BARR during early planning if some details are not yet known.
Talk to a stormwater specialist
Planning a stormwater detention project?
Tell us about your site and storage requirements. BARR Plastics can help you explore EcoBloc configurations, review project constraints and prepare a quote.
Prefer to speak with our team? 1-800-665-4499 · stormwater@barrplastics.com