Green Infrastructure & Low-Impact Development Solutions Using 3D Cellular Confinement

New developments can enhance public spaces and provide basic needs, such as housing and employment; however, we must consider the environmental effects of these developments in the design stage. As more impervious surfaces are introduced into the natural environment, concerns such as stormwater runoff and the heat-island effect have increasingly been addressed through the adoption of green infrastructure and low-impact development practices. This can be accomplished by integrating systems that reduce runoff and promote natural water infiltration within the ever-increasing built environment.

Incorporating vegetated systems provides myriad benefits when it comes to meeting green infrastructure goals. Vegetated systems not only offer a natural aesthetic but also promote critical stormwater infiltration. These systems are also much cooler than traditional asphalt or concrete surfaces, thus reducing the heat-island effect. While green space is desired, soil stabilization and erosion control solutions are often required for developments. 

The GEOWEB® 3D Soil Stabilization System (geocells) transforms infill through confinement, providing strength and stabilization to cohesionless soils for applications including porous pavements, green retaining walls and slopes, stormwater channels, and tree root protection. The GEOWEB system minimizes environmental impact and offers cost-effective means for creating sustainable, long-term solutions.

Porous Pavements Double as Load-Support Structure & On-Site Stormwater Management System

The Clean Water Act stipulates the need for stormwater management, and most states have developed non-point pollution regulations with specific targets. Local governing bodies may require even more stringent standards if the project is near a protected wetland or water source. Porous pavements help meet these regulations while performing to load-bearing requirements.

In heavier traffic areas where permeability is desired, the GEOWEB® Porous Pavement System offers an economical and environmentally friendly alternative to traditional hard-paved surfaces. The systems perform double duty as a load support structure and an on-site water detention/retention storage basin, reducing or eliminating long-term maintenance requirements and costs for on-site stormwater systems. Fire lanes and occasional-use traffic areas can be built with topsoil/aggregate engineered infill for load-supporting grass pavements, and with GEOWEB reinforcement, the porous pavement system can be designed to accommodate heavy-weight emergency and maintenance vehicles with HS25 loading and greater with minimal required base.

Reduce Runoff with Swales & Vegetated Stormwater Channels

Grassed swales help collect runoff from parking lots by slowing and infiltrating the water while directing it to storm drains. Swales and drainage ditches are typically intended for low- to moderate-intermittent flows. The GEOWEB 3D system helps confine the topsoil while promoting vegetation to prevent failure through erosion.

Testing performed at Colorado State University shows how the GEOWEB geocells function in channel and embankment applications. The results show that vegetated channels can be designed for higher flows when stabilized with the geocells technology and turf reinforcement mat (TRM). The GEOWEB channels can withstand up to 30 feet per second compared to five to six feet per second with erosion blankets.

The GEOWEB vegetated channels can also be designed as tiered retaining wall structures. Intended for low-moderate, or intermittent higher flows during storm events, these channels can be designed with a narrow horizontal footprint to accommodate more volume to help mitigate flooding.

Repair & Prevent Erosion with Green Slopes & Walls

The GEOWEB® Slope Protection System is an economical solution to surface-stability problems on challenging slopes. The GEOWEB system stabilizes the upper soil layer to resist sliding, prevent recurring erosion caused by surface runoff and thereby allowing for the construction of steeper slopes at challenging or complex sites. The system also provides a means of fully vegetating sloped surfaces that otherwise could not support sustainable plant life. 

An embankment along a Maryland state highway was experiencing severe erosion caused by runoff from the impervious roadway. The Maryland State High Administration required a solution to stabilize the slope surface and prevent further degradation. The project engineers selected the GEOWEB Slope Protection System to hold the soil in place while allowing the water to run over the surface, preventing the formation of gullies. The vegetated surface provided a deep root system to further stabilize the slope. 

Retaining walls built with the GEOWEB® system are an economical, green alternative to MSE wall systems—creating a naturally vegetated living structure while meeting structural design requirements. The GEOWEB Retaining Walls can be designed in a variety of configurations to meet specific site requirements. Individual wall panels consist of an interconnected network of corrosion-resistant, HDPE-based geocells that are installed in a step-like configuration to create horizontal terraces. The exposed outer fascia cells create a natural environment for select vegetation and plantings. Indigenous vegetation or specified plantings may be incorporated for aesthetic appeal and sustainability as desired.

Typical applications for GEOWEB Retaining Walls include the following:  bioengineered walls, steepened embankments, dike and levee protection, culvert headwalls, vegetated channel structures, change-in-grade landscape walls, resource protection barriers, and sound berms.

Presto offers a free GEOWEB MSE design program, and you can create vegetated and non-vegetated MSE designs for reinforced slopes, as well as gravity and geogrid-reinforced walls. The software is based on industry-standard design methods and contains specific algorithms that capture the unique interaction between the GEOWEB System, infill, foundation and backfill soils, geogrid reinforcement, and desired safety factors. Presto also offers a SPECMaker® Tool where you can create a customized 3-part CSI-format specification for your project within minutes.

Protect Tree Roots from Traffic Damage

When construction vehicles and equipment intrude upon a tree’s critical root zone, they negatively impact the soil environment through compaction and damage to near-surface roots—ultimately endangering the structural integrity of the tree. By distributing loading and limiting vertical stresses on the soil, the GEOWEB Tree Root Protection (TRP) system protects the critical root zone from damage. The GEOWEB TRP system is especially beneficial in soft soil areas or where no-dig restrictions apply. The tree root protection system can be a temporary or permanent solution.

With a permeable topsoil/vegetation infill, the perforated GEOWEB cell walls offer environmental benefits, such as:

• water infiltration
• lateral movement of air and water
• water and nutrient migration
• promotion of root development

Earn LEED® Green Building Credits by Creating Sustainable Environments

Reducing a site’s overall environmental impact can help reach Green Infrastructure, Low-Impact Development, and green building goals when building in protected or densely populated areas. It can also help meet stormwater regulations that limit the amount of hard surface area in your communities. Integrating the GEOWEB system into development projects may contribute to LEED® green rating credits.

Credit categories include: 

• Reduced Site Disturbance: by creating permeable surfaces and natural stormwater detention facilities
• Stormwater Management: by using vegetated or permeable surfaces that provide stormwater infiltration and reduce stormwater runoff
• Heat Island Effect: Non-Roof: by creating a cooler surface with a vegetated or open-grid pavement system to minimize the impact on microclimate and human and wildlife habitat

Design Support & Resources for Green Infrastructure Solutions 

The engineering team at Presto Geosystems works closely with civil engineers and landscape architects, offering free project evaluation services and on-site support for GEOWEB® 3D Soil Stabilization System solutions. Contact the Presto Geosystems team to request a free project evaluation or learn more about the GEOWEB® 3D system.