April showers bring May flowers … and stormwater runoff! Rainwater and melting snow flowing over solid surfaces in our city carries pollutants like chemicals, litter, and pet waste into our creeks and waterways.
Stormwater runoff also contributes to an increased risk of flooding, erosion, water pollution and habitat degradation. When the amount of runoff exceeds the amount that can be held at Combined Sewer Overflow (CSO) Tanks and processed by the wastewater treatment plants, these systems overflow to release untreated, diluted wastewater directly into our waterways.
Reducing runoff and preventing our stormwater system from becoming overwhelmed during storm events starts by soaking up more rain where it falls.
Permeable pavement solutions offer a promising way to reduce runoff issues. Liz from Green Venture explored permeable surface options at a conference, meeting manufacturers reshaping urban landscapes. In this blog post, you will learn about the issues stormwater runoff causes and some of the permeable alternatives on the market.
Garden beds surrounded by hand laid pavers and Porous Pave (a surface that looks like asphalt, but is permeable)
The Role of Permeable Pavement and Surfaces
Permeable pavement and surfaces are designed to allow water to infiltrate through them, reducing runoff and promoting groundwater recharge. They offer several benefits, including:
Stormwater Management:
By allowing water to penetrate the surface, permeable pavements reduce the volume and velocity of stormwater runoff, minimizing erosion and flooding risks.
Water Quality Improvement:
These surfaces filter pollutants and contaminants as water percolates through them, improving water quality before it reaches water bodies.
Heat Island Mitigation:
Permeable surfaces can help mitigate urban heat islands by reducing surface temperatures compared to traditional impermeable materials.
Enhanced Landscaping:
They can support vegetation growth and landscaping efforts by providing a natural infiltration pathway for water and nutrients.
Building a permeable pathway with gravel
Types of Permeable Pavement and Surfaces
Here are some examples of commonly used permeable surfaces:
Permeable Interlocking Concrete Pavers (PICP):
PICP consists of interlocking concrete units with gaps filled with small stones or gravel. These pavers allow water to infiltrate through the joints, reducing runoff and providing structural stability.
Porous Asphalt:
Porous asphalt is designed with larger aggregate particles and less fine material, creating voids that allow water to pass through. It is commonly used in parking lots, driveways, and low-traffic roadways.
Permeable Concrete:
Permeable concrete incorporates a more open structure than traditional concrete, enabling water to permeate through and be stored or infiltrated into the soil below. It offers durability and load-bearing capabilities.
Gravel or Crushed Stone:
Simple yet effective, gravel or crushed stone surfaces provide permeability and can be used in various applications, including pathways, driveways, and stormwater management areas.
Permeable Rubber Surfacing:
Made from recycled rubber, permeable rubber surfacing offers a flexible and porous solution for playgrounds, sports courts, and walkways. It allows water to drain through while providing cushioning and safety.
Implementation and Considerations
When considering permeable pavement and surface options, several factors come into play:
- Site Conditions: Assess soil types, drainage patterns, and existing infrastructure to determine the most suitable permeable solution for the site.
- Maintenance: Regular maintenance, such as debris removal and surface vacuuming, is essential to ensure optimal performance and longevity of permeable surfaces.
- Design Considerations: Proper design, including slope gradients, drainage paths, and subsurface storage, is crucial for effective stormwater management and infiltration.
- Local Regulations: Familiarize yourself with local regulations and guidelines regarding permeable pavement installation, stormwater management practices, and permits.
A house with a permeable gravel driveway, flagstone path and large garden
Manufacturers and suppliers
Green Venture is not associated with or sponsored by any of these manufacturers or suppliers. These are the products we have tested at various green infrastructure demonstration gardens or learned about at the Source to Stream conference:
Oaks Landscape Products
Representing the landscape division of Brampton Brick Limited, Oaks Landscape Products is a solutions-driven manufacturer of interlocking concrete pavement and segmental retaining wall systems.
Oaks permeable interlocking pavers were developed for various degrees of traffic, living street appeal, and northern climates, with consideration for pedestrian safety and wheelchair accessibility.
Unilock
For fifty years, Unilock has been helping people create beautiful outdoor spaces that become treasured places to build lasting memories. Permeable pavers are designed with unique spacer bars and have a wider gap between the stones, allowing rainwater to seep through and absorb naturally into the ground below. These prevent the water from flowing off the surface and into storm drains, where it can become a flood hazard.
Permacon
The unique design of the AquaPave® permeable paver system allows rainwater to drain through six vertical channels built into the paver at a rate of 9000 mm/hr (354 in/hr). The rainwater is also filtered through an Inbitex® geotextile membrane to remove most pollutants before being discharged in a controlled manner into the subsoil and evacuated into an existing sewer system or collected for reclamation and reuse.
Romex
Romex makes permeable hardscapes, offers expert advice, planning, estimates, installer training and more! Contact their experienced and friendly team to learn more about the products and services.
Stormflow Surfacing
Stormflow Surfacing is a permeable pavement company which prides themselves on an environmentally friendly product made from recycled tires. Green Venture worked with Stormflow Surfacing at our demonstration site at 579-581 Barton St E to install a permeable surface for the tenants garage access and loading dock.
Ecoraster
Ecoraster delivers advanced, permeable paving solutions that stand the test of time. This is a heavy duty plastic grid system which can be filled with gravel or another medium.
Hahn Plastics
Hahn Plastics offers several recycled plastic porous paving and ground reinforcement systems that are permeable. Green Venture has worked with Hahn Plastics for a few demonstration sites across Hamilton. Green Venture has worked with Hahn Plastics to install a picnic bench and seating area at 621 Barton St E.
Conclusion
A rain spout leads into a garden by a fence in front of a permeable stone paved drivewayPermeable pavement and surface options offer a sustainable and eco-friendly approach to managing stormwater runoff where hard surfaces for parking, or amenities are required. By allowing water to infiltrate into the ground, these solutions reduce pollution, minimize flooding risks, and support a healthier urban environment. Whether through permeable pavers, porous asphalt, or other innovative materials, integrating these technologies into urban design projects can make a significant impact on water conservation and quality. As we continue to prioritize sustainable practices, embracing permeable surfaces is a step towards creating more resilient and environmentally conscious communities.
Read our Permeable Webinar Recap blog to learn about other installation considerations. https://greenventure.ca/permeable-webinar-recap/
