Green Stormwater Infrastructure: Depaving & Permeable Pavement
Depaving is the removal and replacement impervious surfaces like concrete and asphalt with pervious solutions. Once pavement is removed, it can be replaced with a variety of options from loose stones, gravel, or open-cell concrete, to permeable concrete or pavers that allow water to soak through. Permeable paving solutions allow water to be absorbed into the ground as opposed to flowing off the surface and into the nearest storm drain. This prevents urban pollutants like oil, fertilizers, and other items from being washed into sewers where they eventually end up in our waterways or must be handled by water-treatment facilities. Depaving also helps to reduce the urban heat island effect as pavement can get hot! Replacing pavement with vegetation can help to cool urban temperatures while creating a more aesthetic urban environment.
- Find a location that can be depaved. Maybe this is an area that already has broken, unsightly concrete and is in need of an update. Consider what you will replace it with: mulch, gravel, vegetation, permeable pavers, etc.
- Secure permission to depave the area and contact your local utility companies to mark underground utility lines.
- Determine what tools you will need to remove the pavement. The tools will depend on the thickness of the pavement (pickaxe, jackhammer, sledgehammer, concrete saw, etc.).
- Identify adult volunteers who can help with this project.
- Determine what you will do with the removed pavement. Can you reuse or recycle it?
- Bring the soil you have exposed back to life by adding organic material such as compost to it. You may need to loosen the compacted soil.
- Now add your pervious materials or plant with some native plants!
- Schools often have regulations about "trip-free" surfaces on school grounds that protect students from trip hazards. Removal of pavement can be in conflict with these restrictions.
- Depaving is hard work and requires the use of tools and heavy lifting. It may be a challenging project to undertake with students. Consider having adult volunteers help with depaving and recruit students to help with replanting if you are using vegetation in place of pavement.
Maintenance Schedule and Other Notes
- Maintenance will depend on what you use to replace your pavement.
- Pavers may need some weeding and sediment removal and gravel may need to be replaced after some time.
Related Lessons and Classroom Integration
- How Natural Areas Filter Water (Nature Works Everywhere)
- Urban Runoff: Design a School Stormwater Management Plan (Nature Works Everywhere)
- Water: Garden Lesson Plan (Nature Works Everywhere)
- Campus Stormwater Audit Lesson (Drain Rangers)
Additional Project Resources
- Sustainable Urban Design: Educator’s Toolkit for Project-Based Learning
- Creating Urban Habitats:
- Changes in Grounds Management:
- Green Stormwater Infrastructure: