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During the next heavy rainstorm, watch how water flows on your driveway. Does it cascade into the street carrying oil, fertilizer, and debris into local streams, or do you see rainfall puddling, then gently disappearing into the ground? Your decision, whether to pave over our planet or install permeable surfaces that allow water to soak in, is a choice between helping to solve water pollution or making it worse. Today’s One Step is about the literal step you take when you go outside: are you walking on impermeable asphalt and concrete, or high-tech permeable pavers and time-tested natural materials like wood chips and crushed stone?

Stormwater runoff pollutes rivers, lakes, and coastal waters, whereas stormwater “soak in” naturally filters fresh water and replenishes groundwater aquifers. When you choose permeable surfaces instead of concrete or asphalt, you allow water to percolate through its natural cycle in a healthy way that sustains all life on Earth.

Quick Start: Test Your Soil and Choose Your Strategy

Conduct a Simple Percolation Test - Before selecting your pathway material, understand how quickly your soil absorbs water. Dig a hole 12" in diameter by 12" deep, with straight sides. Fill the hole with water and let it sit overnight to allow the soil around it to become saturated. The next day, refill the hole with water and measure the water level every hour. Ideal soil drainage is approximately 2 inches per hour, although rates between 1 and 3 inches per hour are generally suitable for most plants. If water drains slower than 1 inch per hour, you'll need enhanced drainage solutions. Along the edge of your driveway and sidewalks, choose plants that are tolerant of wet conditions.

Start Small with Natural Materials - If youare creating a new path or can excavate an existing concrete or asphalt walkway, begin with a small section using locally available materials to determine what works best for you. Wood chips are a good option, and are often free because in many places arborists are looking for places to dispose of them. Wood chip paths can generally last two years, varying with climate, foot traffic, and upkeep, before you’ll need to add more chips. Apply wood chips to a depth of three inches to suppress weeds naturally while allowing water infiltration. Over time, the bottom layers will decompose into rich topsoil. Using a stirrup hoe to kill weeds before covering them will accelerate their decomposition into your soil.

Choose the Right Natural Material - Pine straw (i.e., dried pine needles) has a natural waxy coating that helps retain moisture, creating a dense mat that is more difficult for weeds to penetrate compared to wood chips. Either pine straw or wood chips work well for high-traffic areas, where repeated foot traffic will compress these materials into a dense mat. If these materials are not compressed and dry out, they may float during heavy rains. Crushed stone or gravel are other natural options that allow water through, but are generally not available for free.

Create Defined Edges - Install simple edging using stones, bricks, or metal strips to contain your pathway material and prevent spreading into garden beds. This helps maintain clean lines while ensuring your permeable surface functions effectively.

Intermediate: Strategic Drainage and Material Selection

Install Crushed Stone Base Layers - For longer-lasting pathways, create a foundation system that provides a stable base. Excavate at least six inches deep, then add at least three inches of crushed stone topped with three inches of your chosen surface material. Permeable, pervious, and porous pavers collect and filter not only stormwater that falls on the actual pavement surface area, but they can also treat runoff from nearby impervious areas, such as rooftops.

Address Slope - Permeable paving is not appropriate on steep slopes where erosion can occur. For slopes greater than 5%, consider terracing or having your path wind along the contours of your terrain.

Enhance Weed Control Naturally - Some pine needles have the added benefit of "allelopathy," meaning they contain naturally occurring compounds that suppress the growth of weed seedlings.

Integrate with Existing Landscape - Design your permeable pathways to connect with rain gardens, bioswales, or other stormwater management features. Direct overflow from your pathway into planted areas rather than toward impervious surfaces or storm drains.

Advanced: Engineering Permeable Solutions

Have Permeable Pavers Installed Professionally - For surfaces that you want to last and need to meet stringent performance requirements, such as the ability to travel in a wheelchair over them, choose from several options: porous concrete and asphalt, interlocking concrete pavers with permeable joints, or plastic grid systems filled with gravel or soil.

Design Layered Infiltration Systems - A critical design detail in poorly draining areas is to place permeable, pervious, and porous pavers on top of layers of gravel and larger stones that create a runoff storage reservoir. An underdrain may be required if you expect large volumes of stormwater or if water can't infiltrate into the surrounding soil quickly enough. Consult a professional if you are unsure about your own abilities to measure soil percolation rates and to install a pavement solution that will meet your needs.

Address Challenging Conditions - For clay soils or areas with poor drainage, consider hybrid approaches combining permeable surfaces with subsurface drainage or bioretention areas. Clay soils easily become waterlogged. Under these conditions, adding organic matter, such as finished compost (humus), will increase porosity, allowing the soil to better absorb water.

Implement Comprehensive Slope Stabilization - Most hillsides can be made relatively stable with plants, whose roots hold soil together. Compared to grasses, herbs and flowers that die back every year, shrubs, trees, and other perennials (plants that live longer than one year) provide deeper root systems that effectively hold soil in place while also providing a canopy that reduces the impact of raindrops on the soil surface.

Expert: Comprehensive Watershed Protection

Create Integrated Stormwater Management Systems - Design permeable pathways as part of a comprehensive approach, incorporating features such as rain gardens, green roofs, and bioswales. When you soak up the rain with trees and rain gardens in your yard, you're adding beauty to the landscape while helping to cool the air and reduce urban heat islands.

Monitor and Measure Performance - Track rainfall infiltration rates, monitor for standing water, and measure the reduction in runoff to nearby storm drains. Document the establishment of vegetation and note improvements in local water quality indicators.

Advocate for Community-Scale Solutions - Work with local government to promote permeable paving requirements for new development and retrofit projects.

Maintain Long-Term Functionality - Maintaining wood chip paths involves replenishing the wood chips to maintain a depth of three inches and edging to define your path's boundaries. For paver systems, regular weeding in joints and occasional replacement of clogged aggregate may be necessary.

Understanding the Science: Why Permeable Pathways Matter

The Water Cycle Connection - In natural forest and grassland environments, most precipitation is absorbed by soil and plants, where it is filtered before reaching aquifers or local waterways. When we cover land with impervious surfaces, we disrupt this natural process, causing severe flooding, erosion, and water pollution.

Soil Health and Root Networks - On a slope, a varied planting of perennials is far more effective for clean water than a monoculture mowed grass lawn. When you have a mixture of plants, you have layers of vegetation that the rainfall hits, and when it finally reaches the ground, the force is much reduced. Deep plant roots create channels that enhance soil permeability while their decomposition adds organic matter that improves water retention.

Pollution Prevention at the Source - As rainwater and snowmelt run off our streets, parking lots, lawns, and other surfaces, they pick up pet waste, pesticides, fertilizer, oil, and other contaminants. If the draining water doesn't evaporate or soak into the ground where it can be filtered, it flushes straight into local waterways or the ocean.

Climate Resilience Benefits - As climates change, becoming generally hotter everywhere while some places become wetter or drier, green infrastructure practices can help communities improve their resiliency. Permeable pathways help mitigate both flooding during intense storms and drought by retaining water underground.

Common Troubleshooting and Maintenance

Preventing Weed Growth - Your grass lawn is the primary source of weeds. Reduce the amount of lawn to reduce weeds. Most pine needles naturally release chemicals that deter weed growth, so consider adding them to your mix if you use wood chips. For crushed rock or gravel, sweep off or pick up leaves and sticks to reduce the amount of organic material in your pathway.

Managing Water Flow - Water always flows downhill. Be a control freak and attempt to keep all the water that falls on your land. Install simple berms, swales, or check dams to slow water movement and encourage infiltration rather than allowing fast flow that takes away topsoil.

Add Material - Over time, most permeable surfaces compact and become less able to absorb water. Weeds can get out of control, especially if you have a lawn and sufficient rainfall. Periodically rake up your pathway, use a stirrup hoe to kill all the weeds, and add new material.

The Ripple Effect: From Your Driveway to the Ocean

Every square foot of impervious surface you replace with permeable alternatives helps the natural water cycle make our planet a great place to live. When you choose permeable pathways, you're not just solving a drainage problem—you're protecting your watershed. Take a step to recharge the aquifers that supply fresh, clean water, reduce flood risks that threaten your community, and protect the waterways that allow fish to spawn and children to play.

References and Resources

Technical Guides and Testing

Natural Materials and Maintenance

Professional Installation and Products

Stormwater Impact and Policy

Slope Stabilization and Erosion Control