How to Reduce Stormwater Runoff at Home
Compiled and fact-checked from cited sources, reviewed by our editorial team.
When rain falls on impervious surfaces like roofs and concrete, it cannot soak into the ground; it runs off across the surface instead. This stormwater runoff causes flooding, erosion, and carries pollution in cities. The good news: with a few simple “green infrastructure” practices at home, you can cut that runoff dramatically. In this comprehensive guide we cover what runoff is, all the main ways to reduce it at home (from rain gardens to bioswales and dry wells), the role of trees and green roofs, and the habits that keep the water clean.
What is stormwater runoff?
Stormwater runoff is rain or snowmelt that flows over impervious surfaces (roofs, driveways, roads) instead of soaking into the ground. Because most urban land is impervious, more than half of the rain that falls becomes runoff.[5] This runoff causes flooding and erosion, and it picks up pollutants such as road oil, fertilizer and sediment and carries them into streams and lakes. The goal is to slow this water down, soak it into the soil, and capture it where possible.[1]
Basic ways to reduce runoff at home
The main methods recommended by EPA’s “Soak Up the Rain” program:
- HowRoof water to lawn/garden
- CostLow
- Effect~30% more infiltration
- BonusFilters pollutants
- HowWater soaks through
- WhereDriveway, patio
- HowStore roof water
- DetailSeparate guide (link)
- HowRetains rain
- BonusAdds insulation
- HowCatch/absorb rain
- EffectHigh
In short:
- Disconnect/redirect the downspout: Send roof water away from concrete and the sewer toward a permeable lawn or garden area, where it soaks into the soil.[3]
- Rain garden: A bowl-shaped, planted depression that collects water from a downspout or driveway; it soaks in about 30% more water than a lawn and filters out pollutants.[6]
- Permeable pavement: Use pervious concrete, porous asphalt or permeable pavers instead of solid concrete; water soaks in at the surface and is stored in the gravel/soil layer below.[2]
- Rain barrel: Captures roof water in a container; it both reduces runoff and provides garden water.
- Green roof and trees: Covered separately below.
Related: We have a separate guide for setting up a rain barrel and capturing roof water: Home rainwater harvesting guide.
More landscape solutions
Beyond the basic methods, you can design your yard to “slow the water down”:
- Bioswale (vegetated channel): A shallow channel lined with amended soil and native plants; it slows and infiltrates water. It absorbs about 30% more water than a lawn and can reduce surface pollution in the runoff by up to 70%.[8]
- Berm (soil/gravel mound): A small mound that redirects water coming off bare soil and slopes toward a chosen spot (for example, a rain garden).[7]
- Dry well / French drain: Systems that take surface water underground into a gravel-filled chamber, where the excess water infiltrates into the soil.[7]
- Reduce impervious surface (“de-paving”): Replace needless concrete and asphalt with trees, shrubs, mulched planting beds, groundcover or permeable surfaces.[7]
- Mulch and soil improvement: Spread bark mulch or compost over exposed surfaces; this dissipates runoff and boosts the soil’s infiltration. Aerating the soil helps too.
- Terrace slopes: Small terraces or berms on hillsides slow the water and reduce erosion.
How do trees reduce runoff?
Trees work in three ways: the canopy (leaf cover) catches part of the rain before it reaches the ground and lets some evaporate (interception); the roots absorb water; and the porous soil around the roots improves infiltration. The effect is large: in the US, if every household planted just one tree, about 62 million gallons of rainwater would be intercepted each year before reaching the ground.[4] Native, deep-rooted plants and groundcovers do the same job on a smaller scale.
How do green roofs reduce runoff?
A green roof is a roof covered with vegetation and a growing medium. It holds rain like a sponge, then slowly releases it through drainage, evaporation and evapotranspiration. This sharply lowers the amount of water that suddenly rushes off the roof; it also provides insulation and cooling for the building.[2]
Habits that reduce pollution
Reducing runoff matters, but keeping the running water clean matters just as much. Simple habits make a big difference:[7]
- Sweep instead of hosing: Clear leaves and debris from the driveway and sidewalk with a broom, not a hose.
- Limit fertilizer and chemicals: Use pesticides/herbicides only when needed and at the recommended amount; the excess washes into the water with the rain.
- Pick up pet waste: It is a source of bacteria; collect it and dispose of it properly.
- Wash the car on grass or at a car wash: Keep soapy water from flowing straight into the storm drain.
- Never pour anything into a storm drain: Oil, paint and chemicals reach the stream directly.
Benefits
Reducing runoff protects not just you, but the environment too:
- Less flooding and erosion.
- Cleaner water: runoff is filtered in the soil instead of carrying pollutants into streams.
- Recharged groundwater: water that soaks into the soil renews freshwater supplies.[5]
Frequently asked questions
What does stormwater runoff mean? It is rain or snowmelt that flows over impervious surfaces instead of soaking into the ground.
What is the easiest way to reduce runoff at home? Disconnect the downspout from the concrete and redirect it to a permeable area like a lawn or garden.
What is the difference between a rain garden and a bioswale? Both are planted infiltration areas; a rain garden is a bowl-shaped spot, while a bioswale is a long channel that also conveys water. A bioswale can reduce pollution by up to 70%.
What does a dry well do? It takes excess surface water underground into a gravel-filled chamber and lets it soak into the soil.
Do trees really make a difference? Yes; the canopy catches rain and the roots absorb it — even one tree per household can hold back millions of gallons of water a year.
Does a green roof reduce runoff? Yes; it holds rain and releases it slowly, lowering the sudden rush, and it also provides insulation.
Sources
- US EPA — Soak Up the Rain. https://www.epa.gov/soakuptherain
- US EPA — Types of Green Infrastructure. https://www.epa.gov/green-infrastructure/types-green-infrastructure
- US EPA — Disconnect / Redirect Downspouts. https://www.epa.gov/soakuptherain/soak-rain-disconnect-redirect-downspouts
- US EPA — Benefits of Green Infrastructure. https://www.epa.gov/soakuptherain/soak-rain-benefits-green-infrastructure
- NRDC — Green Infrastructure: How to Manage Water Sustainably. https://www.nrdc.org/stories/green-infrastructure-how-manage-water-sustainable-way
- Illinois Extension — Rain Gardens and Bioswales. https://extension.illinois.edu/blogs/good-growing/2025-05-23-soak-it-rain-gardens-and-bioswales
- Mass.gov — Stormwater Solutions for Homeowners. https://www.mass.gov/info-details/stormwater-solutions-for-homeowners-fact-sheet-preventing-erosion
- Alabama Extension — Rainscaping Your Yard. https://www.aces.edu/blog/topics/fish-water/rainscaping-your-yard-to-protect-water-quality/