Gardening and Landscaping
Capture stormwater in a planted basin that drains safely
A downspout can send substantial water across a yard during a storm. A rain garden collects that flow in a shallow basin, where it can pond briefly and soak into suitable soil.
Place the basin where water can reach it by gravity, on relatively level ground and away from sensitive features. Check local stormwater guidance before choosing a distance from the house.
Use the roof area connected to the downspout, local design-storm requirements, soil infiltration, and planned ponding depth. One basin size will not suit every roof or site.
Pre-wet a small test hole, refill it, then observe how quickly the water level drops. Follow local test dimensions and acceptance criteria, and check more than one spot if soil varies.
Mark the basin, inlet, and overflow before digging. Excavate to the planned depth and make the bottom level so water spreads across the planting area instead of collecting in one corner.
Shape stable, gentle sides and keep the inlet from eroding. Plan a safe overflow route for water that exceeds the basin’s capacity, so excess runoff does not damage the garden or nearby areas.
Choose locally suitable plants that tolerate temporary wet soil and dry spells. Put the wettest-soil plants in the basin center, with plants suited to faster drainage along the outer edge.
Inspect the inlet, basin floor, and overflow after storms for sediment, bare soil, or erosion. Clear sediment before it buries plants or blocks water flow, and water new plants during establishment.
Existing puddles may signal compacted soil, a high seasonal water table, or poor drainage. Connecting more than one downspout may work if the basin is sized for all connected roof area.
A successful rain garden combines a suitable location, tested soil, a basin sized for its roof area, protected flow paths, and plants suited to wet and dry conditions.
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