Rain Garden
A landscaped depression designed to capture and filter stormwater runoff, featuring plants that can tolerate both wet and dry conditions. Rain gardens serve as both beautiful landscape features and functional stormwater management systems, helping to reduce flooding, prevent erosion, filter pollutants, and recharge groundwater while providing habitat for beneficial wildlife.
Key Features
Strategic Placement
Located to intercept runoff from impervious surfaces like roofs, driveways, and patios, typically positioned at least 10 feet from building foundations to prevent water damage.
Bowl-Shaped Design
Shallow depression with gently sloping sides that temporarily holds water during rain events, allowing it to slowly infiltrate into the ground rather than flowing into storm drains.
Specialized Soil Mix
Well-draining amended soil blend that balances water infiltration with filtration capabilities, typically containing sand, compost, and native soil in specific proportions.
Moisture-Adaptive Plants
Species that can withstand both periodic flooding and dry periods between rain events, often arranged in zones based on water tolerance from the wettest center to drier edges.
Inlet and Overflow
Designed entry point for water to flow into the garden and a planned overflow area for safely directing excess water during heavy rain events to prevent flooding.
Mulch Layer
Protective covering of shredded hardwood or similar material that prevents soil erosion, suppresses weeds, retains moisture, and provides additional filtration of pollutants.
Design Variations
Native Plant Rain Garden
Features indigenous species adapted to local climate conditions, requiring minimal maintenance once established while providing maximum ecological benefits and habitat value.
Formal Rain Garden
Incorporates more structured design elements with defined edges, organized plantings, and architectural features while maintaining stormwater management functionality.
Streetside Rain Garden
Specialized design for capturing road runoff in urban or suburban settings, often in public right-of-way areas with plants tolerant of road salt and other urban pollutants.
Cascading Rain Garden
Series of connected rain gardens at different elevations that manage water flow on sloped properties, creating a stepped system that slows and filters water as it moves downhill.