The Importance of Rain Gardens in Summer Storms

Rain gardens are designed to manage stormwater runoff from impervious surfaces such as roofs, driveways, and sidewalks. They allow water to slowly infiltrate into the ground rather than flowing directly into storm drains or waterways.

They are typically designed as shallow depressions in the ground with sloping sides. The size and shape of the garden depend on factors such as the amount of runoff, soil type, and available space. Rain gardens are made with a well-draining medium, and plants and grasses that tolerate both wet and dry conditions. Downspout extensions or surface grading directs water flow to the rain garden.

During intense summer storms, rain gardens can play an important role.

1. Stormwater Capture: During summer storms, rain gardens act as collection basins, for a significant amount of rainwater that would otherwise flow off impervious surfaces. Rain gardens help reduce the volume and intensity of stormwater runoff.

2. Flood Prevention: Summer storms often bring heavy rainfall in a short period, increasing the risk of flooding. Rain gardens temporarily hold and slow down stormwater runoff. The shallow depression and sloping sides of the rain garden allow it to retain water, giving it time to slowly infiltrate into the ground rather than overwhelming storm drains or causing immediate flooding.

3. Water Absorption and Infiltration: Rain gardens facilitate the infiltration of rainwater into the ground. The materials used are well-draining, allowing water to percolate slowly into the soil. This process helps recharge groundwater supplies and reduces the burden on municipal stormwater systems during summer storms.

4. Erosion Control: Summer storms can generate high-velocity runoff that erodes soil and causes sedimentation in waterways. The vegetation and mulch in rain gardens act as natural erosion control measures, holding the soil in place and preventing excessive erosion.

5. Water Quality Improvement: During summer storms, runoff from impervious surfaces can carry various pollutants, such as sediment, fertilizers, pesticides, and oils, into water bodies. Rain gardens function as natural filters, trapping and retaining pollutants in the soil. The plants in rain gardens also help uptake excess nutrients, improving water quality.

6. Environmental Benefits - Rain gardens can provide food and habitat for birds, butterflies, and other wildlife.

7. Aesthetics and Landscape Value: Rain gardens can be functional and also designed to be aesthetically pleasing and can enhance the overall look of a property. Plants chosen can provide color, texture, and visual interest throughout the year.

By including rain gardens near lakes and rivers, and in areas with significant impervious surfaces, the impacts of summer storms can be mitigated. Rain gardens help reduce the risk of flooding, prevent erosion, improve water quality, and contribute to the overall sustainable management of stormwater during periods of heavy rainfall.