Rain Gardens: The Stormwater Solution Your Backyard

By: Grace Xie

Do you live in an area with many streets, sidewalks, and parking lots? Do you notice water

pooling around after rain? Infrastructure, such as roads, are impervious surfaces that don’t allow

water to be absorbed back into the earth, and some low-lying areas form puddles that struggle

to drain away. Chances are, these places could benefit from a rain garden. Aside from bringing

much-needed color and nature to cities, these gardens have many other environmental benefits.

One of these benefits is runoff mitigation. Rain often deposits more water than the ground can

absorb; runoff is when this water flows over the land’s surface. Impervious surfaces worsen

runoff because even less water is absorbed into the earth. Runoff brings various negative

ecological impacts. It primarily pollutes water and other environments. As it flows over the land,

water picks up many pollutants. Fertilizer, pesticides, oil, bacteria– all are highly detrimental to

plants, animals, and their ecosystems. For example, fertilizer runoff into bodies of water upsets

the natural balance by causing eutrophication, where algae blooms caused by excessive

nutrients deplete oxygen and other resources for wildlife. However, rain gardens can help

mitigate runoff by decreasing the speed of runoff. Water moves significantly slower through

vegetation than impervious surfaces. Vegetation can also serve to filter out pollutants. One way

is through mulch layers, which foster microorganisms that can break down organic material and

products that are petroleum-based. In addition, clay can serve to trap metals, chemicals, and

nutrients. Plants also undergo phytoremediation, where they trap or break down pollutant

particles with their leaves and roots.

Another benefit of rain gardens is stormwater management. First, they intercept runoff from

impervious surfaces such as concrete. Such gardens provide depressions for water to collect

instead of continuing to flow, giving water time to absorb into the earth. For best results, rain

gardens are filled with plants that best maximize water absorption in the area and are positioned

strategically to intercept runoff. The added benefit of better water drainage is the replenishment

of groundwater supplies and an improved visual landscape. Rain gardens are an undervalued

asset in flood risk prevention in many areas.

Additional benefits of rain gardens include a new habitat for small wildlife. They can take refuge

in the vegetation and search for resources. Just like any garden, they can attract butterflies,

birds, small reptiles, and insects among others. Rain gardens can also serve as an important

educator, bringing awareness to runoff pollution and flood risk to visitors. They can teach people

about the many resources found in nature and how citizens can help improve it.

Creating a rain garden isn’t difficult. One simply needs to select an adequate location with

sunlight and water, prepare soil, and choose the best plants. The entire community can even get

involved to help!