By Laci Leblanc
As part of the growing list of ways that humans are trying to save the earth, rainwater is now the target of many climate-conscious people. Polluted stormwater is a topic of many actions and legislation. However, continued development and lax laws have led to toxic dangers to our water sources.
When it rains, surfaces such as concrete and asphalt prevent the natural drainage of water. Instead, this water collects and follows the least-resistant path. Along the way, it gathers chemicals, fertilizers, and other toxins as it carves through the ground and erodes the soil.
Fortunately, there is a solution to address runoff and ensure groundwater quality. Rain gardens are a low-cost/high-impact answer. They help the natural land, add much visual appeal, and, with enough of them, can help save the environment by keeping toxins out of our water.
What is a rain garden?
In simple terms, a rain garden is a landscaped area designed to collect and absorb water. Usually, this is done to absorb stormwater runoff and excess flood water during heavy rains. They are particularly useful in areas that have reduced the normal drainage of the area. This includes neighborhoods and other developed areas.
Specifically, existing landscaping and use of non-permeable materials lead to drainage issues. When water pools and eventually flows through the streets, it picks up dirt and pollution. In time, this water will make it back into the system through drains, rivers, and lakes. Every time this happens, the environment is damaged, and we suffer for it.
Through some crafty but easy design and maintenance, rain gardens act as cleaning devices. By channeling storm and extra water into rain gardens, the pollutants are filtered out through the plants and ground. This filtered water then returns to the system through natural means. Therefore, it is clean and safe for the environment.
How Does it Work?
Rain gardens are backyard solutions for the natural world - working through the natural action of the environment. Rain garden sites are chosen for their ability to “catch” water, including depressions, bottom of sloped areas and parts of a yard that constantly flood.
After preparing the area, the major step involves planting deep-rooted plants. These can include flowers, trees, and shrubs. However, it is extremely important to use plants native to the area. Rain gardens should be low maintenance, as should the plants. Consider various properties when selecting plants. These include:
Drought tolerance
Expansive root systems
Absorption rate
Benefits to the local area and animals
Once the garden is planted, it can be treated as any other garden. Properly mulched and kept free of weeds, it will maintain itself with some standard watering. Eventually, it will become a native fixture of the land. It will re-emerge after winter, grow itself, and flourish without any help.
And, all the while, it will be controlling pollution and potential floods.
How Does it Help the Environment?
A rain garden helps with two major issues: stormwater pollution and excess flooding. Human lifestyles generate plenty of pollution. As well, construction alters the drainage capabilities of the ground. Together, these two issues create a massive problem.
Stormwater Runoff
Stormwater runoff is dirty stuff. Full of toxins, it can pollute drinking water. It can also lead to erosion through the chemicals that it carries. In flood-prone areas, such as coastal communities and watersheds, polluted stormwater damages the already fragile water system.
Without natural drainage and filtration, this toxic pollution makes it back into lakes, streams, and our water supplies. This can lead to harmful and dangerous algae blooms in lakes and reservoirs. Plus, it can damage the local flora and fauna.
Rain gardens act as those drainage solutions. Trees, bushes, and other plants absorb water through their roots. Rain gardens use plants with high absorption rates and deep, expansive root systems.
When planted in an area prone to holding water, this filtered drainage system cleans the water. Rain gardens can filter 90% of chemicals and 80% of sediments from stormwater. That’s 30% more than a standard lawn.
As climate change advances, runoff will only continue to grow. Weather patterns will change; water tables and sea levels will rise; and erosion will increase. Rain gardens, though small, are the front line solutions to help protect against climate change until the rest of the world follows.
Flood Control
In addition to filtration, rain gardens are great for creating natural irrigation. They replace the natural water cycle that has been interrupted by humans, creating an area to collect and drain water that helps divert polluted flood streams from going into bodies of water.
In addition to the abovementioned pollution control, rain gardens help to reduce erosion. The water is kept contained throughout all seasons. This helps limit ground destruction during wet months, and even potholes in cold months.
Rain gardens are designed to drain within 24 hours. This “fast” absorption helps keep mosquitoes away from areas prone to standing water, while water and natural plants will provide shelter and food for native birds and insects.
As water levels rise, flooding will continue to be an issue. Rain gardens and other drainage features can help prop up the natural cycles, especially in areas where human development has broken the natural flow of water.
How Do You Make a Rain Garden?
Making a rain garden is simple. With a bit of planning, and a little dirty work, your garden can immediately start helping the environment.
Find the Right Spot
The first step should be determining where to place the garden. Look for flood-prone areas, such as ditches and dips in the ground, as well as features that are directing water. Common location tips include:
Within 30 feet of a downspout
At least 10 feet from a foundation
Away from all utility lines and septic tanks
On areas of proper soil composition
These factors will determine the proper size for a rain garden. Clay soils will slow down absorption. This will require a larger garden to ensure a 24-hour cycle. On the other hand, sand is highly absorbent; it can absorb plenty in a small area.
Finally, be sure to consider curb appeal. Rain gardens can be used to increase a home’s value. If possible, plant a rain garden to showcase its beauty and function. Placing a garden in an easily viewable area will also help raise awareness of its purpose.
Use the Right Tools and Plants
Once you’ve found a spot, it’s time to start. Remove enough soil from your measured areas to create an 8-inch berm around the garden. Depending on your soil type, the new hole should be backfilled with topsoil and the right mix of sand to achieve optimum absorption.
After that, it’s time to plant. Choosing plants can take some extra time. Common factors to look for are:
Hardiness zones: Different plants will grow best in specific locations.
Root structure: Deep and voluminous roots absorb more water.
Water tolerance: This provides additional absorption speed or resistance to drought.
Self-sustainability: Will it survive and/or regrow on its own?
Decoration: They should create an area of beauty.
Once planted, use mulch over the top of the garden. This will help keep weeds down, and it will provide additional absorption and filtration. Crushed stones and gravel can be used for the same purpose. Consider additional stones to help direct water and for decoration.
Built correctly, a rain garden will require minimal attention. Provide standard watering for the first year. You can supply fresh mulch and compost during the second spring season. After that, it should be a naturally-cycling ecosystem.
A rain garden is a great tool to fight climate and environmental destruction. Any spot of ground can be altered to create a naturally beautiful filter.
Rain gardens are a natural way to combat man-made problems by saving neighborhoods and protecting local waterways. Not only do they help keep floodwaters in check, but they also filter storm runoff of harmful toxins and debris. They are simple to make, and they are powerful tools to help keep our groundwater clean.