What is a Rain Garden?

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You may have heard the term Rain Garden a few times, but what exactly is it? A rain garden is an earthen depression in the ground often filled with amended soil, decorative rock, and native plants. Rain gardens act as natural sponges, effectively capturing and managing rainwater runoff from new developments and large additions to existing homes. By incorporating these gardens into the landscape, they not only prevent flooding and erosion but also protect water quality and promote sustainable urban development.

The Necessity of Rain Gardens

In bustling urban environments like Metro Nashville and the City of Franklin, managing stormwater runoff is a top priority. The rapid expansion of waterproof surfaces like rooftops, patios, and driveways have led to increased runoff, putting a strain on municipal stormwater systems and causing flooding in some areas. To address this issue, state and local authorities have recognized the importance of rain gardens as an eco-smart solution.

The Design of Rain Gardens

At the heart of a rain garden’s success lies its unique design. Careful planning and selection of native plant species ensure optimal functionality and aesthetics. When rainwater flows off surfaces on your property, it is directed towards the rain garden, where a natural process unfolds:

Special Amended Soil

The local authorities in Metro Nashville and the City of Franklin require the use of specially amended soil within rain gardens. This amended soil enhances drainage, allowing rainwater to seep into the ground more effectively. Also, it supports healthy plant growth, creating a flourishing ecosystem.

Capturing Rainwater

As rainwater enters the rain garden, the amended soil acts as a sponge, absorbing the water and preventing it from overwhelming the main stormwater system.

Filtering and Purifying

The unique blend of amended soil not only facilitates water infiltration but also acts as a natural filter ensuring cleaner water reaches the groundwater table.

Native Plant Haven

Metro Nashville and the City of Franklin encourage the use of native plant species within rain gardens. These plants adapt to the local climate and soil conditions, making them hardy and resilient. As they grow, their roots enhance soil structure, further promoting filtering and deep drainage.

Building Your Rain Garden

If you are required to build a rain garden on your property, the local municipality will have standards for the contractor to abide by. If you are not required by a municipality to install a rain garden and would like to install one for water mitigation and aesthetic appeal, collaborating with landscape professionals experienced in rain garden design is a wise choice. Here is a general outline of the installation process:

  • Compliance with Regulations: Ensure your rain garden design adheres to the guidelines set by Metro Nashville and the City of Franklin if required.
  • Site Selection: Identify a suitable location where rainwater naturally collects or flows. You will have to think about how water will discharge from this location if it was to fill up. You do not want it to flood an area close to a structure. Consult with experts to determine the ideal size and shape for your rain garden.
  • Excavation and Amended Soil: The rain garden basin is excavated and the specially amended soil is introduced. This soil mix improves how water flows through the ground and nurtures plant growth.
  • Native Plant Selection: Choose native plant species best suited to your area’s climate and soil. 
  • Professional Installation: Engage a qualified landscaping team to handle the installation process. They will ensure the rain garden is expertly crafted and all necessary steps are followed. If the garden is being installed for a municipality, the installation team will need to document the process for dimensions and certify where materials came from for approval.


Rain gardens are not only a visual delight but also a powerful tool in relieving stormwater runoff in urban environments. By embracing these gardens and incorporating specially amended soil, you will not only comply with local regulations but also enjoy numerous benefits. From flood prevention to improved water quality and vibrant wildlife habitat, rain gardens offer a sustainable and beautiful solution for controlling rainwater runoff.

If you are ready to create a rain garden on your property or have any questions about this eco-smart solution, our team of experts is here to assist you every step of the way. 

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