So much of our work in helping community members address stormwater issues relies on the ability to capture stormwater runoff and keep it onsite, which helps to prevent flooding and erosion. Best management practices like permeable pavement, dry wells, and rain gardens require varying levels of excavation when they’re installed to ensure that runoff captured within the practice has a place to accumulate and infiltrate into the native soils below.
When considering what type of stormwater management practice may be suitable for a given location, one of the key site characteristics we have to work with is the depth to the water table beneath the proposed practice location. If the water table is too close to the surface, there won’t be any room for captured runoff to infiltrate into the ground and the practice would remain inundated. This is unfortunately a common issue in Coastal Virginia, so it’s often necessary to implement creative stormwater management techniques.
One such technique is a “rain garden in a box,” where a rain garden is installed in an above-ground container, eliminating the need for any excavation. The basic components of traditional rain gardens, including a permeable soil media, mulch, and native plants, are still utilized within the rain garden in a box, so most of the overall function remains the same. A rain garden in a box just has the added requirement of an underdrain to ensure that excess runoff beyond what the system was designed to treat can be released to a stable overflow location away from any building foundations.
This image shows a general cross section for a rain garden in a box. Based on a graphic created by the RE Store
Rain gardens in a box not only allow us to implement stormwater conservation practices where they’re otherwise prevented by high water tables, but they’re also great for properties with limited space for landscaping changes. If you’re interested in learning more about rain gardens in a box, which are also eligible for cost-share funding through the Virginia Conservation Assistance Program, feel free to reach out to me or Emma Rich.
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