The first step in managing runoff is to observe your property during a rain. It can be useful to sketch your observations on a printout of your property from Google Maps/Earth. The ruler tool on these apps can also help you measure distances from buildings and septic fields. As you observe, document any hard surfaces that are shedding water (roof, driveway, patio, etc.) and where that water is going. Look for opportunities to direct water to an area where it can soak into the ground.

An estimated 25-50% of total water usage on residential and commercial sites goes towards irrigating landscapes. This can lead to costly water bills. Why not install a rain barrel to capture the “free” rainwater falling on your roof and use it to water the lawn, garden, or houseplants? A rain barrel is a storage container used to collect rainwater, typically from a rooftop via a series of pipes, for later use. Commercially available rain barrels are made of plastic, stainless steel, or repurposed wooden barrels like those used by wineries or distilleries. Rain barrels come in all sizes, depending on your watering needs and budget. Some gardeners find that a 55-gallon rain barrel fills quickly and doesn’t provide enough water for their needs.

Rainscaping is a way to manage runoff by designing your landscape to keep rain on site where it nourishes plants and soaks into the ground. Rain gardens are like any other landscaped bed, except they are designed to collect and store water long enough for it to soak into the ground. They are bowl-shaped features that receive runoff from a rooftop downspout or any hard surface that sheds water. Filled with native plants that tolerate dry and wet periods, rain gardens provide an attractive habitat for birds and pollinators.

The keys to a successful rain garden include proper site selection, size, and plant choice. Rain gardens are sized to catch the first inch of rainfall in a bowl that is 12-13 inches deep, with a footprint that is at least 10% of the area draining into it. For example, a rain garden that collects runoff from a 500-square-foot roof should be at least 50 square feet in size (500 sq ft X 0.1). If you have the space and want a larger rain garden, there is no harm in going bigger. Avoid building on steep slopes and select a site with soils that drain in 72 hours or less.

For steeper slopes, you still have the option of creating a swale. Swales are linear rain gardens built on contour (that is, perfectly level across the slope). Often, people build multiple swales that are interconnected so that when one fills, it overflows downhill to the next swale. See our guides to rain gardens and swales for a simple soil drainage test, plant list, and other construction tips. 

Trees are considered green infrastructure, as they can be super useful in managing stormwater runoff. As rain falls on the canopy of a tree, the leaves intercept the rain drops, slowing down the potential erosive force as they gather. Rain then flows off the leaf surface and along the branches and trunk of the tree where it can soak into the ground and be taken up by the tree roots. Of course, trees provide many additional services from the cooling benefits of their shade, cleaner air, carbon capture, and food for wildlife, to name just a few.

Flowing waters tie us together more steadily than any other natural force. If spring showers have been creating problems on your property…or if you’re just looking to lower your water bill and boost the natural functionality of your landscaping…April is a great time to make plans for harnessing the rainwater in your life. Clean water in the French Broad is quite literally on us!