How to Build a Rain Garden for Catching Rainwater

raingarden surrounded by mulch
If you’re concerned that the run-off from rainstorms and snowmelt coming off of your rooftops, patios, and driveways will cause localized flooding, standing water issues, or soil erosion in your carefully designed and maintained landscape, take heart. There’s a low-tech, organic way to control these potential problems that won’t take much time or cost a lot of money: a rain garden.

A well-designed rain garden is an organic and low-tech method that will channel and direct runoff toward a lower-lying section of your yard and away from any buildings. Fertilizers and pollutants, such as animal waste, brake dust, oils, and automotive chemicals, that get caught in the runoff will be washed into the rain garden’s natural filtration and cleansing system.

When dug into a shallow bowl shape, a rain garden can help to control soil erosion simply by retaining stormwater runoff. Sunken planting beds capture the run-off and hydrate the plants in your landscape. As excess water filters down through the soil, salts and chemical residues are removed before the run-off seeps below the surface into underground aquifers.

As a bonus, your new rain garden will be easy to maintain and attractive to butterflies, birds, frogs, toads, and other wildlife. Consider planting deep-rooted native perennials including Black-Eyed Susans and Ajuga Bugle plants, or hearty native ferns in shadier areas. An Inkberry shrub or dwarf conifer will add nice texture and provide visual interest throughout the winter.

As beautiful and helpful as a rain garden can be, select its location carefully. When property is situated on a hillside where you will likely get a lot of run-off, locate your rain garden in the lowest section of the backyard. Consider burying a plastic drainpipe under the lawn to connect it with the primary downspout for delivering runoff from the roof. We suggest sculpting a shallow channel with gently sloping sides into the landscape to better direct the snowmelt and stormwater runoff.

Positioning your rain garden at least 10 feet from your home or other structures will reduce the amount of rain than could potentially cause water problems in your basement or cellar. By holding this relatively clean water and allowing it to soak into the ground, a rain garden can reduce localized flooding, replenish the local groundwater, and improve water quality.