My name is Craig Stark, Owner, Landscape Designer, and Consultant of Ecoscapes Sustainable Landscaping. I graduated from the University of Minnesota, with a degree in environmental design in 2004. Since then I have immersed myself in rain gardens and native plants as a solution to stormwater problems and loss of habitat for native fauna.

As you think about the neighborhood you live in, imagine being a gallon of water in a rain storm. What do you land on? A roof? A driveway or street? On turf or something that resembles a natural area? What do you pick up and carry with you? Oil, grass clippings, fertilizer, or pet feces? Now, where do you go as newly polluted water?  If you landed in my neighborhood you would eventually make it into the Mississippi River.  Before development of my neighborhood and many like it across the US, it took days or weeks for rain water to make it back to lakes and rivers. After development that natural process is short- circuited via our storm sewers. Water that falls now is quickly drained from our neighborhoods at a rate many waterways cannot handle. Most of this flows to our treasured bodies of water completely untreated. We as designers, architects, engineers, and planners alike must treat water as the precious resource it is as opposed to a waste product to be discarded.

Why not put nature's gift of stormwater to work watering our landscaping instead? Rain gardens capture water that would normally run untreated into sewers. They allow the rain water to infiltrate into the ground as it would have done naturally before development, and allow for a breakdown of excess nutrients, providing a fertile growing area.  As a further benefit these gardens reduce the sediment loads in our waterways.  With their use we can recharge the ground water many of us depend, and that is continually depleting as population growth continues.

Rain gardens have become one of the most environmentally friendly options for my clients and the communities I service.  As stewards of our built environment I would look at replacing our unsustainable landscape practice of shedding water as quickly as possible, with practices that try to capture our stormwater and allow it to infiltrate into the ground. A well draining 200 sq. ft. rain garden can take and infiltrate the water from a 1000 sq. ft. roof and look beautiful to boot.

When planning a rain garden many things must be accounted for: infiltration rate of soil, area draining to rain garden, slope of area, inlet and overflow of rain garden, and last but not least the plants used to make up the area. In planning a rain garden you first must look at siting the rain garden so that water from hard surfaces can be directed to that location. Simplicity is the key, and allowing water to flow naturally to a rain garden is the most cost effective and maintenance free option. A traditional swale is often the easiest method and sometimes drain tile or a French ditch will be needed. A rock creek spillway (dry creek bed) is another attractive way to tackle this issue. Rain gardens should always be sited a minimum of 10’ from any structure with a foundation to avoid any complications.

Sizing a rain garden is dependent upon the soil, the area draining to the rain garden, and the goal time to draining out after a rain event. Rain gardens in clay soils should not exceed 6” in ponding depth and may need soil replacement with engineered soil for very slow draining soils. Sandy soils are much easier to work with as they drain easier and can have a deeper ponding depth up to 12” or more depending on the site. Commercial areas will often need engineered soils to allow for more holding capacity for larger sites and contributing hard surfaces. Rain gardens should always have a planned inlet and outlet. Sometimes the inlet and outlet may be the same thing, and other times it may drain over an entire berm that holds the water in the garden.

Plants are a very key part of this type of project. The right plants will tolerate or even enjoy being temporarily flooded as well as potentially being very dry in times of drought. In our area native meadow or wetland edge plants often work the best, plants that inhabit a similar niche in our natural environment.  In the Twin Cities Metro and the State of Minnesota we have many organizations that are dedicated to our bodies of water and protecting our water resources.

Our traditional solutions for stormwater management are not working or working poorly at best. When I see a traditional stormwater retention basin, I see a mucky pond filled with garbage and excessive amount of nutrients. As land becomes more valuable we can create rain gardens that are assets to our properties as well as solve an environmental problem. We as professionals in the built environment must look at all the environmental benefits or negative impacts of everything we do. Sometime the choices we face are very difficult: balancing budgets, customers’ demands, zoning requirements, and even watershed or city hard surface requirements. These difficulties are often where a rain garden can offer a great low cost solution that isn’t just functional, but will turn the heads of people using our built environments.

About the Author
Craig Stark is a landscape designer, consultant, and owner of Ecoscapes Sustainable Landscaping. Craig spends his free time gardening, remodeling his house, and anything else that gets him outside. He is also excited to have his first child on the way! Ecoscapes Sustainable Landscaping is a full service design / build / do-it-yourself landscaping company serving the Twin Cities metro area.  We specialize in rain gardens, shoreline stabilization, native plantings, traditional landscapes, permeable and traditional pavers, retaining walls, drainage, outdoor kitchens, and entertaining spaces. Please visit their website at www.ecoscapes1.com or contact Craig at craigstark@ecoscapes1.com