Green & Growing… GARDENS & THE GULF

by Linda Wiggen Kraft


Our gardens, lawns and landscapes upstream from the Gulf of Mexico have an impact on the now greatly distressed Gulf.  We may feel helpless with the oil spill so many miles away, but we can help by absorbing, holding and cleansing the water that drains to the Mississippi river from our roofs, hard surfaces, lawns and garden. We can help by having rain gardens, rain barrels, water collection systems and pervious porous surfaces that absorb rain runoff.  We can also switch to organic lawns and gardens to keep toxic chemicals out of the sewers that send these pollutants downstream.  It is estimated that 20% of the dead zone at the Gulf is due to residential lawn and garden chemicals that wash into the Mississippi river.

With St. Louis area’s all too common heavy rains, rain runoff enters the sewer systems and overloads it.  Each year billions of gallons of raw sewage goes directly into tributaries and the Mississippi.  Flooding also occurs that damages property, causes erosion and sometimes drownings, even in urban areas.  In Oct. 2009 the EPA ordered more stringent water quality standards for the 29 miles of river that flow past St. Louis.  Changes are being made with the sewer systems, but homeowners and business property owners are being asked to make changes to help solve these problems, and save tax dollars by not requiring bigger sewage treatment plants.

It’s hard to think that our beautiful gardens and lawns, along with more development, are helping create these problems, but they are.  If each piece of property absorbed and contained rain that falls on it, we would have no problems. “Volume based hydrology” is the emphasis by experts who deal with runoff.  Its goal is to stop runoff in the first place, then deal with it through a “treatment train” of multiple systems to contain and cleanse the water.  An ideal treatment train first involves creating hard surfaces that absorb water such as green roofs, pervious porous concrete or paver type driveways, sidewalks, patios, and parking areas.  Along with rain gardens and rain harvesting through rain barrels or water collection systems. Organic practices and products eliminate toxic chemicals that wash downstream. Homeowners in new or older homes can help in many ways.

Unless a home has a green roof, there is a great deal of roof runoff.  Many older homes have downspouts that go directly into the sewer.  Some homes have downspouts that send water into streets.  Roof water can be collected in rain barrels and cisterns for later use. It can also be channeled for rain gardens.  The ground should slope away from a home, but away from a home it can be sloped for rain gardens.  Some homes already have a wet area that will be enhanced with a rain garden.  A beautiful rain garden will not only stop water from entering the sewer and filter pollutants, it will be a blooming wildlife habitat that will bring beauty and life to the landscape.

Often the runoff from one property to the next is a problem.  In University City six homeowners along one side of a hilly street have signed up for a multi year study of how rain gardens will effect their drainage problems and the runoff that goes into the sewers.  Measurements are being taken this summer before construction of the rain gardens in the fall. The Deer Creek Water Shed Alliance, a project of Missouri Botanical Garden and its partners MSD, Washington University, MO Dept. of Natural Resources and MO Conservation Dept., are studying this and two other rain runoff sites that will demonstrate the impact of rain gardens in multiple neighbors landscapes and commercial settings.

The best way to find out about rain gardens, other measures to alleviate rain runoff problems, and how to improve water quality is through websites of local organizations.  These sites have lists of plants, how to evaluate your landscape, how to construct a rain garden and improving water quality.   They are:  Show Me Rain Gardens –  www.showmeraingardens.com,  Shaw Nature Reserve with the most complete info about site evaluation, construction, maintenance and plants – www.shawnature.org/nativeland/raingarden.aspx, Grow Native with native plant info that can be sorted by growing conditions – www.grownative.org, Deer Creek Watershed Alliance with info about water quality – www.deer creekfriends.net, Missouri Botanical Garden’s list of plants in its rain garden – www.mobot.org/hort/rain_garden/default.asp, and Kansas City’s initiative to create 10,000 rain gardens – www.rainkc.com.

Bring beauty and wildlife to your home by letting the rain nourish your gardens and landscape through some or all of these measures.  You will help the local environment and the Gulf’s environment downstream.