NC Cooperative Extension Service
Since there is always just about the same amount of water on earth, ever wonder how it gets clean? Most cities have a system to clean the water using mechanical processes. But this is a small fraction of the world’s water. The rest is cleaned by nature through the cycling of nutrients.
When rainwater falls on the ground it is likely to hit one of two landscapes: urban or rural. On the rural landscape the drop will likely hit plants, dirt, fertilizer, pesticides, and manure. If it hits the urban landscape it hits gas byproducts, oil, litter, and more. Needless to say, off of either landscape that water is not something you want to swim in, drink, or eat a fish out of.
The raindrops that hit these landscapes slide over the land surface, picking up any loose debris. It enters the waterways and streams, then meanders into lakes and ponds. All the while, a small percent of the water evaporates, leaving whatever was picked up along the way in higher concentrations. If it did this without any filtration, rather than clear, clean lakes and ponds we would have stinky sewage slurries. After all, once the debris get into a lake or pond, they are there until something removes them.
The trick to nature’s cleaning is an old saying: One man’s trash is another man’s treasure. While much nitrate-nitrogen in our water would be unhealthy for us, soil bacteria find this quite delicious. They are able to convert this waste product into Nitrogen gas. Nitrogen gas is harmless, and naturally makes up about 78 percent of air.
The most enthusiastic of nature’s “dumpster divers” are the wetlands. Containing large amounts of macro and micro biota (they provide 50 percent of all nest sites for bird species in this country), these seemingly useless pieces of land can filter out 85 percent of the nitrate-nitrogen, sediment, and phosphorus from the water that passes through them, according to research sited by the University of North Carolina’s Cooperative Extension.
At the same time as they are treasuring our trash, they are also producing their own trash, which we treasure. They are responsible for 75 percent of all commercially harvested fish, according to the US EPA, and, again, cleaner water.
They also do not take up much space. North Carolina Cooperative Extension found research that indicated 30-50 feet of wetland, prior to entering a stream can reduce nitrate-nitrogen content of the run-off water by 85 percent annually. They found another study that shows 13 feet of wooded buffer can reduce sediment and phosphorus by 85-90 percent. Urban forested buffers along streams were found to reduce nitrate-nitrogen level to within drinking water levels, exceeding the minimum standards.
This is good news for the health and vitality of our landscape, and why, once their importance was realized, the U.S. government has chosen to protect wetlands in the farm landscape. Despite its efforts, it is believed the United States has lost over half its natural wetlands; over 110 million acres of loss since the 1600s. This loss has been through urban and farm settlement.
In recent years, as the buildup of pollutants in our water bodies have begun causing major issues, a renewed emphasis has been placed on the benefits on nature’s recycling system.
Building a wetland in your back yard or incorporated in your farm scape is a bit tricky, but with a little knowledge and effort can create beautiful landscaping as well as healthier water, more bird activity, and healthier fisheries.
Blue flag iris, cardinal flower, and swamp milkweed are some attractive native flowering wetland species. Red Osier Dogwood, Winterberry, and Pussy Willow are native decorative shrubs that add texture to your plant palette. For larger weltands, red maples, white oaks, and sycamores can add shade.
Wetlands need to be placed where they will receive water, either naturally or from an artificial source, like a street, gutter, or driveway. The water, once in the wetland needs to move slowly most of the time, though not stagnant. Natural wetlands are found on the banks of rivers, low spots, and wide flat areas of rivers.
For more information on how to create a wetland in your backyard, check out: http://www.nrcs.usda.gov/wps/portal/nrcs/detail/national/newsroom/features/?cid=nrcs143_023525
If you are a farmer interested in creating, fixing, or simply protecting a wetland on your farm, give us a call (937) 492-6520. There are programs financial incentive programs that can help. The NRCS is an equal opportunity provider and employer.