A New Wetland

Few of us have the luxury of living with a wetland in our home landscape. Developers purposely build in uplands and use fill to make sure that the lots they  build on are elevated enough to protect the new homes from flooding. That makes sense. Across this nation and, I suspect, most others we end up residing in landscapes too well drained to support wetland plants.  Many of us accept that situation and the result is that we deprive ourselves of some outstanding plants that require lots of moisture.
I have created wetlands in my landscapes now for a great many decades, however, and it is not difficult to do. I have posted to this blog previously about creating a small wetland using a large landscape pot, but such an arrangement limits the number and diversity of plants I can add. I would need at least a half dozen such pots to include the pollinator plants my landscape plan calls for. A simpler approach is the one I've just finished here in my new home in Holiday.  It requires no advanced engineering degree and a minimal investment in materials.
If you have an area in your landscape that receives runoff from your rain gutters, it is an ideal location as long as the site is also relatively sunny.  This area is in my back yard and was a mix of turf grass and weeds. Water from the downspout was essentially wasted on an area that was doing nothing for the natural world. It is easy to access and it will eventually be at the outer edge of where I intend to install my deciduous "forest".  Since it is at the southern edge, it will continue to get good sunlight even after the trees mature. It seemed like an ideal location for this project.
I could have made this larger, but I chose to make it circular with a diameter of about six feet. Once I outlined the area, I dug the dirt out to a depth of about 2 feet. I will not be planting it with woody species and herbaceous wetland wildflowers have very shallow root systems. There is no need to dig it deeper. Once the hole is dug, the area has to be measured in order to get the right sized pond liner. Pond supply companies (and I suspect many others) carry pond liner material and they cut this to my specifications. I only had to give them the dimensions - they did the math.  Purchase a heavy duty pond liner - made for this purpose. Do not skimp by purchasing a thinner piece of black plastic as it won't wear well over the years.

This piece of liner cost about $40 dollars from my local pond supply company. Stretch the liner out into the hole and make sure that it is firmly touching the bottom - everywhere. It will take some time to move soil around to make sure it is.
With the liner in place, it is time to backfill the hole with the dirt you originally excavated.  Make sure that the newly added soil is firm and completely covers the liner. it also should be level with the original elevation. You'll want one edge to be a bit lower than the rest so that excess water drains off in the direction you intend. DO NOT let it back up against your home, but away from it.  This difference in elevation does not have to be more than an inch or two.

Wetland soils will form naturally in these conditions. There is no reason not to use your original dirt to backfill your wetland area.  I have stabilized the downspout with a large flat rock and further reduced the erosion that might occur by adding some large pieces of wood I rescued from a woodland that was slated for development.  The last piece of this puzzle is to clearly mark and weigh down the edges of your liner. Without that, you will eventually forget where the exact edge of your liner is and may inadvertently dig a hole for a plant in the liner itself. I've made that mistake several times in the past.

Here is my finished wetland. It will stay saturated during the rainy season and slowly dry up during the drier months - just like a natural wetland does. Over the years, I have only rarely had to water such a wet area with a hose to supplement it. I have already added a few of the plants I took from my former residence. In the future, I will add wetland milkweeds to feed monarch and queen butterflies. I may add some native hibiscus and cardinal flower as well. That part of my plan is still developing, but I now have a functional wetland that will allow me to create more diversity than I would have had otherwise. I also think it will be an especially aesthetic addition as well.
My landscape is starting to take shape. Now I just have to get the wildlife to find me.