Alex Šilbajoris - Technical Writer, Technical Editor, Research Specialist
My Ongoing Rain Garden Project at Home
I have a rain garden in my back yard, begun in 2015 and still in development. I need a rain basin because my soil is very poor and resistant to letting water soak in, so I get ponding and flooding around the house. My house's basement walls show a history of foundation repairs. The yard is very flat so there is no incline and no potential for a site located downslope from the house. I had to create a slope by digging.
Here's PVC pipe connecting to the patio downspout which used to spill onto the yard and to the downspout for the rear half of my house's roof, which used to flood the side yard..
I quickly realized that I would need a bigger basin.
I continue to expand the basin to handle larger rain events. This was in 2016, after two inches of rain fell in one afternoon.
The basin reaches brim full, and the yard begins to flood once it can't drain to the basin. The basin can prevent yard flooding only up this point. Without it, all of that captured water would be up around the house.
The basin can hold water for days because the soil is so slow to drain. As I add more organic material to the soil blend, it acts as a wick to soak up water. The garden may appear to be dry; you coud walk across it; but a little bit of digging will reveal water below the surface.
I've only begun planting in the garden, partly because I don't yet.know where the edges will be. These dwarf irises were planted on the east rim of the basin, and later the basin extended farther east, leaving them on an island of former bank.
I intend to establish native wildflowers as found in other rain gardens, but I'm having poor luck in getting them started. The garden is not under or over any utilities, so there is room for some big centerpiece like a tree.
Because the drainage is so poor, I'm planning to rely transpiration through plants to help remove water and make room for the next rain event.