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High-capacity dry well. This recycled-plastic Flo-Well barrel holds about 50 gallons of stormwater runoff. Its bottom is open to allow fast absorption by the soil; side holes can be opened to let the water out faster.
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“Our backyard slopes down to a swale that floods completely after heavy rains or snow thaws. A sump pump and downspout also discharge water into the swale. What’s the best way to get rid of this excess water, or at least control it?”—JAKE GITTLESON, AURORA, IL

It’s good that your backyard slopes away from the house, but all that standing water is not good for your property.

The best solution would be to install a dry well—basically a lined hole in the ground—to temporarily contain the water that normally collects in the swale and let it percolate back into the soil. Because this project will involve lots of digging, before you start, be sure to call 811 so your utilities can check for underground pipes and wires.

Steps for Installing a Drywell

A level placed on the pipe, laid in a trench lined with landscape fabric and stone, confirms for Mark that it has sufficient slope—1/4 inch per foot—to drain water into the stone-filled dry well. 
THE PITCH IS GOOD. A level placed on the pipe, laid in a trench lined with landscape fabric and stone, confirms for Mark that it has sufficient slope—1/4 inch per foot—to drain water into the stone-filled dry well.
Makayla Townsend
  1. Before starting the project, call the local utility locating service and have them mark out any potential underground utilities that could get in the way of the dry well.
  2. Lay out the PVC pipe and determine the location for the dry well. The solid pipe will go closest to the house, and the perforated pipe will go closest to the dry well.
  3. Use the shovel to cut into the soil just underneath the grass and move the top layer to a tarp. That way, the grass can be put back in place once the trench is dug.
  4. Next, dig a trench to accommodate the PVC pipe that’s roughly 8-10 inch deep. As the trench gets closer to the dry well, make the trench slightly deeper and slightly wider to ensure no water leeches back towards the house.
  5. Now start digging the hole for the dry well. It should be about 4 foot in diameter and 3 foot deep.
  6. Cover the bottom of the dry well with a few layers of landscape fabric until the hole is completely covered.
  7. Use the remaining landscape fabric to line the trench. It only needs to go as far as the perforated pipe.
  8. Pour the crushed stone into the hole one wheelbarrow full at a time. Between each pour, tamp down the crushed stone with a hand tamper. Repeat this process until the hole is filled to the level of the trench.
  9. Put a thin layer of crushed stone in the trench.
  10. Connect the PVC pipes using the couplings and the PVC glue. Use the elbow to connect a vertical piece to catch the rainwater from the gutter. Once it dries, place the pipe in the trench.
  11. Fill the rest of the trench and the hole with the remaining crushed stone, leaving just enough room at the top for the layer of grass.
  12. Fold over the landscape fabric to cover the crushed stone.
  13. Backfill the hole and the trench with the grass.

Resources

Installing a simple dry well requires a few tools and materials. Mark lined the trench with landscape fabric, which can be found at any home center. He then filled the trench and the hole with crushed stone, which can be found at masonry supply stores and some home centers.

The pipe he installed was two sections of solid PVC pipe and one section of 4-inch perforated PVC pipe. The pipe and the PVC glue required to secure the connections are found at home centers.

When installing a dry well in a small yard with little space for leeching, Mark also suggests installing a plastic basin in the hole to allow for more controlled drainage. The yard in the video was massive and slightly sloped downhill away from the house, so the plastic basin wasn’t necessary.


Materials

Tools