Build a Dry Well
Similar to French drains, dry wells are installed as a method of moving standing water to temporary holding areas. This allows the water to drain slowly without damaging foundations or eroding topsoil. You can build a dry well inexpensively by following some basic steps.
Steps
- Dig a 12-inch (30.5 cm) deep trench from the area of standing water to the location of the dry well holding tank. The trench should begin at ground level and gradually angle down to a 10 percent grade at the holding tank.
- Enlarge the soil drainage test pit to fit the holding container. The lip of the container should be 8 inches (20.3 cm) below the surface after 2 inches (5 cm) of gravel is added to the bottom of the pit.
- Spread approximately 2 inches (5 cm) of gravel along the bottom of the trench and bottom of the holding tank pit.
- Sink the holding container into the holding tank pit.
- Drill 25 to 30 drainage holes along the bottom and halfway up the sides of the holding container.
- Cut an entry hole in the side of the holding container approximately 10 inches (25.4 cm) below the top of the container.
- Place 6 inches (15.2 cm) of rock in the bottom of the holding container and line the interior of the holding container with landscape fabric.
- Place the solid (50 percent of total length) PVC pipe from the water source into the trench and, using the PVC connection ring, attach to the perforated (50 percent of total length) PVC pipe and place it in the trench.
- Wrap the end of the entry pipe in landscape fabric and insert end of perforated PVC pipe into entry hole in holding container. Caulk the pipe entry point and allow to dry for 1 hour.
- Pour water at the top of the pipe to verify that the water runs down into the holding tank.
- Place the cover on the holding tank. Bury the tank and the pipe.
Tips
- This is a common design to build a dry well but be sure to check that this design will meet or exceed building codes in your area.
- Before you begin to build a dry well, you need to test the soil drainage where you will place the holding tank. This is done by digging a narrow hole approximately 4 feet (1.22 m) deep and filling it with water. Allow the water to drain and then re-fill with water. If the water continues to drain, the soil will allow for proper drainage. If the water stops draining, you will need to find a different location with better drainage.
- Check your local regulations before you begin; you may be required to get a permit before you build a dry well.
- Some municipalities require dry wells to be registered so, before you start construction, contact your local government to find out if yours will need to be registered.
- Just dig a hole {{safesubst:#invoke:convert|convert}} diameter hole down to the sand layer, usually about {{safesubst:#invoke:convert|convert}}. Fill this hole with sand.This simple, inexpensive procedure solves any standing water problems.
Warnings
- Never place the holding tank for the dry well less than 10 feet (3.05 m) from any structure with a below grade foundation; this can allow for the water to seep back and cause damage the foundation.
- Do not try to drill the drainage holes in the holding container before you place it in the pit. Soft plastic can bend unexpectedly allowing the drill to slip and cause injury.
Things You'll Need
- Shovel
- 4 to 6 inches (10.2 cm to 15.2 cm) of polyvinyl chloride (PVC) pipe equaling the distance between your drainage point and the holding tank. One half of the total PVC pipe should be perforated and the other half solid.
- Gravel and clean landscape rock (river rock is ideal) 1 inch to 4 inches (2.5 cm to 10.2 cm) in diameter
- Landscape fabric
- Large covered holding container (such as a garbage can)
- Hole saw or hole saw attachment for drill
- Exterior caulking
- Drill with .5-inch (1.3 cm) bit
- PVC connection ring the same diameter as your pipe
Related Articles
Sources and Citations
- http://www.ci.milwaukie.or.us/building/drywell-requirements
- http://www.azdeq.gov/environ/water/permits/drywell.html#reg
