Building Your Own Dry Well

If you’re lucky enough to have an underground drainage system on your property, this article may not be important to you. If someone went through all the trouble and cost of installing drain lines around your place, you probably don’t have a water-ponding problem. The rest of us aren’t so lucky. We must rely on passively managed drainage. That’s where the contour of the ground surrounding our home gradually slopes away from the house, and toward the public storm drain system. When it rains, when snow melts and when excessive irrigation occurs, water is supposed to travel along the surface to a safe place away from the house…without puddling or ponding. But it doesn’t always happen that way. When surface water doesn’t do what it’s supposed to, you can expect problems.

House shifting? Got a leaky basement? Is ponding water in your yard a problem? Want to know an easy way to divert that bog-causing liquid and make it all go away? Without designing and building a full-blown underground drainage system? All you have to do is create your own “dry well”, sort of a mini storm-drain system. The toughest part of the job is digging and the most expensive part is nothing more than a plastic trash can.

Installing a conventional underground drainage system can be difficult at best. It can involve burying hundreds of feet of pipe. And once a yard has been fully landscaped the level of difficulty increases substantially. Patios, walks, decks, sheds and fences can be insurmountable obstacles. With a dry well, existing obstructions aren’t so important. That’s because there’s usually only a very short distance between the location where the flooding is taking place and the point where the water will be discharged. Here’s what it’s all about.

A dry well is a simple and clever system used for draining excess water out of a low spot or from a water-laden area such as at the foot of a downspout. A dry well is a surprisingly inexpensive system that consists of a buried drainpipe that runs from a small catch basin (where the water ponds) to a collection container (a plastic trash can in our example) somewhere away from the house. And get this. The collection container never has to be emptied. That’s because it gets filled with holes. Excess water drains into the buried container and then escapes through the holes where it goes into the surrounding soil. Rocks are placed within the collection container and serve a couple of important functions. The weight prevents the container from popping up out of the ground. Also, it prevents the container from being crushed…no cave-ins here.

Step one is to dig a trench from the area where the water is ponding to the location of the dry well. The trench should be about 18 inches deep and just wide enough to hold your perforated drainpipe. The trench should slope downward as it travels from the catch basin location to the dry well. The slope should be approximately one-quarter to one-half inch per foot (more slope is better). In any event, water poured into the trench should drain readily toward the dry well.

With the trench completed, it’s time to bury the trash can. Nothing special here, just dig. You can leave a portion of the can above grade or completely bury it…whichever you prefer. However, before the can is placed in the hole, line both the trench and the hole with landscape fabric or burlap. Be sure that the excess fabric laps over the edges of the trench. The fabric prevents surrounding earth from getting into the system and clogging it up. Place the can in the hole and fill it with larger rocks.

With the container now in place, you cover the fabric in the trench with a couple of inches of gravel or small drain rock. Installing the drainpipe (perforations down) from the catch basin to the dry well follows. Cut a hole in the container just large enough for one end of the drainpipe to fit through. The drainpipe should protrude into the container about 2- to 3-inches. The drainage grate should be connected to the other end and back-filled.

Finally, cover the top of the drainpipe and the top of the container with the fabric and cover with dirt. You have just created your own mini storm-drain system.

Incidentally, the drainage receptacle doesn’t have to be a trash can. For smaller puddle problems, a bucket can be used.

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