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Dig a hole deep enough to accommodate your dry well and the overflow tube. Haul away most of the dirt, but keep some handy to partially refill the hole.
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Dig the trench deep enough to drain downhill from the side of the dry well. You'll also need at least 3 in. of crushed rock to add to the bottom of the trench to promote water absorption.
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Knock out the drainage ports in the sides of the dry well. First score around the "knock-out hole" with a utility knife, then strike it with a hammer.
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Assemble the dry well once the perforations are knocked out of the sides. Next, screw the top of the dry well to the side walls with the 2-in. stainless steel screws.
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Lower the dry well into the hole after wrapping the sides with a special silt-blocking landscape fabric. To tuck the fabric under the dry well top cover, loosen the screws, push an inch of fabric under the cover, then retighten the screws. Once it's lowered into place, insert the top drain fitting and make sure it's level with the surrounding soil.
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Measure the depth of your trench using a line level. Pound a stake in near the house to use as a reference point. Tie the string exactly level to each stake and measure the depth. You'll need to increase the depth as you get farther from the well. Adjust the gravel at the base of the trench as needed.
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Slip the fabric sock over the tubes, leaving a few inches at each end to overlap the adjacent section of tubing. The fabric filters out small particles of soil to prevent the tube from eventually clogging with sludge.
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Check the drainage tubing with a 4-ft. level to make sure you have at least 1/8 in. of slope per foot of tubing (1/2 in. every 4 ft.). Adjust the gravel base as needed. Overlap the sock ends after you connect them.
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Snap the downspout tube into the main drain line. Use a Y-fitting to make the connection. Slip the sock over the connection. Once the tubing is in place, cover it with at least 3 in. of gravel. Cover the gravel with landscape fabric and spread topsoil over the trench.
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Screw a drain cover over the end of the tubing as it approaches daylight to keep critters out. To prevent erosion, make a rock bed around the end of the tube.
I've had a water problem with it getting into my garage for years from a hill behind my house. The water would get under the slab and over the years crack it in winter. I had a new garage floor poured and a trench dug around the garage which was connected to tubing that ran into a catch basin in the middle of my driveway and out to the street. I also had a new driveway poured after the drainage system was installed.Gutters and downspouts on the garage are also connected to the system.
Well, I just finished reading the whole article and seeing the step by step photos and I must say it is a very well done article and the pictures make sense. I have a horrible situation in my back yard and I am thinking of doing this very thing, and although I'm not sure how well it will work by itself it may be the main effort of an all out war against poor drainage in our back yard.