Lining drainage ditches with rocks creates a drainage system called French drains. The rocks are used to allow for greater drawing of water from the source area where the water was pooling. The water will flow into the rocks instead of being absorbed into the surrounding soil. You can easily install a French drain ditch in a flood-prone area such as the level ground around foundations of houses or near gutter spouts where water pools when the ground is saturated. Lining the ditch with rocks will be cheaper than paying for repairs when your property floods.
Dig your ditch from the origin point of water all the way to the area you want the water to drain into following a downward slope. The decline should go down 1/4- inch steeper per foot of drainage pipe. Ideally, the water should eventually drain into a sewer.
Check the depth of the ditch to ensure that it can accommodate the draining materials. Add 4 inches for the rocks to the diameter of the draining pipes and make sure the ditch is at least that deep. The drain should be at least 1-foot deep at a minimum.
Adjust the width of the ditch so it allows for the width of the drainpipe plus 2 inches for rocks. You can use a pipe in the ditch as a guide when digging, so you can monitor your progress.
Spread the rocks in the bottom of the ditch in a 2-inch thick layer. The rocks should cover the entire bottom but not the sides of the ditch.
Lay the connected pieces of drainpipe on top of the rocks so they run the entire length of the ditch. Make sure the connections are tight because you would have to dismantle the ditch in order to access them again.
Pour more rocks around and on top of the pipes. The rocks on top of the pipes should be laid on in a 2-inch layer.
Cover the rocks and fill the ditch with the soil you removed when digging the ditch. None of the rocks should be visible when the soil is in place.