How To Add Backyard Drainage

If water collects or pools in your backyard, protect your landscape by adding extra backyard drainage. To start, identify the high and low points of your yard, and plan to build the drain between these points.

Step 1 – Decide the Route

It isn’t always a convenient straight line from the highest point to the lowest, so you must decide which route your drainage will take. Try to calculate the route so that you can dig your backyard drainage to a constant depth. Keep in mind that while the direct route might be shorter, this doesn't necessarily mean it will be more effective. In fact, a longer route will expose a much wider area, which will be better for drainage. Mark the route you choose with spray paint or chalk powder.

Step 2 – Dig a Trench 6 to 8 Inches Wide

Along the route, dig a narrow trench about 2 feet deep. As you cut the sod, put it to one side for later use. Try to maintain a steady depth and ensure that there is a downward slope all the way.

Step 3 – Compact the Trench Bottom

Once you are happy with the trench and the steady downward slope, walk up and down it a few times to compact the bottom. If you have a compacting tool, use that as well.

Step 4 – Layer the Gravel

Cover the whole of the bottom of the trench with 2 to 3 inches of gravel. It is important that you distribute the gravel evenly to avoid an irregular depth developing in the trench.

Step 5 – Pipe Wrap

Arrange the pipe wrap on top of the gravel, making sure that it reaches both sides of the trench from end to end.

Step 6 – Perforated Drain Pipe

With the holes facing downward, lay the perforated drain pipe along the center line of the trench. Wrap the pipe wrap around the pipe. The pipe wrap is designed to prevent the holes in the perforated drainage pipes from getting blocked by sand and mud.

Step 7 – Fill the Trench With Gravel Almost to the Top.

Try not to disturb the drain pipe while you are doing this. Try to compact the gravel by inserting the spade a few inches and moving it backwards and forwards.

Step 8 – Replace the Sod

Cover the top of the gravel with the sod you cut when starting the trench.

If this trench does not solve the flooding problem, consider digging a second trench for trainage.

If the water that is causing the flooding is coming from a particular direction, you may be able to dig the trench across the flow and have the trench emptying at 2 different low spots.