French Drain Solution to a Flooded Yard

From on October 10, 2008 in Landscaping

French DrainA few years back, we had a disaster that nearly ruined our yard and patio. We needed a quick fix and had little money available. The problem happened back in July of 2002, during the Biscuit Fires here in Southern Oregon. Most of the homes in the neighborhood, including ours and those of our immediate neighbors, had above-ground pools. During the summer in our rural area, irrigation is the main source of watering, especially where there is or once was farmland. There was an irrigation ditch that ran along the length of the property lines at the back of our chain link fence. That summer, water from the ditches was dumped, right on time, to put out the fires. But that was the beginning of our problem.

The fires all around were so bad for a couple of days, you could see red from the flames. Can you imagine what ash can do to a pool, along with 110 degree temperatures? The pool will become an algae factory. As a result, everyone started dumping their pool water, including the neighbors who owned the 5’x10’ pool behind us. After this, we had irrigation water and pool waters flooding our downsloping yard, flooding to the point that our porch was covered in water. We didn’t know what to do with our pool water, let alone how to get rid of all the water in our yard.

This problem was solved in two stages. First, we pumped out the water from our pool and off the porch into the existing drainage pipe in the yard, while waiting for the water on the ground to drain. This took about two days. The county stopped the irrigation from flowing, so it could be used for the fires. Pumping out the water helped clear things up at that time, but we worried about the same problem happening again, especially if everyone decided to drain their pools at same time. So we decided to install a French drain.

These are the steps we took:

  • Planned the measurements and cost. It took two days to install the drain in our small yard. It wasn’t very difficult and the cost surprised me at being very inexpensive. Of course, it did help to be married to a landscaper. If you don’t have one of those in your family, you might want to consult one for help with planning and details.
  • Gauged the slope of our yard. To do this, we watched which direction the water drained. I decided that I wanted it to look like a dried creek bed to go along with the raised veggie beds and the rock garden surrounding the existing drain pipe. My husband says it was about a 1% grade, so we only had to dig about two foot deep and three feet wide. The drain was about 70 ft long.
  • We then staked each end of the trench, running a string from one stake to the other. Going back to the beginning of the trench, we dug out more along the trench, moving the string on the end side down as we dug so that the end was about ½ ft. deeper than the beginning. This gave us a downslope for draining properly.
  • We lined a nice, clean trench with landscaping fabric.
  • We placed a 4” perforated drain pipe wrapped in cloth with a small drywell at the deep end of our trench and into our rock garden. The other end was capped for cleaning if it ever plugged up.
  • We shored up the pipe with more gravel, covered over the ends of the landscaping fabric, and poured sand on top of everything. You could then cover with top soil, but I wanted it to look like a creek bed, so we poured small river rock and placed larger rocks throughout for that effect.

The whole thing turned out beautifully. It looked as though the creek was coming from somewhere on the other side of the big pine tree in one corner of the yard, then running to the rock garden at the opposite corner. We put a little walking bridge by the rock garden and with the raised flower and veggie beds alongside our patio—the effect was very nice indeed.

We did have to drain our pool a couple more times that summer and with the rainy, wet winter we had that year, the drain worked perfectly.

Photo Credit: Drainage Portland