How to Install a Cheap Gravel Drain to Divert Rainfall

You can install this simple gravel drain in one day to divert storm water and eliminate erosion in your yard.

Three of the four downspouts on my home are buried near the corners of the foundation and extend about 10 feet from the house. There, they drain onto the lawn. This is a great setup for pulling water away from the foundation of the house, as long as the mouth of each drain pipe is kept open.

But it turns out the previous owners of my new home hadn’t maintained two of the drain pipes. These gutters drain at the same point (see photo) and it was so overgrown with weeds and soil that it was completely hidden from view. I had walked over it probably a hundred times and never knew it was there.

Because of this, each time we had significant rainfall, something akin to a lake collected in the rear corner of my yard. As it was on the downside of a hill, I assumed that the lake was being created by hill runoff. Logical, right? Nope. It was the submerged gutter drain pipes and overflowing gutters on the house.

Water running down the outside walls told me I had a rain gutter problem.

Early the first spring after buying my home we were hammered by a string of rainstorms. Water was everywhere, and when I saw it coursing down the outside wall on the back of my house, I knew there was a gutter problem. Braving the driving rain, I stepped outside to have a look. Sure enough, water was spilling over the top of the gutter. From where the gutter drain pipe entered the ground, I walked nine to ten feet in every direction, but for the life of me I couldn’t figure out where the opening of that pipe was. But I was sure that was the culprit. It had to be cleared.

Then I saw it: Mud was bubbling like a pot of hot chocolate with bits of grass in it.

I ran to the garden shed, grabbed my shovel, plunged it into the bubbling mud and eureka! Water came gushing out like a dam had broken (because in fact it had…). With the water came soil, those maple tree seeds, bugs, bird feathers, small stones, bits of roof shingle, and various other unidentifiable things – a roof and gutter rainwater soup. Picture what would collect in your rain gutters after a year or two of them draining at a snail’s pace. And now it was running at my feet directly into the “lake”. But at least it wasn’t coming down the wall anymore.

So now I knew the source of the problem. The gutter had been draining but below ground, with the subterranean rainwater winding its way to the lake-y area. It was the lowest spot in my backyard, so naturally, water would collect there if it couldn’t dissipate elsewhere.

First I tried diverting the water with new grass.

After things dried out, I attempted to use the same technique I used in Part 2, How to Combat Erosion in Your Yard to restore the decimated lawn between the gutter drain and the “lake”. But the grass seed I planted, even though covered in burlap, washed away to the base of my Quince trees, just beyond the “lake”. Submitted as evidence: a profoundly luxurious tuft of new lawn from the base of the Quince trees out two feet, while the part I actually planted was eroded, bare patches interspersed with weakling weeds and grass the roots of which (I found later) were being consumed by Japanese Beetle grubs.

A simple gravel drain offered the cheapest solution

I read up on grading and diverting water flow, and guessed that the simplest and least expensive thing to do was to install a short gravel drain. This is not as complex as a French drain which involves burying pipes or drain tiles.

Steps to build my gravel drain

• Starting at the mouth of the gutter drainpipes in the yard, I dug a small trench one foot wide, three feet long (in a straight line from the mouths) and one shovel spade deep (about 8 inches). The dimensions were strictly a guess on my part and were not derived from any kind of math based on the flow of water, the grade of the land, and all that jazz. Like Indiana Jones, I just made it up as I went along.
• I lined the trench walls on the long sides with old garden bricks (the kind for borders), making sure that they didn’t extend too far above the soil surface. That way I could pass my lawn mower over them without destroying the blade. The bricks would act like walls and provide a durable channel for the storm water.
• The end of the drain opposite the drain pipes was left open, running onto a row of Arborvitae. Mature shrubs would do a good job of managing the runoff.
• I added about 3 inches of sand into the bottom of the drain to allow the water to percolate through. This would allow some of the runoff to drain down into the soil vs adding a material like landscape fabric which would slow water movement.
• I added about 4 inches of stones and pea gravel to improve drainage of the water down to the sand bed.

That was it. Now I just had to wait for rain.

When the next hard rain came, I ran outside, took a look, and declared the new gravel drain a success. I was amazed by how well it worked. What had once gushed with fury was now a timid trickle that dissipated harmlessly in the lawn. And wouldn’t you know it? NO MORE LAKE. The water never had a chance to get to the back of the yard.

Reducing the flow and volume of the water made renewing the lawn much easier. The soil had been water tortured for years, so I had to aerate it every Fall and Spring for three seasons, but that was simple. I also added finely ground compost and peat moss over top of the grass seed and covered it with burlap until germination.

Now this area of my backyard is full of vitality, with new shrubs of various kinds, a River Birch tree, some ferns, and lots of grass. I’m turning it into a shade garden where I’ll be able to relax on hot summer days after working in the vegetable garden.