Pardon My French…Drain

Estimated reading time: 9 minutes

Three ways to fix yard drainage problems

The lawn and landscaping around a home are often a matter of pride for homeowners. A beautiful, healthy lawn gives a great first impression to visitors and looks great every time the owner leaves or comes home. One of the most common reasons for an unattractive lawn is poor drainage. Proper water drainage will keep grass and other plants healthy and green, but poor drainage could lead to a muddy lawn, fungus growth, and sick, dying plants. There are, however, many ways to fix yard drainage problems. Three of the most effective ways to fix drainage issues are French drains, surface regarding, and retaining walls.

French Drains

A French drain is a useful way to improve yard drainage. They work on a simple downhill process, using the law of gravity. The process starts with digging a trench and placing a perforated pipe at the bottom, followed by filling the channel with gravel and loose rock. A thick layer of either larger rocks or grates is then placed on top. The loose rock allows water to drain down from the yard into the holes of the pipe and then away from the yard.

Surface Regrading

Surface regrading alters the natural slope of the yard. The yard topography gradually sloped away from the house or landscape elements to facilitate drainage. This allows water to flow away from the house and landscape features. The downward slope can lead to a drainage ditch or other drainage area. In heavy rains, grasses and weaker plants may fall over due to high amounts of water flowing over them, but they will pop back up once rains have stopped since the water now has a path to run off.

Retaining Walls

A retaining wall is a wall that typically separates two areas of the yard that are at different elevations. The area behind the retaining wall usually is higher, and water can be trapped behind the retaining wall, much like a dam. This effectively prevents too much water from draining down onto the lower section. The retaining wall itself typically is installed with some form of drainage to let water escape through specific areas. This will keep the higher part from becoming flooded. Using this method in tandem with a French drain or a sloping yard can help encourage better drainage.

French Drains might be your answer

If your North Texas home or lawn has drainage problems, a French drain might be the answer. Henry French, a Massachusetts farmer, invented it back in 1859, so don’t be fooled by the name—it’s not a drain from France.

If your yard is flat, there may be nowhere for the water to run after rain. Too much water damages everything around it, including your carefully grown grass.

The Concepts Behind the French Drain

A French drain provides a channel for the water to flow through. The method diverts water safely away from your yard and home.

We all know that water flows the best downhill. A trench is created with a slight slope when using a French drain. Round gravel and a pipe are then added to divert the water away from the area. The water goes into the trench then into the pipe at the bottom of the trench. This unwanted water will empty into a drainage ditch or a street. The most important thing is that the water will run away from your house.

Not a Do-it-Yourself Project

Creating this type of drainage system is not a do-it-yourself project. You’ll want an experienced outdoor contractor. The installation can be a complicated process. If not done correctly, it can lead to further problems with excess water. A professional will be able to assess the problem.

First and foremost, the source of the excess water needs to be determined. A professional will be able to decide on where the French drains will be installed.

Benefits of French Drains

There are many advantages to this type of drainage system. If you’ve experienced flooding in your home following a sudden downpour, you know how damaging it can be. If you notice standing water in your yard, something needs to be done before your foundation is damaged.

French drains prevent:

• Damage to hardscape or landscaping
• Damage to the foundation of your home
• Soil erosion
• Standing water
• Excess water

Yard Drainage Problems

Yard drainage problems can happen any time of year. In North Texas, we get a little bit of everything from frigid icing conditions to scorching heat and everything in between. This diverse climate can make keeping drainage consistent throughout the year somewhat problematic. The consequences of poor drainage are far more than just aesthetic. A chronically wet outdoor environment directly impacts your house and can cause structural damage. It can also ruin expensive landscaping and damage driveways, retaining walls, and fences. Fortunately, you can solve most yard drainage problems if correctly diagnosed and addressed by a drainage professional. Here are some of the major issues that typically affect homeowners and some of the options for resolving them.

Foundation Damage

Chronically wet areas due to yard drainage problems often occur around the immediate perimeter of the house. If this saturated area never dries, water can seep into tiny cracks and pores in the concrete foundation. It’s not a good scenario any time of year but can be particularly damaging in winter. When freezing temperatures strike, the moisture absorbed into the foundation freezes and expands, causing larger cracks. These openings admit still more water, and the severity of damage to the foundation accelerates. Structural foundation damage is a serious matter and an expensive proposition to repair. Taking preventative measures ahead of time can help you avoid more costly repairs in the long run.

A French drain will take groundwater away from the perimeter of the house before it can infiltrate the foundation. A French drain consists of a perforated PVC pipe buried in a gravel-filled ditch. Water takes the path of least resistance and percolates through the gravel and into the pipe. Drainage pipes are installed on a gentle slope and routed to a discharge point far away from the house such as a low-lying area of the property or out to the curb to flow into a storm sewer. To prevent foundation water damage, you should bury a French drainpipe about two feet deep in a gravel trench approximately eighteen inches wide.

Two more ideas make sense to prevent foundation damage from water. Grade the landscape around the perimeter of the house, so water flows away and doesn’t pool next to the foundation. Also, keep your gutters clear of fallen leaves. During heavy rain or melting snow, clogged and overflowing gutters can lead to deeply saturated soil.

Chronically Soggy Spots 

First, consider the topography of the yard. If the wet spot is also the lowest spot in the yard, regrading and adding additional soil to the low-lying area may be the most direct way of eliminating yard drainage problems. Perhaps the soil in that part of the yard is very clay-like and impermeable. In that event, it may be necessary to remove that soil to some depth and then replaced it with a more permeable type of soil in order to make the area level with the rest of the yard.

A shallow yard drain, similar to a French drain, is another option. A four-inch pipe in a gravel trench a foot or so deep is sloped at a rate of 1/8 inch per foot to provide adequate gravity flow to a proper discharge point. If there’s no good option to discharge water without creating another soggy spot, you can install a gravel-bottom dry well several feet in the ground. Water flowing from the drainpipe fills the well and then gradually soaks through the gravel into deeper soil.

How to clean a french drain

Knowing how to clean a French drain may give you the ability to tackle the project yourself. Understanding it may also help you to determine if the situation requires a professional. A fully functional French drain is critical to keep your lawn dry. It will also help prevent water infiltration into the foundation or walls of your house.

A French drain is typically a perforated plastic pipe wrapped in permeable landscape fabric and buried in a gravel-filled ditch. Groundwater percolates through the gravel and enters the pipe. Once in the pipe, the water is taken away from the home’s perimeter or the place that the drain is protecting. French drains can empty into an underground gravel area, or in an aboveground gutter leading to the sewer.

Why Good Drains Go Bad

Over time, a French drain may become clogged. Tiny soil and clay granules slip through the pores of the landscape fabric and gradually build up inside the pipe. Another common cause of French drain clogs is root intrusion from grass, shrubs, and trees. Because the drain contains moisture, plant roots invade the pipe looking for water.

Signs of a Clog

You’ll know your French drain is clogged if you start seeing drainage problems that your drain was supposed to correct. Areas of the lawn may appear chronically soggy, or water may get in through your foundation or basement walls. You’ll see these symptoms during heavy rainfall, but not as much during dry spells when groundwater is reduced.

Doing It Yourself

There are a few things you can try if you don’t already know how to clean a French drain. Because most of the length of the drainpipe is buried, cleanouts that extend to the surface are often built into the pipe to allow access to segments of the span for removing clogs. To clear the pipe yourself, open a cleanout, insert a garden hose into the pipe, and turn the water on full force. To get as close as possible to the clog in the event there are multiple cleanouts, try flushing each one in sequence, beginning at the cleanout farthest from the discharge point. If the French drain discharges aboveground, you can also try flushing the pipe with the hose inserted at the point of discharge.

When to Call a Professional

If flushing with a hose doesn’t clear the clog, it’s probably time to call in a professional. Renting a powered drain snake as you’d use for indoor plumbing is usually not something DIYers should do. The perforations in the French drain pipe tend to interfere with the movement of the snake. Professionals with specialized snake sizing and prior experience should handle this method.

Most professionals will use a water-jet system. An operator puts a thin hose through a head and sprays high-pressure water into the underground drain pipe. The head incorporates several jets that emit knife-like streams of pressurized water strong enough to obliterate tree roots, accumulated dirt, and other naturally occurring blockages. The strong flow of water also flushes the disintegrated obstructions down and out of the pipe. Plumbers and landscape contractors typically use these systems.