What is The Best Fill Dirt For Drainage?

Fill dirt refers to the layer of subsoil immediately beneath the topsoil. There are many different fill dirt varieties, which can contain pebbles, sand, and rocks. Fill dirt should not contain any organic material, which can cause the soil to settle over time. 

Most often generated during large construction projects, fill dirt is versatile and has several different applications. Fill dirt is commonly used to build and maintain the shoulders of new roads and highways. Fill dirt is also used to create foundations for new buildings and to raise and level low-lying construction sites. 

Fill dirt also has several landscaping applications and can be used to create low hills and ridges. It can also correct drainage problems in flat or low-lying areas. If you’re struggling with runoff or flooding on your property, read on to figure out the best fill dirt for drainage issues, and solve your drainage problem now.  

Related: Amending Clay Soil Without Tilling

Clean Fill

Sometimes referred to as “fill dirt” or “screened fill dirt,” According to Mcgowan Insurers, clean fill refers to the subsoil distilled to remove anything over ¾ inches wide. Clean fill is uniform in color and consistency, although the color can vary depending on the clean fill’s point of origin. 

Although it is somewhat more expensive than non-screened fill dirt, there are several advantages to using clean fill as a drainage solution. The biggest advantage is that since the soil contains no rocks, garbage, and roots, you won’t have any surprises to work around.

Clean fill is a standard solution for new residential construction and roads. Clean fill allows you to work with precision on the sloped ground with drainage issues, so you won’t be forced to buy costly extra fill dirt. Since most clean fill is also processed to remove chemicals, using clean fill also means non-polluted runoff when it rains.    

Fill Sand

Fill sand is composed of fine particles of rock broken down into sand. Fill sand is a good option if you’re looking for a quick and easy way to fill in low-lying areas around your yard or property. 

The folks at Dirt Connections say that fill sand is your best bet if your goal is to improve drainage around specific problem areas such as ponds or septic tanks. Fill sand tends to compact on its own, and because of this, it also tends to shift and move. Since it’s also more aesthetically pleasing than gravel, fill sand is also a good option for “exposed” drainage projects such as flowerbeds or landscaping.

While fill sand can help correct drainage issues around ponds, flower beds, and septic tanks, it is not a good backfill solution for homes or buildings’ foundations. It tends to settle after a time, absorbing water that flows toward foundations rather than channeling it away.   

Drain Rock

Frequently referred to as river rock, the good people over at Builders Sand and Gravel say drain rock is a material composed of porous stones that comes in a wide variety of colors depending on what area of the country you’re in. They can vary in size from slightly larger than gravel to the size of a football or larger. They can vary in shape from rounded to jagged.

Drain rock makes a good foundation or lining material in hardscapes such as driveways and patios. When used in hardscapes, drain rock can absorb runoff from pavement and prevent flooding or pooling when topsoil becomes saturated with rain. Drain rock can also be a substitute for mulch in landscaping since it can prevent roots from becoming oversaturated. 

Drain rock is standard in french drain constructions. A french drain is a perforated tube laid in a trench with a thick layer of drain rock poured around and on top of it. When drain rock is part of a french drain construction, the porous rocks absorb excess water while channeling it into the perforated tube and away from the flood-prone area. 


A picture of gravel.

Gravel is one of the most widely-used building materials on earth; gravel can build roads and walkways and many different drainage applications. Gravel is machine-made, and because of this, it is often uniform in color, size, and texture. Gravel can range in size from rounded, minuscule “pea gravel” to triangular pieces that are slightly smaller than drain rock. 

Gravel has several different advantages as a drainage solution. It’s heavy, so it won’t move, settle, or compact on its own. Gravel can substitute mulch or be mixed with mulch or topsoil to prevent evaporation and erosion. 

Gravel works best as a quick drainage solution to absorb excess water around drains, gutters, and downspouts. However, because gravel “clumps” more than drain rock, it is typically not recommended for french drain installations.   


While the different varieties of fill dirt for drainage solutions we’ve covered have been sterile substances processed to make sure they contain no organic material, that doesn’t mean that nutrient-rich topsoil has no use in a yard with drainage issues. 

According to Wikipedia, many different topsoils are available from big-box retailers. They can be used in conjunction with many other materials such as mulch or gravel to backfill disturbed landscaping that might be holding water. While there are many varieties of topsoil available, sandy varieties of topsoil are the most effective at handling minor drainage issues in your yard or garden. 

Topsoil can conceal or repair damaged areas of your lawn, and it can also fill in sloped or low-lying areas that are holding water. Besides its advantages as a small-scale drainage solution, topsoil can also promote new lawn or vegetation growth.

Finding the Best Fill Dirt for Drainage Can Be Difficult

Whatever the size and scope of your drainage project, it’s best to do your research and contact a professional if you have any questions. 

While some drainage problems can be handled DIY and with a minimal amount of know-how, others are quite serious and require you to call in a professional. Unsafe digging could result in you or a loved one hitting an active power line, or using the wrong type of fill dirt could jeopardize the integrity of your home’s foundation. More serious drainage issues might also require you to obtain municipal or county permits.

Always remember that it’s up to you to understand the safest and most effective way to fill dirt to deal with drainage issues in your yard or around your home.  

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