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How To Put Rocks Around Culvert

When you have a soggy garden because of too much standing water, driveway culvert landscaping can be necessary. The stone around driveway culvert ideas can help create solutions for functional stream crossings or drain rainwater away from your home.

However, even with these, as plants grow around the opening, they have issues, such as soil erosion or blockage. Luckily, with minimal effort, there are ways to overcome this and make any culvert or drainage ditch a garden feature rather than an eyesore and just something to direct water flow away from your home and garden.

The culvert pipe can be protected from erosion, dirt buildup, and additional damage by having culvert rocks surround it as it emerges from the ground on both ends. However, it can be costly to install or replace when damaged by water velocity. In our guide, you can learn more about how to stop erosion around a culvert.

By the end, you’ll see that rather than dump a load of rocks, you need to stack them course by course so they create a culvert retaining wall. Once you do this, the water inlet can be protected and look like a creek or stream. (Learn How Many Bales Of Hay In A Ton)

How To Put Rocks Around Culvert

How Long Will Culvert Retaining Wall Last?

A culvert is necessary for driveway areas that frequently flood or where the water level is higher than the surroundings. Drainage culverts help stop erosion, flooding, and water accumulation on your land. However, soil composition, traffic patterns, and weather affect how long a culvert retaining wall can last.

Here are a few things to consider when wondering how long your culvert could last:

  • Depending on the manufacturer, metal culverts often come with a lifetime warranty, yet last twenty to fifty years.
  • Even longer-lasting versions are reinforced concrete structures. A concrete-lined culvert has a lifespan of 100 years or more.
  • Culverts are frequently replaced by many people purely for aesthetic reasons.
  • To overcome the blandness of metal or concrete, rocks and boulders around culverts are rising in popularity. They make excellent DIY projects and transform gardens, besides diverting rain effectively.
  • To guarantee optimal performance and long-term use, ditch and drainage experts advise examination, cleaning, and repair of culvert retaining walls to maintain effectiveness.
  • If culverts are not cleaned of silt, they can choke and back up with deeper water that would have otherwise been able to drain if the culvert were clear.

How To Put Rocks Around Drainage Culverts

Small streams may cross your property, but they can be dry most of the year. If they have a bank, there will be a small culvert beneath the area where cars cross so that water can flow underneath.

When water drains the soil from surrounding your culvert, problems can occur. If it is not fixed, people and cars may be in danger. To prevent erosion and potential accidents, it is crucial to surround the culvert with rocks.

Before moving on, ensure you have all the supplies, equipment, and labor.

What You Need:

  • Asphalt
  • Gravel
  • Sand
  • Soil
  • Rock and boulders (riprap)


  • Backhoe – digger or excavator for heavy digging
  • Roller
  • Strong labor

Step-by-step of how to lay rock so it won’t wash away:

1. Prepare Your Base

The first step is to create the entire surface next to the culvert with a layer of big rocks. An area that can support large machines needs to be covered, and here you can find your backhoe and roller a blessing, along with enough help to dig and roll.

The density and cohesiveness of the material affect how compact it is. Pebbles or small rocks must be positioned closer together if they are to be compacted by the roller.

You can scatter the material across the ground and periodically roll it over if it is a coarse material like sand, gravel, or crushed rock. (Read Pine Flakes For Muddy Yard)

2. Use Step 2: Add Landscaping Material

Following the step of the base, the gravel layer is covered with a geotextile fabric layer for protection. Geotextile serves as a material that separates the ground from the gravel and silt.

It helps to enclose anything beneath, and for the gravel base, this could be soil or rocks that were taken from the area surrounding the culvert and stacked up. Rip rap, or large rocks around the geotextile material or landscape fabric, can secure it.

The materials placed underneath are held firmly in place by this rock material, which also serves as support.

3. Fill In Your Area

After that is finished, you can add a layer of gravel to the area surrounding the culvert. This layer must be roughly three inches thick, and roller-compacted.

The rock might not be strong enough to support heavy vehicles if the material isn’t thick enough. If it is excessively thick, the gravel’s weight will be dispersed across a wider area and cause the culvert to “sink.”

Pave the space where cars will cross with asphalt.

drainage ditch plant

How To Protect Culverts Being Washed Away

A bridge relies on gravity, whereas culverts need water to flow. Because of this, water flow is higher in a smaller culvert pipe. Here, the rock and soil erosion around your culvert compromises its ability to function, leaving them vulnerable to flow velocity and washing away soil.

When a culvert fails, any water level can rise at the crossing, thus adding more pressure on downstream culverts.

Culverts can be protected in several ways, depending on the material they are placed in.

  • Protect your culverts by filling dangerous areas with riprap.
  • Fill voids with resin on a small culvert.
  • Use geofoam for a larger roadway system.

How To Stop Culvert Erosion

Here are some of the best ways to stop culverts from washing away as rain hits and water levels rise:

1. Install the Correct Size Of Culvert

Your culvert will quickly result in substantial soil erosion and blockage if it is too small. The size of the culvert is determined by the volume of water and debris it has to pass to prevent erosion.

The pipe needs to be sufficiently big and strong to support traffic, so here, you’ll find most driveway culverts with a diameter of 12 to 15 inches. To determine the size you need, check local building codes, and also ensure the pipe is long enough to reach beyond both ends of the road or bank. (Read Clean Up Pine Needles Guide)

2. Digging Deep Enough

Install the culvert in an excavation deep enough for the pipe’s bottom to be level with the stream or drainage ditches bottom. Install the pipe at an angle so that the upstream and downstream portions are marginally higher than each other.

With no significant drop-off as it exits the pipe and travels downstream, the pipe can carry water flow through the pipe naturally.

3. Backfill With Dirt Or Rock

Add backfill to the area where your pipe culvert is placed to keep it in place and reduce erosion.

Backfill the area around the pipe with soil of the same type that naturally occurs there. Pack the dirt in as tightly as possible, covering it at 12 inches.

A good layer of rock or riprap can further help prevent erosion and soil washaway.

4. Plant Flowers

Planting vegetation around a culvert is a fully natural technique to stop erosion along the bank, plant vegetation. As water flows through the culvert, it will hold the soil once they have taken root. This method will also create an ideal habitat for insects and birds.

riprap large rocks

5. Use Rip-Rap and Larger Rock

Around the culvert’s entrances on either end, surround them with rocks. This will stop erosion by stabilizing the slope. If erosion issues continue, add more rip-rap, a manufactured rocky material used to stabilize slopes, to the bank. (Learn How To Redirect Water From Driveway)


Can I Fill My Drainage Ditch With Gravel?

A drainage ditch should be covered with gravel. Gravel stone keeps water flowing while it can stabilize the earth.

How Can You Decorate a Drainage Ditch?

Be creative with your design project if the drainage ditch isn’t blocked. Garden ornaments, stones, plants, or a birdbath can make your drainage ditch beautiful where birds can settle to get wet safely.

How Do You Cover a Drainage Ditch?

Cover your drainage ditch with a lot of water to keep children safe. Level the gravel and slope it away from your property. If you have a deeper drainage ditch over a larger area? A drainage pipe is a good idea to drain water faster than gravel alone.

Wrap a perforated pipe in landscaping mesh and place it in the drainage ditch. Ensure the drainage pipe leads to existing culverts so water may drain. Sand, soil, or mud can be washed into the drainage pipe’s holes, so you can add sand and dirt after covering your pipe with gravel.

What Can I Plant in My Drainage Ditch?

Sometimes, all you need is grass to create a drainage ditch project that is at least passable. When in doubt, look for dense turfgrass to help keep your ditch in good condition. You must choose plants that can survive in the muddy soil of the drainage ditch bottom. (Learn How To Fix Water Pooling In Yard)

Can I Put Rocks in My Drainage Ditch?

Rocks can be just functional, or if you have any particularly impressive rocks, you can add them to the area as a feature.

In any situation where there is water, rocks are impressive. With some flat garden stones, you could create stepping stones to create a natural bridge as the water flows around them.

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