A picture of a culvert underneath a public path.

A culvert is an underground passage used to carry stormwater runoff from a road, bridge or building site. It can also be used to connect different waterways. They differ from pipes in that the inside of a culvert is sloped so that water flows under gravity instead of against it. A lot of residences and small businesses are unaware that culverts could be running beneath their property and they may only find out when a problem occurs. This emphasises the importance of culvert inspections and regular maintenance.

When there is a damaged culvert, there are several methods used to repair them. These include replacing the entire culvert structure, repairing a section of damaged culvert, or repairing one part of it separately from another part in order to limit water spillage into adjacent properties and roads.


What is a culvert?

A culvert is a channel for rain water, storm water, or sewage. It may be made of concrete, metal, or wood. In some places, the culvert is buried in the ground, while in other areas it is above ground and constructed of metal or wood.

Culverts are used to divert water from one place to another. For example, they are used to carry water from an irrigation ditch into a city’s sewer system. They can also carry storm water runoff from an area that has been damaged by a flood into nearby waterways.

Are Your Culverts Regularly Inspected & Maintained?

If your culverts are showing signs of damage or you’re experiencing problems, it’s time to get a drainage specialist to have a look.

How does damage to culverts occur?

Damage to culverts can occur if they are not maintained properly or if they aren’t built properly in the first place. If they are not maintained properly, they may collapse under their own weight or because of too much pressure from heavy rains and floods. For example, if a culvert isn’t properly built and doesn’t have proper drainage holes drilled into it along its length, then when it rains heavily enough, the water will pool up at one end of it and cause it to collapse on itself. It’s important that we take care of our culverts with regular culvert inspections and cleaning.

Different Repair Methods

There are several different methods that can be used to repair damaged culverts. The type of damage will dictate the best method of repair. Some common methods include replacing damaged sections, relining the culvert with a new pipe, or repairing cracks and joints with sealant or grout.

Replacing Damaged Sections
This is often the best option for major damage such as large holes or complete collapse. The entire section of culvert will need to be removed and replaced with new materials. This can be a challenging repair depending on the size and location of the damage. Access may be limited, and special equipment may be required.

Relining Culvert with New Pipe
If the damage is not too severe, it may be possible to reline the culvert with a new pipe without having to replace the entire section. This option can save time and money while still providing a durable repair.

Repairing Cracks & Joints
Smaller cracks and joints can often be repaired using sealant or grout material injected into the voids. This option is typically only feasible for smaller repairs as it does not address larger structural issues like collapsed sections or significant holes in the pipe.

Pipe bursting
One method of repairing culverts is by using a technique called Pipe bursting. This involves breaking up the existing pipe and replacing it with a new one. This is usually done when the damage is significant and there is little chance of repairing the existing pipe.

Pipe relining
Another method that can be used is called pipe relining. This involves insert and pregnant liner in to the old pipe to repair the damaged area. This new pipe will be less likely to become damaged and will provide better drainage than the old one. Relining is often used as a preventive measure to avoid future problems with culverts.

Excavation and Replacement
This is the most common method of repairing damaged culverts. The first step is to excavate around the culvert so that it can be removed. Once the culvert has been removed, a new one can be installed in its place.

If there is damage to the outside of the culvert, resurfacing may be necessary. This involves removing any loose or damaged material and then applying a new layer of concrete or asphalt over top.

Debris Removal
In many cases, debris such as rocks or logs can build up around a culvert and cause damage when they shift during heavy rains or floods. It may be necessary to remove this debris before repairing any other damage.

If the damage to a culvert is not too severe, then it may be possible to use patching or grouting to repair it. Patching involves covering over any holes or cracks in the culvert with material that will seal them off and prevent water from coming through. Grouting involves filling any voids or gaps in the culvert with mortar or concrete, which will also help to seal off any leaks.

Importance of Culverts

Culverts are an important part of our drainage systems, allowing water to pass under roads and other obstacles. Here are 10 reasons why culverts are so important:

To prevent flooding: By directing water away from vulnerable areas, culverts help to reduce the risk of flooding.

To improve road safety: Flooded roads can be dangerous, but culverts help to keep the roads clear by draining water away quickly.

To protect against erosion: Erosion can cause serious damage to infrastructure and buildings, but culverts can help to minimize this by dissipating the energy of flowing water.

To support wildlife: Culverts provide essential habitat for many species of wildlife, including fish, amphibians, invertebrates, and mammals.

To increase connectivity: Culverts can reconnect fragmented habitats and allow animals to move between them more easily. This is especially important for dispersing young animals and connecting populations of rare species.

To improve water quality: By preventing erosion and promoting infiltration, culverts help to improve water quality in rivers and streams by reducing sedimentation levels downstream. 

To provide sustainable drainage: Culvert pipes that have been designed with sustainability in mind can offer a number of benefits over traditional materials such as concrete or plastic, including improved durability, flexibility, and resistance to corrosion. 

To create green infrastructure: Incorporating culverts into green infrastructure projects such as rain gardens or riparian buffers can help to manage stormwater runoff more effectively while also providing aesthetic, ecological, and social benefits. 

To Mitigate the Urban Heat Island effect: The Urban Heat Island (UHI) effect is caused by the build-up of heat in urban areas, which can lead to considerable negative consequences such as increased rates of trespassing incidents and poorer air quality. One way to combat the UHI effect is by incorporating cooling elements into urban design, such as using light -coloured paving materials planting trees and vegetation.

For Aesthetic value: While some people might not think of them as being particularly attractive features, culverts done right can actually add a bit of fun flair to an otherwise mundane landscape. This is especially true if they’re used as elements of green infrastructure or incorporated into urban design schemes.

Don’t Let Problems Escalate – Take Care Of Your Culverts

Culverts are essential for drainage systems, so make sure your culverts are regularly inspected and maintained. Our enginers are here for you.

Final Thoughts

Culverts provide access through low points in the landscape to streams or roadways. Wildlife may also move through culverts, and they can help reduce erosion along sensitive waterscapes. In short, removing or failing to replace damaged culverts can have devastating effects on local environments. Thankfully there are a number of repair methods that can be used when damage occurs.