Must-Have Drainage Solution for 2-Foot Retaining Walls in Canadian Landscapes

Retaining walls, a common solution for minor grade changes in your backyard, can serve multiple purposes. They not only help manage the sloping grade in your yard but can also double up as seat walls, often forming part of the seating around a fire pit. But when you’re building these walls, there’s a crucial question you need to ask: does a 2 foot retaining wall need drainage?

If your wall is built to hold decorative landscaping or light structures, drainage might not seem necessary. However, it’s still recommended to keep the area behind the wall dry to prevent any damage. But the uncertainty around whether your specific retaining wall needs drainage can be challenging to navigate.

The importance of drainage in a retaining wall is often overlooked. Without proper drainage, your wall could face serious consequences such as leakage, erosion behind the wall, or poor stability. But the necessity of drainage depends on the specific circumstances of the retaining wall and the soil conditions in the area. In general, a wall 4 feet or taller should have proper drainage. So, a 2 foot retaining wall might not need drainage, but it’s always best to consult with a professional or a local building code authority.

Does a 2 Foot Retaining Wall Need Drainage?

You’ve probably seen them adorning backyards, seat walls or retaining walls around one and a half to two feet tall. More than just aesthetic elements, these structures can solve minor grade changes and double up as additional seating around your fire pit.

However, there’s a question that might be lingering in your mind. Does a 2 foot retaining wall need drainage? When building these walls, do you need to consider any features of larger retaining walls?

You might think that if your wall is holding decorative landscaping or light structures, drainage isn’t necessary. However, it’s recommended to keep the area behind the wall dry to prevent any damage. Every wall is unique, and so are the specific circumstances it’s built in and the soil conditions of the area. Therefore, you’re better off consulting with a professional or a local building code authority when you’re unsure about your specific retaining wall needing drainage.

Regardless of the wall’s height, having proper drainage is a key factor to a successful retaining wall. Without it, your wall could face serious consequences such as leakage, erosion behind the wall, or even instability.

These problems can be easily avoided with proper drainage. For retaining walls 4 feet or taller, it’s generally recommended to have proper drainage to prevent water from building up behind the wall and causing instability or erosion.

So, back to our question, does a 2 foot retaining wall need drainage? It’s a general suggestion from civil engineers that a 2 foot retaining wall does not need drainage. However, always remember to consider the specific circumstances of your wall and consult with a professional to make the best decision.

To put it simply, when in doubt, it’s better to be safe than sorry.

Importance of Drainage in Retaining Walls

Retaining walls are both functional and aesthetic additions to your landscape. They can manage sloping grades, serve as seat walls, and even enhance the overall appeal of your garden. Regardless of the size, whether it’s a towering 4-foot structure or a modest 2-foot wall, one element remains crucial – drainage.

Prevents Soil Saturation

The first and foremost purpose of a retaining wall drainage system is to prevent soil saturation. When it rains, water seeps into the ground, and without proper drainage, the soil behind your wall could become oversaturated. This can lead to a host of problems. For instance, oversaturated soil is prone to erosion, which can in turn undermine the stability of your retaining wall. Additionally, if you’ve planted anything behind the wall, oversaturation can drown the roots and kill your plants.

Reduces Hydrostatic Pressure

Another key reason to consider drainage for your retaining wall, regardless of its height, is to reduce hydrostatic pressure. This is the pressure that builds up when water accumulates behind the wall. Over time, this pressure can increase to the point where it starts to push against the wall. And if the pressure gets too high, it could cause the wall to crack or even collapse.

So, even though a 2-foot wall might not seem like it needs drainage, it’s still worth considering. As with any construction project, it’s better to be safe than sorry. Without proper drainage, you might end up dealing with costly repairs down the line.

To determine whether your 2-foot retaining wall needs drainage, consider consulting with a professional or checking with your local building code authority. They can offer guidance based on your specific circumstances and soil conditions. While a wall 4 feet or taller generally needs drainage, the necessity for smaller walls can vary.

Remember, a well-drained retaining wall isn’t just about preventing damage. It’s about ensuring that your wall continues to serve its purpose and enhance the beauty of your landscape for years to come.

And on that note, let’s delve deeper into the types of drainage systems suitable for retaining walls.

Proper drainage for Retaining Wall

Factors to Consider for Drainage in a 2 Foot Retaining Wall

Proper drainage is a vital aspect of any retaining wall construction, regardless of its height. Now, you might be wondering: does a 2-foot retaining wall really need drainage? The answer lies in various factors that can influence the necessity and design of your drainage system. Here, we’ll discuss three such factors: soil type, water table level, and wall material.

Soil Type

The type of soil behind your retaining wall plays a critical role in determining the need for drainage. Soil types like clay and silt have poor drainage characteristics. They tend to hold onto water, causing soil saturation. This can lead to erosion and damage to your plants. On the other hand, sandy soil is more permeable, allowing water to seep through more easily. This doesn’t mean you can forego drainage if you’ve sandy soil. You’ll still need to consider other factors.

Water Table Level

The water table level in your area is another factor to ponder on. If you’re living in an area with a high water table, the need for a drainage system increases. A high water table can lead to hydrostatic pressure build-up, threatening the integrity of your retaining wall. Even a 2-foot wall can crack or collapse under high hydrostatic pressure. Regularly draining the area behind the wall can help mitigate this risk.

Wall Material

Lastly, the material of your retaining wall also influences the necessity for drainage. Materials like stone and brick are porous and can absorb water, increasing the risk of damage over time. In such cases, a drainage system can help keep these materials dry, prolonging the lifespan of your wall. Conversely, if you’ve a wall made of non-porous materials like concrete, the need for drainage might be less but it’s still recommended to prevent soil saturation and erosion.

Remember, while these factors can guide you, it’s always best to consult with a professional or local building code authority to determine the necessity for drainage in your 2-foot retaining wall.

Types of Drainage Systems for Retaining Walls

Retaining walls require effective drainage systems to ensure their longevity. It’s important to recognise there isn’t a one-size-fits-all solution. Various factors such as the wall’s height, material, and the surrounding soil type play a role in determining the most suitable drainage system. Here, you’ll find two commonly used drainage systems for retaining walls.

French Drain

A French drain is a popular option for managing water behind retaining walls. It’s essentially a trench filled with gravel or rock, enclosing a perforated pipe which collects and diverts water away from the wall.

This system is particularly beneficial when you’re dealing with clay or silt soils, known for their poor drainage characteristics. The French drain helps to prevent soil saturation and erosion, two common issues associated with these types of soil.

While installing a French drain, it’s crucial to ensure the trench’s slope is directed away from the wall. This facilitates proper water flow, preventing any water build-up behind the retaining wall. Additionally, geotextile fabric is often used to wrap the pipe and gravel, preventing soil from clogging the system.

Weep Holes

Another effective drainage system for retaining walls is the use of weep holes. These are small openings within the wall that allow water to escape, thereby reducing hydrostatic pressure.

Weep holes are typically recommended for walls built with porous materials such as brick or stone. These materials tend to absorb water, which can lead to damage over time. Weep holes provide an exit route for this absorbed water, helping to maintain the integrity of the wall.

Installation of weep holes requires careful planning. They should be evenly spaced throughout the wall for optimal drainage. Additionally, their size and number may vary depending on the wall’s height and the local climate conditions.

While these drainage systems can greatly extend the life of your retaining wall, it’s always advisable to consult with a professional or local building code authority about your specific situation. They can provide expert insight and recommendations, ensuring you have the most effective drainage solution for your 2-foot retaining wall.

Installation of Drainage System in a 2 Foot Retaining Wall

Drainage systems are key to maintaining the integrity of any retaining wall. A 2 foot retaining wall, while not as imposing as its larger counterparts, still requires effective drainage to ensure its longevity.

Excavation and Preparation

Before you can install a drainage system, you’ll first need to prepare the area. This involves excavating the space behind the wall and creating a trench that is suitable for the drainage pipe and backfill material. It’s crucial to ensure that this trench is deep enough to accommodate the drainage system and wide enough to allow for efficient water flow.

While excavating, be careful not to damage the wall or any existing structures. Always remember, safety should be your top priority during this process.

Installing Drainage Pipes

Once the trench is ready, it’s time to install the drainage pipes. For a French drain system, this involves laying a perforated pipe along the entire length of the trench. The holes in the pipe should face downwards to allow water to be easily absorbed into the pipe and then transported away from the wall.

Remember to wrap the pipe in a permeable landscape fabric. This is critical to prevent silt and other debris from clogging the pipe over time.

Backfilling and Compacting

With the drainage pipe in place, you can now proceed to backfill the trench. This typically involves filling the trench with a layer of gravel or rock, which facilitates water flow and reduces the risk of soil erosion.

Once the backfill material is in place, it’s time to compact it. Compaction is crucial for stability and ensures that the backfill material doesn’t shift or settle unevenly over time.

The installation of a drainage system in a 2 foot retaining wall may seem daunting, but with careful planning and execution, it’s a task that you can complete successfully. Always remember, the longevity of your wall depends greatly on the effectiveness of its drainage system.

(Please remember to consult with a professional or local building code authority to ensure that your drainage system is compliant and effective.)

importance of a proper drainage

Consequences of Not Having Drainage in a 2 Foot Retaining Wall

Ignoring the importance of a proper drainage system in 2-foot retaining walls can lead to serious problems. Not only does it affect the wall’s stability but also its overall lifespan. Let’s delve into the potential consequences of such an oversight.

Soil Erosion

One of the most noticeable effects of improper or absent drainage in retaining walls is soil erosion. Without a proper drainage system in place, water has nowhere to go. It begins to seep into the soil behind the wall, making it saturated and heavy. Over time, this excess water can lead to soil erosion, washing away the vital soil and nutrients supporting your plants and landscape. This can then lead to an unsightly mess and, more worryingly, destabilise the wall.

Wall Failure

The second, and potentially more catastrophic consequence, is wall failure. As the soil behind the retaining wall becomes saturated, the increased pressure can cause the wall to bulge, crack or even collapse entirely. This can present a significant safety risk, especially if the wall is near a walkway or building.

A 2-foot retaining wall might not seem like a significant structure, but even a wall of this size can cause considerable damage if it fails. It’s not just a matter of replacing the wall – there could be damage to adjacent structures or landscaping to consider, not to mention the potential for personal injury.

So, while a 2-foot retaining wall might seem insignificant, it’s crucial to install an effective drainage system. This not only ensures the wall remains stable and intact but also extends its lifespan, saving you from potential repair or replacement costs down the line.

Remember, every retaining wall, regardless of its size, plays a crucial part in maintaining the structural integrity of your garden or landscape. Don’t underestimate the power of water and the damage it can do if not correctly managed.


So, you’ve got it now. Don’t overlook the need for a good drainage system in your 2-foot retaining wall. Without it, you’re inviting trouble. Water seeping into the soil behind the wall can cause soil erosion and even destabilise your wall. It’s not just about the wall crumbling down – it’s a safety risk that can damage nearby structures too. By installing an effective drainage system, you’re not just ensuring your wall stands strong for years to come, you’re also safeguarding your property and those around it. Remember, it’s not just about building a wall, it’s about building it right.

Curb Wise