Poor drainage isn’t just an inconvenience. It can quietly damage your home over time. Without the right stormwater management in place, rainwater can overflow gutters, pool near foundations, and seep into the surrounding soil. This leads to cracked paving, waterlogged gardens, and even structural issues.
Installing solutions like stormwater pits and soakwells helps prevent water from collecting where it shouldn’t, keeping your property dry and stable during heavy downpours.
Each system works differently depending on your soil type, block size, and runoff needs. Choosing the right setup is key to protecting your home from costly water damage.
Key Differences Between Soakwells and Stormwater Pits
Both soakwells and stormwater pits play a role in managing excess water, but they work in very different ways. Understanding how each fits into broader stormwater infrastructure can help in choosing the right system for your property. Here’s a quick breakdown:
1. Soakwells
- Designed for water absorption directly into the surrounding soil
- Help replenish groundwater by allowing stormwater to soak into the earth
- Ideal for sandy or free-draining soils
- A more natural approach to stormwater control, keeping runoff on-site
2. Stormwater Pits
- Collect and redirect stormwater flow into a closed stormwater system
- Part of larger stormwater management solutions that connect to the main stormwater network
- Better for areas with poor drainage or heavy rainfall
- Help prevent surface flooding by quickly moving excess water away
Here’s a comparison table:
| Aspect | Stormwater Pit (Drainage Pit) | Soakwell (Infiltration Pit) |
|---|---|---|
| Primary Function | Collects and temporarily holds runoff, then conveys it to a discharge point or piped network. Acts as a catch basin/detention to prevent immediate surface flooding. | Collects stormwater and gradually disperses it into the soil on-site, allowing infiltration instead of off-site discharge. |
| Design & Structure | Enclosed, non-perforated chamber (box or cylinder) with solid walls. Features grated inlets on top (or side entry) and one or more pipe outlets. Often includes a sump at the bottom to trap sediment. Built to contain water until it flows out via pipes. | Perforated or porous-walled chamber (often a vertical cylinder) with open/perforated base to maximise soil contact. No floor or an open bottom; water seeps out through sides and bottom into surrounding earth. Typically wrapped in geotextile to prevent soil ingress. |
| Common Materials | Precast concrete is most common (durable for traffic loads). Also found in plastic or PVC for small domestic pits. Grates/covers in cast iron or steel (rated to load class). Pits must be structurally sound to hold soil and vehicle loads. | Concrete rings or modules (often reinforced for strength) are traditional; polypropylene/plastic units are also used (lightweight, modular). Surrounding gravel often used to aid infiltration. Needs structural lid if in driveway. Concrete soakwells preferred for longevity and structural stability. |
| Installation Location |
– Residential: Low points in yards, beneath downpipe outlets, or at property boundaries as connection to public drain. – Commercial: Parking lots, courtyards, roof drainage systems, etc. – Public: Common in streets, kerbs, and car parks as part of the municipal drainage grid. |
– Residential: Buried in yards to handle roof or patio runoff, often 1–2 m from footings. – Commercial: Used under open areas for infiltration if soil conditions allow. – Public: Limited to designated infiltration zones like sumps or rain gardens, not installed beneath roadways. |
| Performance | High flow capacity. Removes large volumes quickly. Works in all soil types if discharge is available. Can be designed to detain and meter out water. Does not reduce total runoff volume—just transfers it elsewhere. | Infiltration capacity depends on soil type. Excellent in sandy soils. Reduces runoff volume, helps with erosion control, and improves water quality. Slower to drain in heavy rain and may overflow in dense or clay soil. |
| Advantages |
– Controls flooding and pooling – Suitable for intense storms – Works on all sites – Keeps water away from structures – Connects with other drainage components easily |
– On-site stormwater control – Reduces runoff and erosion – Recharges groundwater – Avoids neighbour and council drain discharge – Supports water-sensitive urban design goals |
| Limitations |
– Needs pipe discharge path – Can increase burden on downstream systems – Needs regular cleaning to avoid blockages – Doesn’t reduce runoff volume – Can be expensive to retrofit without existing connections |
– Only suitable in well-draining soils – Slower during intense rainfall – Clogs from sediment if unfiltered – Requires space and clearance from structures – Lightweight models can fail under heavy loads |
| Typical Maintenance |
– Clean sediment and leaves from grate and sump regularly – Inspect after storms and in autumn – Check pipes for blockages – Replace broken grates or walls as needed |
– Clean gutters and downpipes – Install filters or traps to reduce debris – Inspect performance during storms – Vacuum out silt every few years – Avoid compacting soil above soakage zones |
What is a Stormwater Pit and How Does It Work?
A stormwater pit is a key part of many residential and commercial drain systems, helping manage excess water flow and prevent flooding and erosion. Here’s how it works and why it’s commonly used:
1. Underground Collection
- A stormwater pit is a grated chamber installed below ground level
- It stores water temporarily during heavy rainfall
2. Connected Infrastructure
- Links to pipes that carry water to the main stormwater network
- Commonly found in driveways, yards, carparks, and drainage channels
3. Material and Design
- Typically built from concrete or plastic for durability
- Covered with a sturdy grate to keep debris out
4. Purpose and Placement
- Used where water can’t seep into the soil naturally
- Ideal for managing high water volume in hardscaped or poorly draining areas
For any homeowner, a stormwater pit offers peace of mind and long-term protection against water damage.
What is a Soakwell and How Does It Manage Stormwater?
A soakwell is an underground solution used to manage stormwater by holding runoff and slowly allowing it to filter into the surrounding soil. Unlike stormwater pits, soakwells aren’t connected to external water systems, making them ideal for containing runoff on-site, which is something many local councils, especially in WA, require.
Here’s how a soakwell works:
1. Design and Materials
- Built from concrete soakwells or modular PVC units with perforations
- Allows gradual absorption into the ground, improving water quality
2. Placement and Function
- Installed below downpipes to capture runoff from roofs during heavy rainfall
- Helps prevent water pooling, soil erosion, and flooding around structures
3. Best Conditions
- Works best in sandy or free-draining soil
- Suitable for both homes and businesses managing frequent heavy rain
4. Additional Features
- Often used with side entry pits to catch debris and sediment before water enters the soakwell
How a Drainage Pit Fits Into Your Drainage System
A drainage pit is a key feature in many residential and commercial properties, especially where excessive water runoff needs to be controlled efficiently. It plays a crucial role in reducing the risk of flooding and structural damage during heavy rainfall.
What Does a Drainage Pit Do?
This type of pit is designed to quickly collect stormwater from hard surfaces like roofs, patios, and driveways. Installed beneath grates or trench drains, it directs the flow of water away from areas prone to pooling on the surface.
Why It’s Important in Your Drainage System
As part of a complete drainage system, a drainage pit helps prevent flooding and soil erosion by keeping water moving and away from foundations. It’s especially effective on sloped blocks or low-lying areas.
Choosing the right system for your property ensures long-term protection against the risk of flooding and soil damage.
Types of Water That Each System Handles
Different stormwater solutions are designed to handle specific types of water, depending on site conditions and rainfall intensity. Here’s how each system works:
1. Stormwater Pits
- Manage large volumes of surface runoff
- Ideal for areas with high-intensity rainfall or poor soil drainage
- Quickly divert water to external systems to prevent flooding
2. Soakwells
- Handle low to moderate types of water from steady rainfall
- Suited to sandy or well-draining soils
- Slowly release water into the ground to reduce surface pooling
Choosing the right setup ensures stormwater is managed safely and efficiently year-round.
Grate Design and Access for Maintenance
A well-designed grate is essential for both performance and upkeep.
In stormwater pits, grated lids or side entry points help capture runoff quickly while allowing for easy inspection and cleaning. These grates are especially important in driveways or traffic areas, where strength and durability matter.
Soakwells, on the other hand, typically have capped or covered openings since they manage water below the surface. While not always visible, access points are still needed to remove debris or sediment build-up.
Installation Factors to Consider with a Professional Installer
Proper installation is essential to ensure your drainage system works effectively and lasts long term. A qualified installer will assess your site and ensure all components are correctly positioned and compliant with local regulations. Key considerations include:
1. Stormwater Pits
- Require accurate depth grading and correct pipe alignment
- Often built using precast concrete for durability and strength
Must be sized to handle water volume and prevent issues that lead to flooding
2. Soakwells
- Soakwells are installed away from footings and underground utilities
- Depth and placement are critical for proper replenishment of groundwater
- Best suited for areas with sandy soils and good drainage
- Can support water treatment when paired with filtration methods
Choosing a licensed installer ensures your system is suitable for areas with specific drainage needs and complies with council standards.
Why Stormwater Drainage Solutions Must Match Your Soil
The effectiveness of any stormwater drainage system depends largely on your property’s soil type. If the system doesn’t suit the ground conditions, it can lead to pooling, erosion, and long-term structural issues.
That’s why selecting the right drainage method starts with understanding the soil beneath your property.
1. Sandy Soils
Sandy soil drains quickly, making it ideal for soakwells. The loose texture allows water to absorb naturally into the ground, reducing surface runoff and keeping excess moisture away from buildings and landscaping.
2. Clay or Rocky Soils
Clay and rocky soils tend to hold water and drain poorly. In these cases, stormwater pits connected to an external system are more effective, as they quickly move water off-site and prevent build-up near foundations.
A professional soil assessment helps determine the most suitable approach, ensuring your stormwater drainage solutions perform reliably in all conditions.
Need Help in Your Drainage System?
All Kind Wastewater provides tailored drainage system solutions for both residential and commercial properties. With years of experience in managing stormwater pit installations and soakwell setups, the team ensures each system suits your site conditions and council requirements.
Whether you’re tackling excess water issues, upgrading an outdated system, or building from scratch, expert advice and reliable service are just a call away.
From initial assessment to final installation, All Kind Wastewater handles every step with precision. Get in touch today to speak with a trusted local drainage specialist.
FAQs
1: Can soakwells and stormwater pits be used together?
Yes. Many properties use both. Soakwells handle day-to-day rainfall, while stormwater pits help during heavy downpours by redirecting overflow.
2: Is one system better than the other for stormwater drainage?
It depends on your soil and site. Soakwells are ideal for sandy soils; pits are better for clay soils or when connection to the stormwater network is needed.
3: Do all councils allow soakwells?
Not always. Some councils require all runoff to connect to their stormwater systems. Others (like in WA) prefer on-site soakage. Check local rules.
4: How do I know which system to choose?
Get a professional assessment of your soil type, runoff patterns, and space. A licensed installer or drainage expert will recommend the best option.
5: Can I install a stormwater pit myself?
DIY installations can be risky. Poor grading or incorrect pipework can lead to failure. It’s safer to hire a licensed installer familiar with council requirements.
