An indicative first check, using the BRE Digest 365 approach. It is not a drainage design and cannot be submitted to a planning authority.
How this is worked out. Storage is taken as the full design rainfall on the impermeable area, with the climate change allowance applied, and no credit taken for water soaking away during the storm: a deliberately conservative simplification of BRE 365, which tests a range of storm durations. Half-drain time uses the side area to half the effective depth, with the base discounted because it silts up. A real design needs site-specific FEH rainfall, several storm durations and return periods, groundwater levels, and agreement with the lead local flood authority.
Anyone who works in civil engineering or construction knows that effective water management is an essential aspect of any development project.
By efficiently managing excess rainwater and preventing flooding or waterlogging, soakaways help to relieve strain on existing water infrastructure whilst also protecting the surrounding environment.
This is why soakaway calculations are so important to get right, but how exactly do you calculate soakaway size?
In this blog, we’ll discover how to calculate soakaway size, explore the potential challenges in determining soakaway size, and understand the significance of soakaway design.
How Do I Calculate Soakaway Design?
The most commonly used method to calculate the size of a soakaway is based on the formula provided by BRE Digest 365, a guide published by the Building Research Establishment in the UK:
It can look complicated at first, so let’s unpack it. This formula considers the design rainfall intensity, multiplied by the surface area for drainage.
This sum is then divided by the soil’s infiltration rate to get the soakaway size in m³. It’s important to note that these parameters may vary based on location and specific project requirements.
Are There Any Challenges to Determining Soakaway Size?
As with any task for developers and engineers, soakaway design poses a significant challenge. The factors outlined in the formula must always be considered to accurately calculate the ideal dimensions:
- Rainfall Intensity: The local climate and rainfall patterns directly impact the volume of water that a soakaway needs to handle. Areas that experience higher rainfall require larger soakaways to accommodate the excess water.
- Soil Permeability: The type of soil plays a crucial role in determining the soakaway’s efficiency. Highly permeable soil allows water to infiltrate more easily, whereas clay-rich soil might require a larger soakaway to manage the same volume of water.
- Surface Area Available: The available land area for constructing the soakaway can also influence its size. Limited space may require innovative soakaway design solutions or alternative drainage methods for optimal efficiency.
- Regulatory Standards: Compliance with local building regulations and environmental standards adds another layer of complexity. The failure to meet these standards can cause project delays or even legal repercussions.
The Significance of Soakaway Design
In order to understand the significance of soakaway design, it’s important to really understand what happens without them. Without well-designed soakaways, the accumulation of excess rainwater can lead to significant consequences like flooding, erosion, and infrastructure damage. Poorly designed soakaways can overwhelm drainage systems, which can compromise the stability of buildings as a result, while also causing water-related hazards. At Onn Point, we specialise in expert soakaway design and soakaway testing, leveraging flood risk assessments and percolation tests to ensure successful soakaway design every time. Our comprehensive approach involves the careful analysis of geographic factors and historical data, enabling us to create bespoke soakaway solutions tailored to your specific project requirements. Powered by a commitment to precision and environmental sustainability, we’re proud to be the leading experts in creating effective soakaway design for diverse development projects. Get in touch with our team today to secure successful and efficient soakaway design for your project.
The science behind soakaway calculations
When it comes to civil engineering, the subtle intricacies of water management systems often remain unseen. However, they play a crucial role in averting flooding disasters and ensuring sustainable infrastructure. Among these critical systems, soakaway designs stand out, as they efficiently divert rainwater into underground reservoirs and mitigate the risks of surface flooding. Here at Onn Point, we specialise in soakaway calculations, and in this blog, we’ll explore the science behind them, their benefits, and more.
What is Soakaway Design?
Soakaway design represents a sophisticated drainage system designed to manage rainwater effectively. These systems work as a robust defence mechanism against surface flooding, directing excess water away from impermeable surfaces and into underground storage areas.
The core principle behind them lies in enabling water to gradually permeate into the soil, reducing the accumulation of water on the surface and preventing potential flooding hazards.
Why are Soakaway Calculations Important?
Accurate calculations are the backbone of every efficient soakaway system. At Onn Point, we recognise the significance of precision in soakaway calculations, adhering to standards such as BRE 365 soakaway testing. This meticulous approach ensures that soakaway designs are tailor-made to meet specific property requirements, enhancing their effectiveness in water drainage and flood prevention.
What are the Benefits of Proper Soakaway Design?
There are many tremendous benefits of proper soakaway design with accurate soakaway calculations, including:
Reduces flood risks significantly:
By providing a controlled drainage route, these systems prevent surface water accumulation and minimise the risks of property damage and urban flooding during heavy rainfall.
Facilitating natural percolation of rainwater into the soil:
Soakaways play a crucial role in the natural water cycle by allowing rainwater to infiltrate the soil and replenish groundwater reservoirs, helping to maintain soil moisture and nourish vegetation.
Alleviates burden on traditional drainage infrastructure:
Effective soakaway systems reduce the strain on conventional drainage networks, such as sewers and stormwater drains. By absorbing and gradually releasing rainwater into the ground, they mitigate overwhelming water flow, easing pressure on municipal drainage systems and preventing overflow related issues.
Aids in groundwater recharge, promoting eco-friendly water management:
Properly designed soakaways act as natural recharge points for groundwater, enhancing the underground water supply. This eco-friendly approach to water management helps sustain water resources and contributes to long-term water conservation efforts.
Mitigates erosion effectively:
By controlling the flow of rainwater and allowing it to percolate into the soil, soakaways prevent excessive surface runoff that can erode soil. This helps maintain soil structure, prevents land degradation, and preserves landscapes from erosion-related damage.
Decreases demand on municipal drainage systems:
With their ability to absorb and redistribute rainwater, soakaways reduce the volume of water entering municipal drainage systems. This decrease in demand alleviates strain on these systems, minimising the risk of urban flooding and preventing potential infrastructure overload.
Contributes to the preservation of natural habitats by replenishing local water sources with rainwater:
Soakaways also aid in preserving the natural balance of local ecosystems by allowing rainwater to replenish natural water sources like ponds, lakes, and underground aquifers. This sustains habitats for flora and fauna, ensuring a healthier environment for diverse wildlife.
How Onn Point Can Help
Here at Onn Point Civil Engineering, our expertise lies in providing comprehensive solutions for civil engineering designs, including percolation tests, flood risk assessments, and intricate soakaway calculations. Our experienced team is dedicated to crafting practical, cost-effective, and sustainable infrastructure designs tailored to meet the specific needs of our clients. Using a blend of unique proficiency and innovation, we ensure that our solutions are not only effective but also future-proof. Embracing cutting-edge technology and leading modelling software is pivotal in our approach. By harnessing these tools, we ensure compliance with local regulations and codes while enhancing the efficacy of our projects. By using advanced software, we’re able to effectively simulate various scenarios, allowing us to optimise designs for maximum efficiency and durability.
In Summary…
Soakaway calculations are the backbone of all efficient water management systems in civil engineering. They play a pivotal role in preventing flooding, ensuring environmental sustainability, and reducing the strain on traditional drainage systems. As you delve into projects involving water management or drainage systems, considering the expertise of professionals like ours here at Onn Point Civil Engineering can make all the difference. Our commitment to precision, sustainability, and innovation ensures that your projects are always in safe hands.
Remember, the success of any infrastructure project heavily relies on the meticulous design and implementation of soakaway systems. By partnering with experts, you not only guarantee efficiency but also contribute to a sustainable future. Get in touch to find out how we can help you perfect your project.