Smart Sustainable Urban Drainage (SUDs)
Smart Sustainable Urban Drainage (SuDS) uses intelligent weather forecast monitoring to automatically manage stored water levels across a development, allowing stormwater attenuation storage to be safely and reliably used for rainwater harvesting, turning attenuation into a high value, water saving asset.
Smart SuDS solutions are designed to meet the National Standards for SuDS by integrating non potable water reuse with robust flood risk management. Developments incorporating these systems have achieved up to 87% reductions in stormwater discharge rates.
Reduce Stormwater Discharge by up to 87%
How Smart SuDS Works
What is Smart Sustainable Urban Drainage?
How Smart SuDS Works
What Makes a System Smart?
Traditional stormwater attenuation systems were designed to hold back large rainfall events to prevent localised flooding and reduce pressure on overloaded wastewater networks. For most of the time, the capacity within these systems sits empty, awaiting the next heavy downpour.
By contrast, traditional rainwater harvesting systems are designed to remain mostly full in order to meet non potable water demands within the building. Because these two approaches manage water in opposing ways, they could not previously be combined.
Smart Sustainable Urban Drainage (SuDS) changes this. By monitoring Met Office weather forecasts up to 72 hours in advance, Smart SuDS systems automatically control stored water levels within the attenuation capacity. This allows water to be safely retained for reuse while ensuring that 100% of attenuation capacity is always available for storm events.
- Rainwater is captured from the roof and directed into the storage system. The storage consists of a small storage tank, housing pre-tank filters and pumps, which is connected to the attenuation crates.
-
The control panel connects with Met Office weather forecasts, predicting rainfall events up to 72 hours in advance.
-
The system calculates the required storage volume to safely attenuate the incoming storm.
-
If excess water is present on site, a valve or pump can operate to drain storage down to a safe level. This water can be sent to infiltration, a basin, or the wastewater network, crucially at a time when these assets are not under pressure from heavy rainfall.
-
The stored water is then boosted for non-potable reuse within the building, including toilet flushing, irrigation, cooling, and laundry.
-
Valve and pump operation is minimal, as most rainwater has already been used to supply the building’s non-potable water demand.
‘Smart’ essentially means that the system collects, analyses, communicates, and acts autonomously based on data to optimise performance and ensure safety. A Smart Sustainable Urban Drainage System does this by:
- Communicating with Met Office weather forecasts up to 72 hours in advance, updating every 5 minutes.
- Collecting data on rainfall event duration and forecasted intensity in millimetres.
- Automatically calculating the predicted tank fill level based on this data.
- Determining the safe level of stored water required to handle the upcoming rainfall event.
- Adjusting the water level through valves or pumps if additional capacity is needed, ensuring the tank is always prepared for incoming storms.
What is Smart Sustainable Urban Drainage?
Traditional stormwater attenuation systems were designed to hold back large rainfall events to prevent localised flooding and reduce pressure on overloaded wastewater networks. For most of the time, the capacity within these systems sits empty, awaiting the next heavy downpour.
By contrast, traditional rainwater harvesting systems are designed to remain mostly full in order to meet non potable water demands within the building. Because these two approaches manage water in opposing ways, they could not previously be combined.
Smart Sustainable Urban Drainage (SuDS) changes this. By monitoring Met Office weather forecasts up to 72 hours in advance, Smart SuDS systems automatically control stored water levels within the attenuation capacity. This allows water to be safely retained for reuse while ensuring that 100% of attenuation capacity is always available for storm events.
How Smart SuDS Works
- Rainwater is captured from the roof and directed into the storage system. The storage consists of a small storage tank, housing pre-tank filters and pumps, which is connected to the attenuation crates.
-
The control panel connects with Met Office weather forecasts, predicting rainfall events up to 72 hours in advance.
-
The system calculates the required storage volume to safely attenuate the incoming storm.
-
If excess water is present on site, a valve or pump can operate to drain storage down to a safe level. This water can be sent to infiltration, a basin, or the wastewater network, crucially at a time when these assets are not under pressure from heavy rainfall.
-
The stored water is then boosted for non-potable reuse within the building, including toilet flushing, irrigation, cooling, and laundry.
-
Valve and pump operation is minimal, as most rainwater has already been used to supply the building’s non-potable water demand.
What Makes a System Smart?
‘Smart’ essentially means that the system collects, analyses, communicates, and acts autonomously based on data to optimise performance and ensure safety. A Smart Sustainable Urban Drainage System does this by:
- Communicating with Met Office weather forecasts up to 72 hours in advance, updating every 5 minutes.
- Collecting data on rainfall event duration and forecasted intensity in millimetres.
- Automatically calculating the predicted tank fill level based on this data.
- Determining the safe level of stored water required to handle the upcoming rainfall event.
- Adjusting the water level through valves or pumps if additional capacity is needed, ensuring the tank is always prepared for incoming storms.
Turn Attenuation into an Asset
The Benefits of Smart Sustainable Urban Drainage (SuDS)
Unlock Buildable Land
Incorporating Smart Sustainable Urban Drainage reduces the required scale of basins. Systems can be installed under public amenities such as parks or parking areas, freeing up more space for buildable development.
Turn Attenuation into an Asset
End users benefit from this approach. Instead of attenuation capacity sitting unused for most of the time and requiring costly maintenance, Smart SuDS transforms it into a valuable water-saving asset, helping to reduce water bills.
Holistic Water Management
Smart SuDS addresses water scarcity and drainage requirements in a single solution, making it easier to secure planning approval.
Comply with Drainage Requirements
Under the National Standards for SuDS, holding rainwater for non-potable reuse is the primary runoff destination, as outlined in Section 1.1.
Reduce Combined Sewer Overflows (CSOs)
By harvesting rainwater on site, Smart SuDS prevents stormwater from entering the wastewater network, freeing capacity and reducing the risk of combined sewer overflows.
Save Water
Smart SuDS treats rainwater as a valuable resource rather than a waste product, enabling water reuse that typically meets up to 75% of a building’s overall non-potable demand.
Ideal Development Types
Housing Developments
On an individual home basis, rainwater collection volumes are often limited. However, when implemented at a communal scale using a Smart SuDS system, significant volumes of rainwater can be captured, stored, and reused across a development.
By integrating communal rainwater harvesting with intelligent control, potable water demand within homes can be reduced by up to 50%, while still ensuring full compliance with drainage and flood risk requirements.
Smart SuDs Systems can supply non-potable water for toilet flushing, washing machines and external taps.
Traditionally, housing developments allocate up to 15% of buildable land to basins and SuDS features. With Smart SuDS, basin sizes can be reduced to manage hardstanding runoff, while roof runoff is managed through the Smart SuDS rainwater harvesting system.
This approach frees up additional land, allowing developers to increase housing density and deliver more homes without compromising drainage performance or planning compliance.
Distribution Centres
Typical distribution centres in the UK are ideal candidates for Smart SuDS technology. These buildings usually have large roof areas, which means attenuation capacity is often required to gain planning approval.
Many UK distribution centres also have HGV washdown facilities, which have historically relied on mains water. With Smart SuDS, harvested rainwater significantly reduces water consumption by supplying sustainable water for HGV washdown, toilets, and irrigation systems.
National distribution centres washing 50–100 HGVs per day can consume up to 15,000 litres of water daily for truck washing alone. The large roof areas and storage potential of these buildings mean this demand can be fully met with harvested rainwater, turning stormwater management into a valuable, sustainable resource.
Offices
High-occupancy office buildings typically have high water demand, primarily from toilet flushing, which can be easily supplied using recycled rainwater collected from the roof.
Because space is often limited on these sites, there is usually insufficient room for separate rainwater harvesting and attenuation systems. Smart SuDS allows these functions to be combined, efficiently managing both water reuse and stormwater attenuation within a single integrated system.
Public Buildings
Many successful Smart SuDS installations have been implemented in schools, colleges, and university buildings. These sites provide excellent opportunities to combine stormwater attenuation and rainwater harvesting in a single integrated system, thanks to their high water-saving potential.
In schools, for example, there are peak flushing periods during which a significant volume of water is consumed. Smart SuDS systems provide sufficient rainwater collection and storage capacity to manage this demand efficiently, safely, and reliably, while still maintaining full attenuation capacity for storm events.
Bespoke Solutions for Water Management
Our solutions
We have a wide variety of ways to incorporate Smart Sustainable Drainage your project.
Reduce SuDs Footprint
Below Ground Active Attenuation
If your project includes attenuation crates, we can easily integrate them with our intelligent Active Attenuation controls, so the system safely manages stormwater and supports non-potable water reuse.
As part of our maintenance-friendly approach, we include a small adjacent tank that acts as a filtration and pumping chamber. This design has come from experience in the field and makes long-term access and tank cleaning much easier, helping you get the most from your system.
It also features built‑in battery backup (for power failure resilience), blockage detection, automated alerts via email or SMS, and seamless BMS integration – with all tank levels and operational data visible in a live portal interface.
Ideal for Basement Set Ups
Above Ground Active Attenuation Option
In high-density developments where space is limited, our Active Attenuation system can be paired with above-ground storage. This approach is ideal for projects where storage can only be located in basement plant areas.
This option uses a single main storage tank for both attenuation and rainwater reuse. The system includes a pre-tank filter for initial filtration, submersible pumps to supply rainwater back into the building, and an automated valve or pump to manage water levels. The pump option is used when drainage connections sit above the tank level.
Integrate with Green Infrastructure
Blue-Green Roof Option
Blue-green roofs are growing in popularity for their biodiversity and cooling benefits – and now they can also support rainwater reuse.
In this option, the blue-green roof stores rainwater, which is then directed into a secondary tank for non-potable use. Smart valves manage the flow, sending water either into the tank or to the drain, depending on storm conditions, to make sure all attenuation needs are met.
CSO Busting Solutions
StormStation Active
StormStation Active offers a modular, plug-and-play solution for stormwater attenuation and rainwater harvesting. StormStation Active combines our active tank management controls with rainwater storage, an automatic mains top-up, controls, filtration, and pumps – everything needed for reliable non-potable water reuse in one compact system.
Because of its ease of installation, many water utility companies choose StormStation Active to retrofit non-household buildings in Combined Sewer Overflow (CSO) hotspots, helping reduce sewer overload and improve water efficiency in the area.
Ideal for Large Housing Developments
Communal Suds & Reuse Options
Communal Active Attenuation is our innovative system that combines rainwater harvesting and attenuation in a single solution. Rainwater is collected from all property roofs, filtered, and stored centrally in underground attenuation crates. From there, it is distributed back to clusters of homes for non-potable uses such as toilet flushing and irrigation.
Using smart weather monitoring, the system automatically manages storage levels to keep full attenuation capacity available at all times. This approach supports housing developments in water-stressed regions and ensures compliance with the latest National Standards for Sustainable Drainage, which prioritise rainwater collection and reuse.
FAQs
Got a Question?
Do Lead Local Flood Authorities Approve Smart SuDS Systems?
Yes. Smart SuDS systems incorporating water reuse have been approved and successfully installed across the UK. When these systems are proposed as part of a development, Lead Local Flood Authorities require clear assurance that flood resilience and attenuation capacity are not compromised under any operating condition. This assurance should be clearly set out within planning submission documents.
Lead Local Flood Authorities will typically require:
- Storage capacity calculations, demonstrating compliance with the agreed design storm events.
- A clear explanation of the system’s role within the wider site drainage strategy.
- A defined list of fail-safe features, confirming that 100% of attenuation capacity is always available when required.
- A comprehensive maintenance and de-sedimentation strategy, demonstrating long-term performance, lifecycle management, and operational responsibility.
What Fail Safes Do Smart SuDS Have?
Smart SuDS systems are designed with robust fail safe measures to ensure that 100% of the required attenuation capacity is always available, regardless of power failures.
Component Failure
If any active component within the Smart SuDS system fails, the system automatically reverts to a passive, or “dumb”, attenuation mode. In this state, stored water is discharged at the site’s agreed design flow rate, ensuring that attenuation performance is maintained without reliance on smart controls.
Electrical Outages
Where a drawdown valve is used, it is designed to fail open. In the event of a power outage, an internal spring mechanism releases, allowing attenuation storage to drain in accordance with the agreed discharge rate.
Where a drawdown pump is required instead of a valve, typically where drainage connections are above the storage level, a dedicated alternative power supply is specified to ensure continuity of operation.
For additional resilience, the control panel responsible for monitoring incoming weather patterns is equipped with a battery backup, maintaining system operation during power outage scenarios.
Any Design Tips?
Yes!
The nature of Active Attenuation means that there will be a collaborative approach needed from both your Civils Design Team and you Public Health Design Team.
This is because the disciplines of drainage and in-building water management are combined into one unified design.
Getting the best approach to managing rainwater does require a little bit of joined-up thinking but we’re here to support you every step of the way with our clear performance specifications.
Can Smart SuDS Manage Stored Water Levels by a Valve or Pump?
Smart SuDS can manage stored water levels using either a drawdown valve or a pump, depending on site conditions.
A drawdown valve is typically used when drainage connections are below the storage capacity, allowing stormwater to gravity feed to the appropriate discharge point.
Where drainage connections are above the storage capacity and gravity flow is insufficient, a drawdown pump is used to boost stormwater to the suitable drainage connection. Pumps are commonly installed in densely populated areas, where attenuation storage is integrated within basements or other sub-structure areas requiring boosted discharge.
Where a pump is used, it is recommended to connect it to a secondary power supply to maintain operation during power failures.
What Happens with Attenuation Requirements for Non-Roof Runoff?
The Smart SuDS system primarily manages rainwater collected from the roof, which is ideal for non-potable reuse within the building due to its high water quality.
Runoff from other sources, such as paved areas or car parks, should be managed separately through a dedicated basin or drainage facility. This ensures that the Smart SuDS system focuses on clean roof water while other runoff is safely attenuated or treated according to standard drainage requirements.
Is a Tank Required if I am Using Attenuation Crates?
Yes!
Attenuation crates are great at what they do – providing high volumes of storage in a cost-effective manner.
Our experience has shown that it is always best to combine attenuation capacity with our smallest size of rainwater harvesting tank – this approach ensures the pre-tank filter and submersible pumps can be properly accessed for tank cleaning and maintenance.
Remember, your system will be operational for a long time and maintenance accessibility is absolutely key!
