The new UWWTD makes stormwater everyone’s problem. SmartFlow makes it manageable - from the roof.
The revised EU Urban Wastewater Treatment Directive (Directive 2024/3019) entered into force in January 2025. For the first time, stormwater overflows and combined sewer systems are squarely inside the directive’s scope - and cities have deadlines.
What changed
Under the recast directive, larger urban areas must prepare integrated urban wastewater management plans that specifically address pollution from stormwater overflows. Member states are transposing the directive into national law now. The direction is unambiguous: cities must reduce the volume of stormwater hitting combined sewers during peak events - and prove it.
Traditional answers - bigger sewers, underground retention basins, separated systems - cost millions and take years of construction.
The source-control alternative
Every liter retained on a roof during peak rainfall is a liter that never reaches the sewer. SmartFlow turns existing flat roofs into active, forecast-driven retention assets:
- Retrofits onto existing roof drainage outlets. No roof modification, no membrane penetration, no structural changes. Under 15 minutes per outlet, installed by the building’s own crew.
- IoT sensors + weather forecasts. The system knows a storm is coming and pre-releases stored water to free capacity - then holds back runoff at exactly the moment the sewer needs relief.
- ~30% more drainage capacity from infrastructure the city already has.
- Measurable and reportable. Every retained liter is logged - data that plugs directly into an integrated urban wastewater management plan.
Who this is for
- Municipalities building their UWWTD management plans and looking for fast, distributed peak-flow reduction.
- Water authorities and utilities managing combined sewer overflow reduction targets.
- Building owners and portfolio managers who want to contribute retention capacity - and get credit for it.
Deployed and proven
SmartFlow holds the Solar Impulse Efficient Solution label and operates 17+ active deployments, including a 14-site network in Acre.
Specific obligations and deadlines vary by member state transposition. SmartFlow supports compliance strategies; consult your national implementation timeline.
Book a 30-minute compliance consult
Tell us which agglomeration you are planning for - we will show how rooftop source control fits an integrated urban wastewater management plan, and what it takes to document it.