Water retention systems | intensive green roofs
The water retention and controlled drainage system for roofgardens with intensive vegetation and pathways. By temporarily or permanently storing rainwater on the roof, peak discharge is reduced, providing a sustainable solution for climate-adaptive stormwater management in urban environments.
The system is based on the ND WSE-50 and ND WSE-100 Water Retention Element in combination with a flow control device. Together, they provide controlled discharge and a temporary water storage capacity of approximately 45 or 90 l/m².
For optimum climate-adaptive performance, Nophadrain recommends combining water retention with water buffering and, where required, capillary water transport. This allows stored rainwater to be used more effectively by the vegetation while keeping the growing medium moist for longer. Catch it. Keep it. Re-use it.
Technical data
Example composition
Intensive vegetation (in combination with pavement)
Root-resistant waterproofing membrane
One complete system for intensive green roofs
Our water retention systems are supplied as a complete solution, from the protection and filter layer to the ND WSE-50 or ND WSE-100 Water Retention Element and the vegetation-supporting growing medium.
The ND WSE-50 and ND WSE-100 have been specifically developed for intensive roof systems with higher load capacities, deeper growing media and pedestrian access. Unlike the ND WSE-80, which is designed for extensive green roofs, these elements are engineered for more demanding applications.
Optional capillary water transport
Where additional water availability for vegetation is required, the system can be enhanced with ND KS Capillary Strips and the ND KV-200 Capillary Geotextile. These components transport stored water by capillary action from the water retention elements into the growing medium, ensuring a more uniform moisture supply for healthy plant growth.
In combination with a flow control device, rainwater is temporarily or permanently stored and discharged at a controlled rate into the roof water outlet. This reduces peak discharge while creating a stable water buffering system on the roof.
Benefits and system solutions
By combining water retention and water buffering, rainwater is temporarily stored on the roof and released in a controlled manner. This reduces peak loads on the roof outlet during heavy rainfall and lowers the risk of urban flooding. At the same time, the system contributes to evapotranspiration, urban cooling and improved stormwater management.
Combined with the ND AFC-100 Adjustable Flow Control, this system provides one integrated solution for water retention, controlled discharge and the reuse of rainwater on roof gardens with intensive vegetation.
