A water infiltration system under the warehouse floor

The Rockflow® storage and infiltration system was selected for several reasons:

1. Rockflow® consists of fully circular stone wool elements which have a large water uptake capacity.
2. Rainwater is stored very quickly and is released (infiltrated) into the subsoil within 24 hours.  
3. Rockflow® can be installed under the warehouse floor, where it fills up the space in between the foundation poles of the building: A space-saving and easy to install solution, thanks to the inherent flexibility of designing and working with Rockflow® stone wool.
4. The system is easy to clean and maintain which guarantees its durability.
5. Rockflow®'s long lifetime of more than 50 years makes it a future-proof investment.

Legal water storage requirement & BREEAM sustainability ambitions

Water storage compensation is a standard requirement for new buildings in many countries. Authorities want to keep rainwater separated from wastewater in the sewer system. By decoupling rainwater and managing on premise, sewer spills can be avoided and local groundwater is replenished. 

In this construction project, the legal standard for water storage is exceeded - the client is committed to sustainable development according to the Dutch BREEAM certificate. As a result, they opted to realise extra water storage - on top of the municipal requirement. This will make the new building even more future-proof and able to withstand the effects of climate change, such as increasingly intensive rain showers.

But rainwater management systems, especially if a lot of water storage is to be realised, often take up a lot of valuable space. So space-saving solutions were sought after.

Decoupling rainwater with Rockflow®

That space-saving solution was found in Rockflow. The stone wool system can be installed under the building floor. The stone wool captures and retains rainwater before it infiltrates into the ground. In case a rain event surpassed the capacity of the Rockflow® system, the water would be directed into a nearby stream through an overflow system.

The Rockflow® system is easy to install in the available space in between the foundation poles of the building. This is because the stone wool system is configured based on individual stone wool elements, allowing for flexibility in the geometric shape of a system. The stone wool elements can be cut with a stone wool knife in the field, to exactly fit the space on site or work around the foundations poles or other obstacles.

An infiltration system situated under a building needs to function for many decades. The Rockflow® system has a lifetime of more than 50 years is designed to be easily inspected and cleaned via manholes located at each side of the building.

Thanks to these unique features, the client could you make a future-proof investment into his property, meet the stringent BREEAM water storage requirement while saving valuable space.

Smart design choices and a phased installation process

Working closely with the builder and the client, the ROCKWOOL Rainwater Systems team has worked out a smart design for the rainwater storage system, which fits perfectly with the space available and the construction schedule. A phased installation plan and just-in-time delivery of the required materials ensured optimal alignment with the overall construction planning.