Work on the sewer system has a major impact on our living environment. Think of the accessibility to homes, shops, businesses and schools. It also involves the diversion of traffic, and causes a nuisance for local residents. An easy-to-install and adaptable underground buffer system can help with this: a system that can be installed more quickly saves costs for the contractor and ensures flexibility, even after the system has been installed. What if a contractor encounters unforeseen cables or pipes underground? Or will a new pipe be needed in the same place in the future? If so, an easily adaptable system is the solution. This is possible with Rockflow.

Rockflow is a flexible water management system made up of stone wool elements. The system buffers precipitation, in order to then allow it to gradually infiltrate into the soil or be discharged into the sewer system. Rockflow is used under streets, squares, parks, roads, water channels and other places where flooding may occur. Rockflow only consists of sustainable stone wool elements. This makes the installation quicker and easier than, for example, an infiltration buffer with lava stone and geocloth.

High installation speed

The quicker an underground buffer system can be installed, the cheaper it will be. Not only for the contractor, but also for the users of the land. With a shorter turnaround time, a public road or car park space can be put back into use much sooner. The speed at which a buffer system can be installed depends on a number of factors. For example, is the location easily accessible? And how deep is the buffer to be laid?

Thanks to the simplicity of the system, the installation speed of Rockflow is very high. With an optimum supply of materials, flow rates of 300 cubic metres per hour can be achieved. Furthermore, the installation of Rockflow requires no heavy equipment. The loose stone wool elements weigh a maximum of 21 kg per block, so a contractor can move them with light equipment and install them manually. A small crane to excavate the construction site, a loader to transport the stone wool blocks and manpower to place the blocks is sufficient to install Rockflow.

Simplicity and speed with a separate system

Traditionally, both rain water and waste water are being transported to a waste water facility via a system of pipes. However, a mixed sewer system often cannot cope with the increasingly extreme rain showers which increases the risk of flooding. Instead of draining clean rainwater into the sewer, a buffer system can be used to buffer the water and, preferably, deliver it to the soil in a gradual manner. This separates the discharge: a wastewater sewer feeds the wastewater to the treatment plant and a separate Rockflow buffer buffers and infiltrates the rainwater where it falls.

Line infiltration is also possible with Rockflow, in which the stone wool elements are installed in a long row, for example parallel to the street. This system was successfully implemented under residential streets in the Limburg municipality of Maasgouw, the Netherlands. Over a total length of nearly 3 kilometres, rainwater is transported from the roofs and streets to underground water storage facilities consisting of stone wool elements. These elements store the water for a short period, and release it to the substrate in less than 24 hours. Thanks to Rockflow, the rainwater no longer enters the sewer system, but is filtered into the subsoil. The chance of flooding during extreme rainfall has thereby been significantly reduced, thanks to Rockflow.

Flexible installation

Rockflow is a modular system that consists of separate stone wool elements. The construction is similar to building with Lego. What if a contractor encounters a pipe or concrete pit underground? The contractor simply cuts a piece out of the stone wool using a stone wool knife, and the system is then laid around the obstruction, without the work being delayed. Every square metre of available space can be filled, and virtually any shape is possible.

Low installation depth, maximum buffer capacity

The Rockflow elements are placed vertically, and are available in different heights, so that the water can be buffered as much as possible in all locations. Rockflow can also be placed relatively close to the surface, which reduces the excavation depth for the contractor. Research shows that an installation depth of 38 cm is technically feasible, reliable and safe for Rockflow. By comparison, other solutions often require an installation depth of at least 70 cm. Rockflow therefore saves time, work and inconvenience, and offers opportunities in areas with high groundwater levels.