The same testing process has also shown that when used in water flow Grasscrete is hydraulically efficient. Under heavy flow, long stemmed grass is flattened with the resulting thatch reducing the Mannings ‘n’ value for hydraulic roughness to as low as 0.03. Pre-cast concrete systems require infill panels to create directional changes. These can cause turbulent flow that becomes a focal point for erosion Grasscrete by contrast is a continuous slab with no such weakness.

The ability to easily link together individual slabs means that Grasscrete can be installed with a number of gangs operating in separate locations. this compares to the linear end-to-end construction required for pre-cast elements.