The performance and service life of vegetated filter systems can be improved by installing a drainage net underground.

The 6-8 mm thick Lite-Net is installed at a depth of approx. 5 cm, directly above the filter material and pulled up the slopes. Even if the filter bottom is silty, water can flow into the drainage net via the unsilty slopes, is distributed in it under the silt layer and then cleaned from the filter material.

The drainage network consists of a highly porous but robust fleece with high water conducting and storing capacity. Since the distribution net is not full coverage, there is no slippage on the slopes, roots can easily grow through the net openings and anchor themselves to the net all around. The water stored in the fleece net also helps the plants through dry periods.