For the construction combination FLOOW (combination Reef-Salverda-Schagen), Koop Watermanegement has the assignment to take care of the entire drainage for the realization of 6 artworks.

The various works of art have been partly emulated simultaneously. The tunnels (artworks) Lentersdijk, Willemsdijk and Boshoek have been placed in a closed road section.

The Kellerlaan tunnel is operated by a Bypass without road closure. The Pothofweg and Holthonerweg tunnels were installed at the end of 2018.