Netherlands – Works for complete or part construction and civil engineering work – Wijkvernieuwing Welgelegen

Project Wijkvernieuwing Welgelegen Nieuw-Vennep involves the comprehensive renovation of a large part of the Welgelegen district in Nieuw-Vennep. This project includes the renewal of surfacing, sewerage and greenery. The project boundaries are approximately the Venneperweg, Westerdreef, Noorderdreef, Wageningenstraat and Van Bemmelenstraat. In this district, the existing mixed system, consisting of a concrete sewer, will be largely replaced by a new mixed system of plastic, which is approximately 2,900 m of sewer with a diameter varying from around 250 to 500 mm. In addition, a new DT system will be laid consisting of approximately 3,600 m of PE pipe with diameters varying from around 200 to around 500 mm. Furthermore, approximately 220 m of concrete culvert around 1,000 mm will be laid at 4 locations. At 3 locations, 90 m of concrete culvert around 500 mm will be demolished and approximately 11,500 m2 of asphalt, 20,000 m2 of tiles, 6,000 m2 of concrete paving stones and 4,000 m2 of bricks will be demolished. The new construction consists of the installation of bricks (approximately 4,000 m2 reused), concrete tiles (20,000 m2) and concrete paving stones (11,500 m2). The carriageways will be arranged in a V-shape, including ground improvement under the foundation of mixed gravel with geogrid reinforcement. The greenery in the district will also be addressed (300 are removed and 160 are laid out) and the district will be climate-adaptively arranged by, among other things, the construction of green parking (3,500 m2), a wadi (400 m3 excavation) and two buffer ponds (4,700 m3 excavation) with SIMMBA weir and intervening ø1,000 mm culverts. The utilities will replace their gas, water, LS and MS networks on a large scale from April 2025. These will largely be completed at the start of the works. The Haarlemmermeerpolder has been designated by Rijnland as a 'vulnerable seepage area'. Research has shown that, in addition to seepage pressure and associated heave risks, there is also a high iron content in the groundwater within the project area. Aerius calculations in the preparation phase have shown that the work cannot be carried out without a degree of electrification of the equipment to be used. The municipality intends to contract a party: that guarantees and is actually able to carry out the contract and will carry it out. Further information such as the RAW contract will be provided in the 2nd phase to those parties that are selected to participate in this tendering phase. The estimated value of this contract is approximately 10 million euros. The works must start on 1 March 2027.