Case Study: Deltapump

Abstract

According to the European Environment Agency (2016, pp. 137–140) annual mean river flow and the frequency of fluvial floods will have increased by 20% before the year 2100, in North-western Europe. It had been postulated in media in reports (De Ingenieur, 2014; „MIRT-verkenning Grevelingen”, 2012; Slootjes et al., 2010; Slootjes, 2013; Lammers, 2014) that because of this, large pumping stations are required in the Rhine-Meuse delta in the Netherlands. To investigate this postulation, a simulation model in Python was created that describes the Rhine- Meuse delta as four separate water basins with flow exchanges and boundary conditions (astronomical tides and river inflow). From this simulation model it was concluded that every 86–137 years, flood flow rates of the rivers are such, that the design maximum water level is compromised. The acceptable flooding risk is only once every 2.000 years, so this situation is unacceptable. Dutch engineer answered to the postulation and invented a high-capacity pump called the „Deltapump”, with a capacity ranging 170–200 m3s-1. Moreover, a conceptual design for a pumping station was created. After a conceptual design creation, verification calculations and a cost-to-merit evaluation, a pumping station with 28 Deltapumps in total, based on the conceptual design of Schut, was created. This pumping station is integrated within the Haringvlietdam and is covers an area of 420 × 190 m2. Its capacity, dependent on water levels in the Haringvliet, ranges 4.900 to 5.250 m3s-1, making it by an extremely large margin, the biggest pumping station in the world. Its costs, expressed as Net Present Value, are estimated at € 915 million by the year 2100, 70% of which covers the mechanical components of the pumping station and 30% the civil components. After the flood risk analysis and the pumping station design, it was posed that, whilst the pumping station itself has advantages—better capacity per unit width and less costs per unit capacity, it is not a cost-effective method to prevent flooding in the Rhine-Meuse delta. Calculations and the simulation show it only requires operation once every 92 years. It would therefore seem more cost-effective, and a permanent solution, to upgrade all dykes and dams along the Rhine-Meuse delta, so that more water can be stored. This should be investigated in future reports.