A new generation flood defences: Dam with tidal power station including pumping capacity

Abstract

A dam including a tidal power station with pumping capacity is a new type of flood defence. The negative ecological impact normally associated with closure dams is partially mitigated by including a tidal power station in the structure. Water can move through the tidal power station resulting in a reduced tidal stroke at the created lake. This tidal stroke plays an important role in maintaining the desired water- and nature quality within the lake. By including pumping capacity in the tidal power station the tidal stroke can be maintained as sea level rises with respect to the mean water level in the artificial lake. The aim of the study is to assess the feasibility of a dam including a tidal power station with pumping capacity given the uncertainty of sea level rise. To this end a few locations worldwide with high flood risk were selected for further analysis. A hydro energetic cost model was developed to simulate a tidal power station with pumping capacity. An optimization model was developed to generate optimal designs for power stations at all locations under evaluation. The economic feasibility of the dam with tidal power station including pumping capacity was assessed through a series of business cases, using the results from the two models. The solution was compared to the business case of other flood protection measures. The analysis showed that the concept has potential mainly as a long term solution, when a strong reduction of the tide at the created lake is allowed, and when a large amount of sea level rise is expected during the lifetime of the structure.