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Delta 21 Plan

The Delta 21 plan proposes solutions for flood protection, energy transition and restoration of nature in the Dutch Southwestern Delta.

The potential of the suggested ideas is presently being studied by several graduate students. They, for instance, study the changes in morphology, the reduction of the flood risk, the design of the pump-turbines, the design of the hydraulic structures plus scour protection and the impact on the ecology. Already completed work is available at the TU Delft repository:

Zhaoy Li
Design of the scour protection as part of the DELTA 21 project

Yordi Paasman
Design for the in- and outlet structure of the Energy Storage Lake within the Delta21 plan

Rubén Ansorena Ruiz
Conceptual design of the Valmeer’s pump storage station of the Delta21 plan

Delta21 is a modular concept with the primary aim to provide a better flood protection to highly flood sensitive areas, under the condition of nature restoration and as by-catch storage of electric power. The plan integrates several functions: a better flood protection, nature-conservation and restoration, water level regulation, generation and storage of renewable energy, fresh water buffer for the Delta21 and Rijnmond area and re-introduction saline tides in the Haringvliet.

The principle is to install huge pumping capacity to discharge the excess of river water during a dangerous flood emergency situation and to use the pumps/turbines under flood safe circumstances to store potential electric power in a water reservoir. The dunes form a reservoir, where the energy can be stored and again generated with help of the same pumps and turbines.


Tidal turbines can optionally be installed in the entrance gate and generate energy using the tidal flows. Additionally floating solar panel parks, an aqua battery park, a big warm water basin and wind farms can be added to the plan.

In principle, the gates of the Haringvliet sluices will remain open all the time, to allow the saline tide to be re-introduced in the Haringvliet and Hollands Diep, restoring the saline and brackish water isotope. The open gates will restore the fish migration between North Sea and Rhine and Meuse. A fresh water supply for Rotterdam, the Delta islands and Northwest Brabant will be guaranteed as well. New areas for aqua culture will be added for the shellfish industry. The combination of all these functions will result in an attractive and healthy area for living and recreation.