The Leeghwater Project expansion adds: 

• A new team, the Netherlands, who use Jan Leeghwater's expertise in water management, adding even more water to your dams.
• The External Works engineer, a set of powerful tiles that can be taken from a new action space. With these, you will be able to perform many actions, but be careful. To unlock the power of the External Works, you will need to burn the required amount of concrete instead of simply assigning it to construction.
• The personal building engineers. You will have the ability to use a combination of five building tiles, each with a different, powerful effect that can be activated by your engineers.
• Two new executives designed to enhance the external works and personal buildings.
• Three new advanced technology tiles intended for the construction of personal buildings.