The number one word about the geography of Netherlands is "flat." Even coming from the sea, the land is flat. This had made the lands incredibly susceptible to floods. Half of the land around Netherlands is only one meter above sea level - with some of the rest of the land being below the sea level. You can see how a strong storm could easily flood the all the areas of land. Because of this the national government and many of the city governments have created a wide system of dams and dykes. Also recently they have placed a multitude of pumping stations to keep the water from sitting in pools of water and overflowing rivers and lakes. They have to be careful of flooding because of the loss of topsoil for any of their agricultural goals.
While some of the land has been taken away or fought for by the sea, the Dutch people have actually won a huge battle against the sea for a piece of land. The entire province of Flevoland was once under the water. Flevoland is the largest man-made island in the world, which is called a polder. The highest elevation of land is in the far Southeast corner only registering 1053 feet above sea level.