ABSTRACT
Texel is the biggest Dutch Wadden island in the North Sea. It is often called Holland in a nutshell (Figure 1a). The population of the island is about 13,000, whereas in summertime, the number of people can be as high as 60,000. A sand-dune area is present at the western side of the island, with phreatic water levels up to 4 m above mean sea level. At the eastern side, four low-lying polders1 with controlled water levels are present (Figures 1b and 2a). The lowest phreatic water levels can be measured in the so-called Prins Hendrik polder (reclaimed as tidal area in 1847), with levels as low as –2.0 m N.A.P.2 In addition, a dune area called De Hooge Berg, which is situated in the southern part of the island in the polder area Dijkmanshuizen, has a phreatic water level of +4.75 m N.A.P. The De Slufter nature reserve in the northwestern part of the island is a tidal salt marsh.
