of the coastal policy is determined annually whether nourishment is required in a given coastal sector. This is done by determining the coastline (TKL) to be tested before the reference date. This is determined in the same way as the BKL, namely by a regression analysis of the MKL values of the previous years. See the attached graph. In this example, a supplementation was carried out in 1990, causing the MKL to shift far seawards. The number of years over which the regression analysis can be carried out is therefore somewhat limited. If there are too few years available, a regression line is usually adopted parallel to the previous regression line (so it is assumed that the erosion before and after supplementation is approximately the same). By the way, the first year after supplementation is often more than average due to adjustment effects. In this case, it appears that the TKL is still just satisfactory for 1995 and is no longer satisfactory for 1996. In principle, a supplement at this location would be required in the course of 1995. Now the decision to supplement does not depend on a single BKL exceedance, but only if multiple profiles are threatened to become negative. In order to assess this, coastal maps are issued annually by Rijkswaterstaat. These maps indicate whether the coast is growing or eroding with a dark green or light green block. A red block indicates that in that place the TKL has exceeded the BKL, and that something has to happen there. A red hatched indicator means that the TKL has exceeded the BKL, but this coastal section has an accreting tendency, so no urgent works are needed Beach nourishment design A beach nourishment to broaden the beach and maintain the coastline can be designed using mathematical calculation models or on the basis of beach measurements. In the Netherlands, Belgium and Germany,a nourishment design is mainly based on measurement, while mathematical models are mainly used elsewhere. A nourishment design for coastal maintenance and beach widening can be made much more reliable based on measurement data, provided that they are present. If there are no good, long-term series of measurements of the beach profile, one must make the design using calculation models. In the Netherlands, the coast has been measured annually for years (JarKus measurements) and therefore the very reliable method based on measurements is used in the Netherlands for