These json files are partly retrieved by netcdf files in opendap here http://opendap.deltares.nl/thredds/catalog/opendap/rijkswaterstaat/BKL_TKL_MKL/catalog.html?dataset=varopendap/rijkswaterstaat/BKL_TKL_MKL/BKL_TKL_TND.nc. After 2001, the shapes received by RWS in 2020 are used: bkl2001, bkl2007, bkl2012, bkl2017. The years in between are filled in by until a new bkl is defined. These json files will be used for the coastviewer.