Please note: In many cases, the station position in our database is accurate
to only one minute. Thus, the tide gauge may not appear to be on the coast.
ALL DUTCH METRIC DATA ARE MEASURED TO NAP (NORMAAL AMSTERDAMSCH PEIL) 1871-1883 VALUES BASED ON READINGS OF HIGH AND LOW WATERS 1884-1920 VALUES BASED ON 4 READINGS/DAY
Documentation added 1991-07-19
IJMUIDEN VALUES FROM 1981 COME FROM A NEW GAUGE ON THE SOUTHERN PIER INSTEAD FROM THE OLD GAUGE AT THE SLUICES.
Documentation added 2011-02-08
After receiving levelling values for NAP from Douwe Dillingh RLR was calculated. NAP was re-levelled in 2005. RLR factors are 6.929m up to 2005 and 6.950m from 2005 onwards.
Documentation added 2016-01-22
The note above stating that periods of the data are MTL is misleading. Sections of the original data were MTL. However, Pub. Sci. 5 states “For these periods a shallow water correction has been added to the mean heights of high and low water in order to give a mean height of sea-level comparable with those otherwise calculated for other periods.” Thus, a correction to MSL has already been applied.
Data Authority
Servicedesk Data Rijkswaterstaat Postbus 556 3000 AN Rotterdam