# Commission Regulation (EU) No 1089/2010 of 23 November 2010 implementing Directive 2007/2/EC of the European Parliament and of the Council as regards interoperability of spatial data sets and services, Division 8.5.4.5: Water Level (WaterLevelValue)

Extent: E+W+S+N.I.

The tidal datum / waterlevel to which depths and heights are referenced.
The allowed values for this code list comprise only the values in the table below.
Values for the code list WaterLevelValue
Value
Definition
equinoctialSpringLowWater
The level of low water springs near the time of an equinox.
higherHighWater
The highest of the high waters (or single high water) of any specified tidal day due to the declination A1 effects of the moon and sun.
higherHighWaterLargeTide
The average of the highest high waters, one from each of 19 years of observations.
highestAstronomicalTide
The highest tidal level, which can be predicted to occur under average meteorological conditions and under any combination of astronomical conditions.
highestHighWater
The highest water level observed at a location.
highWater
The highest level reached at a location by the water surface in one tidal cycle.
highWaterSprings
An arbitrary level, approximating that of mean high water springs.
indianSpringHighWater
A tidal surface datum approximating the level of the mean of the higher high water at spring tides.
indianSpringLowWater
A tidal surface datum approximating the level of the mean of the lower low water at spring tides.
localDatum
An arbitrary datum defined by an authority of a local harbour, from which levels and tidal heights are measured by that authority.
lowerLowWater
The lowest of the low waters (or single low water) of any specified tidal day due to the declination A1 effects of the moon and sun.
lowerLowWaterLargeTide
The average of the lowest low waters, one from each of 19 years of observations.
lowestAstronomicalTide
The lowest tide level that can be predicted to occur under average meteorological conditions and under any combination of astronomical conditions.
lowestLowWater
An arbitrary level conforming to the lowest tide observed at a location, or somewhat lower.
lowestLowWaterSprings
An arbitrary level conforming to the lowest water level observed at a location at spring tides during a period shorter than 19 years.
lowWater
An approximation of mean low water adopted as the reference level for a limited region, irrespective of better determinations later.
lowWaterDatum
An approximation of mean low water that has been adopted as a standard reference for a limited area.
lowWaterSprings
A level approximating that of mean low water springs.
meanHigherHighWater
The average height of higher high waters at a location over a 19-year period.
meanHigherHighWaterSprings
The average height of higher high water at spring tides at a location.
meanHigherLowWater
The average of the higher low water height of each tidal day observed over a National Tidal Datum Epoch.
meanHighWater
The average height of all high waters at a location over a 19-year period.
meanHighWaterNeaps
The average height of the high waters of the neap tide.
meanHighWaterSprings
The average height of the high waters of spring tides.
meanLowerHighWater
The average of the lower high water height of each tidal day observed over a National Tidal Datum Epoch.
meanLowerLowWater
The average height of the lower low waters at a location over a 19-year period.
meanLowerLowWaterSprings
The average height of lower low water at spring tides at a location.
meanLowWater
The average height of all low waters at a location over a 19-year period.
meanLowWaterNeaps
The average height of the low waters of the neap tide.
meanLowWaterSprings
The average height of the low waters of spring tides.
meanSeaLevel
The average height of the sea at a tide station measured from a fixed predetermined reference level.
meanTideLevel
The arithmetic mean of mean high water and mean low water.
meanWaterLevel
The average of all hourly water levels over the available period of record.
nearlyHighestHighWater
An arbitrary level approximating the highest water level observed at a location, usually equivalent to the high water springs.
nearlyLowestLowWater
A level approximating the lowest water level observed at a location, usually equivalent to Indian spring low water.
tropicHigherHighWater
The highest of the high waters (or single high water) of the tides occurring semimonthly when the effect of the Moon's maximum declination is greatest.
tropicLowerLowWater
The lowest of the low waters (or single low water) of the tides occurring semimonthly when the effect of the Moon's maximum declination is greatest.

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Source: https://www.legislation.gov.uk/eur/2010/1089/annex/II/division/8/division/8.5/division/8.5.4/division/8.5.4.5 (the official version)
Page: https://openlegislation.uk/eu-regulation-2010-1089/annex-II/division-8/division-8.5/division-8.5.4/division-8.5.4.5
Contains public sector information licensed under the Open Government Licence v3.0. Source: legislation.gov.uk, The National Archives.