CHS Low Water Mark Lines

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Published by the Ministry of Forests, Lands, Natural Resource Operations and Rural Development - GeoBC
Licensed under Open Government Licence - British Columbia

The Canadian Hydrographic Service (CHS) Low Water Mark Lines provide alongshore and across-shore geomorphological and biological attributes of the low water mark shoreline. The lines are used in the CHS nautical charts to represent the level reached by sea water at low tide.

Data and Resources

Dataset Extent

Latitude: 48.0° to 60.0°
Longitude: -139.5° to -113.5°

Additional Information


Shorezone information attached to Canadian Hydrographic Service (CHS) Low Water Mark Lines

Data Quality

The British Columbia Coastal Resource Information System (CRIMS) is an internet based interactive map for viewing coastal and marine data. A wide variety of coast and marine resources are included, such as aquaculture, shoreline classification, selected fisheries information, and offshore oil and gas information. The development of the Coastal Resource Information System is ongoing. The application provides access to data currently held in the BC Geographic Warehouse. As additional layers are added to the BCGW, subsequent releases of the application will include these additional layers and further enhancements.

Lineage Statement

This dataset was formally a depiction of the SHZN_CHS_LOW_WATER_MARK_SP warehouse layer.

Contact Information

NameBrad Mason M.R.M. (pointOfContact)
OrganizationMinistry of Forests, Lands, Natural Resource Operations and Rural Development
NameGeoBC Inquiries (pointOfContact)
OrganizationMinistry of Forests, Lands, Natural Resource Operations and Rural Development

Access & Security

Who can view this dataset? Public
Who can download this dataset?Public

Metadata Information

Record Published 2013-04-15
Record Last Modified 2019-05-10
Resource Status completed

Object Description


Short Name: CHS_LWM_S

Column Name Short Name Data Type Data Precision Comments
CHS_LOW_WATER_MARK_LINE_ID CHS_LW__ID NUMBER 10 The CHS LOW WATER MARK ID is the system-generated unique identifier assigned to the individual CHS LOW_WATER MARK LINE. It is assigned by SDE.
PHYIDENT PHYIDENT VARCHAR2 4000 PHYIDENT is a 13-character slash-delimited (/) concatenation of the shoreunits REGION, SECTION, UNIT and SUBUNIT that uniquely identifies the shoreunit for use in the shorezone mapping system, e.g., 01/02/0345/01.
REGION REGION NUMBER 2 REGION is a unique number assigned to a particular region. A region is a large subdivision area of a project used for administrative purposes. The regions are numbered 1 to 13, e.g., 1, 2, 3.
SECTION SECTION NUMBER 2 SECTION is a unique number assigned to a particular section of a region. A section is a subdivision of a region used for administrative purposes, e.g., 1, 2, 3.
UNIT UNIT NUMBER 4 UNIT is a number assigned to the primary unit of measure in the shorezone coverage. This main subdivision of a SECTION forms the "along-shore" physical unit. There are a maximum of 9,999 UNITS within a SECTION, i.e. 1324.
SUBUNIT SUBUNIT NUMBER 38 SUBUNIT is a number used to show the across-shore component of the shoreline. In the PHYIDENT, the SUBUNIT portion is at the end of the phyident and typically has a leading "0". A subunit of 00 signifies a homogeneous unit while subunits identified with 01, 02, etc. signify variants or anomalies in the unit, usually features that have only a short alongshore length, e.g., 0,1,2.
REP_TYPE REP_TYPE NUMBER 2 REP TYPE is a commonly-used abbreviated term for REPETITIVE SHORE TYPE, which is a descriptor code that loosely quantifies the shoreunit's COASTAL CLASSes in terms of geomorphology. The REP TYPE is stored as a number, e.g., 5.
REP_TYPE_NAME RP_TYP_NM VARCHAR2 50 REP TYPE NAME is a commonly-used shortened form of Repetitive Shoretype Name which is the name assigned to the repetitive shoretype. Repetitive shoretypes are a geomorphic descriptor used to quantify the shoreunit's overall character, e.g., Rock with Gravel Beach, Sand and gravel flat.
COASTAL_CLASS CSTL_CLSS NUMBER 2 COASTAL CLASS is a coded summary of shoreunit morphology and substrate in terms of one of 36 different criteria categories defined by a systematic consideration of substrate, sediment, width and slope. Using these categories, the Coastal Class is an indicator of repeatable collections of across-shore detail on the morphology and sediment components contained within the shoreunit. The Coastal Class is stored as a number, e.g., 5.
COASTAL_CLASS_NAME CSTL_CLSSM VARCHAR2 50 COASTAL CLASS NAME is the name given to a particular Coastal Class, which is a geomorphic descriptor of the shore unit that describes its overall texture, e.g., Rock with Gravel Beach > 10 m.
EXP_FINAL EXP_FINAL VARCHAR2 4000 EXP FINAL is a calculated value that represents the 'best' available exposure code based on data confidence. An exposure code is a grade of the relative exposure to the elements in nature (primarily the ocean waves) that affect the shoreunit, e.g., SE (for Semi-exposed).
CHART CHART VARCHAR2 15 CHART is the literal number(s) assigned to any CHS (Canadian Hydrographic Service) chart used for mapping the shoreunit. Most shoreunits are contained on mone CHS chart but occasionally span several. In this case, the chart numbering is condensed with forward slashes to a maximum of 3 chart numbers, e.g., 3824 (for a single chart), 3311/2 (this means the charts used for mapping were CHS chart 3311 and 3312) .
SCALE SCALE VARCHAR2 12 SCALE is the scale of the CHS chart from which the linework was derived. Scale on a map is a ratio between a certain distance on the map and the distance on the ground, e.g., 50,000 means the map scale is 1:50000.
SHORENAME SHORENAME VARCHAR2 50 SHORENAME is the proper geographic name assigned to a shoreunit, e.g., Meares Island
FEATURE_LENGTH_M FEAT_LEN NUMBER 19 FEATURE LENGTH M is the system calculated length or perimeter of a geometry in meters.
SHAPE SHAPE SDO_GEOMETRY 1 SHAPE is the column used to reference the spatial coordinates defining the feature.
OBJECTID OBJECTID NUMBER 38 OBJECTID is a column required by spatial layers that interact with ESRI ArcSDE. It is populated with unique values automatically by SDE.
SE_ANNO_CAD_DATA ANNO_CAD BLOB 4000 SE ANNO CAD DATA is a binary column used by spatial tools to store annotation, curve features and CAD data when using the SDO_GEOMETRY storage data type.