🆕waterlinkwidthderivationmethodvalue

This page details upcoming data that will be provided for the new Water Link Width Derivation Method Code List in the OS NGD from the end of September 2025 to give you early insight. This code list is currently not available through the live access services. The information on this page is as accurate as possible, but is subject to change before launch.

This code list is used in association with the Width Derivation Method attribute which is present within the Water Link Feature Type.

Label	Definition
Calculated From Polygon	For Water Links which represent a body of water captured as a topographic area feature, calculations of average, minimum and maximum widths based on the topographic area feature geometry.
Modelled From Network	For Water Links which represent a water feature captured as a topographic line feature, average width shall be a modelled width based on the upstream and downstream characteristics of the network.
Default Value For Geographic Region	For Water Links captured as a topographic line feature (where no width has been processed), average width shall be a default width based on the capture specification.