The End of Life notice for the OS MasterMap Water Network Layer product, containing key dates, the reasoning behind the product withdrawal, product migration guidance, and FAQs.
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The OS MasterMap Water Network Layer product (also referred to as OS MasterMap Networks – Water Layer) will become End of Life on 31 March 2026. As of this date, Ordnance Survey will cease to maintain or publish updates, and access to the product will be removed from the OS Data Hub, OS Features API and OS Vector Tile API.
Final publication of the product: January 2026
Full withdrawal date: 31 March 2026
As part of our strategic product roadmap, OS is committed to the evolution of geospatial data and services in order to meet customers’ needs. Through the (PSGA), OS continuously delivers enhancements to the OS National Geographic Database (OS NGD) to provide new, richer data across all market sectors. We’ve improved usability by providing customers with access to the latest OS NGD data enhancements via new systems (the OS Data Hub and APIs) rather than via older and less efficient mechanisms. As a result, some of our existing products will become out of date and reach the end of their life.
The OS MasterMap Water Network Layer product is the first OS MasterMap Premium Download product to become End of Life, and we are actively working to migrate existing customers to the OS NGD.
We understand this change will impact customers, and we are committed to providing guidance and support to facilitate a smooth migration to OS NGD.
The update frequency is quarterly for both the OS MasterMap Water Network Layer product and the OS NGD Water Network Collection (January, April, July, October).
Pricing and licensing terms for the OS NGD Water Network Collection are comparable for OS Partners.
It provides greater analytical ability from more detailed attribution (for example, describing watercourse type and physical containment).
The names of watercourses (where present) are given at primary, secondary and tertiary levels, including language alternatives.
The enhancement to improve the width of watercourses, due in September 2025, offers improved methods of calculation and greater coverage across Great Britain to support hydrological modelling.
We recommend you migrate to using the data in the as it contains very similar data content to OS MasterMap Water Network Layer – see the page for a full comparison of the data supply, available formats, and attribution between the two products.
Data is accessed through the and is available to download from OS Select+Build in two widely adopted and simple to use formats – GeoPackage and CSV (comma-separated values). Data is also available via two OS NGD APIs: OS NGD API – Features and OS NGD API – Tiles.
The provides a single geometry for a complete named watercourse, making it easier to understand whole rivers.
You can perform analytics and visual interpretation for flood modelling, particularly when used in combination with data from other OS NGD collections (for example, the ).
This page will be regularly updated with additional documentation, including specific migration guidance and to support you.
– This page provides a technical summary of things to consider when migrating from OS MasterMap Water Network Layer to the OS NGD Water Network Collection. It covers data supply and formats, as well a comparison of the attribution of the two products.
Reach out to our if you have any concerns or questions.
