April 2025

This release note provides information about the April 2025 release of OS MasterMap Water Network Layer.

Feature counts

Feature Type	Count
WatercourseLink	4 733 541
HydroNode	4 752 874

Errors

Error Type	Count
Links with spikes	1
Single link loops	44
Multi-link circular flow loops that include River links	4
Multi-link circular flow loops on Drains	25

Product improvements

Details of live and resolved data issues for the OS MasterMap Water Layer product will be communicated on the OS MasterMap Water Network Layer Known Data Issues page. This page will provide details of their impacts and updates on the expected time frame for their resolution.

Next release

The next release of OS MasterMap Water Network Layer is scheduled for July 2025.