> For the complete documentation index, see [llms.txt](https://docs.os.uk/os-downloads/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://docs.os.uk/os-downloads/resources/product-resources/end-of-life-product-documentation/os-mastermap-water-network-layer/release-notes/january-2026.md).

# January 2026

## Feature counts

<table><thead><tr><th width="436">Feature Type</th><th>Count</th></tr></thead><tbody><tr><td>WatercourseLink</td><td>5 027 435</td></tr><tr><td>HydroNode</td><td>4 902 543</td></tr></tbody></table>

## Errors

<table><thead><tr><th width="434">Error Type</th><th>Count</th><th data-hidden></th></tr></thead><tbody><tr><td>Links with spikes</td><td>0</td><td></td></tr><tr><td>Single link loops</td><td>48</td><td></td></tr><tr><td>Multi-link circular flow loops that include River links</td><td>4</td><td></td></tr><tr><td>Multi-link circular flow loops on Drains</td><td>29</td><td></td></tr></tbody></table>

## Notices

{% hint style="warning" %}

## OS MasterMap Water Network Layer product will soon become End of Life

The OS MasterMap Water Network Layer product 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.

We recommend you migrate to using the data in the [OS NGD Water Network Collection](https://docs.os.uk/osngd/data-structure/water/water-network) as it contains very similar data content to OS MasterMap Water Network Layer – ​see the [Comparison of Water Network Products page](https://docs.os.uk/more-than-maps/os-ngd-migration/comparison-of-water-network-products) for a full comparison of the data supply, available formats, and attribution between the two products.

Further information can be found on the [End of Life Notice – OS MasterMap Water Network Layer page](/os-downloads/resources/product-resources/end-of-life-product-documentation/os-mastermap-water-network-layer/end-of-life-notice-os-mastermap-water-network-layer.md).
{% endhint %}

## Final release

{% hint style="warning" %}

#### No further releases scheduled

This January 2026 OS MasterMap Water Network release is the final publication of this product, with no further releases scheduled. Please see the End of Life notice above for further details.
{% endhint %}


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