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Holbrook Gill

A stream near Warnham, West Sussex. No gauge of its own: what the river map and the banked data say about it.

Holbrook Gill is a stream on Ordnance Survey’s river map near Warnham, West Sussex, with about 980 m of mapped channel. On the map it flows into Channells Brook, which flows on into Boldings Brook, then the River Arun and out to the sea.

Next gauge downstream

Alfoldean on the River Arun, about 12 km along the river below where Holbrook Gill ends on the map.

0.06 mASD Normal · easing 30 min ago

After that, New Bridge, about 29 km along the river.

No gauge measures Holbrook Gill itself. A gauge downstream shows water that has already passed it, mixed with everything else that has joined on the way, so it says nothing exact about this stream.

Water-sampling points on Holbrook Gill

1 Environment Agency sampling point is placed on this stream. These are dated samples taken by hand, not live readings, and FloodRadar does not grade them.

North Heath Copse Horsham
Last sampled 2 Jul 2026 · 3 months ago · 19 samples banked

A sample is taken on a date; it says nothing about the water today. A sample below an overflow does not by itself show where anything in it came from.

Water samples: Environment Agency Water Quality Archive, © Environment Agency and/or database right 2026, Open Government Licence v3.0.

On the map

The map needs JavaScript. Everything it shows is listed on this page.

The blue line is Holbrook Gill; grey lines are other mapped watercourses. Lines from OS Open Rivers (edition 2026-04).

RH12 5QA, a postcode page near where it ends on the map (about 90 m away) →All rivers with gauges →

What this page can and cannot tell you

Its line, its name and where it flows come from Ordnance Survey’s river map (OS Open Rivers, edition 2026-04), which leaves out many small streams, ditches and culverts. “Flows into” is the map’s word: a channel that is not on the map is not shown here, which does not mean it is not there.
No gauge measures Holbrook Gill itself, so its own level is not known here.
No storm overflow is placed on this stream on the river map. That is not the same as none: the map cannot place every overflow.
Water samples are England’s only (the Environment Agency’s archive), placed where the map can place their sampling point.
Nothing on this page says whether any place floods. For an address, see its postcode page.

This uses Environment Agency flood and river level data from the real-time data API (Beta). Licence: Open Government Licence v3.0.