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River Grom

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

The River Grom is a stream on Ordnance Survey’s river map near Groombridge, East Sussex, with about 7.2 km of mapped channel. On the map it flows into the River Medway and out to the sea.

Next gauge downstream

Chafford on the River Medway, about 4.8 km along the river below where the River Grom ends on the map.

0.10 mASD Normal · rising slightly 30 min ago

After that, Colliers Land Bridge, about 5.9 km along the river.

No gauge measures the River Grom 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.

Storm overflows on the River Grom

3 storm overflows are placed on this stream on the river map. Each status is the water company’s own monitor.

Groombridge Wwps Not discharging
Southern Water · into River Grom · 2025: 21 spills, 199 h
Tunbridge Wells South WwTW Status unknown
Southern Water · into The River Grom · 2025: 50 spills, 167 h
Tunbridge Wells South WwTW Not discharging
Southern Water · into The River Grom · 2025: 52 spills, 536 h

A status says whether an overflow is discharging now, never how much or why. A monitor that is offline or has not reported is not “not discharging”. Sewage in Britain’s rivers →

Live status: © Southern Water storm overflow activity data, licensed under CC BY 4.0. Annual spill figures: Environment Agency Event Duration Monitoring return, © Environment Agency copyright and/or database right, Open Government Licence (OGL) v3.0.

Water-sampling points on the River Grom

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

River Grom Groombridge
Last sampled 1 Sep 2026 · 30 days ago · 27 samples banked
River Grom confluence with Medway
Last sampled 6 Aug 2026 · 56 days ago · 17 samples banked
Grom downstream of Tunbridge Wells S sewage treatment works
No sample published 1 Oct 2023 – 30 Sep 2026

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.

Places along it

From its source towards its mouth, the settlements within a kilometre of it on the map: Nevill Park, Ramslye, Groombridge.

On the map

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

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

The River Medway, the river it joins →TN7 4BJ, a postcode page near where it ends on the map (about 820 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 the River Grom itself, so its own level is not known here.
Storm overflows are listed only where the river map places them on this stream; an overflow it could not place is not counted.
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.