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Olway Brook water levels

1 gauge, at Olway Inn River Station. It is not above its typical high. No storm overflow upstream is discharging now. Gauges in Monmouthshire; levels are checked every 15 minutes.

1gauge
0above normal
0overflows upstream discharging

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Gauges

Monitoring stations, source to mouth

StationTownLevel nowStatusTrend
Olway Inn River Station—0.13 m 17m agoWithin its typical range—

Stations are listed from source to mouth as the water flows, traced on the river map (OS Open Rivers) and the Environment Agency’s own links between its gauges. A distance “by river” is along the river, and is shown only where the map traces the path.

Contains OS data © Crown copyright and database rights 2026.

Gauged tributaries

Streams and rivers with a gauge whose water joins Olway Brook above one of its gauges, from the source down. Named streams without a gauge that have a page here are listed at the end.

No gauged tributary joins Olway Brook above Olway Inn River Station on the river map. Streams without a gauge are not counted here.

Where Olway Brook goes

No gauge below Olway Inn River Station is known on the river map.

Tributaries and where they join are traced on the river map (OS Open Rivers, edition 2026-04) and the Environment Agency’s links between its gauges. The map holds distances between gauges, not the junctions themselves, so a junction is placed between two gauges, and no further up than the tributary’s own lowest gauge. Contains OS data © Crown copyright and database rights 2026.

Streams without a gauge

Named streams on the river map that flow into Olway Brook and have no gauge of their own. Each has a page with what is known about it: the next gauge downstream, and any storm overflows or water-sampling points placed on it.

Storm overflows upstream

1 storm overflow is traced upstream of Olway Inn River Station, Olway Brook’s lowest gauge on the river map: on Olway Brook itself, on its gauged tributaries, and on smaller streams that join above there.

  • 0 report discharging now
  • 1 not discharging
  • 0 offline or silent: 0 monitor offline, 0 status unknown, 0 no live feed

Official figures for 2025, for the overflow traced upstream of Olway Inn River Station: 24 spills over 30 hours.

Each overflow is listed in the stretch above the first gauge its water reaches, from the source down, as on the Gauges tab. A stretch of Olway Brook includes the smaller streams that join it there.

Above Olway Inn River Station, Olway Brook’s highest gauge1 overflow
  • Raglan WwTW Storm Overflow Not discharging
    Dwr Cymru Welsh Water · into Nant Y Wilcae · 9.0 km by river above Olway Inn River Station · 2025: 24 spills, 30 h

Near these gauges, connection not known

Within 3 km of one of Olway Brook’s gauges in a straight line, but the river map cannot say whether their water reaches it.

  • Cwrt Bryn Derwen Storm Overflow Not discharging
    Dwr Cymru Welsh Water · into Olway Brook · 330 m from Olway Inn River Station in a straight line · too close to Olway Inn River Station to say which side · 2025: 1 spill, 3.3 h

2 other overflows within 3 km of these gauges are placed below Olway Brook’s lowest gauge or on another river, so not listed.

A status is the water company’s own monitor: it says whether an overflow is discharging, never how much or why, and a spill does not by itself explain a change in a river level. A status older than two hours is shown as unknown. Annual figures are the official returns: 12/24-hour spills for England and Wales, overflow events for Scotland (Scottish Water counts differently, so the two cannot be compared). “No data” means the monitor produced no usable data that year, not zero. Overflows are placed on OS Open Rivers (edition 2026-04), which leaves out many small channels: an overflow the map cannot place may still drain here. Contains OS data © Crown copyright and database rights 2026. Sewage in Britain’s rivers →

Live status: © Dŵr Cymru Welsh Water, from its Storm Overflow Map. Annual figures for Wales: Dŵr Cymru Welsh Water’s return to Natural Resources Wales, as compiled by The Rivers Trust, Open Government Licence.